JP2007129090A - Wafer test system, prober, wafer test method and probe card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a wafer test system in which the temperature of a device inspected can be set accurately through a simple arrangement. <P>SOLUTION: The wafer test system comprises a tester 21, a prober, and a communication path 25 connecting the tester and the prober and performs electrical inspection of a semiconductor device formed on a wafer. The prober comprises a probe card 17 having a probe 18, a wafer chuck 11 for holding a wafer W, a means 20 for regulating the temperature of a wafer chuck, and a control section 16. The tester 21 detects the temperature of the semiconductor device by detecting the electric characteristics of an element formed in the semiconductor device and transmits detected temperature data to the prober via the communication path. The control section 16 of the prober controls the temperature regulation means 20 based on the received temperature data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wafer test system and a wafer test method for electrically inspecting a plurality of semiconductor devices (devices) formed on a semiconductor wafer, a prober constituting the wafer test system, and a probe card used therein, In particular, the present invention relates to a wafer test system, a wafer test method, a prober, and a probe card that can perform inspection in a high and low temperature environment by heating and cooling the surface of a wafer chuck that holds a wafer.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of chips (dies) each having a semiconductor device (device). Each die is inspected for electrical characteristics, then separated by a dicer, and then fixed to a lead frame and assembled. The inspection of the electrical characteristics is performed by a wafer test system composed of a prober and a tester. The prober fixes the wafer to the stage and brings the probe into contact with the electrode pad of each die. The tester supplies power and various test signals from a terminal connected to the probe, and analyzes the signals output to the electrodes of the die with the tester to confirm whether it operates normally.

  Semiconductor devices are used in a wide range of applications, and there are semiconductor devices (devices) that can be used in low-temperature environments such as -55 ° C and high-temperature environments such as 200 ° C. It is required that the inspection can be performed. Therefore, a wafer temperature adjusting means for changing the surface temperature of the wafer chuck such as a heater mechanism, a chiller mechanism, and a heat pump mechanism is provided under the wafer mounting surface of the wafer chuck for holding the wafer in the prober. The wafer held on is overheated or cooled.

  FIG. 1 is a diagram showing a schematic configuration of a wafer test system including a prober having a wafer temperature adjusting means. The prober includes a wafer chuck 11 for holding the wafer W, a probe card 17 having a probe 18 made in accordance with the electrode arrangement of a semiconductor chip to be inspected, and a control unit 16. A coolant path 12 and a heater 13 are provided in the wafer chuck 11. A cooling liquid flows from the cooling device 14 to the cooling liquid path 12 via the path 15 to cool the surface of the wafer chuck 11 holding the wafer W. The heater 13 generates heat to heat the surface of the wafer chuck 11 that holds the wafer W. The control unit 16 controls the cooling device 14 and the heater 13 based on the temperature detected by the temperature sensor 19 provided near the surface of the wafer chuck 11 so that the surface of the wafer chuck 11 reaches a desired temperature. To. In addition to this, the prober detects the position of the probe and the triaxial movement / rotation mechanism of the wafer chuck 11 in the X, Y, and Z directions, the alignment camera that detects the arrangement direction of the dies formed on the wafer, and the probe. A needle position detection camera and a housing for housing them are provided, and the probe card 17 is attached to a card holder provided in the housing. Since such components are not directly related to the present invention, illustration is omitted here.

  The tester includes a tester body 21, a connection part 22, and a connection part 23 that electrically connects the terminal of the connection part 22 and the terminal of the probe card 17. The connection part 22 has a connection terminal mechanism using a spring, a so-called spring pin structure. The tester and the prober are connected by a communication path 25, and the prober performs measurement in cooperation with the tester in the wafer test. The power supply system and the mechanism part are devices independent of the tester body and the test head.

  In addition, a vacuum path or the like for vacuum-sucking the wafer W is provided in the wafer chuck 11, and there are various modified examples of the arrangement of the coolant path 12, the heater 13, and the vacuum path in the wafer chuck 11. . In the following description, the cooling mechanism including the coolant path 12 and the cooling device 14 and the heating mechanism including the heater 13 are collectively referred to as wafer temperature adjusting means. Therefore, the wafer temperature adjusting means may have only one of a cooling mechanism and a heating mechanism.

  The wafer temperature adjusting means can set the wafer W held on the wafer chuck 11 to an arbitrary temperature from −55 ° C. to + 200 ° C., for example. The wafer temperature adjusting means can also be realized by a heat pump mechanism or the like.

  When the wafer is inspected at a predetermined temperature, the control unit 16 controls the wafer temperature adjusting means based on the temperature detected by the temperature sensor 19 while the wafer W is held on the wafer chuck 11. Set to a predetermined temperature. The wafer chuck 11 is made of a material having good thermal conductivity such as aluminum, copper, or ceramic, and the surface holding the wafer W is considered to have substantially the same temperature. Therefore, only one temperature sensor 19 is provided, and control is performed assuming that the detected temperature of the wafer chuck 11 is the same in other portions.

  Since the configuration of the prober and wafer test system described above is widely known, further description is omitted here.

JP 2001-210683 A (Overall)

  When inspecting the electrical characteristics of a device, a power supply and a signal are supplied to the device to operate, and an output signal is detected. Therefore, the device generates heat during inspection. However, even if heat is generated, the heat capacity of the wafer chuck 11 is large and the thermal conductivity of the wafer chuck 11 is good. Therefore, it has been controlled that the temperature of the device under inspection can be detected by the temperature sensor 19.

  However, the wafer chuck 11 also cannot be said to have a sufficiently low surface thermal resistance due to the internal structure and the like, and when the held wafer device generates heat, the temperature of that part rises above the temperature of the other part. I understood it. It has been found that the difference between the actual temperature of the device being inspected and the temperature detected by the temperature sensor cannot be ignored, especially when testing a device with a large amount of heat generated and the temperature sensor is far from the device being inspected. . In other words, there is a problem that the device to be inspected cannot be set to the inspection temperature accurately.

  In order to solve such a problem, Patent Document 1 divides the surface of the wafer chuck 11 into a plurality of regions, and includes temperature adjusting means (heating mechanism and cooling mechanism) and a temperature sensor that can be controlled independently for each region. Although it is described that the temperature adjusting means in each region is controlled based on the temperature detected by each temperature sensor, there is a problem that the cost increases.

  Further, the wafer W has a thin plate shape, and when it is attracted to and held by the wafer chuck 11, the thermal resistance between the wafer W and the surface of the wafer chuck 11 is sufficiently small, and the entire surface of the wafer W can be quickly removed from the wafer chuck 11. 11 surface temperatures have been considered. However, it has been found that the thermal resistance between the surface of the wafer W and the wafer chuck 11 is not sufficiently small due to the roughness of the surface of the wafer chuck 11 in practice. Therefore, reducing the surface roughness of the wafer chuck 11 to reduce the thermal resistance between the held wafer and the surface of the wafer chuck also reduces the difference between the temperature of the device under inspection and the temperature detected by the temperature sensor. Although effective above, there is still a problem that the cost is high and the effect is not sufficient.

  The present invention solves such problems, and more accurately detects the temperature of a device under inspection with a wafer test system and method, and a prober used therein, so that the device can be accurately set to a desired temperature. The purpose is to be able to set.

  The inventor of the present application has the above problem because the temperature detected by the temperature sensor is the temperature of the wafer chuck, not the temperature of the device. If the temperature of the device can be detected directly, We focused on solving such problems. As a method of directly detecting the temperature of the device, the temperature of the device can be detected by detecting the electrical characteristics of the elements formed in the device, so the method of detecting using a tester and the probe of the probe card are Since the wafer surface near the device to be inspected is contacted, there is a method in which a probe for detecting the temperature is provided on the probe card and the temperature of the portion of the wafer surface in contact with the probe for detecting the temperature is detected.

  A wafer test system according to a first aspect of the present invention includes a tester, a prober, and a communication path connecting the tester and the prober, and performs a wafer test for performing electrical inspection of a semiconductor device formed on the wafer. The prober has a probe that contacts an electrode of the semiconductor device, a probe card that connects the electrode of the semiconductor device to a terminal of the tester, a wafer chuck that holds a wafer, and the wafer chuck Temperature adjusting means for adjusting the temperature of the part holding the wafer and a control unit for controlling each part, and the tester detects the electrical characteristics of the elements formed in the semiconductor device. The temperature of the semiconductor device is detected, and the detected temperature data is transmitted to the prober via the communication path, and the control unit of the prober And controlling the temperature adjusting means based on the temperature data of said received semiconductor device.

  According to the first aspect of the present invention, since the tester directly detects the temperature of the device by detecting the electrical characteristics of the elements in the semiconductor device (device), the temperature of the device can be accurately detected. it can. Moreover, even in the conventional system, the tester and the prober are connected via a communication path, and it is only necessary to transmit temperature data using the communication path, which can be realized by changing the software without adding hardware. . What is prescribed in the inspection is the temperature of the device. In the present invention, temperature control is performed based on the directly detected device temperature, so that the device can be accurately set to the inspection temperature.

  In order for the tester to detect the temperature of the device, it is necessary that the probe is in contact with the electrode of the device and in a state where it can be inspected. Therefore, even if the inspection is not performed immediately, the probe may be brought into contact with the electrode of the device so that the temperature can be detected. However, as in the prior art, a temperature sensor is provided on the wafer chuck to control the temperature of the portion holding the wafer. When detecting and not inspecting the device, it is desirable to control the temperature adjusting means based on the temperature data detected by the temperature sensor. In this case, since the device does not generate heat in the wafer chuck and the wafer, the temperature difference across the entire surface is small and does not cause a problem. For example, when the device is set to a predetermined temperature, control is performed based on temperature data detected by the temperature sensor until the temperature approaches the predetermined temperature, and the probe is inspected at the stage where the temperature is approached to some extent. Control is performed based on the temperature of the device that is contacted and detected by the tester, and inspection is started when the temperature reaches a predetermined temperature.

  In the conventional configuration, the prober constituting the wafer test system of the first aspect makes it possible to receive data related to the temperature of the semiconductor device on the wafer transmitted from the outside, and adjust the temperature based on the received temperature data of the semiconductor device. Configure to control the means.

  A prober according to a second aspect of the present invention is a prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect a plurality of semiconductor devices formed on the wafer with a tester. A probe card for contacting the electrode of the semiconductor device; a probe card for connecting the electrode of the semiconductor device to a terminal of the tester; a wafer chuck for holding a wafer; and a temperature of a portion of the wafer chuck for holding the wafer. A probe temperature sensor for detecting temperature of the contact portion and outputting temperature data by contacting the semiconductor device on the wafer. And the control unit controls the temperature adjusting unit based on temperature data of the probe temperature sensor.

  According to the second aspect of the present invention, the probe card temperature detection probe directly contacts the wafer surface in the vicinity of the device to be inspected, and detects the temperature of the contacted wafer surface. Can be detected. Therefore, in the present invention, the device can be accurately set to the inspection temperature. The temperature detection probe is a probe that is not directly related to the inspection by the tester, and is provided separately. Desirably, the temperature detection probe contacts, for example, an electrode pad that is not used for inspection of the device, or a portion where a circuit element between the devices is not formed (for example, a portion where a groove is formed during dicing). It is not desirable to directly contact the part where the circuit element is formed. If contact is made with a part of the circuit element, contact is made with a low contact pressure using a spring probe or the like. The temperature detection probe can be constituted by, for example, a probe having a thermistor at the tip.

  When a thermistor is used, the detection circuit that supplies and detects the voltage to the thermistor at the tip of the temperature detection probe may be provided on the probe card or outside the probe card, and only the wiring may be connected. Good.

  As described above, according to the present invention, the device temperature can be accurately set to a desired temperature at a low cost.

  FIG. 2 is a diagram showing a configuration of a wafer test system having a prober according to the first embodiment of the present invention. As is apparent from comparison with FIG. 1, the wafer test system of the first embodiment has a configuration similar to that of the conventional example. The temperature adjusting unit 20 includes both or one of a cooling mechanism configured by the cooling path 12, the cooling device 14 and the path 15, and a heating mechanism configured by the heater 13. The temperature adjusting means 20 may be anything as long as the temperature of the portion of the wafer chuck 11 that holds the wafer W can be adjusted.

  As described above, the wafer test system of the first embodiment has a configuration similar to that of the conventional example, but the tester main body 21 detects the electrical characteristics of the elements formed in the device on the wafer W, thereby detecting the device. And the temperature data is transmitted to the prober control unit 16 via the communication path 25, and the control unit 16 controls the temperature adjusting means 20 based on the received temperature data. Different.

  There are various methods for detecting the temperature of an element, that is, the temperature of a device by detecting an electrical characteristic. For example, when a voltage is applied to a diode to detect a voltage-current characteristic, the characteristic changes depending on the temperature. So the temperature can be detected.

  In order to detect the temperature of the device with the tester, the probe 18 needs to be in contact with the electrode of the device and in a state where it can be inspected. Therefore, even when the inspection is not performed, the temperature of the device can be detected by bringing the probe 18 into contact with the electrode of the device. However, in the first embodiment, the temperature sensor 19 is provided on the wafer chuck 11 as in the conventional example. Therefore, when the device is not inspected, the temperature adjusting means 20 is adjusted based on the temperature data detected by the temperature sensor 19. To do. For example, when the device is set to a predetermined temperature, control is performed based on temperature data detected by the temperature sensor 19 until the device approaches the predetermined temperature, and the probe 18 is inspected when the device approaches the predetermined temperature to some extent. Control is performed based on the temperature of the device detected by the tester in contact with the electrode, and inspection is started when the temperature reaches a predetermined temperature.

  When the control is performed based on the temperature detected by the temperature sensor 19, the device does not generate heat. Therefore, the temperature difference between the wafer chuck 11 and the wafer W is almost the same, with a small temperature difference across the entire surface.

  As described above, in the wafer test system of the first embodiment, since the tester directly detects the device temperature, it is possible to accurately detect the device temperature, and through a communication path provided conventionally. The temperature data can be transmitted to the prober, and the prober controls the temperature adjusting means based on the received temperature data, so that the device to be inspected can be accurately set to a predetermined inspection temperature.

  FIG. 3 is a diagram showing a configuration of a wafer test system having a prober according to the second embodiment of the present invention. As apparent from the comparison with FIG. 2, the wafer test system of the second embodiment has a configuration similar to that of the system of the first embodiment, except that the probe card 17 is provided with a probe temperature sensor. The probe temperature sensor has a thermistor provided at the tip of a spring probe 31 different from the probe 31 and a detection circuit 30 that supplies power to the thermistor and detects the temperature of the contact portion of the spring probe 31 with the wafer W. . The control unit 16 reads the temperature data output from the detection circuit 30 and controls the temperature adjustment unit 20. In the second embodiment, the tester body 21 does not transmit the device temperature data to the prober control unit 16 via the communication path 25 as in the first embodiment.

  The spring probe 31 directly contacts the wafer surface in the vicinity of the device to be inspected, and detects the temperature of the contacted wafer surface. Therefore, since the temperature of the device can be accurately detected, the device can be accurately set to the inspection temperature. The spring probe 31 contacts, for example, an electrode pad that is not used for the inspection of the device, or a portion where a circuit element between the devices is not formed, for example, a portion where a groove is formed during dicing. However, if the contact pressure of the spring probe 31 is small, the circuit is not destroyed even if it directly contacts the portion where the circuit element is formed, but it is not very desirable. The detection circuit 30 may be provided on the probe card 23 or in a prober near the probe card 23.

  The other control of the system of the second embodiment is the same as that of the first embodiment. In the second embodiment, since the temperature of the device is directly detected, the temperature of the device can be accurately detected. Since the temperature adjusting means is controlled based on the data, the device to be inspected can be accurately set to a predetermined inspection temperature.

  As mentioned above, although the Example of this invention was described, it cannot be overemphasized that various modifications are possible.

  The present invention can be applied to any prober that inspects a wafer under a predetermined temperature condition such as high temperature or low temperature. By applying the present invention, the temperature of a device to be inspected can be accurately set with a simple configuration.

It is a figure which shows schematic structure of a wafer test system provided with the prober which has a wafer temperature adjustment mechanism. It is a figure which shows the structure of the wafer test system of 1st Example of this invention. It is a figure which shows the structure of the wafer test system of 1st Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Wafer chuck 16 Control part 17 Probe card 18 Probe 19 Temperature sensor 20 Temperature adjustment means 21 Tester main body 32 Control part W Wafer

Claims (8)

A wafer test system comprising a tester, a prober, and a communication path connecting the tester and the prober, and performing an electrical inspection of a semiconductor device formed on the wafer,
The prober is
A probe card for contacting the electrode of the semiconductor device, and a probe card for connecting the electrode of the semiconductor device to a terminal of the tester;
A wafer chuck for holding the wafer;
Temperature adjusting means for adjusting the temperature of the portion of the wafer chuck that holds the wafer;
A control unit for controlling each unit,
The tester detects the temperature of the semiconductor device by detecting the electrical characteristics of elements formed in the semiconductor device, and transmits the detected temperature data to the prober via the communication path.
The wafer test system, wherein the control unit of the prober controls the temperature adjusting means based on the received temperature data of the semiconductor device. The prober includes a temperature sensor that detects a temperature of a portion of the wafer chuck that holds the wafer,
The wafer test system according to claim 1, wherein the control unit of the prober controls the temperature adjusting unit based on temperature data detected by the temperature sensor when the semiconductor device is not inspected. A prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect a plurality of semiconductor devices formed on the wafer with a tester,
A probe card for contacting the electrode of the semiconductor device, and a probe card for connecting the electrode of the semiconductor device to a terminal of the tester;
A wafer chuck for holding the wafer;
Temperature adjusting means for adjusting the temperature of the portion of the wafer chuck that holds the wafer;
A control unit for controlling each unit;
A communication path with the outside,
The prober receives data relating to the temperature of the semiconductor device on the wafer transmitted from the outside via the communication path,
The prober, wherein the controller controls the temperature adjusting means based on the received temperature data of the semiconductor device. A temperature sensor that detects a temperature of a portion of the wafer chuck that holds the wafer;
4. The prober according to claim 3, wherein the control unit controls the temperature adjusting unit based on temperature data detected by the temperature sensor when the semiconductor device is not inspected. A wafer test method for performing electrical inspection of a semiconductor device formed on a wafer,
The tester detects the temperature of the semiconductor device by detecting the electrical characteristics of the elements formed in the semiconductor device, and transmits the detected temperature data to the prober.
The wafer test method, wherein the prober controls the temperature of a wafer chuck that holds a wafer based on the received temperature data of the semiconductor device.   When the prober is not inspecting the semiconductor device, the prober detects a temperature of a portion holding the wafer by a temperature sensor provided in the wafer chuck, and based on the temperature data detected by the temperature sensor, the prober The wafer test method according to claim 5, wherein the temperature is controlled. A prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect a plurality of semiconductor devices formed on the wafer with a tester,
A probe card for contacting the electrode of the semiconductor device, and a probe card for connecting the electrode of the semiconductor device to a terminal of the tester;
A wafer chuck for holding the wafer;
Temperature adjusting means for adjusting the temperature of the portion of the wafer chuck that holds the wafer;
A control unit for controlling each unit,
The probe card includes a probe temperature sensor that contacts a semiconductor device on a wafer, detects a temperature of a contact portion, and outputs temperature data;
The prober, wherein the control unit controls the temperature adjusting means based on temperature data of the probe temperature sensor. A probe card for connecting electrodes of a plurality of semiconductor devices formed on a wafer to each terminal of a tester,
A probe card comprising a probe temperature sensor that contacts a semiconductor device on a wafer, detects the temperature of the contact portion, and outputs temperature data.

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