WO2024140201A1

WO2024140201A1 - Photoresist stripping method and system for chip-on-wafer process

Info

Publication number: WO2024140201A1
Application number: PCT/CN2023/138335
Authority: WO
Inventors: 张晓燕; 仰庶; 濮佳益
Original assignee: 盛美半导体设备(上海)股份有限公司
Priority date: 2022-12-30
Filing date: 2023-12-13
Publication date: 2024-07-04
Also published as: CN118276420A

Abstract

The present application relates to a photoresist stripping method and system for a chip-on-wafer process. The photoresist stripping method for a chip-on-wafer process comprises: wetting a wafer to be subjected to photoresist removal; and controlling the rotating speed of said wafer to be within the range of 30 to 200 RPM, and applying megasonic waves to said wetted wafer for a first preset time, so as to perform photoresist removal. The present application solves the problem in the prior art of the production yield being low as a final result of the next process being affected by splashed liquid, which is generated due to an excessively high rotating speed, being attached to an inner wall of a cavity and dripping onto the surface of a wafer, thereby improving the production yield.

Description

Photoresist stripping method and system for chip-on-wafer process

Technical Field

The present application relates to the field of semiconductor manufacturing, and in particular to a photoresist stripping method and system for a chip on wafer (Chip On Wafer) process.

Background technique

With the development of Moore's Law and the rise of 2.5D/3D stereo packaging technology, the new Chip On Wafer packaging process technology has become an indispensable part of today's advanced packaging. Photoresist stripping refers to the process of removing photoresist from the surface of the wafer after the semiconductor manufacturing photolithography process. Its main purpose is to remove the photoresist after the definition of the pattern is completed, reduce the photoresist residue, metal and particles on the wafer surface, and is one of the important links in the advanced packaging process. The debonding effect has a key impact on the product yield.

In the current advanced packaging process, the common photoresist removal process is mainly divided into immersion stripping process and single-wafer stripping process. The principle is to use photoresist stripping liquid to react with the photoresist on the wafer, so as to achieve the purpose of dissolving and removing the photoresist. The photoresist removal process generally uses photoresist stripping liquid to strip the single wafer for 10 to 20 minutes, or soaks for 20 to 30 minutes and then uses single-wafer stripping to rinse for 5 to 10 minutes.

The chip height is uncertain, usually ranging from 50μm to 800μm (or even higher). During the research process, it was found that in the single-wafer degumming process, the excessively high height will cause the channel formed between the chips to cause the edge chips to be unable to be fully processed, and it is difficult to fully process the entire wafer. In order to achieve the degumming effect and the cleaning effect after degumming, the wafer rotation speed is generally controlled above 500RPM. Due to the high wafer rotation speed, it is very easy to cause splashing, and the centrifugal force of the high-speed rotation of the wafer will cause the edge chip to shift or even fly out. As shown in Figure 1, the effect diagram when the wafer rotation speed is 600RPM and the single-wafer degumming time is 150s, 300s and 350s respectively. It can be seen from Figure 1 that a good degumming effect can only be achieved when the single-wafer degumming time is 350s and the rotation speed is 600RPM. However, a long degumming time will lead to a decrease in production. And when the wafer rotation speed is above 500RPM, splashing is easy to occur. The splashed liquid adheres to the inner wall of the chamber and may drip onto the surface of the wafer, affecting the next process and ultimately causing poor production. The rate is reduced.

Summary of the invention

The embodiments of the present application provide a photoresist stripping method and system for chip-on-wafer processes, so as to at least solve the problem in the prior art of splashing liquid due to excessively high rotation speed, which causes the splashed liquid to adhere to the inner wall of the cavity and drip onto the surface of the wafer, affecting the next process and ultimately leading to low production yield.

In a first aspect, an embodiment of the present application provides a photoresist stripping method for a chip-on-wafer process, comprising:

Wetting the wafer to be subjected to photoresist removal;

The rotation speed of the wafer to be subjected to photoresist removal is controlled within a range of 30RPM to 200RPM, and megasonic waves are applied to the wafer to be subjected to photoresist removal for a first preset time after being wetted to perform photoresist removal.

In some embodiments, after controlling the rotation speed of the wafer to be subjected to photoresist removal within a range of 30RPM to 200RPM and applying megasonic waves for a first preset time to the wafer to be subjected to photoresist removal after wetting to perform photoresist removal, the method further comprises:

The rotation speed of the wafer to be subjected to photoresist removal is controlled within a range of 30RPM to 200RPM, and megasonic waves are applied to the wafer to be subjected to photoresist removal for a second preset time for cleaning.

In some of the embodiments, before controlling the rotation speed of the wafer to be photoresist removed within the range of 30RPM to 200RPM and applying megasonic waves for a second preset time to the wafer to be photoresist removed for cleaning, the method further includes: wetting the wafer to be photoresist removed.

In some embodiments, the frequency of the megasonic wave is between 15 MHz and 40 MHz.

In some embodiments, before controlling the rotation speed of the wafer to be subjected to photoresist removal to be within the range of 30RPM to 200RPM and applying megasonic waves for a first preset time to the wafer to be subjected to photoresist removal after wetting to perform photoresist removal, the method further comprises:

Detecting the total amount of photoresist residue on the surface of the wafer to be subjected to photoresist removal;

Determine the preset threshold range where the total amount of photoresist residue falls;

The first preset time corresponding to the preset threshold interval is matched from a first preset database based on the preset threshold interval.

In some embodiments, after detecting the total amount of photoresist residue on the surface of the wafer to be subjected to photoresist removal, the method further comprises:

When the total amount of photoresist residue is greater than a preset total amount of photoresist residue, the wafer to be subjected to photoresist removal is placed in a soaking tank and soaked for a third preset time.

In some embodiments, before placing the wafer to be subjected to photoresist removal into a soaking tank and soaking for a third preset time, the method further comprises:

The third preset time corresponding to the preset threshold interval is matched from a second preset database based on the preset threshold interval.

In a second aspect, an embodiment of the present application provides a photoresist stripping system for a chip-on-wafer process, the system comprising:

A wafer holding device, used for holding a wafer to be subjected to photoresist removal;

A nozzle, used for spraying a photoresist stripping liquid onto a wafer to be subjected to photoresist removal;

A megasonic wave device is used to perform megasonic wave photoresist removal on a wafer to be subjected to photoresist removal;

A rotation driving device, used for driving the wafer holding device to drive the wafer to be subjected to photoresist removal to rotate;

The controller is used to control the nozzle to spray photoresist stripping liquid to wet the wafer to be removed from the photoresist, and control the rotation drive device to drive the wafer to be removed from the photoresist to rotate at a speed of 30RPM to 200RPM, and control the megasonic wave device to apply megasonic waves for a first preset time to the wafer to be removed from the photoresist after wetting to remove the photoresist.

In the traditional single-chip degumming method, the degumming and cleaning processes must be combined with a high rotation speed of more than 500RPM to ensure the degumming capability. If the rotation speed is too low, it is difficult to strip and remove the dissolved photoresist. However, the high rotation speed and the relatively high chip thickness will cause liquid splashing in the chamber. The photoresist stripping method for the chip process on the wafer of the present application is used for degumming and cleaning. The degumming and cleaning are performed at a low rotation speed of 30RPM to 200RPM, and no splashing occurs. Megasonic waves are used for degumming and cleaning to ensure that all chips on the wafer are fully processed.

In the traditional single-chip degumming method, the degumming and cleaning processes must be carried out at a high speed of more than 500RPM to ensure the degumming ability. Therefore, the channels between the chips may cause the liquid film height of the degumming liquid and the cleaning liquid in the non-Nozzle Scan area (that is, the area where the photoresist stripping liquid is not sprayed) to be less than 300μm. When the chip on the wafer is higher than 300μm, the wafer cannot form a liquid film sufficient to cover the entire edge. The film causes the edge chips to be unable to be fully processed, and the photoresist stripping method for the chip process on the wafer of the present application is used for debonding and cleaning. In the debonding and cleaning process at a low speed of 30RPM to 200RPM, the liquid film can cover the chips at the edge of the wafer, and megasonic waves are used for debonding and cleaning to ensure that all chips on the wafer are fully and effectively processed.

In the traditional single-wafer degumming method, the degumming and cleaning processes must be combined with a high speed of more than 500RPM to ensure the degumming capability. The high speed of more than 500RPM and the relatively high chip height can cause the chip to be easily displaced or even fly out of the wafer due to centrifugal force. The photoresist stripping method for chip-on-wafer process of the present application is used for degumming and cleaning, and the degumming and cleaning processes are completed at a low speed of 30RPM to 200RPM, so that the degumming and cleaning processes can be completed at a relatively low speed, greatly reducing the risk of the defect.

Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

FIG1 is a schematic diagram of the effect of single-chip debonding in the prior art;

FIG2 is a flow chart of a photoresist stripping method for a chip-on-wafer process according to an embodiment of the present application;

FIG3 is a schematic diagram of the effect of photoresist stripping using megasonic waves according to an embodiment of the present application;

FIG4 is a second schematic diagram of the effect of photoresist stripping using megasonic waves according to an embodiment of the present application;

FIG5 is a third schematic diagram of the effect of photoresist stripping using megasonic waves according to an embodiment of the present application;

FIG6 is a fourth schematic diagram of the effect of photoresist stripping using megasonic waves according to an embodiment of the present application;

FIG. 7 is a structural block diagram of a photoresist stripping system for a chip-on-wafer process according to an embodiment of the present application.

Preferred embodiments of the present invention

In order to make the purpose, technical solutions and advantages of this application more clear, the following is a The present application is described and illustrated by way of examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as the contents disclosed in the present application are insufficient.

Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And/or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and/or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

The embodiment of the present application provides a photoresist stripping method for a chip-on-wafer process, and FIG2 is a flow chart of the photoresist stripping method for a chip-on-wafer process according to the embodiment of the present application. As shown in FIG2, the method comprises the following steps:

Step S201, wetting the wafer from which the photoresist is to be removed.

In this step, the nozzle may be controlled to spray photoresist stripping liquid to wet the wafer from which the photoresist is to be removed, so as to facilitate the subsequent removal of the photoresist on the wafer.

It should be noted that the time for wetting the wafer from which the photoresist is to be removed and the flow rate of the photoresist stripping liquid sprayed from the nozzle can be set according to specific process requirements.

Step S202, controlling the rotation speed of the wafer to be subjected to photoresist removal to be within the range of 30RPM to 200RPM, and applying megasonic waves for a first preset time to the wafer to be subjected to photoresist removal after being wetted to perform photoresist removal.

Figures 3 to 6 show the effect diagrams corresponding to the degumming time. Referring to Figures 3 and 6, the rotation speed of the wafer in Figures 3 and 6 is 150RPM, the time for degumming by megasonic waves in Figure 3 is 150s, 300s and 350s respectively, and the time for degumming by megasonic waves in Figure 6 is 62s, 124s and 186s respectively. It can be obtained from Figures 1 and 3 that, under the same time, the embodiment of the present application uses megasonic waves and combines the degumming method of 150RPM to degumming, and the degumming effect of 150s and the degumming effect of 300s are both better than the degumming effect in the prior art. Secondly, it can be obtained from Figures 3 and 6 that the embodiment of the present application uses megasonic waves and combines the degumming method of 150RPM to degumming, and can achieve a good degumming effect when the time is 186s and the rotation speed is 150RPM. Therefore, in summary, compared with the single-wafer debonding in the prior art, this embodiment saves debonding time and can achieve a good debonding effect while reducing the wafer rotation speed.

Continuing to refer to FIG. 3 to FIG. 5 , it can be seen that the wafer can be debonded at a rotation speed of 30 RPM, 150 RPM, and 200 RPM, and the debonding effect is better than that in the prior art.

When the rotation speed of the wafer is below 30RPM, there will be a problem that the glue washed off the wafer cannot be thrown out by centrifugal force due to insufficient centrifugal force. Therefore, in order to achieve a better degumming effect, in this step, by controlling the rotation speed of the wafer to be removed from the photoresist within the range of 30RPM to 200RPM, and applying megasonic waves for a first preset time to the wafer to be removed from the photoresist after wetting, the degumming is achieved below 200RPM to remove the photoresist, avoiding the splashing liquid caused by the high rotation speed in the prior art, and then causing the splashing liquid to adhere to the inner wall of the cavity and drip on the surface of the wafer to affect the next process, and finally leading to the problem of low production yield, and at the same time, it can also avoid the problem that the chip at the edge of the wafer is displaced and flies out due to the centrifugal force caused by the high rotation speed.

It should be noted that the first preset time can be set according to specific process requirements. Step 201 The step S202 and step S203 may be performed simultaneously in any order.

The megasonic wave in the present embodiment can be a spatial alternating phase shift (SAPS) megasonic wave technology, or other megasonic wave technologies that can achieve the purpose of the present application. The spatial alternating phase shift megasonic wave technology is to achieve a uniform distribution of megasonic wave energy on the surface of the wafer by controlling the relative motion of the half-wavelength range between the megasonic wave generator and the wafer, so as to achieve the most optimized cleaning effect. In the present embodiment, the removal of the photoresist is achieved by adopting the above-mentioned spatial alternating phase shift (SAPS) megasonic wave technology and combining the low rotation speed of 30RPM-200RPM, and the effective removal of the photoresist is achieved within the range of 30RPM to 200RPM, which not only ensures the effective removal of the wafer photoresist, but also avoids the problem of splashing caused by the wafer rotation speed being too high.

In some embodiments, after step S202, the rotation speed of the wafer can also be controlled within the range of 30RPM to 200RPM, and the wafer can be cleaned by applying megasonic waves for a second preset time. By controlling the rotation speed of the wafer within the range of 30RPM to 200RPM, and applying megasonic waves for a second preset time to the wafer after executing step S202, the wafer after degumming can be cleaned at less than 200RPM, avoiding the problem of splashing liquid due to excessive rotation speed during wafer cleaning in the prior art, so that the splashed liquid adheres to the inner wall of the cavity and then drips on the surface of the wafer, affecting the next process, and ultimately leading to the problem of low production yield. At the same time, in the case of low rotation speed, it can also avoid the problem of the chip at the edge of the wafer being displaced and flying out under the action of centrifugal force due to excessive rotation speed of the wafer.

Based on the above embodiment, in some other embodiments, before controlling the rotation speed of the wafer within the range of 30RPM to 200RPM and applying megasonic waves for a second preset time to the wafer for cleaning, the wafer after step S202 may be wetted. The wafer after step S202 may be wetted by controlling the nozzle to spray cleaning liquid.

It should be noted that the cleaning liquid may be, but is not limited to, deionized water or water dissolved with carbon dioxide.

In some embodiments, the frequency of the megasonic wave is between 15 MHz and 40 MHz. A frequency of the megasonic wave that is too high or too low may lead to a problem of low production yield. Therefore, in order to avoid the problem of production yield caused by a frequency of the megasonic wave that is too high or too low, in this embodiment, by controlling the frequency of the megasonic wave to be between 15 MHz and 40 MHz, the problem of the frequency of the megasonic wave that is too high or too low affecting the production yield can be avoided.

It should be noted that the megasonic frequency in the embodiment of the present application can be used in both the degumming process and the cleaning process, and is not specifically limited here.

In some embodiments, the rotation speed of the wafer is controlled within a range of 30 RPM to 200 RPM, and Before applying megasonic waves for a first preset time to the wafer after wetting for debonding, the total amount of photoresist residue on the surface of the wafer to be removed can also be detected; the preset threshold range in which the total amount of photoresist residue is located is determined; and based on the preset threshold range, the first preset time corresponding to the preset threshold range is matched from the first preset database.

In this embodiment, by determining the preset threshold interval in which the total amount of photoresist residue is located; and matching the first preset time corresponding to the preset threshold interval from the first preset database based on the preset threshold interval, the first preset time for megasonic wave stripping is accurately determined according to the preset threshold interval in which the total amount of photoresist residue is located, and adaptive adjustment of the first preset time is achieved, thereby avoiding the problem of incomplete photoresist removal due to too short stripping time when there is too much photoresist, and also avoiding the problem of increased process time due to too long stripping time when there is too little photoresist.

It should be noted that the first preset database stores the first preset time corresponding to each preset threshold interval, and the first preset time corresponding to each preset threshold interval is different.

In this embodiment, the method for determining the total amount of photoresist residues may be, but is not limited to, taking a photo of the wafer to be subjected to photoresist removal, then measuring the size of each residual region based on the photographed photo and calculating the area of each residual region and the residual photoresist thickness in the corresponding residual region, and finally calculating the total amount of photoresist residues according to the residual photoresist thickness. In addition to the above method, other methods that can realize the calculation of the total amount of photoresist residues may also be used, and the embodiments of the present application are not limited thereto.

In some of the embodiments, after detecting the total amount of photoresist residue on the surface of the wafer to be removed from the photoresist, if the total amount of photoresist residue is greater than the preset total amount of residue, the wafer to be removed from the photoresist can be placed in an immersion tank and immersed for a third preset time.

In order to facilitate the subsequent removal of the photoresist, in this embodiment, when the total residual amount of the photoresist is greater than the preset total residual amount, the clamping mechanism is first controlled to place the wafer to be subjected to photoresist removal into the immersion tank for a third preset time to achieve preliminary removal of the photoresist, which is beneficial to improving the efficiency of subsequent photoresist removal using megasonic waves.

Therefore, in some of the embodiments, before controlling the clamping mechanism to place the wafer to be subjected to photoresist removal into the immersion tank for immersion for the third preset time, the third preset time corresponding to the preset threshold interval can be matched from the second preset database based on the preset threshold interval. By matching the third preset time corresponding to the preset threshold interval from the second preset database based on the preset threshold interval, the third preset time for immersion in the immersion tank can be accurately determined according to the preset threshold interval where the total amount of photoresist residue is located. time, thereby achieving adaptive adjustment of the third preset time, so that the subsequent megasonic wave debonding is more efficient.

In some embodiments, the photoresist stripping method for chip-on-wafer process in the present application can also be used in combination with the photoresist stripping method in the prior art, in the following manner:

Method 1 is to first undergo the existing single-wafer degumming, preliminary degumming, rinsing and drying processes for the wafer, during which the wafer does not need to be spun dry; then the wafer is taken out, and the photoresist stripping method for the chip process on the wafer in this application is executed. During this process, the degumming and cleaning processes use megasonic waves and are carried out at a rotation speed of 30RPM to 200RPM.

Method 2 is to first use the existing trough stripping method to remove the photoresist by immersion; then take out the wafer and perform the photoresist stripping method for the chip process on the wafer in this application. In this process, the stripping and cleaning process uses megasonic waves and is carried out at a rotation speed of 30RPM to 200RPM.

Method three, you can first go through the existing tank stripping, use the immersion method to peel off the photoresist; then go through the existing single-chip stripping; and then perform the photoresist stripping method for the chip-on-wafer process in this application. In this process, the stripping and cleaning process uses megasonic waves and is carried out at a rotation speed of 30RPM to 200RPM.

Through the above-mentioned method, the photoresist stripping method for the chip process on the wafer of the present application is to remove the photoresist by combining megasonic waves with a low rotation speed of 30RPM to 200RPM, which solves the defects of the existing stripping technology, improves the efficiency of stripping photoresist and improves the stripping quality, and uses megasonic wave technology to strip and clean the wafer. While improving the stripping and cleaning capabilities and increasing production capacity, the low rotation speed advantage of 30RPM to 200RPM of the present application can effectively prevent splashing, so that the chip at the edge of the wafer can be fully processed, and prevent the edge chip from being displaced or even flying out of the wafer.

The present application embodiment also provides a kind of photoresist stripping system for chip process on wafer, and this system is used to realize above-mentioned embodiment and preferred implementation mode, and has been described no more.Term " module ", " unit ", " subunit " etc. as used below can be the combination of software and/or hardware realizing predetermined function.Although the system described in the following embodiment is preferably realized with software, hardware, or the realization of the combination of software and hardware is also possible and conceived.

FIG. 7 is a structural block diagram of a photoresist stripping system for a chip-on-wafer process according to an embodiment of the present application. As shown in FIG. 7 , the system includes:

A wafer holding device 76, used to hold a wafer 75 to be subjected to photoresist removal;

The nozzle 71 is disposed above the wafer holding device 76 and is used to spray the photoresist stripping liquid toward the wafer 75 to be subjected to photoresist removal;

A megasonic wave device 72 is used to perform megasonic wave photoresist removal on a wafer 75 to be subjected to photoresist removal;

A rotation driving device 73, connected to the wafer holding device 76, for driving the wafer holding device 76 to rotate, thereby driving the wafer 75 to be subjected to photoresist removal to rotate;

The controller 74 is electrically connected to the nozzle 71, the megasonic wave device 72 and the rotation drive device 73, and is used to control the nozzle 71 to spray photoresist stripping liquid to wet the wafer 75 to be removed from the photoresist, and to control the rotation drive device 73 to drive the wafer 75 to be removed from the photoresist to rotate at a speed of 30RPM to 200RPM, and to control the megasonic wave device 72 to apply megasonic waves for a first preset time to the wafer 75 to be removed from the photoresist after wetting to remove the photoresist.

In this embodiment, based on the photoresist stripping system for the chip process on the wafer, the photoresist can be removed at below 200RPM, avoiding the splashing caused by the excessively high wafer rotation speed in the prior art, which causes the splashed liquid to adhere to the inner wall of the cavity and drip onto the wafer surface and affect the next process, ultimately leading to the problem of low production yield, thereby improving the production yield.

In some embodiments, the controller 74 is also used to control the rotation drive device 72 to drive the wafer 75 to rotate at a speed of 30RPM to 200RPM, and control the megasonic wave device 72 to apply megasonic waves for a second preset time to clean the wafer 75 after degumming.

In some embodiments, the nozzle 71 is also used to spray cleaning liquid to wet and clean the wafer.

In some embodiments, the frequency of the megasonic waves is between 15 MHz and 40 MHz.

In some embodiments, the system also includes: a detector for detecting the total amount of photoresist residue on the surface of the wafer 75 to be subjected to photoresist removal; a calculator for determining a preset threshold interval in which the total amount of photoresist residue is located; and a matcher for matching a first preset time corresponding to the preset threshold interval from a first preset database based on the preset threshold interval.

It should be noted that the detector in this embodiment can be a camera, or other hardware devices in the prior art that can be used to detect the total amount of photoresist residue on the surface of the wafer to be subjected to photoresist removal. The calculator and the matcher in this embodiment can be implemented by software in the controller 74. In some embodiments, the calculator and the matcher can also be hardware devices with corresponding functions.

In some embodiments, the system further comprises a clamping mechanism, wherein the controller is electrically connected to the clamping mechanism, It is used to control the clamping mechanism to put the wafer to be photoresist removed into the immersion tank and immerse it for a third preset time when the total photoresist residue is greater than the preset total residue.

In some embodiments, the matcher is used to match a third preset time corresponding to the preset threshold interval from a second preset database based on the preset threshold interval.

Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

A photoresist stripping method for chip-on-wafer process, characterized by comprising:

Wetting the wafer to be subjected to photoresist removal;

The rotation speed of the wafer to be subjected to photoresist removal is controlled within a range of 30RPM to 200RPM, and megasonic waves are applied to the wafer to be subjected to photoresist removal for a first preset time after being wetted to perform photoresist removal.
The photoresist stripping method for chip-on-wafer process according to claim 1 is characterized in that after controlling the rotation speed of the wafer to be subjected to photoresist removal within the range of 30RPM to 200RPM, and applying megasonic waves for a first preset time to the wafer to be subjected to photoresist removal after wetting to perform photoresist stripping, the method further comprises:

The rotation speed of the wafer to be subjected to photoresist removal is controlled within a range of 30RPM to 200RPM, and megasonic waves are applied to the wafer to be subjected to photoresist removal for a second preset time for cleaning.
The photoresist stripping method for chip-on-wafer process according to claim 2 is characterized in that before controlling the rotation speed of the wafer to be subjected to photoresist removal within the range of 30RPM to 200RPM and applying megasonic waves for a second preset time to the wafer to be subjected to photoresist removal for cleaning, the method further comprises:

The wafer to be subjected to photoresist removal is wetted.
The photoresist stripping method for chip-on-wafer process according to claim 1 or 2 is characterized in that the frequency of the megasonic wave is between 15 MHz and 40 MHz.
The photoresist stripping method for chip-on-wafer process according to claim 1 is characterized in that before controlling the rotation speed of the wafer to be subjected to photoresist removal within the range of 30RPM to 200RPM and applying megasonic waves for a first preset time to the wafer to be subjected to photoresist removal after wetting to perform photoresist stripping, the method further comprises:

Detecting the total amount of photoresist residue on the surface of the wafer to be subjected to photoresist removal;

Determine the preset threshold range where the total amount of photoresist residue falls;

The first preset time corresponding to the preset threshold interval is matched from a first preset database based on the preset threshold interval.
The photoresist stripping method for chip-on-wafer process according to claim 5 is characterized in that In other words, after detecting the total amount of photoresist residue on the surface of the wafer to be subjected to photoresist removal, the method further comprises:

When the total amount of photoresist residue is greater than a preset total amount of photoresist residue, the wafer to be subjected to photoresist removal is placed in a soaking tank and soaked for a third preset time.
The photoresist stripping method for chip-on-wafer process according to claim 6 is characterized in that before the wafer to be subjected to photoresist removal is placed in the immersion tank and immersed for a third preset time, the method further comprises:

The third preset time corresponding to the preset threshold interval is matched from a second preset database based on the preset threshold interval.
A photoresist stripping system for chip-on-wafer process, characterized in that the system comprises:

A wafer holding device, used for holding a wafer to be subjected to photoresist removal;

A nozzle, used for spraying a photoresist stripping liquid onto a wafer to be subjected to photoresist removal;

A megasonic wave device is used to perform megasonic wave photoresist removal on a wafer to be subjected to photoresist removal;

A rotation driving device, used for driving the wafer holding device to drive the wafer to be subjected to photoresist removal to rotate;

The controller is used to control the nozzle to spray photoresist stripping liquid to wet the wafer to be removed from the photoresist, control the rotation drive device to drive the wafer to be removed from the photoresist to rotate at a speed of 30RPM to 200RPM, and control the megasonic wave device to apply megasonic waves for a first preset time to the wafer to be removed from the photoresist after wetting to remove the photoresist.
According to the photoresist stripping system for chip-on-wafer process as described in claim 8, it is characterized in that the controller is also used to control the rotation drive device to drive the wafer to rotate at a speed of 30RPM to 200RPM, and control the megasonic wave device to apply megasonic waves for a second preset time to clean the wafer after degumming.
The photoresist stripping system for chip-on-wafer process according to claim 8 is characterized in that the nozzle is also used to spray cleaning liquid to wet and clean the wafer.