JP2009008890A - Display device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device or a display device, which can normally operate even when part of circuits causes operation failure. <P>SOLUTION: The display device includes a pixel unit and either a gate driver or a source driver, wherein one of shift registers in the gate driver and the source driver is provided with redundant circuits and with a selection circuit that selects a circuit to be operated among the redundant circuits. Accordingly, even when one circuit among the redundant circuits causes operation failure in either the gate driver or the source driver, switching is made to another circuit to compensate the operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a semiconductor device. More specifically, the present invention relates to a display device or an electronic device.

Development of integrated circuits using a semiconductor substrate called silicon-on-insulator (hereinafter referred to as SOI) with a thin single-crystal semiconductor layer on an insulating surface instead of a silicon wafer produced by thinly slicing a single-crystal semiconductor ingot Has been. An integrated circuit using an SOI substrate has attracted attention as an element that reduces the parasitic capacitance between the drain of the transistor and the substrate and improves the performance of the semiconductor integrated circuit.

A method of manufacturing an SOI substrate is disclosed in Patent Document 1. In Patent Document 1, a single crystal silicon thin film obtained by using a smart cut method is formed on crystallized glass which is high heat resistant glass.
JP-A-11-163363

In the conventional technique, a single crystal silicon thin film is bonded to a substrate by a smart cut method. However, there may be a problem that a part of the single crystal silicon thin film is not bonded to the substrate. Furthermore, even if all the single crystal silicon thin films can be bonded to the substrate, there is a problem that the single crystal silicon thin film peels off from the substrate over time. Thus, if a semiconductor film such as a single crystal silicon thin film is not sufficiently bonded to the substrate, a circuit formed using the substrate and the semiconductor film may not operate normally and malfunction. .

In view of such a problem, it is an object to provide a semiconductor device that can operate normally without malfunction even when a circuit is defective and cannot operate normally, more specifically, a display device. .

The present invention is a semiconductor device that includes a plurality of circuits, and is output from a circuit that is determined to be capable of normal operation, and is not output from a circuit that is determined to be unable to operate normally.

More specifically, one embodiment of the present invention includes a pixel portion including a plurality of pixels, and a source driver electrically connected to the pixel portion, the source driver including a first shift register, Two shift registers, a latch circuit, a level shifter, a buffer, and the first shift register and the second shift register are electrically connected to the first shift register and the second shift register. And a selection circuit that selects any one of the signals and outputs the selected signal to the pixel portion.

Note that in one embodiment of the present invention, the source driver may include a transistor including a semiconductor layer, and the semiconductor layer may be a single crystal semiconductor.

One embodiment of the present invention includes a pixel portion having a plurality of pixels, and a gate driver electrically connected to the pixel portion. The gate driver includes a first shift register, a second shift register, A latch circuit, a level shifter, a buffer, and the first shift register and the second shift register are electrically connected to the first shift register and the second shift register, and one of the signals of the first shift register and the second shift register is selected. And a selection circuit that outputs to the pixel portion.

Note that in one embodiment of the present invention, the gate driver may include a transistor including a semiconductor layer, and the semiconductor layer may be a single crystal semiconductor.

In the first aspect of the present invention, a first comparison circuit that is electrically connected to the first shift register and compares a signal of the first shift register with a reference signal, and the second shift register And a second comparison circuit that compares a signal of the second shift register with a reference signal, and electrically connects the first comparison circuit, the second comparison circuit, and the selection circuit. Are connected to each other, and a signal for controlling the selection circuit is output from the storage element storing the data of the reference signal and the comparison result in the first comparison circuit and the comparison result in the second comparison circuit. A configuration including a comparison result determination circuit is also possible.

In one embodiment of the present invention, the selection circuit includes a first analog switch electrically connected to the first shift register and the pixel portion, and a second analog circuit electrically connected to the second shift register and the pixel portion. It is also possible to have a configuration having a second analog switch connected to.

In one embodiment of the present invention, the selection circuit includes a first clocked inverter that is electrically connected to the first shift register and the pixel portion, and a second clock register that is electrically connected to the second shift register and the pixel portion. It is also possible to have a configuration having a second clocked inverter connected to each other.

One embodiment of the present invention includes a pixel portion including a plurality of pixels, a source driver and a gate driver electrically connected to the pixel portion, and the source driver includes a first shift register, a second shift register, A shift register, a first latch circuit, a first level shifter, a first buffer, the gate driver, a third shift register, a fourth shift register, a second latch circuit, A second level shifter; a second buffer; a signal of one of the third shift register and the fourth shift register electrically connected to the third shift register and the fourth shift register And a second selection circuit that outputs to the pixel portion.

Note that in one aspect of the present invention, a first comparison circuit that is electrically connected to the first shift register and compares a signal of the first shift register and a signal serving as a first reference; A second comparison circuit that is electrically connected to the shift register and compares a signal of the second shift register with a first reference signal, the first comparison circuit, the second comparison circuit, And a storage element electrically connected to the first selection circuit and storing data of the signal serving as the first reference, a comparison result in the first comparison circuit, and a comparison result in the second comparison circuit The first comparison result determination circuit for outputting a signal for controlling the first selection circuit, and the third shift register are electrically connected to the third shift register signal and the second reference. Compare the signals A second comparison circuit that is electrically connected to the fourth shift register and compares a signal of the fourth shift register with a second reference signal, and the first comparison circuit A storage element electrically connected to the second comparison circuit and the second selection circuit and storing data of a signal serving as the second reference, a comparison result in the first comparison circuit, and the A second comparison result determination circuit that outputs a signal for controlling the second selection circuit from a comparison result in the second comparison circuit may be used.

In one embodiment of the present invention, the first selection circuit includes a first analog switch electrically connected to the first shift register and the pixel portion, the second shift register, and the pixel portion. A second analog switch electrically connected to the second shift circuit, and the second selection circuit includes a third analog switch electrically connected to the third shift register and the pixel portion; A structure including the fourth shift register and a fourth analog switch electrically connected to the pixel portion may be employed.

In one embodiment of the present invention, the first selection circuit includes a first clocked inverter electrically connected to the first shift register and the pixel portion, the second shift register, and the pixel. A second clocked inverter electrically connected to the pixel portion, and the second selection circuit includes a third clocked inverter electrically connected to the third shift register and the pixel portion. A structure including an inverter and a fourth clocked inverter electrically connected to the fourth shift register and the pixel portion may be employed.

Note that in one embodiment of the present invention, any of the gate driver and the source driver may include a transistor including a semiconductor layer, and the semiconductor layer may be a single crystal semiconductor.

In the present invention, the pixel may include a transistor having a semiconductor layer, and the semiconductor layer may be a single crystal semiconductor.

One aspect of the present invention is an electronic device including the display device described above.

Note that various types of switches can be used. Examples include electrical switches and mechanical switches. That is, it is only necessary to be able to control the current flow, and is not limited to a specific one. For example, as a switch, a transistor (eg, bipolar transistor, MOS transistor, etc.), diode (eg, PN diode, PIN diode, Schottky diode, MIM (Metal Insulator Metal) diode, MIS (Metal Insulator Semiconductor) diode, diode-connected Transistor), a thyristor, or the like can be used. Alternatively, a logic circuit combining these (for example, an analog switch or a clocked inverter) can be used as a switch.

An example of a mechanical switch is a switch using MEMS (micro electro mechanical system) technology such as a digital micromirror device (DMD). The switch has an electrode that can be moved mechanically, and operates by controlling connection and disconnection by moving the electrode.

In the case where a transistor is used as a switch, the transistor operates as a mere switch, and thus the polarity (conductivity type) of the transistor is not particularly limited. However, when it is desired to suppress off-state current, it is desirable to use a transistor having a polarity with smaller off-state current. As a transistor with low off-state current, a transistor having an LDD region, a transistor having a multi-gate structure, and the like can be given. Alternatively, an N-channel transistor is preferably used in the case where the transistor operates as a switch when the potential of the source terminal of the transistor is close to the potential of the low potential power supply (Vss, GND, 0 V, or the like). On the other hand, it is desirable to use a P-channel transistor when operating in a state where the potential of the source terminal is close to the potential of the high potential side power supply (Vdd or the like). This is because an N-channel transistor operates when the source terminal is close to the potential of the low-potential side power supply, and a P-channel transistor operates when the source terminal is close to the potential of the high-potential side power supply. This is because the absolute value of the voltage between them can be increased, so that more accurate operation as a switch can be performed. This is because the source follower operation is rare and the output voltage is less likely to decrease.

Note that a CMOS switch may be used as a switch by using both an N-channel transistor and a P-channel transistor. When a CMOS switch is used, a current flows when one of the P-channel transistor and the N-channel transistor is turned on, so that the switch can easily function as a switch. For example, the voltage can be appropriately output regardless of whether the voltage of the input signal to the switch is high or low. Further, since the voltage amplitude value of the signal for turning on or off the switch can be reduced, the power consumption can be reduced.

Note that when a transistor is used as a switch, the switch has an input terminal (one of a source terminal or a drain terminal), an output terminal (the other of the source terminal or the drain terminal), and a terminal for controlling conduction (a gate terminal). is doing. On the other hand, when a diode is used as the switch, the switch may not have a terminal for controlling conduction. Therefore, the use of a diode as a switch rather than a transistor can reduce the wiring for controlling the terminal.

In addition, when it is explicitly described that A and B are connected, A and B are electrically connected, and A and B are functionally connected. , A and B are directly connected. Here, A and B are objects (for example, devices, elements, circuits, wirings, electrodes, terminals, conductive films, layers, etc.). Therefore, it is not limited to a predetermined connection relationship, for example, the connection relationship shown in the figure or text, and includes things other than the connection relation shown in the figure or text.

For example, when A and B are electrically connected, an element (for example, a switch, a transistor, a capacitor, an inductor, a resistance element, a diode, or the like) that enables electrical connection between A and B is provided. 1 or more may be arranged between A and B. Alternatively, when A and B are functionally connected, a circuit (for example, a logic circuit (an inverter, a NAND circuit, a NOR circuit, etc.), a signal conversion circuit that enables functional connection between A and B (DA conversion circuit, AD conversion circuit, gamma correction circuit, etc.), potential level conversion circuit (power supply circuit (boost circuit, step-down circuit, etc.), level shifter circuit that changes signal potential level), voltage source, current source, switching circuit , Amplifier circuits (circuits that can increase signal amplitude or current amount, operational amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, control circuits, etc.) between A and B One or more of them may be arranged. Alternatively, when A and B are directly connected, A and B may be directly connected without sandwiching other elements or other circuits between A and B.

Note that in the case where it is explicitly described that A and B are directly connected, when A and B are directly connected (that is, another element or other circuit between A and B). ) And A and B are electrically connected (that is, A and B are connected with another element or another circuit sandwiched between them). ).

Note that in the case where it is explicitly described that A and B are electrically connected, another element is connected between A and B (that is, between A and B). Or when A and B are functionally connected (that is, they are functionally connected with another circuit between A and B). And a case where A and B are directly connected (that is, a case where another element or another circuit is not connected between A and B). That is, when it is explicitly described that it is electrically connected, it is the same as when it is explicitly only described that it is connected.

Note that a display element, a display device that is a device including a display element, a light-emitting element, and a light-emitting device that is a device including a light-emitting element can have various modes or have various elements. For example, as a display element, a display device, a light-emitting element, or a light-emitting device, an EL (electroluminescence) element (an EL element including an organic substance and an inorganic substance, an organic EL element, an inorganic EL element), an electron-emitting element, a liquid crystal element, electronic ink, Electrophoretic elements, grating light valves (GLV), plasma displays (PDP), digital micromirror devices (DMD), piezoelectric ceramic displays, carbon nanotubes, etc., due to electromagnetic action, contrast, brightness, reflectance, transmittance, etc. It is possible to use a display medium that changes. Note that a display device using an EL element is an EL display, and a display device using an electron-emitting device is a liquid crystal display such as a field emission display (FED) or a SED type flat display (SED: Surface-conduction Electron-Emitter Display). Liquid crystal displays (transmission type liquid crystal display, transflective type liquid crystal display, reflection type liquid crystal display, direct view type liquid crystal display, projection type liquid crystal display), display devices using electronic ink and electrophoretic elements There is electronic paper.

Note that an EL element is an element having an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. Note that the EL layer uses light emission from singlet excitons (fluorescence), uses light emission from triplet excitons (phosphorescence), and emits light from singlet excitons (fluorescence). And those using triplet excitons (phosphorescence), those made of organic matter, those made of inorganic matter, those made of organic matter and those made of inorganic matter And a high molecular weight material, a low molecular weight material, a high molecular weight material and a low molecular weight material, or the like can be used. However, the present invention is not limited to this, and various EL elements can be used.

An electron-emitting device is a device that draws electrons by concentrating a high electric field on a sharp cathode. For example, as an electron-emitting device, a Spindt type, a carbon nanotube (CNT) type, a metal-insulator-metal laminated MIM (Metal-Insulator-Metal) type, and a metal-insulator-semiconductor laminated MIS (Metal-Insulator). -Semiconductor) type, MOS type, silicon type, thin film diode type, diamond type, surface conduction emitter SCD type, odd type, metal-insulator-semiconductor-metal type thin film type, HEED type, EL type, porous silicon type A surface conduction (SED) type or the like can be used. However, the present invention is not limited to this, and various types of electron-emitting devices can be used.

Note that a liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal and includes a pair of electrodes and liquid crystal. Note that the optical modulation action of the liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). As liquid crystal elements, nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, discotic liquid crystal, thermotropic liquid crystal, lyotropic liquid crystal, lyotropic liquid crystal, low molecular liquid crystal, polymer liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, main chain Type liquid crystal, side chain polymer liquid crystal, plasma addressed liquid crystal (PDLC), banana type liquid crystal, TN (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, IPS (In-Plane-Switching) mode, FFS (Fringe Field) Switching) mode, MVA (Multi-domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment), ASV (Ad anced Super View) mode, ASM (Axially Symmetric aligned Micro-cell) mode, OCB (Optical Compensated Birefringence) mode, ECB (Electrically Controlled Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, PDLC (Polymer Dispersed Liquid Crystal) mode, guest host mode, and the like can be used. However, the present invention is not limited to this, and various liquid crystal elements can be used.

Electronic paper includes those displayed by molecules such as optical anisotropy and dye molecule orientation, those displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change. It is displayed by moving, displayed by color development / phase change of molecules, displayed by light absorption of molecules, displayed by light emission when electrons and holes are combined, etc. . For example, as electronic paper, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic heat sensitivity Formula, electrowetting, light scattering (transparent white turbidity), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, leuco dye extinction Color, photochromic, electrochromic, electrodeposition, flexible organic EL, etc. can be used. However, the present invention is not limited to this, and various electronic papers can be used. Here, by using microcapsule electrophoresis, aggregation and precipitation of electrophoretic particles, which is a drawback of the electrophoresis system, can be solved. The electronic powder fluid has advantages such as high-speed response, high reflectivity, wide viewing angle, low power consumption, and memory properties.

Note that the plasma display encloses a rare gas with a substrate having an electrode formed on the surface and a substrate having an electrode and a minute groove formed on the surface and a phosphor layer formed in the groove facing each other at a narrow interval. It has a structure. In addition, a display can be performed by generating an ultraviolet-ray by applying a voltage between electrodes and making fluorescent substance light. The plasma display may be a DC type PDP or an AC type PDP. Here, as the plasma display panel, ASW (Address Wide Sustain) driving, ADS (Address Display Separated) driving that sub-frames are divided into a reset period, an address period, and a sustaining period, CLEAR (Low Energy Censored and Reduced Sequential Sequential Sequential Sequential Sequential Sequential Sequential Sequential Sequential) ) Drive, ALIS (Alternate Lighting of Surfaces) system, TERES (Technology of Reciprocal Sustainer) drive, and the like can be used. However, the present invention is not limited to this, and various types of plasma displays can be used.

Note that a display device that requires a light source, such as a liquid crystal display (transmission type liquid crystal display, transflective type liquid crystal display, reflection type liquid crystal display, direct view type liquid crystal display, projection type liquid crystal display), or a grating light valve (GLV) is used. As a light source for a display device using a conventional display device or a digital micromirror device (DMD), electroluminescence, a cold cathode tube, a hot cathode tube, an LED, a laser light source, a mercury lamp, or the like can be used. However, the present invention is not limited to this, and various light sources can be used.

Note that various types of transistors can be used as the transistor. Thus, there is no limitation on the type of transistor used. For example, a thin film transistor (TFT) including a non-single-crystal semiconductor film typified by amorphous silicon, polycrystalline silicon, microcrystalline (also referred to as semi-amorphous) silicon, or the like can be used. There are various advantages when using a TFT having such a semiconductor. For example, since manufacturing can be performed at a lower temperature than that of single crystal silicon, manufacturing cost can be reduced or a manufacturing apparatus can be increased in size. Since the manufacturing apparatus can be enlarged, it can be manufactured on a large substrate. Therefore, since a large number of display devices can be manufactured at the same time, it can be manufactured at low cost. Furthermore, since the manufacturing temperature is low, a substrate with low heat resistance can be used. Therefore, a transistor can be manufactured on a transparent substrate. Then, light transmission through the display element can be controlled using a transistor over a transparent substrate. Alternatively, since the thickness of the transistor is small, part of the film included in the transistor can transmit light. Therefore, the aperture ratio can be improved.

Note that by using a catalyst (such as nickel) when manufacturing polycrystalline silicon, it is possible to further improve crystallinity and to manufacture a transistor with favorable electrical characteristics. As a result, a gate driver circuit (scanning line driving circuit), a source driver circuit (signal line driving circuit), and a signal processing circuit (signal generation circuit, gamma correction circuit, DA conversion circuit, etc.) can be integrally formed on the substrate. .

Note that when a microcrystalline silicon is manufactured, by using a catalyst (such as nickel), crystallinity can be further improved and a transistor with favorable electrical characteristics can be manufactured. At this time, crystallinity can be improved only by applying heat treatment without laser irradiation. As a result, a part of the gate driver circuit (scanning line driver circuit) and the source driver circuit (analog switch or the like) can be integrally formed on the substrate. Furthermore, in the case where laser irradiation is not performed for crystallization, the crystallinity unevenness of silicon can be suppressed. Therefore, an image with improved image quality can be displayed.

However, it is possible to produce polycrystalline silicon or microcrystalline silicon without using a catalyst (such as nickel).

Note that it is preferable to improve the crystallinity of silicon to be polycrystalline or microcrystalline, but the present invention is not limited to this. The crystallinity of silicon may be improved only in a partial region of the panel. The crystallinity can be selectively improved by selectively irradiating laser light. For example, the laser beam may be irradiated only to the peripheral circuit region that is a region other than the pixel. Alternatively, the laser beam may be irradiated only on a region such as a gate driver circuit or a source driver circuit. Or you may irradiate a laser beam only to the area | region (for example, analog switch) of a source driver circuit. As a result, crystallization of silicon can be improved only in a region where the circuit needs to operate at high speed. Since it is not necessary to operate the pixel region at high speed, the pixel circuit can be operated without any problem even if the crystallinity is not improved. Since the region for improving crystallinity is small, the manufacturing process can be shortened, the throughput can be improved, and the manufacturing cost can be reduced. Since the number of manufacturing apparatuses required can be reduced, the manufacturing cost can be reduced.

Alternatively, a transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. Accordingly, a transistor with small variations in characteristics, size, shape, and the like, high current supply capability, and small size can be manufactured. When these transistors are used, low power consumption of the circuit or high integration of the circuit can be achieved.

Alternatively, a transistor having a compound semiconductor or an oxide semiconductor such as ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO, or SnO, or a thin film transistor in which these compound semiconductor or oxide semiconductor is thinned can be used. I can do it. Accordingly, the manufacturing temperature can be lowered, and for example, the transistor can be manufactured at room temperature. As a result, the transistor can be formed directly on a substrate having low heat resistance, such as a plastic substrate or a film substrate. Note that these compound semiconductors or oxide semiconductors can be used not only for a channel portion of a transistor but also for other purposes. For example, these compound semiconductors or oxide semiconductors can be used as resistance elements, pixel electrodes, and transparent electrodes. Furthermore, since these can be formed or formed simultaneously with the transistor, cost can be reduced.

Alternatively, a transistor formed using an inkjet method or a printing method can be used. By these, it can manufacture at room temperature, manufacture at a low vacuum degree, or can manufacture on a large sized board | substrate. Since the transistor can be manufactured without using a mask (reticle), the layout of the transistor can be easily changed. Furthermore, since it is not necessary to use a resist, the material cost is reduced and the number of processes can be reduced. Further, since a film is formed only on a necessary portion, the material is not wasted and cost can be reduced as compared with a manufacturing method in which etching is performed after film formation on the entire surface.

Alternatively, a transistor including an organic semiconductor or a carbon nanotube can be used. Thus, a transistor can be formed over a substrate that can be bent. Therefore, it can be strong against impact.

In addition, transistors with various structures can be used. For example, a MOS transistor, a junction transistor, a bipolar transistor, or the like can be used as the transistor. By using a MOS transistor, the size of the transistor can be reduced. Therefore, a large number of transistors can be mounted. By using a bipolar transistor, a large current can flow. Therefore, the circuit can be operated at high speed.

Note that a MOS transistor, a bipolar transistor, or the like may be formed over one substrate. Thereby, low power consumption, miniaturization, high-speed operation, etc. can be realized.

In addition, various transistors can be used.

Note that the transistor can be formed using various substrates. The kind of board | substrate is not limited to a specific thing. As the substrate, for example, single crystal substrate, SOI substrate, glass substrate, quartz substrate, plastic substrate, paper substrate, cellophane substrate, stone substrate, wood substrate, cloth substrate (natural fiber (silk, cotton, hemp), synthetic fiber) (Including nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, stainless steel substrates, substrates with stainless steel foil, etc. can be used. . Alternatively, a transistor may be formed using a certain substrate, and then the transistor may be transferred to another substrate, and the transistor may be disposed on another substrate. As a substrate to which the transistor is transferred, a single crystal substrate, an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a paper substrate, a cellophane substrate, a stone substrate, a wood substrate, a cloth substrate (natural fiber (silk, cotton, hemp), Use synthetic fibers (nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, stainless steel substrates, substrates with stainless steel foil, etc. Can do. Alternatively, a transistor may be formed using a certain substrate, and the substrate may be polished and thinned. As substrates to be polished, single crystal substrates, SOI substrates, glass substrates, quartz substrates, plastic substrates, paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk, cotton, hemp), synthetic fibers) (Including nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, stainless steel substrates, substrates with stainless steel foils, etc. can be used. . By using these substrates, it is possible to form a transistor with good characteristics, a transistor with low power consumption, manufacture a device that is not easily broken, impart heat resistance, reduce weight, or reduce thickness.

Note that the structure of the transistor can take a variety of forms and is not limited to a specific structure. For example, a multi-gate structure having two or more gate electrodes can be applied. When the multi-gate structure is employed, the channel regions are connected in series, so that a plurality of transistors are connected in series. With this multi-gate structure, the off-state current can be reduced and the reliability can be improved by improving the withstand voltage of the transistor. In addition, due to the multi-gate structure, even if the drain-source voltage changes when operating in the saturation region, the drain-source current does not change much, and the slope of the voltage / current characteristics can be made flat, By using this characteristic with a flat slope of voltage and current characteristics, it is possible to realize an ideal current source circuit and an active load with a very high resistance value. As a result, a differential circuit with good characteristics And a current mirror circuit can be realized.

  Furthermore, as another example of the structure of the transistor, a structure in which gate electrodes are provided above and below a channel can be used. With the structure in which the gate electrodes are arranged above and below the channel, the channel region increases, so that the current value can be increased or the S value can be reduced because a depletion layer can be easily formed. With the structure in which the gate electrodes are arranged above and below the channel, the structure has the same function as a structure in which a plurality of transistors are connected in parallel.

In addition, a structure in which the gate electrode is disposed above the channel region, a structure in which the gate electrode is disposed below the channel region, a normal staggered structure or an inverted staggered structure, a structure in which the channel region is divided into a plurality of regions, A structure in which channel regions are connected in parallel or a configuration in which channel regions are connected in series can also be applied. Further, a structure in which a source electrode or a drain electrode overlaps with a channel region (or part of it) can be used. With the structure where the source electrode and the drain electrode overlap with the channel region (or part thereof), unstable operation due to accumulation of electric charge in part of the channel region can be prevented. A configuration in which an LDD region is provided can also be applied. By providing the LDD region, the off-state current can be reduced or the reliability can be improved by improving the withstand voltage of the transistor. Alternatively, by providing an LDD region, when operating in the saturation region, even if the drain-source voltage changes, the drain-source current does not change so much and the slope of the voltage-current characteristic is flat. be able to.

  Note that various types of transistors can be used, and the transistor can be formed using various substrates. Therefore, all the circuits necessary for realizing a predetermined function can be formed on the same substrate. For example, all the circuits necessary for realizing a predetermined function can be formed using a glass substrate, a plastic substrate, a single crystal substrate, or an SOI substrate. Since all the circuits necessary to realize a given function are formed using the same substrate, the cost can be reduced by reducing the number of components, or the reliability can be improved by reducing the number of connection points with circuit components. Can be planned. Also, a part of a circuit necessary for realizing a predetermined function may be formed on a certain substrate, and another part of a circuit necessary for realizing a predetermined function may be formed on another substrate. Is possible. That is, it is possible to form all the circuits necessary for realizing a predetermined function using the same substrate. For example, a part of a circuit necessary for realizing a predetermined function is formed on a glass substrate with a transistor, and another part of a circuit necessary for realizing a predetermined function is formed on a single crystal substrate. In addition, an IC chip including a transistor formed using a single crystal substrate can be connected to a glass substrate by COG (Chip On Glass), and the IC chip can be arranged on the glass substrate. In addition, the IC chip can be connected to a glass substrate using TAB (Tape Automated Bonding) or a printed circuit board. In this way, by forming part of the circuit on the same substrate, it is possible to reduce costs by reducing the number of components or improve reliability by reducing the number of connection points with circuit components. In addition, since the power consumption of the circuit with the high drive voltage and the high drive frequency is high, such a circuit is not formed on the same substrate. Instead, for example, on a single crystal substrate. If an IC chip formed with the circuit is used, an increase in power consumption can be prevented.

One pixel means one element whose brightness can be controlled. Therefore, as an example, one pixel represents one color element, and brightness is expressed by one color element. Therefore, at that time, in the case of a color display device composed of R (red), G (green), and B (blue) color elements, the minimum unit of an image is an R pixel, a G pixel, and a B pixel. It is assumed to be composed of three pixels. Note that the color elements are not limited to three colors, and three or more colors or colors other than RGB can be used. For example, RGBW (W is white) may be added by adding white. It is also possible to add one or more colors such as yellow, cyan, magenta, emerald green, vermilion, etc. to RGB. In addition, for example, a color similar to at least one of RGB can be added to RGB. For example, R, G, B1, and B2 can be used. B1 and B2 are both blue, but have slightly different frequencies. Similarly, R1, R2, G, and B can be used. By using such color elements, it is possible to perform display closer to the real thing and to reduce power consumption.

  As another example of one pixel, when brightness is controlled using a plurality of areas for one color element, it is possible to set one area to one pixel. Therefore, as an example, when area gradation is performed or when sub-pixels (sub-pixels) are provided, there are a plurality of areas for controlling brightness for each color element, and the gradation is expressed as a whole. It is also possible to use one pixel for one area for controlling brightness. Therefore, in that case, one color element is composed of a plurality of pixels. Alternatively, even if there are a plurality of areas for controlling the brightness in one color element, it is possible to combine them into one color element as one pixel. Therefore, in that case, one color element is composed of one pixel. Alternatively, when the brightness is controlled using a plurality of areas for one color element, the size of the area contributing to display may be different depending on the pixel. Alternatively, it is possible to widen the viewing angle by slightly different signals supplied to each of the brightness control areas, which are plural for each color element. That is, for one color element, the potentials of the pixel electrodes in each of a plurality of regions may be different from each other. As a result, the voltage applied to the liquid crystal molecules is different for each pixel electrode, so that the viewing angle can be widened.

In addition, when it is explicitly described as one pixel (for three colors), it is assumed that three pixels of R, G, and B are considered as one pixel. When it is explicitly described as one pixel (for one color), it is assumed that when there are a plurality of areas for one color element, they are considered as one pixel.

Note that the pixels may be arranged (arranged) in a matrix. Here, the arrangement (arrangement) of pixels in a matrix includes a case where pixels are arranged side by side in a vertical direction or a horizontal direction, or a case where they are arranged on a jagged line. Therefore, for example, when full-color display is performed with three color elements (for example, RGB), the case where stripes are arranged or the case where dots of three color elements are arranged in a delta arrangement is included. Furthermore, the case where a Bayer is arranged is included. The color elements are not limited to three colors, and may be more than that, for example, RGBW (W is white), or RGB in which one or more colors of yellow, cyan, magenta, and the like are added. The size of the display area may be different for each dot of the color element. Thereby, it is possible to reduce power consumption or extend the life of the display element.

Note that an active matrix method in which an active element is included in a pixel or a passive matrix method in which an active element is not included in a pixel can be used.

In the active matrix system, not only transistors but also various active elements (active elements and nonlinear elements) can be used as active elements (active elements and nonlinear elements). For example, MIM (Metal Insulator Metal) or TFD (Thin Film Diode) can be used. Since these elements have few manufacturing steps, manufacturing cost can be reduced or yield can be improved. Furthermore, since the size of the element is small, the aperture ratio can be improved, and low power consumption and high luminance can be achieved.

Note that as a method other than the active matrix method, a passive matrix type that does not use active elements (active elements, nonlinear elements) can be used. Since no active element (active element or nonlinear element) is used, the number of manufacturing steps is small, and manufacturing cost can be reduced or yield can be improved. Since an active element (an active element or a non-linear element) is not used, the aperture ratio can be improved, and low power consumption and high luminance can be achieved.

Note that a transistor is an element having at least three terminals including a gate, a drain, and a source, has a channel region between the drain region and the source region, and the drain region, the channel region, and the source region. A current can be passed through. Here, since the source and the drain vary depending on the structure and operating conditions of the transistor, it is difficult to limit which is the source or the drain. Therefore, in this document (specification, claims, drawings, etc.), regions functioning as a source and a drain may be referred to as a first terminal and a second terminal, respectively. Alternatively, they may be referred to as a first electrode and a second electrode, respectively.

Note that the transistor may be an element having at least three terminals including a base, an emitter, and a collector. Similarly in this case, the emitter and the collector may be referred to as a first terminal and a second terminal.

Note that a gate refers to the whole or part of a gate electrode and a gate wiring (also referred to as a gate line, a gate signal line, a scan line, a scan signal line, or the like). A gate electrode refers to a portion of a conductive film that overlaps with a semiconductor forming a channel region with a gate insulating film interposed therebetween. Note that a part of the gate electrode may overlap an LDD (Lightly Doped Drain) region or a source region (or a drain region) with a gate insulating film interposed therebetween. A gate wiring is a wiring for connecting the gate electrodes of each transistor, a wiring for connecting the gate electrodes of each pixel, or a wiring for connecting the gate electrode to another wiring. Say.

However, there are portions (regions, conductive films, wirings, etc.) that also function as gate electrodes and function as gate wirings. Such a portion (region, conductive film, wiring, or the like) may be called a gate electrode or a gate wiring. That is, there is a region where the gate electrode and the gate wiring cannot be clearly distinguished. For example, when a part of the gate wiring extended and the channel region overlap, the portion (region, conductive film, wiring, etc.) functions as the gate wiring, but also as the gate electrode It is functioning. Therefore, such a portion (region, conductive film, wiring, or the like) may be called a gate electrode or a gate wiring.

Note that a portion (a region, a conductive film, a wiring, or the like) formed using the same material as the gate electrode and connected to form the same island (island) as the gate electrode may be called a gate electrode. Similarly, a portion (a region, a conductive film, a wiring, or the like) formed using the same material as the gate wiring and connected by forming the same island (island) as the gate wiring may be referred to as a gate wiring. In a strict sense, such a portion (region, conductive film, wiring, or the like) may not overlap with the channel region or may not have a function of being connected to another gate electrode. However, due to specifications at the time of manufacture, etc., the part (region, conductive film, wiring, etc.) that is formed of the same material as the gate electrode or gate wiring and forms the same island (island) as the gate electrode or gate wiring. ) Therefore, such a portion (region, conductive film, wiring, or the like) may also be referred to as a gate electrode or a gate wiring.

Note that, for example, in a multi-gate transistor, one gate electrode and another gate electrode are often connected to each other with a conductive film formed using the same material as the gate electrode. Such a portion (region, conductive film, wiring, or the like) is a portion (region, conductive film, wiring, or the like) for connecting the gate electrode and the gate electrode, and thus may be referred to as a gate wiring. These transistors can be regarded as a single transistor, and may be referred to as a gate electrode. That is, a portion (region, conductive film, wiring, or the like) that is formed using the same material as the gate electrode or gate wiring and is connected to form the same island (island) as the gate electrode or gate wiring is connected to the gate electrode or gate wiring. You can call it. Further, for example, a conductive film in a portion where the gate electrode and the gate wiring are connected and formed of a material different from the gate electrode or the gate wiring may be referred to as a gate electrode. You may call it.

Note that a gate terminal means a part of a part of a gate electrode (a region, a conductive film, a wiring, or the like) or a part electrically connected to the gate electrode (a region, a conductive film, a wiring, or the like). .

Note that in the case of calling a gate wiring, a gate line, a gate signal line, a scanning line, a scanning signal line, or the like, the gate of the transistor may not be connected to the wiring. In this case, the gate wiring, the gate line, the gate signal line, the scanning line, and the scanning signal line are simultaneously formed with the wiring formed in the same layer as the gate of the transistor, the wiring formed of the same material as the gate of the transistor, or the gate of the transistor. It may mean a deposited wiring. Examples include a storage capacitor wiring, a power supply line, a reference potential supply wiring, and the like.

Note that a source refers to the whole or part of a source region, a source electrode, and a source wiring (also referred to as a source line, a source signal line, a data line, a data signal line, or the like). The source region refers to a semiconductor region containing a large amount of P-type impurities (such as boron and gallium) and N-type impurities (such as phosphorus and arsenic). Therefore, a region containing a little P-type impurity or N-type impurity, that is, a so-called LDD (Lightly Doped Drain) region is not included in the source region. A source electrode refers to a portion of a conductive layer which is formed using a material different from that of a source region and is electrically connected to the source region. However, the source electrode may be referred to as a source electrode including the source region. The source wiring is a wiring for connecting the source electrodes of the transistors, a wiring for connecting the source electrodes of each pixel, or a wiring for connecting the source electrode to another wiring. Say.

However, there are portions (regions, conductive films, wirings, and the like) that also function as source electrodes and function as source wirings. Such a portion (region, conductive film, wiring, or the like) may be called a source electrode or a source wiring. That is, there is a region where the source electrode and the source wiring cannot be clearly distinguished. For example, in the case where a part of a source wiring that is extended and the source region overlap with each other, the portion (region, conductive film, wiring, etc.) functions as a source wiring, but as a source electrode Will also work. Thus, such a portion (region, conductive film, wiring, or the like) may be called a source electrode or a source wiring.

Note that a portion (region, conductive film, wiring, or the like) that is formed using the same material as the source electrode and forms the same island (island) as the source electrode, or a portion (region) that connects the source electrode and the source electrode , Conductive film, wiring, etc.) may also be referred to as source electrodes. Further, a portion overlapping with the source region may be called a source electrode. Similarly, a region formed of the same material as the source wiring and connected by forming the same island as the source wiring may be called a source wiring. Such a portion (region, conductive film, wiring, or the like) may not have a function of connecting to another source electrode in a strict sense. However, there is a portion (a region, a conductive film, a wiring, or the like) that is formed using the same material as the source electrode or the source wiring and connected to the source electrode or the source wiring because of specifications in manufacturing. Therefore, such a portion (region, conductive film, wiring, or the like) may also be referred to as a source electrode or a source wiring.

Note that, for example, a conductive film in a portion where the source electrode and the source wiring are connected and formed using a material different from that of the source electrode or the source wiring may be referred to as a source electrode or a source wiring. You may call it.

Note that a source terminal refers to a part of a source region, a source electrode, or a portion (region, conductive film, wiring, or the like) electrically connected to the source electrode.

Note that in the case of calling a source wiring, a source line, a source signal line, a data line, a data signal line, or the like, the source (drain) of the transistor may not be connected to the wiring. In this case, the source wiring, the source line, the source signal line, the data line, and the data signal line are the wiring formed in the same layer as the source (drain) of the transistor and the wiring formed of the same material as the source (drain) of the transistor. Alternatively, it may mean a wiring formed simultaneously with the source (drain) of the transistor. Examples include a storage capacitor wiring, a power supply line, a reference potential supply wiring, and the like.

The drain is the same as the source.

Note that a semiconductor device refers to a device having a circuit including a semiconductor element (a transistor, a diode, a thyristor, or the like). Furthermore, a device that can function by utilizing semiconductor characteristics may be called a semiconductor device. Alternatively, a device including a semiconductor material is referred to as a semiconductor device.

Note that a display element means an optical modulation element, a liquid crystal element, a light emitting element, an EL element (an organic EL element, an inorganic EL element or an EL element containing an organic substance and an inorganic substance), an electron-emitting element, an electrophoretic element, a discharge element, and a light reflection An element, a light diffraction element, a digital micromirror device (DMD), etc. are said. However, it is not limited to this.

Note that a display device refers to a device having a display element. Note that the display device may include a plurality of pixels including a display element. Note that the display device may include a peripheral driver circuit that drives a plurality of pixels. Note that the peripheral driver circuit that drives the plurality of pixels may be formed over the same substrate as the plurality of pixels. Note that the display device includes a peripheral drive circuit arranged on the substrate by wire bonding or bumps, an IC chip connected by so-called chip on glass (COG), or an IC chip connected by TAB or the like. May be. Note that the display device may include a flexible printed circuit (FPC) to which an IC chip, a resistor element, a capacitor element, an inductor, a transistor, and the like are attached. Note that the display device may include a printed wiring board (PWB) connected via a flexible printed circuit (FPC) or the like to which an IC chip, a resistor element, a capacitor element, an inductor, a transistor, or the like is attached. Note that the display device may include an optical sheet such as a polarizing plate or a retardation plate. Note that the display device may include a lighting device, a housing, a voice input / output device, an optical sensor, and the like.

The lighting device includes a backlight unit, a light guide plate, a prism sheet, a diffusion sheet, a reflection sheet, a light source (LED, cold cathode tube, hot cathode tube, etc.), cooling device (water cooling type, air cooling type), and the like. It means the device.

Note that a light-emitting device refers to a device having a light-emitting element or the like. In the case where the display element includes a light-emitting element, the light-emitting device is one example of the display device.

In addition, a reflection apparatus means the apparatus which has a light reflection element, a light diffraction element, a light reflection electrode, etc.

Note that a liquid crystal display device refers to a display device having a liquid crystal element. Liquid crystal display devices include direct view type, projection type, transmission type, reflection type, and transflective type.

Note that a driving device refers to a device having a semiconductor element, an electric circuit, and an electronic circuit. For example, a transistor that controls input of a signal from a source signal line into a pixel (sometimes referred to as a selection transistor or a switching transistor), a transistor that supplies voltage or current to a pixel electrode, or a voltage or current to a light-emitting element A transistor that supplies the voltage is an example of a driving device. Further, a circuit for supplying a signal to the gate signal line (sometimes referred to as a gate driver or a gate line driver circuit) and a circuit for supplying a signal to the source signal line (sometimes referred to as a source driver or source line driver circuit). ) Is an example of a driving device.

Note that a display device, a semiconductor device, a lighting device, a cooling device, a light-emitting device, a reflecting device, a driving device, and the like may overlap with each other. For example, the display device may include a semiconductor device and a light-emitting device. Alternatively, the semiconductor device may include a display device and a driving device.

In addition, when it is explicitly described that B is formed on A or B is formed on A, it is limited that B is formed in direct contact with A. Not. The case where it is not in direct contact, that is, the case where another object is interposed between A and B is also included. Here, A and B are objects (for example, devices, elements, circuits, wirings, electrodes, terminals, conductive films, layers, etc.).

Therefore, for example, when it is explicitly described that the layer B is formed on the layer A (or on the layer A), the layer B is formed in direct contact with the layer A. And the case where another layer (for example, layer C or layer D) is formed in direct contact with the layer A, and the layer B is formed in direct contact therewith. Note that another layer (for example, the layer C or the layer D) may be a single layer or a multilayer.

Furthermore, the same applies to the case where B is explicitly described as being formed above A, and is not limited to the direct contact of B on A. This includes the case where another object is interposed in. Therefore, for example, when the layer B is formed above the layer A, the case where the layer B is formed in direct contact with the layer A and the case where another layer is formed in direct contact with the layer A. (For example, the layer C or the layer D) is formed, and the layer B is formed in direct contact therewith. Note that another layer (for example, the layer C or the layer D) may be a single layer or a multilayer.

In addition, when it is explicitly described that B is formed in direct contact with A, it includes a case in which B is formed in direct contact with A. It shall not be included when an object is present.

The same applies to the case where B is below A or B is below A.

In addition, about what is explicitly described as singular, it is preferable that it is singular. However, the present invention is not limited to this, and a plurality of them is also possible. Similarly, a plurality that is explicitly described as a plurality is preferably a plurality. However, the present invention is not limited to this, and the number can be singular.

With the configuration including the plurality of circuits and the selection circuit, even if one of the plurality of circuits malfunctions, another circuit of the plurality of circuits can compensate for the operation of the one circuit. That is, a display device having redundancy can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode. Note that in the structures of the present invention described below, reference numerals indicating the same parts are denoted by the same reference numerals in different drawings, and detailed description of the same portions or portions having similar functions is omitted.

(Embodiment 1)
In this embodiment mode, a semiconductor device of the present invention will be described.

The semiconductor device in this embodiment includes a plurality of circuits, and a signal is output from any one of the plurality of circuits. For example, it is assumed that a malfunction occurs in one of a plurality of circuits. Then, no signal is output from one circuit, and a signal is output from another circuit among the plurality of circuits. That is, the operation of one circuit is supplemented by another circuit.

The semiconductor device in this embodiment includes a plurality of transistors. Note that the semiconductor device can include a resistor, a capacitor, a display element, or the like in addition to the transistor. As a substrate and a semiconductor layer of this transistor, it is preferable to use a substrate having an insulating surface and a single crystal semiconductor layer (SOI layer) with a fixed crystal orientation bonded to the insulating substrate. Since the crystal orientation of the single crystal semiconductor is constant, a uniform and high-performance transistor can be obtained. That is, non-uniformity of characteristic values important as transistor characteristics such as threshold voltage and mobility can be suppressed, and high performance such as high mobility can be achieved. However, the invention is not limited thereto, and a single crystal semiconductor such as an amorphous semiconductor, a microcrystalline semiconductor, or a polycrystalline semiconductor, a single crystal semiconductor, or the like can be used as a semiconductor layer of the transistor.

Next, a more specific structure of the semiconductor device in this embodiment is described with reference to FIG.

The semiconductor device includes a first circuit 101, a second circuit 102, and a selection circuit 110. The selection circuit 110 includes a first switch 111 and a second switch 112.

In the semiconductor device, signals are output from the first circuit 101 and the second circuit 102 to the selection circuit 110, respectively. Then, either the signal of the first circuit 101 or the signal of the second circuit 102 is selected by the selection circuit 110. The selected signal is output from the output terminal OUT.

Here, the first circuit 101 and the second circuit 102 can have the same structure. However, the present invention is not limited to this, and the first circuit 101 and the second circuit 102 may have different configurations.

Although not shown, the first circuit 101 receives a power supply voltage, a signal for controlling the first circuit 101, or the like. Then, the first circuit 101 outputs a signal to the selection circuit 103.

Although not shown, the second circuit 102 receives a power supply voltage, a signal for controlling the second circuit 102, or the like. Then, the second circuit 102 outputs a signal to the selection circuit 103.

Here, the first circuit 101 and the second circuit 102 have similar functions. However, the present invention is not limited to this, and even if the first circuit 101 and the second circuit 102 have different functions, some of them have the same function, or even if they have different functions, they supplement each other's circuits. If it has a function that can be applied, it can be applied.

The selection circuit 103 selects either the signal input from the first circuit 101 or the signal input from the second circuit 102. This signal selection is performed by turning on and off the first switch 111 and the second switch 112. The selected signal is output from the output terminal OUT. However, the invention is not limited to this, and the selection circuit 103 can select both the signal of the first circuit 101 and the signal of the second circuit 102. By doing so, a large load can be connected to the output terminal OUT.

For example, FIG. 1B illustrates the operation of the semiconductor device in the case where the signal of the first circuit 101 is selected. The first switch 111 is turned on and the second switch 112 is turned off. Then, the signal of the first circuit 101 is output from the output terminal OUT via the first switch 111. At this time, the signal of the second circuit 102 is not output from the output terminal OUT because the second switch 112 is off.

As another example, FIG. 1C illustrates operation of the semiconductor device in the case where the signal of the second circuit 102 is selected. The first switch 111 is turned off and the second switch 112 is turned on. Then, the signal of the second circuit 102 is output from the output terminal OUT via the second switch 112. At this time, the signal of the first circuit 101 is not output from the output terminal OUT because the first switch 111 is off.

The semiconductor device described above can obtain various merits. Advantages that the semiconductor device can obtain will be described below.

The semiconductor device can obtain redundancy. This is because even if a malfunction occurs in one of the first circuit 101 and the second circuit 102, an erroneous signal is not output from the semiconductor device. That is, the signal of the circuit that is operating normally is selected by the selection circuit 110 out of the signal of the first circuit 101 and the signal of the second circuit 102.

Therefore, a transistor in which a semiconductor layer is attached to a substrate, and a circuit using the transistor may malfunction due to part of the semiconductor layer being peeled off the substrate due to the passage of time or a process failure. Even when the semiconductor device is high, since the semiconductor device has redundancy, an erroneous signal is not output from the semiconductor device.

In the semiconductor device, the first circuit 101 and the second circuit 102 can be cut off by the selection circuit 110, so that a short circuit between power supplies can be prevented. This short-circuit between power supplies occurs when the timing or potential of the signal of the first circuit 101 and the signal of the second circuit 102 are different. For example, it is assumed that the H signal is output from one of the first circuit 101 and the second circuit 102 and the L signal is output from the other. Then, if the selection circuit 110 is not provided, the high power supply for outputting the H signal and the low power supply for outputting the L signal are short-circuited. However, since the semiconductor device can cut off the first circuit 101 and the second circuit 102 by the selection circuit 110, the high power supply and the low power supply are not short-circuited.

Further, by using a single crystal semiconductor for the semiconductor layer, the driving voltage of the semiconductor device can be reduced and a higher redundancy effect can be obtained. This is because non-uniformity of transistor characteristics such as threshold voltage and mobility is suppressed, so that the selection operation of the first circuit and the second circuit can be performed more accurately. This is because the mobility can be increased and the threshold voltage can be decreased.

In addition to the semiconductor device described above, there are various configurations or driving methods.

For example, the number of circuits having a redundancy effect is not limited, and a configuration having three or more circuits can also be used. FIG. 2 shows a structure in the case where the semiconductor device has N circuits (N: natural number) having the same function. Note that portions common to FIG. 1A are denoted by common reference numerals, and description thereof is omitted. The semiconductor device includes a first circuit 101 to an Nth circuit 104 and a selection circuit 110. The selection circuit 103 includes a first switch 111 to an Nth switch 114. As described above, when the semiconductor device includes a plurality of circuits having a redundancy effect, the semiconductor device can further increase the redundancy.

As another example, a configuration in which one of the first circuit 101 and the second circuit 102 is driven and the other circuit is not driven may be employed. That is, the signal output from one circuit is selected by the selection circuit 110. The signal input to the other circuit is in an inactive state (a constant potential). Therefore, the power consumption of the other circuit is greatly reduced.

Here, the signal output from the other circuit has a constant potential. However, the signal output from one circuit changes according to the input signal. That is, since the signal output from one circuit and the signal output from the other circuit are different, a short circuit between power supplies occurs. However, the arrangement of the selection circuit 110 can prevent a short circuit between power supplies.

Next, another structure of the semiconductor device in this embodiment is described with reference to FIG.

An outline of the semiconductor device shown in FIG. 3 will be described. The semiconductor device illustrated in FIG. 3 has a structure in which a control circuit 120 is added to the semiconductor device illustrated in FIG. The control circuit 120 determines whether the signals output from the first circuit 101 and the second circuit 102 are normal or not. Then, the control circuit 120 controls the selection circuit 103 according to the determined result. Thus, either the signal of the first circuit 101 or the signal of the second circuit 102 is output from the output terminal OUT.

The semiconductor device is composed of a plurality of transistors. Note that the semiconductor device may include a resistor, a capacitor, a display element, or the like in addition to the transistor. As a substrate and a semiconductor layer of this transistor, it is preferable to use a substrate having an insulating surface and a single crystal semiconductor layer (SOI layer) having a fixed crystal orientation bonded to the insulating substrate. Since the crystal orientation of the single crystal semiconductor is constant, a uniform and high-performance transistor can be obtained. That is, non-uniformity of characteristic values important as transistor characteristics such as threshold voltage and mobility can be suppressed, and high performance such as high mobility can be achieved. However, the invention is not limited thereto, and a non-single-crystal semiconductor such as an amorphous semiconductor, a microcrystalline semiconductor, or a polycrystalline semiconductor, a single-crystal semiconductor, or the like can be used as a semiconductor layer of the transistor.

Next, an example of a specific configuration of the control circuit 120 will be described.

The semiconductor device includes a first circuit 101, a second circuit 102, a selection circuit 110, and a control circuit 120. The selection circuit 110 includes a first switch 111 and a second switch 112. The control circuit 120 includes a first comparison circuit 121, a second comparison circuit 122, a memory 123, and a comparison result determination circuit 124.

Here, the first circuit 101 and the second circuit 102 can each have the same configuration. However, the present invention is not limited to this, and the first circuit 101 and the second circuit 102 may have different configurations.

Here, the first circuit 101 and the second circuit 102 have similar functions. However, the present invention is not limited to this, and even if the first circuit 101 and the second circuit 102 have different functions, some of them have the same function, or even if they have different functions, they supplement each other's circuits. If it has a function that can be applied, it can be applied.

The memory 123 stores data. The data stored in the memory 123 corresponds to a normal signal of the first circuit 101. Alternatively, even data corresponding to a normal signal of the second circuit 101 can be stored in the memory 123.

The first comparison circuit 121 compares the data stored in the memory 123 with the signal of the first circuit 101. Then, the first comparison circuit 121 outputs the comparison result to the comparison result determination circuit 124.

The second comparison circuit 122 compares the data stored in the memory 123 with the signal of the second circuit 102. Then, the second comparison circuit 122 outputs the comparison result to the comparison result determination circuit 124.

Based on the comparison result of the first comparison circuit 121 and the comparison result of the second comparison circuit 122, the comparison result determination circuit 124 determines whether the first circuit 101 and the second circuit 102 are malfunctioning or normal operation. Determine whether you are doing. Then, the comparison result determination circuit 124 outputs a control signal to the selection circuit 110. Specifically, the comparison result determination circuit 124 controls ON and OFF of the first switch 111 and the second switch 112 included in the selection circuit 110, respectively.

For example, assume that the comparison result determination circuit 124 determines that the first circuit 101 operates normally and the second circuit 102 malfunctions. Then, the comparison result determination circuit 124 outputs a signal that turns on the first switch 111 and turns off the second switch 112 to the selection circuit 110. Therefore, the signal of the first circuit 101 is output from the output terminal OUT via the first switch 111. The signal of the second circuit 102 is not output from the output terminal OUT because the second switch 112 is off.

As another example, assume that the comparison result determination circuit 124 determines that the first circuit 101 is malfunctioning and the second circuit 102 is normal operation. Then, the comparison result determination circuit 124 outputs a signal that turns off the first switch 111 and turns on the second switch 112 to the selection circuit 110. Accordingly, the signal of the second circuit 102 is output from the output terminal OUT via the second switch 112. The signal of the first circuit 101 is not output from the output terminal OUT because the first switch 111 is off.

As another example, assume that the comparison result determination circuit 124 determines that the first circuit 101 and the second circuit 102 are operating normally. Then, the comparison result determination circuit 124 outputs a signal that turns on the first switch 111 and turns on the second switch 112 to the selection circuit 110. Accordingly, the signal of the first circuit 101 and the signal of the second circuit 102 are output from the output terminal OUT via the first switch 111 and the second switch 112, respectively. By doing so, a large load can be connected to the output terminal OUT.

The semiconductor device in this embodiment described above can obtain various merits. Advantages that can be obtained by the semiconductor device in this embodiment will be described below.

The semiconductor device in this embodiment can obtain redundancy. This is because even if a malfunction occurs in one of the first circuit 101 and the second circuit 102, an erroneous signal is not output from the semiconductor device. That is, the signal of the circuit that is operating normally is selected by the selection circuit 110 out of the signal of the first circuit 101 and the signal of the second circuit 102.

Therefore, a transistor in which a semiconductor layer is attached to a substrate, and a circuit using the transistor may malfunction due to part of the semiconductor layer being peeled off the substrate due to the passage of time or a process failure. Even if the semiconductor device is high, since the semiconductor device has redundancy by the first circuit and the second circuit, an erroneous signal is not output from the first circuit and the second circuit. Absent.

Further, by using a single crystal semiconductor for the semiconductor layer, the driving voltage of the semiconductor device can be reduced and a higher redundancy effect can be obtained. This is because non-uniformity of transistor characteristics such as threshold voltage and mobility is suppressed, so that the selection operation of the first circuit and the second circuit can be performed more accurately. This is because the mobility can be increased and the threshold voltage can be decreased.

In the semiconductor device in this embodiment, since the first circuit 101 and the second circuit 102 can be cut off by the selection circuit 110, a short circuit between power supplies can be prevented. This short-circuit between power supplies occurs when the timing or potential of the signal of the first circuit 101 and the signal of the second circuit 102 are different. For example, it is assumed that the H signal is output from one of the first circuit 101 and the second circuit 102 and the L signal is output from the other. Then, if the selection circuit 110 is not provided, the high power supply for outputting the H signal and the low power supply for outputting the L signal are short-circuited. However, since the semiconductor device can cut off the first circuit 101 and the second circuit 102 by the selection circuit 110, the high power supply and the low power supply are not short-circuited.

In addition to the semiconductor device described above, there are various configurations or driving methods.

For example, the number of circuits having the same function is not limited, and the semiconductor device can include three or more circuits having the same function. When the semiconductor device includes three or more circuits having the same function, the semiconductor device can have higher redundancy.

As another example, a configuration in which one of the first circuit 101 and the second circuit 102 is driven and the other circuit is not driven may be employed. That is, the selection circuit 110 selects a signal output from one circuit. The signal input to the other circuit is in an inactive state (a constant potential). Therefore, the power consumption of the other circuit is greatly reduced.

Here, the signal output from the other circuit has a constant potential. However, the signal output from one circuit changes according to the input signal. That is, since the signal output from one circuit and the signal output from the other circuit are different, a short circuit between power supplies occurs. However, the arrangement of the selection circuit 110 can prevent a short circuit between power supplies.

As another example of the semiconductor device in this embodiment, data corresponding to a signal of the normal first circuit 101 and data corresponding to a signal of the normal second circuit 102 are respectively stored in different memories. May be saved.

Note that in this embodiment mode, description has been made using various drawings. However, the contents (or part of the contents) described in each figure may be different from the contents (or part of the contents) described in another figure. , Application, combination, or replacement can be appropriately performed. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (or part of the contents) described in each drawing of this embodiment can be applied, combined, or replaced with the contents (or part of the contents) described in the drawings of another embodiment. Etc. can be appropriately performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each portion with a portion of another embodiment. Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of a case, an example of a case where it is described in detail, an example of a case where it is applied, an example of a related part, and the like are shown. Therefore, the contents described in other embodiment modes can be applied to, combined with, or replaced with this embodiment mode as appropriate.

(Embodiment 2)
In this embodiment, a display device to which a semiconductor device is applied is described.

First, a display panel included in a display device will be described with reference to FIG.

An overview of the display panel 500 will be described. In the display panel 500, the semiconductor device described in Embodiment 1 is applied to the source driver 510 and the gate driver 520. That is, the source driver 510 and the gate driver 520 each include a plurality of circuits having the same function.

The display panel 500 includes a pixel portion 501, a source driver 510, and a gate driver 520. The pixel portion 501 has a plurality of pixels.

Note that the source driver 510 and the gate driver 520 each include a plurality of circuits, and the plurality of circuits can have a function of supplementing operations with each other. However, the present invention is not limited to this, and various structures can be used for the display panel 500. For example, only one of the source driver 510 and the gate driver 520 may include a plurality of circuits, and the plurality of circuits may have a function of supplementing the operation of each other. The pixel included in the portion 501 may include a plurality of circuits, and the plurality of circuits may have a function of supplementing operations.

The source driver 510 outputs a video signal to the pixel portion 501. Video signals are often voltages. However, the present invention is not limited to this, and a current can also be applied to the video signal. Furthermore, video signals are often analog signals. However, the present invention is not limited to this, and a digital signal can be applied to the video signal.

In addition, the gate driver 520 outputs a selection signal to the pixel portion 501.

In the pixel portion 501, the state of light is controlled according to the video signal. By doing so, the pixel portion 501 can display an image. Specifically, a pixel is selected by a selection signal. Then, the video signal is input to the selected pixel, and the pixel holds the video signal. Here, a display element or an element (such as a transistor or a capacitor) that controls the display element is disposed in each pixel. The display element or the element that controls the display element changes its state in accordance with the video signal. Note that as the display element, a liquid crystal element, an EL element, an element used in an FED, DMD, or the like can be used.

Next, an example of the source driver 510 will be described with reference to FIG.

An overview of the source driver 510 will be described. Sampling pulses are output from the first shift register 511 and the second shift register 512, respectively. Then, one of the sampling pulse of the first shift register 511 and the sampling pulse of the second shift register 512 is selected by the selection circuit 513.

The source driver 510 is composed of a plurality of transistors. Note that the source driver 510 may include a resistor, a capacitor, a display element, or the like in addition to the transistor. As a substrate and a semiconductor layer of this transistor, it is preferable to use a substrate having an insulating surface and a single crystal semiconductor layer (SOI layer) having a fixed crystal orientation bonded to the insulating substrate. Since the crystal orientation of the single crystal semiconductor is constant, a uniform and high-performance transistor can be obtained. That is, non-uniformity of characteristic values important as transistor characteristics such as threshold voltage and mobility can be suppressed, and high performance such as high mobility can be achieved. However, the invention is not limited thereto, and a non-single-crystal semiconductor such as an amorphous semiconductor, a microcrystalline semiconductor, or a polycrystalline semiconductor, a single-crystal semiconductor, or the like can be used as a semiconductor layer of the transistor.

The source driver 510 includes a first shift register 511, a second shift register 512, a selection circuit 513, a first latch circuit 516, a second latch circuit 517, a level shifter 518, and a buffer 519. The selection circuit 513 includes a plurality of first switches 514 and a plurality of second switches 515. Note that the first shift register 511 and the second shift register 512 can be referred to as a first circuit and a second circuit, respectively.

Here, the first shift register 511 and the second shift register 512 have the same configuration. However, the present invention is not limited to this, and the first shift register 511 and the second shift register 512 can have different configurations.

Although not shown, the first shift register 511 receives a start pulse (SP), a clock signal (CK), and a clock inversion signal (CKB). Then, the first shift register 511 outputs a sampling pulse to the selection circuit 513 in accordance with the input signal. The sampling pulses are sequentially output from the terminals S1_1 to Sm_1. Further, the first shift register 511 outputs a signal from the first output terminal SOUT1. This signal is necessary for determining whether the first shift register 511 is operating normally or malfunctioning.

Although not shown, the second shift register 512 receives a start pulse (SP), a clock signal (CK), and a clock inversion signal (CKB). Then, the second shift register 512 outputs a sampling pulse to the selection circuit 513 in accordance with the input signal. The sampling pulses are sequentially output from the terminals S1_2 to Sm_2. Further, the second shift register 512 outputs a signal from the first output terminal SOUT2. This signal is necessary for determining whether the second shift register 512 is operating normally or malfunctioning.

Here, the first shift register 511 and the second shift register 512 have similar functions. However, the present invention is not limited to this, and the first shift register 511 and the second shift register 512 have different functions even if they have the same function in part, or supplement each other's circuits even if they have different functions. If it has a function capable of being applied, it can be applied.

The selection circuit 513 selects either the sampling pulse input from the first shift register 511 or the sampling pulse input from the second shift register 512. This selection is performed by turning on and off the first switch 514 and the second switch 515. Then, the selected sampling pulse is output to the first latch circuit 516. Note that the selection circuit 513 can select both the sampling pulse input from the first shift register 511 and the sampling pulse input from the second shift register 512.

For example, when the sampling pulse of the first shift register 511 is selected, the first switch 514 is turned on and the second switch 515 is turned off. Then, the sampling pulse of the first shift register 511 is output to the first latch circuit 516 via the first switch 514. At this time, the sampling pulse of the second shift register 512 is not output to the first latch circuit 516 because the second switch 515 is off.

As another example, when the sampling pulse of the second shift register 512 is selected, the first switch 514 is turned off and the second switch 515 is turned on. Then, the sampling pulse of the second shift register 512 is output to the first latch circuit 516 via the second switch 515. At this time, the sampling pulse of the first shift register 511 is not output to the first latch circuit 516 because the first switch 514 is off.

Here, whether the sampling pulse of the first shift register 511 or the sampling pulse of the second shift register 512 is selected is output from the first output terminal SOUT1 and the second output terminal SOUT2. Determined by the signal. Specifically, as shown in Embodiment 1, the correct signal is compared with the signals output from the first output terminal SOUT1 and the second output terminal SOUT2. Then, on / off of the first switch 514 and the second switch 515 is controlled by the comparison result.

The first latch circuit 516 holds the data signal in each column in accordance with the timing at which the sampling pulse is input. When the holding of the video signal to the last column is completed, a latch pulse (LAT) is input to the first latch circuit 516 during the horizontal blanking period. Then, the data signals held in the first latch circuit 516 are output to the second latch circuit 517 all at once.

The second latch circuit 517 holds the data signal input from the first latch circuit 516. Thereafter, the data signal held in the second latch circuit 517 is output to the level shifter 518 for one row at the same time.

The level shifter 518 changes the amplitude voltage of the data signal input from the second latch circuit 517. Then, the data signal is output as a video signal from the terminals S1_1 to Sm_1 through the buffer 519.

Here, while the data signal held in the second latch circuit 517 is output to the level shifter 518, the first shift register 511 or the second shift register 512 sends the sampling pulse to the first latch circuit 516 again. Output. Then, the first latch circuit 516 holds the data signal in each column in accordance with the timing at which the sampling pulse is input. That is, two operations are performed simultaneously.

In this way, the source driver 510 can perform line sequential driving. Thereafter, the source driver 510 repeats such an operation.

Note that the source driver 510 is not limited to this, and can have various configurations. For example, FIG. 17 illustrates a configuration in the case where the source driver 510 includes the digital-analog conversion circuit 530. In FIG. 17, the data signal is output from the second latch circuit 517 to the digital-analog conversion circuit 530. The digital-analog conversion circuit 530 converts the data signal input from the second latch circuit 517 into an analog signal. The converted data signal is output as a video signal from each of the terminals S1_1 to Sm_1.

As another example, FIG. 18 shows a configuration capable of dot-sequential driving. In FIG. 18, the sampling pulse is output from the selection circuit 513 to the sampling circuit 531. A data signal is input to the sampling circuit 531. The sampling circuit 531 sequentially outputs a data signal as a video signal from the terminals S1 to Sm according to the sampling pulse. Note that the video signal may be output one column at a time or may be output multiple columns.

The source driver 510 described above can obtain various merits. The advantages that the source driver 510 can obtain will be described below.

The source driver 510 can obtain redundancy. This is because an erroneous signal is not output from the source driver 510 even if a malfunction occurs in one of the first shift register 511 and the second shift register 512. That is, the sampling circuit 513 selects the sampling pulse of the circuit that is operating normally out of the sampling pulse of the first shift register 511 and the sampling pulse of the second shift register 512.

Therefore, a transistor in which a semiconductor layer is attached to a substrate, and a circuit using the transistor may malfunction due to part of the semiconductor layer being peeled off the substrate due to the passage of time or a process failure. Even if the source driver 510 is high, the source driver 510 has redundancy, so that an erroneous signal is not output from the semiconductor device.

Further, by using a single crystal semiconductor for the semiconductor layer, the driving voltage of the source driver 510 can be reduced, and a higher redundancy effect can be obtained. This is because the shift register selection operation can be performed more accurately by suppressing non-uniformity in transistor characteristics such as threshold voltage and mobility. This is because the mobility can be increased and the threshold voltage can be decreased.

Since the source driver 510 can block the first shift register 511 and the second shift register 512 by the selection circuit 513, a short circuit between power supplies can be prevented. This short circuit between the power supplies occurs when the timing or potential of the sampling pulse of the first shift register 511 and the sampling pulse of the second shift register 512 are different. For example, it is assumed that the H signal is output from one of the first shift register 511 and the second shift register 512 and the L signal is output from the other. Then, if the selection circuit 513 is not provided, the high power supply for outputting the H signal and the low power supply for outputting the L signal are short-circuited. However, since the source driver 510 can cut off the first shift register 511 and the second shift register 512 by the selection circuit 513, the high power supply and the low power supply are not short-circuited.

In addition to the source driver 510 described above, there are various configurations or driving methods.

For example, the number of circuits having the same function is not limited, and the source driver 510 can include three or more shift registers. When the source driver 510 includes three or more shift registers, the source driver 510 can further increase redundancy.

As another example, a structure in which one circuit of the first shift register 511 and the second shift register 512 is driven and the other circuit is not driven may be employed. That is, the signal output from one circuit is selected by the source driver 510. The signal input to the other circuit is in an inactive state (a constant potential). Therefore, the power consumption of the other circuit is greatly reduced.

Here, the signal output from the other circuit has a constant potential. However, the signal output from one circuit changes according to the input signal. That is, since the signal output from one circuit and the signal output from the other circuit are different, a short circuit between power supplies occurs. However, by arranging the selection circuit 513, a short circuit between power supplies can be prevented.

Next, an example of the selection circuit 513 included in the source driver 510 is described with reference to FIG. Note that FIG. 13A illustrates the selection circuit 513 of the i−1 column, the i column, and the i + 1 column (i: 1 to m) among the 1 column to the m column.

The selection circuit 513 includes a plurality of first analog switches 461 and a plurality of second analog switches 462. The first analog switch 461 and the second analog switch 462 correspond to the first switch 514 and the second switch 515, respectively.

The terminal Si_1 in the i-th column of the first shift register 511 and the terminal Si in the i-th column of the selection circuit 513 are electrically connected via a first analog switch 461 in the i-th column. The i-th column terminal Si_2 of the second first shift register 512 and the i-th column terminal Si of the selection circuit 513 are electrically connected via the i-th column second analog switch 462. ing.

Each of the first analog switches 461 has a first control terminal electrically connected to the first wiring 463 and a second control terminal electrically connected to the second wiring 464. Each of the second analog switches 462 has a first control terminal electrically connected to the second wiring 464 and a second control terminal electrically connected to the first wiring 463.

Here, the first control terminal corresponds to a gate electrode of a P-channel transistor included in the analog switch. The second control terminal corresponds to a gate electrode of an N-channel transistor included in the analog switch.

The operation of the selection circuit 513 will be described. When the first shift register 511 sampling pulse is selected, the first analog switch 461 is turned on and the second analog switch 462 is turned off. In order for the selection circuit 513 to perform such an operation, the L signal is input to the first wiring 463 and the H signal is input to the second wiring 464. Similarly, when the video signal of the second shift register 512 is selected, the first analog switch 461 is turned off and the second analog switch 462 is turned on. In order for the selection circuit 513 to perform such an operation, an H signal is input to the first wiring 463 and an L signal is input to the second wiring 464.

Next, an example of another selection circuit 513 will be described with reference to FIG. Note that FIG. 13B illustrates the selection circuit 513 of the i-1 column and the i column (i: any one of i: 1 to m) out of the 1 column to the m column.

The selection circuit 513 includes a plurality of first clocked inverters 471 and a plurality of second clocked inverters 472. The first clocked inverter 471 and the second clocked inverter 472 correspond to the first switch 514 and the second switch 515, respectively.

The i-th column terminal Si_1 of the first shift register 511 and the i-th column terminal Si of the selection circuit 513 are electrically connected via a first clocked inverter 471 in the i-th column. The i-th column terminal Si_2 of the second shift register 512 and the i-th column terminal Si of the selection circuit 513 are electrically connected via a second clocked inverter 472 in the i-th column. .

Each of the first clocked inverters 471 has a first control terminal electrically connected to the first wiring 473 and a second control terminal electrically connected to the second wiring 474. In each of the second clocked inverters 472, the first control terminal is electrically connected to the second wiring 474, and the second control terminal is electrically connected to the first wiring 473.

Here, the first control terminal corresponds to one gate electrode of a plurality of P-channel transistors included in the clocked inverter. The second control terminal corresponds to one gate electrode of the plurality of N-channel transistors included in the clocked inverter.

The operation of the selection circuit 513 will be described. When the sampling pulse of the first shift register 511 is selected, the first clocked inverter 471 is turned on and the second clocked inverter 472 is turned off. In order for the selection circuit 513 to perform such an operation, the L signal is input to the first wiring 473 and the H signal is input to the second wiring 474. Similarly, when the sampling pulse of the second shift register 512 is selected, the first clocked inverter 471 is turned off and the second clocked inverter 472 is turned on. In order for the selection circuit 513 to perform such an operation, an H signal is input to the first wiring 473 and an L signal is input to the second wiring 474.

Next, an example of the gate driver 520 will be described with reference to FIG.

An outline of the gate driver 520 will be described. Signals are output from the first shift register 521 and the second shift register 522, respectively. Then, one of the signal of the first shift register 521 and the signal of the second shift register 522 is selected by the selection circuit 523.

The gate driver 520 includes a plurality of transistors. Note that the gate driver 520 may include a resistor, a capacitor, a display element, or the like in addition to the transistor. As a substrate and a semiconductor layer of this transistor, it is preferable to use a substrate having an insulating surface and a single crystal semiconductor layer (SOI layer) having a fixed crystal orientation bonded to the insulating substrate. Since the crystal orientation of the single crystal semiconductor is constant, a uniform and high-performance transistor can be obtained. That is, non-uniformity of characteristic values important as transistor characteristics such as threshold voltage and mobility can be suppressed, and high performance such as high mobility can be achieved. Note that the semiconductor layer of the transistor is not limited thereto, and an amorphous semiconductor, a microcrystalline semiconductor, a polycrystalline semiconductor, a non-single-crystal semiconductor, a single-crystal semiconductor, or the like can be used.

The gate driver 520 includes a first shift register 521, a second shift register 522, a selection circuit 523, a level shifter 526, and a buffer 527. The selection circuit 523 includes a plurality of first switches 524 and a plurality of second switches 525. Note that the first shift register 521 and the second shift register 522 can be referred to as a first circuit and a second circuit, respectively.

Here, the same structure is used for the first shift register 521 and the second shift register 522. However, the present invention is not limited to this, and the first shift register 521 and the second shift register 522 can have different structures.

A start pulse (SP), a clock signal (CK), and a clock inversion signal (CKB) are input to the first shift register 521. Then, the first shift register 521 outputs a signal that sequentially selects according to the input signal. This signal is sequentially output from the terminals G1_1 to Gn_1 to the selection circuit 523. Further, the first shift register 521 outputs a signal from the first output terminal GOUT1. This signal is such that it can be determined whether the first shift register 521 is operating normally or malfunctioning.

A start pulse (SP), a clock signal (CK), and a clock inversion signal (CKB) are input to the second shift register 522. Then, the second shift register 522 outputs a signal that sequentially selects according to the input signal. This signal is sequentially output from the terminals G1_2 to Gn_2 to the selection circuit 523. Further, the second shift register 522 outputs a signal from the second output terminal GOUT2. This signal is such that it can be determined whether the second shift register 522 is operating normally or malfunctioning.

Here, the first shift register 521 and the second shift register 522 have the same function. However, the present invention is not limited to this. Even if the first shift register 521 and the second shift register 522 have different functions, some of them have the same function or different functions, If it has a function that can be supplemented, it can be applied.

The selection circuit 523 selects either the signal input from the first shift register 521 or the signal input from the second shift register 522. This selection is performed by turning on and off the first switch 524 and the second switch 525. Then, the selected signal is output to the level shifter 526. However, the invention is not limited to this, and the selection circuit 523 can select both the signal input from the first shift register 521 and the signal input from the second shift register 522.

For example, when the signal of the first shift register 521 is selected, the first switch 524 is turned on and the second switch 525 is turned off. Then, the signal of the first shift register 521 is output to the level shifter 526 via the first switch 524. At this time, the signal of the second shift register 522 is not output to the level shifter 526 because the second switch 525 is off.

As another example, when the signal of the second shift register 522 is selected, the first switch 524 is turned off and the second switch 525 is turned on. Then, the signal of the second shift register 522 is output to the level shifter 526 via the second switch 525. At this time, the signal of the first shift register 521 is not output to the level shifter 526 because the first switch 524 is off.

Here, whether to select the signal of the first shift register 521 or the signal of the second shift register 522 depends on the signals output from the first output terminal GOUT1 and the second output terminal GOUT2. It is determined. Specifically, as shown in the first embodiment, the correct signal is compared with the signals output from the first output terminal GOUT1 and the second output terminal GOUT2. Then, on / off of the first switch 524 and the second switch 525 is controlled by the comparison result.

The level shifter 526 changes the amplitude voltage of the signal input from the selection circuit 523. The signals are sequentially output from the terminals G1 to Gn through the buffer 527 as selection signals.

Note that the buffer 527 may have a function of changing the pulse width of the selection signal.

The gate driver 520 described above can obtain various merits. The advantages that the gate driver 520 can obtain will be described below.

The gate driver 520 can obtain redundancy. This is because even if a malfunction occurs in one of the first shift register 521 and the second shift register 522, an erroneous signal is not output from the gate driver 520. That is, the selection circuit 523 selects the signal of the circuit that is operating normally out of the signal of the first shift register 521 and the signal of the second shift register 522.

Therefore, a transistor in which a semiconductor layer is attached to a substrate, and a circuit using the transistor may malfunction due to part of the semiconductor layer being peeled off the substrate due to the passage of time or a process failure. Even if the gate driver 520 is high, the gate driver 520 has redundancy, so that an erroneous signal is not output from the gate driver 520.

Further, by using a single crystal semiconductor for the semiconductor layer, the driving voltage of the gate driver 520 can be reduced, and a higher redundancy effect can be obtained. This is because the shift register selection operation can be performed more accurately by suppressing non-uniformity in transistor characteristics such as threshold voltage and mobility. This is because the mobility can be increased and the threshold voltage can be decreased.

Since the gate driver 520 can block the first shift register 521 and the second shift register 522 by the selection circuit 523, a short circuit between power supplies can be prevented. The short circuit between the power supplies occurs when the timing or potential of the signal of the first shift register 521 and the signal of the second shift register 522 are different. For example, it is assumed that the H signal is output from one of the first shift register 521 and the second shift register 522 and the L signal is output from the other. Then, if the selection circuit 523 is not provided, the high power supply for outputting the H signal and the low power supply for outputting the L signal are short-circuited. However, since the gate driver 520 can cut off the first shift register 521 and the second shift register 522 by the selection circuit 523, the high power supply and the low power supply are not short-circuited.

In addition to the gate driver 520 described above, there are various configurations or driving methods.

For example, the number of shift registers is not limited, and the gate driver 520 can include three or more shift registers. Since the gate driver 520 includes three or more shift registers, the gate driver 520 can further increase redundancy.

As another example, a structure in which one circuit of the first shift register 521 and the second shift register 522 is driven and the other circuit is not driven may be employed. That is, a signal output from one circuit is selected by the gate driver 520. The signal input to the other circuit is in an inactive state (a constant potential). Therefore, the power consumption of the other circuit is greatly reduced.

Here, the signal output from the other circuit has a constant potential. However, the signal output from one circuit changes according to the input signal. That is, since the signal output from one circuit and the signal output from the other circuit are different, a short circuit between power supplies occurs. However, by arranging the selection circuit 513, a short circuit between power supplies can be prevented.

Next, an example of the selection circuit 523 included in the gate driver 520 is described with reference to FIG. Note that FIG. 14A illustrates the selection circuit 523 of the j−1 row, the j row, and the j + 1 row (j: any one of n: 1 to n) of the 1 row to the m row.

The selection circuit 513 includes a plurality of first analog switches 481 and a plurality of second analog switches 482. The first analog switch 481 and the second analog switch 482 correspond to the first switch 524 and the second switch 525, respectively.

The terminal Gj_1 in the i-th column of the first shift register 521 and the terminal Gj in the j-th column of the selection circuit 523 are electrically connected via the first analog switch 481 in the j-th column. The terminal Gj_2 of the jth column of the second shift register 522 and the terminal Gj of the jth column of the selection circuit 523 are electrically connected via the second analog switch 482 of the jth column.

Each of the first analog switches 481 has a first control terminal electrically connected to the first wiring 483 and a second control terminal electrically connected to the second wiring 484. Each of the second analog switches 482 has a first control terminal electrically connected to the second wiring 484 and a second control terminal electrically connected to the first wiring 483.

Here, the first control terminal corresponds to a gate electrode of a P-channel transistor included in the analog switch. The second control terminal corresponds to a gate electrode of an N-channel transistor included in the analog switch.

The operation of the selection circuit 523 will be described. When the signal of the first shift register 521 is selected, the first analog switch 481 is turned on and the second analog switch 482 is turned off. In order for the selection circuit 523 to perform such an operation, an L signal is input to the first wiring 483 and an H signal is input to the second wiring 484. Similarly, when the signal of the second shift register 522 is selected, the first analog switch 481 is turned off and the second analog switch 482 is turned on. In order for the selection circuit 523 to perform such an operation, an H signal is input to the first wiring 483 and an L signal is input to the second wiring 484.

Next, an example of another selection circuit 523 will be described with reference to FIG. Note that FIG. 14B illustrates the selection circuit 523 of the j−1 column and the j column (j: any one of n: 1 to n) out of the 1st column to the nth column.

The selection circuit 523 includes a plurality of first clocked inverters 491 and a plurality of second clocked inverters 492. The first clocked inverter 491 and the second clocked inverter 492 correspond to the first switch 524 and the second switch 525, respectively.

The j-th column terminal Gj_1 of the first shift register 521 and the j-th column terminal Gj of the selection circuit 523 are electrically connected via a first clocked inverter 491 in the j-th column. The terminal Gj_2 of the jth column of the second shift register 522 and the terminal Gj of the jth column of the selection circuit 523 are electrically connected via the second clocked inverter 492 of the Jth column. .

Each of the first clocked inverters 491 has a first control terminal electrically connected to the first wiring 493 and a second control terminal electrically connected to the second wiring 494. Each of the second clocked inverters 492 has a first control terminal electrically connected to the second wiring 494 and a second control terminal electrically connected to the first wiring 493.

Here, the first control terminal corresponds to one gate electrode of a plurality of P-channel transistors included in the clocked inverter. The second control terminal corresponds to one gate electrode of the plurality of N-channel transistors included in the clocked inverter.

The operation of the selection circuit 523 will be described. When the signal of the first shift register 521 is selected, the first clocked inverter 491 is turned on and the second clocked inverter 492 is turned off. In order for the selection circuit 523 to perform such an operation, the L signal is input to the first wiring 493 and the H signal is input to the second wiring 494. Similarly, when the signal of the second shift register is selected, the first clocked inverter 491 is turned off and the second clocked inverter 492 is turned on. In order for the selection circuit 523 to perform such an operation, an H signal is input to the first wiring 493 and an L signal is input to the second wiring 494.

As described above, when the source driver and the gate driver have the above structure, the display device can have redundancy.

By disposing only two shift registers, the display device can have sufficient redundancy even if the circuit scale and area of the source driver and the gate driver are not significantly increased. This is because if the shift register malfunctions in some part, it also malfunctions in other parts. On the other hand, circuits other than the shift register (for example, the first latch circuit, the second latch circuit, the level shifter, the buffer, the digital-analog converter circuit, etc.) may malfunction in some parts but malfunction in other parts. Absent. That is, even if the shift register has only redundancy, the display device in this embodiment can have sufficient redundancy.

By disposing only two shift registers, the display device can have sufficient redundancy without requiring large power consumption. This is because the shift register can be driven with a small amplitude voltage.

Note that in this embodiment mode, description has been made using various drawings. However, the contents (or part of the contents) described in each figure may be different from the contents (or part of the contents) described in another figure. , Application, combination, or replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (or part of the contents) described in each drawing of this embodiment can be applied, combined, or replaced with the contents (or part of the contents) described in the drawings of another embodiment. Etc. can be appropriately performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each portion with a portion of another embodiment. Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of a case, an example of a case where it is described in detail, an example of a case where it is applied, an example of a related part, and the like are shown. Therefore, the contents described in other embodiment modes can be applied to, combined with, or replaced with this embodiment mode as appropriate.

(Embodiment 3)
In this embodiment mode, an SOI substrate applicable to the semiconductor device or the display device of the present invention is described.

An SOI substrate applicable to the semiconductor device or display device of the present invention is shown in FIGS. In FIG. 20A, a base substrate 240 is a substrate having an insulating surface or an insulating substrate, and various glass substrates used for the electronic industry such as aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass are applied. . In addition, a semiconductor substrate such as quartz glass or a silicon wafer is also applicable. The SOI layer 242 is a single crystal semiconductor, and typically, single crystal silicon is used. In addition, a crystalline semiconductor layer made of a compound semiconductor such as silicon, germanium, gallium arsenide, indium phosphide, or the like that can be peeled off from a single crystal semiconductor substrate or a polycrystalline semiconductor substrate by a hydrogen ion implantation separation method is applied. You can also.

A bonding layer 244 that has a smooth surface and forms a hydrophilic surface is provided between the base substrate 240 and the SOI layer 242. A silicon oxide film is suitable as the bonding layer 244. In particular, a silicon oxide film formed by a chemical vapor deposition method using an organosilane gas is preferable. Examples of the organic silane gas include ethyl silicate (TEOS: chemical formula Si (OC ₂ H ₅ ) ₄ ), tetramethylsilane (TMS: chemical formula Si (CH ₃ ) ₃ ), tetramethylcyclotetrasiloxane (TMCTS), and octamethylcyclotetrasiloxane. It is possible to use a silicon-containing compound such as (OMCTS), hexamethyldisilazane (HMDS), triethoxysilane (SiH (OC ₂ H ₅ ) ₃ ), trisdimethylaminosilane (SiH (N (CH ₃ ) ₂ ) ₃ ). it can.

The bonding layer 244 that has a smooth surface and forms a hydrophilic surface is provided with a thickness of 5 nm to 500 nm. With this thickness, it is possible to smooth the surface roughness of the film formation surface and ensure the smoothness of the growth surface of the film. In addition, distortion with the substrate to be bonded can be reduced. A similar silicon oxide film may be provided on the base substrate 240. That is, when the SOI layer 242 is bonded to a substrate having an insulating surface or an insulating base substrate 240, a bonding made of a silicon oxide film formed preferably using organosilane as a raw material on one or both surfaces of the bonding. By providing the layer 244, a strong bond can be formed.

FIG. 20B illustrates a structure in which a barrier layer 245 and a bonding layer 244 are provided over the base substrate 240. In the case where the SOI layer 242 is bonded to the base substrate 240, it is possible to prevent the SOI layer 242 from being contaminated by diffusion of mobile ion impurities such as alkali metal or alkaline earth metal from the glass substrate used as the base substrate 240. Can do. The bonding layer 244 on the base substrate 240 side may be provided as appropriate.

FIG. 21A illustrates a structure in which a nitrogen-containing insulating layer 260 is provided between the SOI layer 242 and the bonding layer 244. The nitrogen-containing insulating layer 260 is formed by stacking one or more films selected from a silicon nitride film, a silicon nitride oxide film, and a silicon oxynitride film. For example, a nitrogen-containing insulating layer 260 can be formed by stacking a silicon oxynitride film and a silicon nitride oxide film from the SOI layer 242 side. The bonding layer 244 is provided to form a bond with the base substrate 240, whereas the nitrogen-containing insulating layer 260 is provided to prevent impurities such as mobile ions and moisture from diffusing into the SOI layer 242 and being contaminated. Is preferred.

Here, the silicon oxynitride film has a composition with a higher oxygen content than nitrogen, and the concentration ranges are oxygen of 55 to 65 atomic%, nitrogen of 1 to 20 atomic%, and Si. 25 to 35 atomic%, and hydrogen is included in the range of 0.1 to 10 atomic%. The silicon nitride oxide film has a composition containing more nitrogen than oxygen, and the concentration ranges of oxygen are 15 to 30 atomic%, nitrogen is 20 to 35 atomic%, and Si is 25 to 25%. 35 atomic% and hydrogen are included in the range of 15 to 25 atomic%.

FIG. 21B illustrates a structure in which a bonding layer 244 is provided over the base substrate 240. A barrier layer 245 is preferably provided between the base substrate 240 and the bonding layer 244. This is to prevent the SOI layer 242 from being contaminated by diffusion of mobile ion impurities such as alkali metal or alkaline earth metal from a glass substrate used as the base substrate 240. A silicon oxide film 261 is formed on the SOI layer 242. This silicon oxide film 261 forms a bond with the bonding layer 244 and fixes the SOI layer over the base substrate 240. The silicon oxide film 261 is preferably formed by thermal oxidation. Alternatively, a film formed by chemical vapor deposition using TEOS as in the case of the bonding layer 244 may be used. Alternatively, chemical oxide can be used for the silicon oxide film 261. The chemical oxide can be formed, for example, by treating the surface of the semiconductor substrate with ozone-containing water. Chemical oxide is preferable because it is formed reflecting the flatness of the surface of the semiconductor substrate.

A method for manufacturing such an SOI substrate will be described with reference to FIGS.

A semiconductor substrate 241 illustrated in FIG. 22A is cleaned, and ions accelerated by an electric field are implanted from a surface thereof to a predetermined depth to form an ion doping layer 233. The ion implantation is performed in consideration of the thickness of the SOI layer transferred to the base substrate. The thickness of the single SOI layer is 5 nm to 500 nm, preferably 10 nm to 200 nm. In consideration of such a thickness, the acceleration voltage for implanting ions is implanted into the semiconductor substrate 241. The ion doping layer is formed by implanting halogen ions typified by hydrogen, helium or fluorine. In this case, it is preferable to implant ions having one or a plurality of the same atoms and having different mass numbers. In the case of implanting hydrogen ions, it is preferable to include H ⁺ , H ₂ ⁺ , and H ₃ ⁺ ions and to increase the ratio of H ₃ ⁺ ions. When hydrogen ions are implanted, H ⁺ , H ₂ ⁺ , H ₃ ⁺ ions are included, and if the ratio of H ₃ ⁺ ions is increased, the implantation efficiency can be increased and the implantation time can be shortened. Can do. With such a configuration, peeling can be easily performed.

Ions must be implanted under a high dose condition, and the surface of the semiconductor substrate 241 may become rough. Therefore, the surface of the rough semiconductor substrate 241 can be improved by providing a protective film against ion implantation with a thickness of 50 nm to 200 nm using a silicon nitride film or a silicon nitride oxide film on the surface into which ions are implanted. It is.

Next, as illustrated in FIG. 22B, a silicon oxide film is formed as a bonding layer 244 on a surface where bonding with the base substrate is formed. As the silicon oxide film, a silicon oxide film formed by a chemical vapor deposition method using an organosilane gas as described above is preferable. In addition, a silicon oxide film manufactured by a chemical vapor deposition method using silane gas can be used. In film formation by chemical vapor deposition, for example, a film formation temperature of 350 ° C. or lower is applied as a temperature at which degassing does not occur from the ion doping layer 233 formed on the single crystal semiconductor substrate. In addition, a heat treatment temperature higher than the deposition temperature is applied to the heat treatment for peeling the SOI layer from the single crystal or polycrystalline semiconductor substrate.

FIG. 22C shows a mode in which the base substrate 240 and the surface of the semiconductor substrate 241 on which the bonding layer 244 is formed are brought into close contact with each other. The surface on which the bond is formed is sufficiently cleaned. Then, the base substrate 240 and the bonding layer 244 are adhered to form a bond. In this bonding, van der Waals force is applied, and by pressing the base substrate 240 and the semiconductor substrate 241 together, a strong bond can be formed by hydrogen bonding.

It is also possible to form a good bond by activating the surface. For example, an atomic beam or an ion beam is irradiated to the surface on which the junction is formed. When an atomic beam or an ion beam is used, an inert gas neutral atom beam or inert gas ion beam such as argon can be used. In addition, plasma irradiation or radical treatment is performed. Such surface treatment makes it easy to form a bond between different materials even at a temperature of 200 ° C. to 400 ° C.

After the base substrate 240 and the semiconductor substrate 241 are bonded to each other through the bonding layer 244, heat treatment or pressure treatment is preferably performed. By performing the heat treatment or the pressure treatment, the bonding strength can be improved. The temperature of the heat treatment is preferably equal to or lower than the heat resistant temperature of the base substrate 240. In the pressure treatment, pressure is applied in a direction perpendicular to the bonding surface, and the pressure resistance of the base substrate 240 and the semiconductor substrate 241 is taken into consideration.

In FIG. 23, after the base substrate 240 and the semiconductor substrate 241 are bonded together, heat treatment is performed to peel the semiconductor substrate 241 from the base substrate 240 with the ion doping layer 233 as a cleavage plane. The heat treatment is preferably performed at a temperature equal to or higher than the deposition temperature of the bonding layer 244 and equal to or lower than the heat resistant temperature of the base substrate 240. For example, by performing heat treatment at 400 ° C. to 600 ° C., deposition changes of minute cavities formed in the ion doping layer 233 occur, and it is possible to cleave along the ion doping layer 233. Since the bonding layer 244 is bonded to the base substrate 240, the same crystalline SOI layer 242 as the semiconductor substrate 241 remains on the base substrate 240.

FIG. 24 shows a step of forming an SOI layer by providing a bonding layer on the base substrate side. FIG. 24A shows a step of forming an ion doping layer 233 by implanting ions accelerated by an electric field into a semiconductor substrate 241 provided with a silicon oxide film 261 to a predetermined depth. Implantation of halogen ions typified by hydrogen, helium, or fluorine is similar to that in the case of FIG. By forming the silicon oxide film 261 on the surface of the semiconductor substrate 241, it is possible to prevent the surface from being damaged by ion doping and the flatness from being impaired.

FIG. 24B illustrates a process in which the base substrate 240 on which the barrier layer 245 and the bonding layer 244 are formed and the surface of the semiconductor substrate 241 on which the silicon oxide film 261 is formed are in close contact with each other. Bonding is performed by bringing the bonding layer 244 over the base substrate 240 into close contact with the silicon oxide film 261 of the semiconductor substrate 241.

After that, the semiconductor substrate 241 is peeled off as shown in FIG. The heat treatment for peeling the semiconductor layer is performed in the same manner as in FIG. In this manner, the SOI substrate shown in FIG. 21B can be obtained.

As described above, according to this embodiment, the SOI layer 242 having a strong bonding force at the joint can be obtained even with the base substrate 240 having a heat resistant temperature of 700 ° C. or lower such as a glass substrate. As the base substrate 240, various glass substrates used for the electronic industry called non-alkali glass such as aluminosilicate glass, aluminoborosilicate glass, or barium borosilicate glass can be applied. That is, a single crystal semiconductor layer can be formed over a substrate whose one side exceeds 1 meter. Using such a large area substrate, not only a display device such as a liquid crystal display but also a semiconductor integrated circuit can be manufactured.

Next, a semiconductor device using an SOI substrate will be described with reference to FIGS. In FIG. 25A, an SOI layer 242 is provided over a base substrate 240 with a bonding layer 244 provided therebetween. A silicon nitride layer 247 and a silicon oxide layer 246 are formed over the SOI layer 242 in accordance with the element formation region. The silicon oxide layer 246 is used as a hard mask when the SOI layer 242 is etched for element isolation. The silicon nitride layer 247 is an etching stopper.

The thickness of the SOI layer 242 is preferably 5 nm to 500 nm, preferably 10 nm to 200 nm. The thickness of the SOI layer 242 can be appropriately set by controlling the depth of the ion doping layer 233 described with reference to FIG. A p-type impurity such as boron, aluminum, or gallium is added to the SOI layer 242 in order to control the threshold voltage. For example, boron as a p-type impurity may be added at a concentration of 5 × 10 ¹⁷ cm ^{−3 to} 1 × 10 ¹⁸ cm ⁻³ .

FIG. 25B shows a step of etching the SOI layer 242 and the bonding layer 244 using the silicon oxide layer 246 as a mask. The exposed end surfaces of the SOI layer 242 and the bonding layer 244 are nitrided by plasma treatment. By this nitriding treatment, a silicon nitride layer 247 is formed at least on the peripheral edge of the SOI layer 242. The silicon nitride layer 247 is insulative and has an effect of preventing leakage current from flowing at the end face of the SOI layer 242. In addition, since there is an oxidation resistance, it is possible to prevent an oxide film from growing from the end face and forming a berth beak between the SOI layer 242 and the bonding layer 244.

FIG. 25C shows a step of depositing an element isolation insulating layer 248. As the element isolation insulating layer 248, a silicon oxide film is deposited by chemical vapor deposition using TEOS. The element isolation insulating layer 248 is deposited thick so that the SOI layer 242 is embedded.

FIG. 25D shows a step of removing the element isolation insulating layer 248 until the silicon nitride layer 247 is exposed. This removal step can be performed by dry etching or chemical mechanical polishing. The silicon nitride layer 247 serves as an etching stopper. The element isolation insulating layer 248 remains so as to be embedded between the SOI layers 242. The silicon nitride layer 247 is then removed.

In FIG. 25E, after the SOI layer 242 is exposed, a gate insulating layer 249, a gate electrode 250, and a sidewall insulating layer 251 are formed, and a first impurity region 252 and a second impurity region 253 are formed. The insulating layer 254 is formed of silicon nitride and is used as a hard mask when the gate electrode 250 is etched.

In FIG. 26A, an interlayer insulating layer 255 is formed. The interlayer insulating layer 255 is formed by forming a BPSG (Boron Phosphorus Silicon Glass) film and planarizing it by reflow. Alternatively, a silicon oxide film may be formed using TEOS and planarized by chemical mechanical polishing. In the planarization process, the insulating layer 254 over the gate electrode 250 functions as an etching stopper. A contact hole 256 is formed in the interlayer insulating layer 255. The contact hole 256 has a self-aligned contact configuration using the sidewall insulating layer 251.

Thereafter, as shown in FIG. 26B, contact plugs 257 are formed by CVD using tungsten hexafluoride. Further, an insulating layer 258 is formed, and an opening is formed in accordance with the contact plug 257 to provide a wiring 259. The wiring 259 is formed of aluminum or an aluminum alloy, and the upper layer and the lower layer are formed of a metal film such as molybdenum, chromium, or titanium as a barrier metal.

In this manner, a field effect transistor can be manufactured using the SOI layer 242 bonded to the base substrate 240. Since the SOI layer 242 according to this embodiment is a single crystal semiconductor with a constant crystal orientation, a uniform and high-performance field effect transistor can be obtained. That is, non-uniformity of characteristic values important as transistor characteristics such as threshold voltage and mobility can be suppressed, and high performance such as high mobility can be achieved.

  As described above, a semiconductor device and a display device with higher redundancy are provided by manufacturing the semiconductor device and the display device of the present invention using the transistor manufactured using the manufacturing method of this embodiment. Can do.

Note that in this embodiment mode, description has been made using various drawings. However, the contents (or part of the contents) described in each figure may be different from the contents (or part of the contents) described in another figure. , Application, combination, or replacement can be appropriately performed. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (or part of the contents) described in each drawing of this embodiment can be applied, combined, or replaced with the contents (or part of the contents) described in the drawings of another embodiment. Etc. can be appropriately performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each portion with a portion of another embodiment. Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of a case, an example of a case where it is described in detail, an example of a case where it is applied, an example of a related part, and the like are shown. Therefore, the contents described in other embodiment modes can be applied to, combined with, or replaced with this embodiment mode as appropriate.

(Embodiment 4)
In this embodiment mode, a method for manufacturing an SOI substrate will be described with reference to FIGS. In FIG. 27A, a silicon oxynitride film 235 is formed to a thickness of 100 nm by a plasma CVD method using SiH ₄ gas and N ₂ O gas on a single crystal silicon substrate 231 from which a natural oxide film has been removed. Further, a silicon nitride oxide film 236 is formed to a thickness of 50 nm using SiH ₄ gas, N ₂ O gas, and NH ₃ gas.

Then, as shown in FIG. 27B, hydrogen ions are implanted from the surface of the silicon nitride oxide film 236 using an ion doping apparatus. The ion doping apparatus is a system in which ionized gas is not mass-separated but is directly accelerated by an electric field and injected into a substrate. When this apparatus is used, high dose ion doping can be performed with high efficiency even on a large-area substrate. In this embodiment mode, hydrogen is ionized to form an ion doping layer 243 in the single crystal silicon substrate 231. Ion doping is performed with an acceleration voltage of 80 kV and a dose of 2 × 10 ¹⁶ / cm ² .

In this case, it is preferable to implant ions having one or a plurality of the same atoms and having different mass numbers. In the case of implanting hydrogen ions, it is preferable to include H ⁺ , H ₂ ⁺ , H ₃ ⁺ ions and to increase the ratio of H ₃ ⁺ ions to about 80%. By including a large amount of high-order ions with a small mass number in this manner, the ion doping layer 243 can be easily cleaved in the heat treatment step. In this case, by providing the silicon nitride oxide film 236 and the silicon oxynitride film 235 on the ion doping surface of the single crystal silicon substrate 231, surface roughness of the single crystal silicon substrate 231 can be prevented by ion doping.

Next, a silicon oxide film 234 is formed over the silicon nitride oxide film 236 as illustrated in FIG. The silicon oxide film 234 is formed with a thickness of 50 nm by plasma CVD using ethyl silicate (TEOS: chemical formula Si (OC ₂ H ₅ ) ₄ ) and oxygen gas. The deposition temperature is set to 350 ° C. or lower so that hydrogen is not separated from the ion doping layer 243.

FIG. 28A shows a process of forming a bond by superposing and pressing a glass substrate 230 and a single crystal silicon substrate 231 which are ultrasonically cleaned using ozone-containing water with a silicon oxide film 234 interposed therebetween. Yes. Thereafter, a heat treatment was performed at 400 ° C. for 10 minutes in a nitrogen atmosphere, a heat treatment was further performed at 500 ° C. for 2 hours, and further maintained at 400 ° C. for several hours, and then gradually cooled to room temperature. Accordingly, a crack is formed in the ion doping layer 243 so that the single crystal silicon substrate 231 is peeled off, and the bonding between the silicon oxide film 234 and the glass substrate 230 can be strengthened.

In this manner, the single crystal silicon layer 232 can be formed over the glass substrate 230 at a temperature at which the glass substrate 230 is not distorted. In this embodiment mode, the single crystal silicon layer 232 to be manufactured is firmly bonded to the glass substrate 230, and the silicon layer does not peel even when a tape peel test is performed. That is, it becomes possible to provide a single crystal silicon layer on various glass substrates used in the electronic industry called alkali-free glass such as aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass, and each side exceeds 1 meter. Various integrated circuits and display devices can be manufactured using the substrate.

  As described above, by manufacturing the semiconductor device and the display device of the present invention using the substrate manufactured using the manufacturing method of this embodiment, a transistor with less variation in characteristics such as a threshold value can be manufactured. A semiconductor device and a display device having higher redundancy can be provided using the transistor.

Note that in this embodiment mode, description has been made using various drawings. However, the contents (or part of the contents) described in each figure may be different from the contents (or part of the contents) described in another figure. , Application, combination, or replacement can be appropriately performed. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (or part of the contents) described in each drawing of this embodiment can be applied, combined, or replaced with the contents (or part of the contents) described in the drawings of another embodiment. Etc. can be appropriately performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each portion with a portion of another embodiment. Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of a case, an example of a case where it is described in detail, an example of a case where it is applied, an example of a related part, and the like are shown. Therefore, the contents described in other embodiment modes can be applied to, combined with, or replaced with this embodiment mode as appropriate.

(Embodiment 5)
In this embodiment, examples of electronic devices are described.

FIG. 4 shows a display panel module in which a display panel 901 and a circuit board 911 are combined. The display panel 901 includes a pixel portion 902, a scanning line driver circuit 903, and a signal line driver circuit 904. For example, a control circuit 912 and a signal dividing circuit 913 are formed on the circuit board 911. The display panel 901 and the circuit board 911 are connected by a connection wiring 914. An FPC or the like can be used for the connection wiring.

FIG. 5 is a block diagram illustrating a main configuration of the television receiver. The tuner 921 receives a video signal and an audio signal. The video signal includes a video signal amplification circuit 922, a video signal processing circuit 923 that converts a signal output from the video signal amplification circuit 922 into a color signal corresponding to each color of red, green, and blue, and a drive circuit for the video signal. Is processed by a control circuit 932 for conversion to the input specification of The control circuit 932 outputs signals to the scanning line driver circuit 934 and the signal line driver circuit 924, respectively. Then, the scan line driver circuit 934 and the signal line driver circuit 924 drive the display panel 931. In the case of digital driving, a signal dividing circuit 933 may be provided on the signal line side and an input digital signal may be divided into m pieces (m is a positive integer) and supplied.

Of the signals received by the tuner 921, the audio signal is sent to the audio signal amplifier circuit 925, and the output is supplied to the speaker 927 via the audio signal processing circuit 926. The control circuit 928 receives control information on the receiving station (reception frequency) and volume from the input unit 929 and sends a signal to the tuner 921 or the audio signal processing circuit 926.

FIG. 6A illustrates a television receiver in which a display panel module different from that in FIG. 5 is incorporated. In FIG. 6A, a display screen 942 housed in a housing 941 is formed of a display panel module. Speaker 943, input means (operation key 944, connection terminal 945, sensor 946 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, voice, time) , Including a function of measuring hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared), a microphone 947) and the like may be provided as appropriate.

FIG. 6B illustrates a television receiver that can carry only a display wirelessly. This television receiver includes a display portion 953, a speaker portion 957, input means (operation keys 956, a connection terminal 958, a sensor 959 (force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, Magnetic, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, smell, or infrared)), microphone 960), etc. are provided as appropriate It has been. A housing and a signal receiver are housed in the housing 952, and the display portion 953, the speaker portion 957, the sensor 959, and the microphone 960 are driven by the battery. The battery can be repeatedly charged by the charger 950. The charger 950 can transmit and receive a video signal, and can transmit the video signal to a signal receiver of the display. The device shown in FIG. 6B is controlled by operation keys 956. Alternatively, the device illustrated in FIG. 6B can send a signal to the charger 950 by operating the operation key 956. That is, it may be a video / audio bidirectional communication device. Alternatively, the device illustrated in FIG. 6B operates the operation key 956 to transmit a signal to the charger 950 and further cause the other electronic device to receive a signal that can be transmitted by the charger 950. Communication control of electronic devices is also possible. That is, a general-purpose remote control device may be used. Note that the contents (or part of the contents) described in each drawing in this embodiment can be applied to the display portion 953.

Next, a configuration example of a mobile phone will be described with reference to FIG.

The display panel 981 is incorporated in the housing 1000 so as to be detachable. The shape or size of the housing 1000 can be changed as appropriate in accordance with the size of the display panel 981. The housing 1000 to which the display panel 981 is fixed is fitted into the printed circuit board 1001 and assembled as a module.

The display panel 981 is connected to the printed circuit board 1001 through the FPC 993. A printed circuit board 1001 includes a speaker 1002, a microphone 1003, a transmission / reception circuit 1004, a signal processing circuit 1005 including a CPU, a controller, and a sensor 1011 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid , Magnetic, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, smell, or infrared). Such a module is combined with an operation key 1006, a battery 1007, and an antenna 1010 and stored in a housing 1009. The pixel portion of the display panel 981 is arranged so that it can be seen from an opening window formed in the housing 1009.

In the display panel 981, a pixel portion and some peripheral driver circuits (a driver circuit having a low operating frequency among a plurality of driver circuits) are formed over a substrate using transistors, and some peripheral driver circuits (a plurality of driver circuits) are formed. A driving circuit having a high operating frequency among the circuits) may be formed over the IC chip, and the IC chip may be mounted on the display panel 981 by COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate using TAB (Tape Auto Bonding) or a printed circuit board. With such a structure, the power consumption of the display device can be reduced, and the usage time by one charge of the mobile phone can be extended. Cost reduction of the mobile phone can be achieved.

The mobile phone shown in FIG. 7 has a function of displaying various information (still images, moving images, text images, and the like). It has a function of displaying a calendar, date or time on the display unit. It has a function of operating or editing information displayed on the display unit. It has a function of controlling processing by various software (programs). Has a wireless communication function. It has a function of making a call with another mobile phone, a fixed phone, or a voice communication device using a wireless communication function. It has a function of connecting to various computer networks using a wireless communication function. It has a function of transmitting or receiving various data using a wireless communication function. The vibrator operates in response to an incoming call, data reception, or alarm. It has a function to generate a sound in response to an incoming call, reception of data, or an alarm. Note that the function of the mobile phone illustrated in FIG. 7 is not limited thereto, and the mobile phone can have various functions.

FIG. 8A illustrates a display, which includes a housing 1021, a support base 1022, a display portion 1023, a speaker 1027, an LED lamp 1029, input means (a connection terminal 1024, a sensor 1025 (force, displacement, position, velocity, acceleration, angular velocity). Includes functions to measure speed, distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation, flow, humidity, gradient, vibration, odor or infrared 1), a microphone 1026, an operation key 1028), and the like. The display illustrated in FIG. 8A has a function of displaying various information (such as a still image, a moving image, and a text image) on the display portion. Note that the function of the display illustrated in FIG. 8A is not limited to this, and the display can have a variety of functions.

FIG. 8B shows a camera, which includes a main body 1031, a display portion 1032, a shutter button 1036, a speaker 1040, an LED lamp 1041, input means (an image receiving portion 1033, operation keys 1034, an external connection port 1035, a connection terminal 1037, and a sensor 1038. (Force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient , Including a function of measuring vibration, odor, or infrared light), a microphone 1039) and the like. The camera illustrated in FIG. 8B has a function of capturing a still image. Has a function to shoot movies. It has a function of automatically correcting captured images (still images, moving images). It has a function of storing captured images in a recording medium (externally or built in a digital camera). It has a function of displaying a photographed image on the display unit. Note that the function of the camera illustrated in FIG. 8B is not limited thereto, and the camera can have a variety of functions.

FIG. 8C illustrates a computer, which includes a main body 1051, a housing 1052, a display portion 1053, a speaker 1060, an LED lamp 1061, a reader / writer 1062, input means (a keyboard 1054, an external connection port 1055, a pointing device 1056, a connection terminal. 1057, sensor 1058 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate Including a function of measuring humidity, gradient, vibration, odor, or infrared)), microphone 1059), and the like. The computer illustrated in FIG. 8C has a function of displaying various information (still images, moving images, text images, and the like) on the display portion. It has a function of controlling processing by various software (programs). It has a communication function such as wireless communication or wired communication. It has a function of connecting to various computer networks using a communication function. It has a function of transmitting or receiving various data using a communication function. Note that the function of the computer illustrated in FIG. 8C is not limited thereto, and the computer can have various functions.

FIG. 31A shows a mobile computer, which includes a main body 1131, a display portion 1132, a switch 1133, a speaker 1139, an LED lamp 1140, input means (operation keys 1134, an infrared port 1135, a connection terminal 1136, a sensor 1137 (force, displacement, Position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, smell or Including a function of measuring infrared rays), a microphone 1138) and the like. A mobile computer illustrated in FIG. 31A has a function of displaying various information (such as a still image, a moving image, and a text image) on a display portion. The display unit has a touch panel function. The display unit has a function of displaying a calendar, date or time. It has a function of controlling processing by various software (programs). Has a wireless communication function. It has a function of connecting to various computer networks using a wireless communication function. It has a function of transmitting or receiving various data using a wireless communication function. Note that the function of the mobile computer illustrated in FIG. 31A is not limited to this, and the mobile computer can have a variety of functions.

FIG. 31B shows a portable image reproducing device (eg, a DVD reproducing device) provided with a recording medium, which includes a main body 1151, a housing 1152, a display portion A 1153, a display portion B 1154, a speaker portion 1157, an LED lamp 1161, Input means (recording medium (DVD, etc.) reading unit 1155, operation key 1156, connection terminal 1158, sensor 1159 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemistry Material, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared, etc.), microphone 1160) and the like. The display portion A1153 can mainly display image information, and the display portion B1154 can mainly display character information.

FIG. 31C shows a goggle type display, which includes a main body 1171, a display portion 1172, an earphone 1173, a support portion 1174, an LED lamp 1179, a speaker 1178, input means (connection terminal 1175, sensor 1176 (force, displacement, position, speed). Measure acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared A microphone 1177) and the like. The goggle type display shown in FIG. 31C has a function of displaying images (still images, moving images, text images, and the like) acquired from the outside on a display portion. Note that the function of the goggle display illustrated in FIG. 31C is not limited to this, and the display can have a variety of functions.

32A shows a portable game machine, which includes a housing 1181, a display portion 1182, a speaker portion 1183, a storage medium insertion portion 1185, an LED lamp 1189, input means (operation keys 1184, a connection terminal 1186, a sensor 1187 (force , Displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration Including a function of measuring odor or infrared), a microphone 1188) and the like. A portable game machine shown in FIG. 32A has a function of reading a program or data recorded in a recording medium and displaying the program or data on a display portion. It has a function of sharing information by performing wireless communication with other portable game machines. Note that the function of the portable game machine illustrated in FIG. 32A is not limited to this, and the portable game machine can have a variety of functions.

FIG. 32B shows a digital camera with a television receiving function, which includes a main body 1191, a display portion 1192, a speaker 1194, a shutter button 1195, an LED lamp 1201, input means (operation keys 1193, an image receiving portion 1196, an antenna 1197, a connection terminal 1198). , Sensor 1199 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, Including a function of measuring humidity, gradient, vibration, odor, or infrared light), a microphone 1200) and the like. The digital camera with a television receiver illustrated in FIG. 32B has a function of shooting a still image. Has a function to shoot movies. It has a function to automatically correct a photographed image. It has a function of acquiring various information from the antenna. It has a function of storing captured images or information acquired from an antenna. It has a function of displaying a captured image or information acquired from an antenna on a display unit. Note that the function of the digital camera with a television receiver illustrated in FIG. 32B is not limited to this, and the digital camera can have a variety of functions.

FIG. 33 shows a portable game machine, which includes a housing 1211, a first display portion 1212, a second display portion 1213, a speaker portion 1214, a recording medium insertion portion 1216, an LED lamp 1220, input means (operation keys 1215, connection terminals 1217). , Sensor 1218 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, Including a function of measuring humidity, gradient, vibration, odor, or infrared)), a microphone 1219) and the like. The portable game machine shown in FIG. 33 has a function of reading a program or data recorded on a recording medium and displaying the program or data on a display unit. It has a function of sharing information by performing wireless communication with other portable game machines. Note that the functions of the portable game machine illustrated in FIG. 33 are not limited thereto, and the portable game machine can have various functions.

As shown in FIGS. 8A to 8C, FIGS. 31A to 31C, FIGS. 32A to 32C, and FIG. 33, an electronic device displays some information. It has a display part.

Next, application examples of the semiconductor device will be described.

FIG. 9 illustrates an example in which a semiconductor device is provided integrally with a building. FIG. 9 includes a housing 1070, a display portion 1071, a remote control device 1072 that is an operation portion, a speaker portion 1073, and the like. The semiconductor device is integrated with the building as a wall-hanging type, and can be installed without requiring a large installation space.

FIG. 10 shows another example in which a semiconductor device is provided integrally with a building in the building. The display panel 1081 is attached to the unit bath 1082 so that a bather can view the display panel 1081. The display panel 1081 has a function of displaying information when operated by a bather. It has a function that can be used as an advertising or entertainment means.

Note that the semiconductor device can be installed not only on the side wall of the unit bus 1082 shown in FIG. For example, a part of the mirror surface or the bathtub itself may be integrated. At this time, the shape of the display panel 1081 may be adapted to the shape of the mirror surface or the bathtub.

FIG. 11 illustrates another example in which the semiconductor device is provided integrally with a building. The display panel 1092 is attached in a curved manner according to the curved surface of the columnar body 1091. Here, the columnar body 1091 is described as a utility pole.

The display panel 1092 illustrated in FIG. 11 is provided at a position higher than the human viewpoint. By installing the display panel 1092 on a building that is standing outdoors like a utility pole, an advertisement can be made to an unspecified number of viewers. Here, since the display panel 1092 can easily display the same image and switch the image instantly by control from the outside, extremely efficient information display and advertising effect can be expected. By providing the display panel 1092 with a self-luminous display element, it can be said that the display panel 1092 is useful as a display medium with high visibility even at night. By installing it on the utility pole, it is easy to secure the power supply means of the display panel 1092. In the event of an emergency such as a disaster, it can also be a means of quickly and accurately communicating information to the victims.

Note that as the display panel 1092, for example, a display panel which displays an image by providing a switching element such as an organic transistor on a film-like substrate and driving the display element can be used.

Note that in this embodiment, a wall, a columnar body, and a unit bus are used as buildings as examples, but this embodiment is not limited to this, and semiconductor devices can be installed in various buildings.

Next, an example in which the semiconductor device is provided integrally with the moving body is described.

FIG. 12 is a diagram illustrating an example in which a semiconductor device is provided integrally with an automobile. The display panel 1102 is attached integrally with the vehicle body 1101 of the automobile, and can display on-demand information on the operation of the vehicle body or information input from inside and outside the vehicle body. Note that a navigation function may be provided.

Note that the semiconductor device can be installed not only in the vehicle body 1101 shown in FIG. 12 but also in various places. For example, it may be integrated with a glass window, a door, a handle, a shift lever, a seat, a room mirror, and the like. At this time, the shape of the display panel 1102 may be adapted to the shape of the object to be installed.

FIG. 29 is a diagram illustrating an example in which a semiconductor device is provided integrally with a train vehicle.

FIG. 29A is a diagram showing an example in which the display panel 1112 is provided on the glass of the door 1111 of the train car. Compared to conventional paper advertisements, there is an advantage that labor costs required for advertisement switching are not incurred. Since the display panel 1112 can instantaneously switch the image displayed on the display unit in response to an external signal, for example, the display panel image is switched every time when the customer class of passengers on the train is switched. More effective advertising effect can be expected.

FIG. 29B is a diagram showing an example in which a display panel 1112 is provided on the glass window 1113 and the ceiling 1114 in addition to the glass of the door 1111 of the train car. As described above, since the semiconductor device can be easily installed in a place where it has been difficult to install in the past, an effective advertising effect can be obtained. Since the semiconductor device can instantaneously switch the image displayed on the display unit by an external signal, the cost and time at the time of advertisement switching can be reduced, and more flexible advertisement operation and information transmission can be achieved. It becomes possible.

Note that the semiconductor device can be installed not only in the door 1111, the glass window 1113, and the ceiling 1114 shown in FIG. 29 but in various places. For example, it may be integrated with a strap, a seat, a rail, a floor or the like. At this time, the shape of the display panel 1112 may be adapted to the shape of the object to be installed.

FIG. 30 is a diagram illustrating an example in which a semiconductor device is provided integrally with a passenger airplane.

FIG. 30A is a diagram showing a shape in use when the display panel 1122 is provided on the ceiling 1121 above the seat of the passenger airplane. The display panel 1122 is integrally attached via a ceiling 1121 and a hinge portion 1123, and the passenger can view the display panel 1122 by extending and contracting the hinge portion 1123. The display panel 1122 has a function of displaying information when operated by a passenger. It has a function that can be used as an advertising or entertainment means. As shown in FIG. 30 (b), it is possible to consider safety during takeoff and landing by folding the hinge part and storing it in the ceiling 1121. In addition, by turning on the display element of the display panel in an emergency, it can be used as an information transmission means and a guide light.

Note that the semiconductor device can be installed not only on the ceiling 1121 shown in FIG. For example, it may be integrated with a seat seat, a seat table, an armrest, a window and the like. A large display panel that can be viewed simultaneously by a large number of people may be installed on the wall of the aircraft. At this time, the shape of the display panel 1122 may be adapted to the shape of the object to be installed.

In this embodiment, examples of the moving body include a train car body, an automobile body, and an airplane body. However, the present invention is not limited to this, but a motorcycle, an automobile (including an automobile, a bus, etc.), a train (monorail) It can be installed on various things such as ships). Since the semiconductor device can instantly switch the display of the display panel in the moving body by an external signal, installing the semiconductor device in the moving body targets a large number of unspecified customers. It can be used for applications such as advertisement display boards and information display boards in the event of a disaster.

As described above, the display device of the present invention can be applied to various electronic devices, and by applying the display device, a display device with less variation in characteristics and higher redundancy can be provided.

Note that in this embodiment mode, description has been made using various drawings. However, the contents (or part of the contents) described in each figure may be different from the contents (or part of the contents) described in another figure. , Application, combination, or replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be a part) described in the figure of another embodiment. Can be done freely. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each portion with a portion of another embodiment.

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of a case, an example of a case where it is described in detail, an example of a case where it is applied, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

2 is a diagram showing a configuration and an operation of a semiconductor device of the present invention in Embodiment 1. FIG. 1 is a diagram showing a configuration of a semiconductor device of the present invention in Embodiment 1. FIG. 1 is a diagram showing a configuration of a semiconductor device of the present invention in Embodiment 1. FIG. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a diagram showing a configuration of a display device of the present invention in Embodiment 2. FIG. 7 is a cross-sectional view showing an SOI substrate applicable to the semiconductor device or display device of the present invention in Embodiment 3. FIG. 7 is a cross-sectional view showing an SOI substrate applicable to the semiconductor device or display device of the present invention in Embodiment 3. FIG. 10 is a cross-sectional view illustrating a method for manufacturing an SOI substrate applicable to the semiconductor device or the display device of the present invention in Embodiment 3. FIG. 10 is a cross-sectional view illustrating a method for manufacturing an SOI substrate applicable to the semiconductor device or the display device of the present invention in Embodiment 3. FIG. 10 is a cross-sectional view illustrating a method for manufacturing an SOI substrate applicable to the semiconductor device or the display device of the present invention in Embodiment 3. FIG. 10 is a cross-sectional view illustrating a method for manufacturing a semiconductor device or a display device of the present invention to which an SOI substrate according to Embodiment 3 is applied. FIG. 10 is a cross-sectional view illustrating a method for manufacturing a semiconductor device or a display device of the present invention to which an SOI substrate according to Embodiment 3 is applied. FIG. 10 is a cross-sectional view illustrating a method for manufacturing an SOI substrate in Embodiment 4. FIG. 10 is a cross-sectional view illustrating a method for manufacturing an SOI substrate in Embodiment 4. FIG. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied. FIG. 10 is a diagram showing an electronic device to which a semiconductor device or a display device of the present invention in Embodiment 5 is applied.

Explanation of symbols

101 circuit 102 circuit 103 selection circuit 104 circuit 110 selection circuit 111 switch 112 switch 114 switch 120 control circuit 121 comparison circuit 122 comparison circuit 123 memory 124 comparison result judgment circuit

Claims (14)

A pixel portion having a plurality of pixels;
A source driver electrically connected to the pixel portion;
The source driver includes a first shift register;
A second shift register;
A latch circuit;
A level shifter,
A buffer,
A selection circuit that is electrically connected to the first shift register and the second shift register, selects one of the signals from the first shift register and the second shift register, and outputs the selected signal to the pixel portion. And a display device. In claim 1,
The source driver includes a transistor having a semiconductor layer,
The display device, wherein the semiconductor layer is a single crystal semiconductor. A pixel portion having a plurality of pixels;
A gate driver electrically connected to the pixel portion;
The gate driver includes a first shift register;
A second shift register;
A latch circuit;
A level shifter,
A buffer,
A selection circuit that is electrically connected to the first shift register and the second shift register, selects one of the signals from the first shift register and the second shift register, and outputs the selected signal to the pixel portion. And a display device. In any one of Claims 1 thru | or 3,
A first comparison circuit that is electrically connected to the first shift register and compares a signal of the first shift register with a reference signal;
A second comparison circuit electrically connected to the second shift register for comparing a signal of the second shift register with a reference signal;
A storage element electrically connected to the first comparison circuit, the second comparison circuit, and the selection circuit, in which data of the reference signal is stored, a comparison result in the first comparison circuit, and the And a comparison result determination circuit for outputting a signal for controlling the selection circuit based on a comparison result in the second comparison circuit. In any one of Claims 1 thru | or 4,
The selection circuit includes a first analog switch electrically connected to the first shift register and the pixel portion;
A display device comprising: the second shift register; and a second analog switch electrically connected to the pixel portion. In any one of Claims 1 thru | or 4,
The selection circuit includes a first clocked inverter electrically connected to the first shift register and the pixel portion;
A display device comprising: the second shift register; and a second clocked inverter electrically connected to the pixel portion. In any one of Claims 3 thru | or 6,
The gate driver includes a transistor having a semiconductor layer,
The display device, wherein the semiconductor layer is a single crystal semiconductor. A pixel portion having a plurality of pixels;
A source driver and a gate driver electrically connected to the pixel portion,
The source driver includes a first shift register;
A second shift register;
A first latch circuit;
A first level shifter;
A first buffer;
The gate driver includes a third shift register;
A fourth shift register;
A second latch circuit;
A second level shifter;
A second buffer;
The second shift register is electrically connected to the third shift register and the fourth shift register, selects one of the signals from the third shift register and the fourth shift register, and outputs the selected signal to the pixel portion. And a selection circuit. In claim 8,
A first comparison circuit that is electrically connected to the first shift register and compares a signal of the first shift register with a first reference signal;
A second comparison circuit that is electrically connected to the second shift register and compares a signal of the second shift register with a first reference signal;
A storage element that is electrically connected to the first comparison circuit, the second comparison circuit, and the first selection circuit and stores data of a signal serving as the first reference, and the first comparison A first comparison result determination circuit that outputs a signal for controlling the first selection circuit from a comparison result in the circuit and a comparison result in the second comparison circuit;
A first comparison circuit that is electrically connected to the third shift register and compares a signal of the third shift register with a second reference signal;
A second comparison circuit that is electrically connected to the fourth shift register and compares a signal of the fourth shift register with a second reference signal;
A storage element electrically connected to the first comparison circuit, the second comparison circuit, and the second selection circuit, in which data of a signal serving as the second reference is stored, and the first comparison And a second comparison result determination circuit for outputting a signal for controlling the second selection circuit from the comparison result in the circuit and the comparison result in the second comparison circuit. In claim 8 or claim 9,
The first selection circuit includes a first analog switch electrically connected to the first shift register and the pixel portion;
A second analog switch electrically connected to the second shift register and the pixel portion,
The second selection circuit includes a third analog switch electrically connected to the third shift register and the pixel portion;
A display device comprising: the fourth shift register; and a fourth analog switch electrically connected to the pixel portion. In claim 8 or claim 9,
The first selection circuit includes a first clocked inverter electrically connected to the first shift register and the pixel portion;
A second clocked inverter electrically connected to the second shift register and the pixel portion;
The second selection circuit includes a third clocked inverter electrically connected to the third shift register and the pixel portion;
A display device comprising: the fourth shift register; and a fourth clocked inverter electrically connected to the pixel portion. In any one of Claims 8 thru | or 11,
Either the gate driver or the source driver includes a transistor having a semiconductor layer,
The display device, wherein the semiconductor layer is a single crystal semiconductor. In any one of Claims 1 to 12,
The pixel includes a transistor having a semiconductor layer,
The display device, wherein the semiconductor layer is a single crystal semiconductor.   An electronic apparatus comprising the display device according to any one of claims 1 to 13.

Images