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

Abstract

This application relates to a photoresist stripping method and system for chip-on-wafer processing. The photoresist stripping method for chip-on-wafer processing includes wetting a wafer to be subjected to photoresist removal, controlling the wafer rotation speed within a range of 30 RPM to 200 RPM, and applying megasonic waves to the wetted wafer for a first predetermined time to remove the photoresist. This application solves a problem in the prior art, in which excessively high rotation speeds cause liquid splashing, which then adheres to the inner walls of the chamber and drips onto the wafer surface, affecting subsequent processes and ultimately reducing production yield, thereby improving production yield.

Description

[Technical Field]

[0001] The present application relates to the field of semiconductor manufacturing, and more particularly to a photoresist stripping method and system for chip-on-wafer processes. [Background technology]

[0002] With the development of Moore's Law and the rise of 2.5D / 3D packaging technology, the new chip-on-wafer packaging process has become an essential element in today's advanced packaging. Photoresist stripping refers to the process of removing photoresist from the wafer surface after the photolithography process in semiconductor manufacturing. The main purpose is to remove the photoresist after pattern formation is complete and reduce photoresist residue, metal, and particles on the wafer surface. Photoresist stripping is one of the key steps in the advanced packaging process, and the photoresist removal effect has a significant impact on product yield.

[0003] In today's advanced packaging processes, the common photoresist removal processes mainly include immersion photoresist removal and single-wafer photoresist removal. The principle is to react the photoresist on the wafer with a photoresist stripper to dissolve and remove the photoresist. In the photoresist removal process, the photoresist is generally removed using a photoresist stripper, and the single wafer is then cleaned for 10 to 20 minutes, or the photoresist is removed after immersion for 20 to 30 minutes, and the single wafer is then cleaned for 5 to 10 minutes.

[0004] The height of chips varies and typically ranges from 50 μm to 800 μm (or more). Research has shown that in single-wafer photoresist removal processes, if chip heights are too high, grooves form between the chips, resulting in insufficient processing of the edge chips and making it difficult to completely process the entire wafer. Furthermore, to achieve both effective photoresist stripping and post-stripping cleaning, the wafer rotation speed is typically controlled at 500 RPM or higher. However, excessively high wafer rotation speeds can easily cause liquid splashing, and the centrifugal force caused by high-speed rotation can cause edge chips to move or fly out. Figure 1 shows the results for a wafer rotation speed of 600 RPM and single-wafer photoresist stripping times of 150, 300, and 350 seconds, respectively. Figure 1 shows that good photoresist removal results are achieved when the single-wafer photoresist stripping time is approximately 350 seconds and the rotation speed is 600 RPM. However, longer photoresist stripping times result in reduced production. In addition, when the wafer rotation speed exceeds 500 RPM, liquid splashing may easily occur, which may adhere to the inner walls of the chamber and drip onto the wafer surface, affecting the next process and ultimately reducing the manufacturing yield. Summary of the Invention

[0005] The embodiments of the present application provide a photoresist stripping method and system compatible with chip-on-wafer processes, and at least solve the problem in the prior art that excessively high rotation speeds cause liquid splashing, which then adheres to the inner walls of the chamber and drips onto the wafer surface, affecting the next process and ultimately reducing yield.

[0006] In a first aspect, an embodiment of the present application provides a photoresist stripping method compatible with chip-on-wafer processes, the method comprising the steps of: wetting a wafer to be photoresist stripped; Controlling the rotation speed of the wafer within a range of 30 RPM to 200 RPM and applying megasonic waves to the wetted wafer for a first predetermined time to remove the photoresist.

[0007] In some embodiments, the method may include controlling the rotation speed of the wafer within a range of 30 RPM to 200 RPM, applying megasonic waves to the wetted wafer for a first predetermined time period to remove the photoresist, and then:

[0008] Controlling the rotation speed of the wafer within the range of 30 RPM to 200 RPM and applying megasonic waves to the wafer for a second predetermined time period to clean it.

[0009] In some embodiments, before controlling the rotation speed of the wafer to be within a range of 30 RPM to 200 RPM and applying megasonic waves to the wafer for a second predetermined time period to clean the wafer, the method may further include the steps of: Wetting the wafer.

[0010] In some embodiments, the frequency of the megasonic waves may be in the range of 15 MHz to 40 MHz.

[0011] In some embodiments, before controlling the wafer rotation speed within a range of 30 RPM to 200 RPM and applying megasonic waves to the wetted wafer for a first predetermined time period to remove the photoresist, the method may further include the steps of: detecting the total amount of photoresist remaining on the wafer surface; determining a predetermined threshold range within which the total amount of photoresist remaining falls; Based on the predetermined threshold range, collating a first predetermined time corresponding to the predetermined threshold range from a first predetermined database.

[0012] In some embodiments, after detecting the total amount of photoresist remaining on the wafer surface, the method may further include the steps of: If the total photoresist residue exceeds the predetermined total residue, placing the wafer in an immersion tank and immersing for a third predetermined period of time.

[0013] In some embodiments, prior to placing the wafer in the immersion tank and immersing for the third predetermined period of time, the method may further include the steps of: Based on the predetermined threshold range, collating a third predetermined time corresponding to the predetermined threshold range from the second predetermined database.

[0014] In a second aspect, an embodiment of the present application provides a photoresist removal system compatible with a chip-on-wafer process, including: a wafer holding device for holding a wafer from which photoresist is to be removed; a nozzle for spraying a photoresist stripper onto the wafer; a megasonic apparatus for performing megasonic photoresist removal on the wafer; a rotation drive device for rotating the wafer holding device and the wafer; A controller that controls the nozzle to spray photoresist stripper solution to wet the wafer, controls the rotary drive to rotate the wafer at a rotational speed of 30 RPM to 200 RPM, and controls the megasonic device to apply megasonic waves to the wetted wafer for a first predetermined time period to remove the photoresist.

[0015] Conventional single-wafer photoresist removal methods require high rotation speeds of over 500 RPM during the photoresist removal and cleaning process to ensure sufficient photoresist removal. A rotation speed that is too low makes it difficult to strip and remove the dissolved photoresist, while a high rotation speed and increased chip thickness can cause liquid splashing within the chamber. However, the photoresist removal method for chip-on-wafer processing in this application is designed to perform photoresist removal and cleaning at low rotation speeds of 30 RPM to 200 RPM without liquid splashing. Furthermore, megasonic photoresist removal and cleaning is used to ensure that all chips on the wafer are thoroughly processed.

[0016] In conventional single-wafer photoresist removal methods, the photoresist removal and cleaning processes must be performed at high speeds exceeding 500 RPM to ensure sufficient photoresist removal capability. Due to the channels between chips, the liquid film height of the photoresist stripper and cleaning solution outside the nozzle scan area (areas where the photoresist stripper is not sprayed) can be less than 300 μm. If the height of the chips on the wafer exceeds 300 μm, a sufficient liquid film cannot be formed to cover the entire peripheral edge of the wafer, resulting in incomplete processing of the chips at the edge. However, the photoresist removal method for chip-on-wafer processing in this application is designed to perform the photoresist removal and cleaning processes at a low rotation speed of 30 to 200 RPM, ensuring that the liquid film covers the chips at the wafer edge. Furthermore, megasonic photoresist removal and cleaning are used to ensure that all chips on the wafer are completely and effectively processed.

[0017] In conventional single-wafer photoresist removal methods, the photoresist stripping and cleaning processes must be performed at a high rotation speed of over 500 RPM to ensure photoresist stripping capability. However, if the chip height is high at a rotation speed of over 500 RPM, the centrifugal force can easily cause the chip to move or fly off the wafer. However, according to the photoresist stripping method for chip-on-wafer processes of the present application, photoresist stripping and cleaning can be performed at a low rotation speed of 30 RPM to 200 RPM, allowing both the photoresist stripping and cleaning processes to be completed at a relatively low rotation speed. This significantly reduces the risk of defects.

[0018] The details of one or more embodiments of the present application are set forth in the drawings and description that follow, in order to provide a more concise and understandable understanding of other features, objects and advantages of the present application. [Brief explanation of the drawings]

[0019] The drawings accompanying this specification are included to provide a further understanding of the present application and constitute a part of this application. The schematic embodiments and the description thereof are for illustrative purposes only and are not intended to unduly limit the present application. In the drawings [Figure 1] FIG. 1 is a schematic diagram showing the effect of single wafer photoresist stripping in the prior art. [Figure 2] FIG. 2 is a flowchart of a photoresist stripping method compatible with a chip-on-wafer process according to an embodiment of the present application. [Figure 3] FIG. 3 is a first schematic diagram illustrating the effect of megasonic photoresist stripping according to an embodiment of the present application. [Figure 4] FIG. 4 is a second schematic diagram illustrating the effect of megasonic photoresist stripping according to an embodiment of the present application. [Figure 5] FIG. 5 is a third schematic diagram showing the effect of photoresist stripping using megasonic waves according to an embodiment of the present application. [Figure 6] FIG. 6 is a fourth schematic diagram illustrating the effect of using photoresist stripping using megasonic waves according to an embodiment of the present application. [Figure 7] FIG. 7 is a configuration block diagram of a photoresist stripping system compatible with a chip-on-wafer process according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0020] In order to more clearly understand the objectives, technical solutions, and advantages of the present invention, the contents of the present invention will be described with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely examples for explaining the present invention and do not limit the present invention. All other embodiments that can be obtained by those skilled in the art based on the embodiments provided in this application without requiring creative efforts are included in the scope of protection of this application. It should be further understood that even if the efforts in such a development process are complex and long, it is merely a normal technical means in the art for those skilled in the art to make partial changes in design, manufacturing, or production based on the technical contents disclosed in this application, and the disclosure of this application should not be interpreted as insufficient.

[0021] The term "embodiment" in this application means that a particular function, structure, or feature described in connection with an embodiment may be included in at least one embodiment of this application. Expressions appearing in various places in the specification do not necessarily refer to the same embodiment, nor do they imply an embodiment that is independent or alternative to other embodiments, and are not exclusive of other embodiments. Those skilled in the art will understand, explicitly or implicitly, that the embodiments described in this specification can be combined with other embodiments without creating a contradiction.

[0022] Unless otherwise defined herein, technical or scientific terms shall have the ordinary meaning commonly understood by those skilled in the art to which this specification pertains. As used herein, terms such as "a," "an," "a kind," and "corresponding to" do not denote a limitation of quantity and may refer to singular or plural. As used herein, the terms "comprise," "include," "have," and variations thereof imply an inclusive and non-exclusive inclusion. For example, a process, method, system, product, or apparatus comprising a series of steps or modules (units) is not limited to the listed steps or units, but may include unlisted steps or units, or may include other steps or units inherent to the process, method, product, or apparatus. As used herein, terms such as "connected," "communicated," and "coupled" are not limited to physical or mechanical connections, but may include direct or indirect electrical connections. As used herein, "plurality" means two or more. "And / or" expresses a relationship between related elements. For example, "A and / or B" indicates that three types of relationships may exist: when only A is present, when both A and B are present, or when only B is present. As used in this application, the terms "first," "second," "third," etc. are used to distinguish between similar elements and do not denote a particular order of the elements.

[0023] An embodiment of the present application provides a photoresist stripping method for a chip-on-wafer process, and Fig. 2 is a flowchart of the photoresist stripping method for a chip-on-wafer process according to an embodiment of the present application. As shown in Fig. 2, the method includes the following steps: Step S201: Wet the wafer that is to be photoresist removed. In this step, the nozzle is controlled to spray the photoresist stripping liquid to wet the wafer from which the photoresist is to be stripped, thereby facilitating the subsequent removal of the photoresist on the wafer. It should be noted that the time for wetting the wafer to be photoresist stripped and the flow rate of the photoresist stripper sprayed from the nozzle can be set according to the specific process requirements. Step S202: Control the rotation speed of the wafer within a range of 30 RPM to 200 RPM, and apply megasonic waves to the wetted wafer for a first predetermined time for photoresist removal.

[0024] 3 to 6 are graphs showing the effect of photoresist stripping time. Referring to FIGS. 3 and 6, the wafer rotation speed in both figures is 150 RPM. The megasonic photoresist stripping times in FIG. 3 are 150 seconds, 300 seconds, and 350 seconds, respectively, and the megasonic photoresist stripping times in FIG. 6 are 62 seconds, 124 seconds, and 186 seconds, respectively. As can be seen from FIGS. 1 and 3, when compared at the same processing time, the embodiment of the present application employs a method that combines a megasonic photoresist stripping method with a rotation speed of 150 RPM, and achieves superior photoresist stripping effects at both 150 and 300 seconds compared to the prior art. Furthermore, as can be seen from FIGS. 3 and 6, the embodiment of the present invention employs a method that combines a megasonic photoresist stripping method with a rotation speed of 150 RPM, achieving good photoresist stripping effects at a stripping time of 186 seconds and a rotation speed of 150 RPM. Therefore, in summary, compared with the conventional single wafer photoresist removal, the present embodiment can shorten the photoresist removal time and achieve good photoresist removal effect while suppressing the wafer rotation speed.

[0025] Further referring to FIGS. 3 to 5, it can be seen that photoresist stripping of wafers is possible at wafer rotation speeds of 30 RPM, 150 RPM, and 200 RPM, and all of the photoresist stripping effects are superior to those of the prior art.

[0026] If the wafer rotation speed is less than 30 RPM, the centrifugal force may be insufficient to remove the photoresist washed off the wafer. Therefore, to achieve a better photoresist stripping effect, the wafer rotation speed in this step is limited to a range of 30 RPM to 200 RPM, and megasonic waves are applied to the wetted wafer for a first predetermined time, thereby achieving photoresist removal at less than 200 RPM. This avoids the problems of the prior art, such as excessively high rotation speeds causing liquid splashing, which can adhere to the inner walls of the chamber and drip onto the wafer surface, affecting subsequent processes and ultimately reducing production yield. At the same time, it also avoids the problem of chips at the edge of the wafer being dislodged due to centrifugal force generated by excessively high rotation speeds.

[0027] It should be noted that the first predetermined time can be set according to specific process requirements. Step S201 and step S202 can be performed simultaneously, in any order.

[0028] The megasonic waves in this embodiment may be spatial cross phase shift (SAPS) megasonic technology or other megasonic technology that can achieve the objectives of this application. SAPS megasonic technology controls the relative motion between a megasonic generator and a wafer within a half-wavelength range to uniformly distribute megasonic energy on the wafer surface, thereby achieving optimal cleaning results. In this embodiment, the SAPS megasonic technology is used to remove photoresist by setting a low rotation speed of 30 RPM to 200 RPM. This effectively removes photoresist at a speed between 30 RPM and 200 RPM, not only ensuring effective removal of photoresist on the wafer but also avoiding the problem of liquid splashing caused by an excessively high wafer rotation speed.

[0029] In some embodiments, after step S202, the wafer rotation speed is controlled to a range of 30 RPM to 200 RPM, and megasonic cleaning is performed on the wafer for a second predetermined time. By controlling the wafer rotation speed to a range of 30 RPM to 200 RPM and performing megasonic cleaning on the wafer for a second predetermined time after performing step S202, cleaning of the wafer after removing the photoresist can be achieved at less than 200 RPM. This avoids problems in the prior art, such as excessive rotation speeds during wafer cleaning, which can cause liquid to splash, adhere to the inner walls of the chamber, and then drip onto the wafer surface, affecting subsequent processes and ultimately reducing production yield. At the same time, it also avoids the problem of chips at the edge of the wafer moving and flying off due to centrifugal force caused by excessively high rotation speeds when using a low rotation speed.

[0030] Based on the above embodiment, in another embodiment, the wafer after performing step S202 can be wetted by controlling the nozzle to spray the cleaning liquid before applying megasonic cleaning to the wafer for a second predetermined time while controlling the wafer rotation speed in the range of 30 RPM to 200 RPM.

[0031] Cleaning fluids include, but are not limited to, deionized water or water with dissolved carbon dioxide.

[0032] In some embodiments, the megasonic frequency is in the range of 15 MHz to 40 MHz. If the megasonic frequency is too high or too low, the problem of reduced production yield may occur. Therefore, in order to avoid the problem of reduced production yield due to the megasonic frequency being too high or too low, in this embodiment, the megasonic frequency is controlled to be between 15 MHz and 40 MHz, thereby avoiding the problem of reduced production yield due to the megasonic frequency being too high or too low.

[0033] The megasonic frequencies in the embodiments of the present application can be used for both photoresist stripping and cleaning processes, but are not limited thereto.

[0034] In some embodiments, the wafer rotation speed is controlled in a range of 30 RPM to 200 RPM, and before applying megasonic photoresist removal to the wetted wafer for a first predetermined time, the total amount of photoresist remaining on the wafer surface to be photoresist stripped can be further detected, a predetermined threshold range to which the total amount of photoresist remains is determined, and the first predetermined time is matched based on the first predetermined threshold range from a first predetermined database.

[0035] In this embodiment, a predetermined threshold range to which the total residual amount of photoresist belongs is identified, and a first predetermined time corresponding to the predetermined threshold range is compared with the first predetermined database based on the predetermined threshold range, thereby accurately determining the first predetermined time for megasonic photoresist removal according to the predetermined threshold range to which the total residual amount of photoresist belongs. This realizes adaptive adjustment of the first predetermined time, avoiding the problem of insufficient removal due to ...

[0036] It should be noted that the first predetermined database stores a first predetermined time corresponding to each predetermined threshold range, and different first predetermined times are set for each predetermined threshold range.

[0037] In this embodiment, the method of determining the total amount of remaining photoresist is, but not limited to, photographing the wafer from which the photoresist is to be removed, measuring the size of each remaining area based on the photograph, calculating the area of ​​each remaining area and the thickness of the remaining photoresist in the corresponding remaining area, and finally calculating the total amount of remaining photoresist based on the thickness of the remaining photoresist. In addition to the above-described method, other methods capable of calculating the total amount of remaining photoresist can also be used, and the embodiments of the present application are not limited to these.

[0038] In some embodiments, after detecting the total amount of photoresist remaining on the surface of the wafer from which the photoresist is to be removed, if the total amount of photoresist remaining exceeds a predetermined total amount, the wafer from which the photoresist is to be removed may be placed in an immersion tank and immersed for a third predetermined period of time.

[0039] In order to facilitate subsequent photoresist removal, in this embodiment, when the total residual amount of photoresist exceeds a predetermined total residual amount, the clamping mechanism is first controlled to place the wafer in an immersion tank and immerse it for a third predetermined time period to perform preliminary photoresist removal, thereby improving the efficiency of subsequent megasonic photoresist removal.

[0040] Therefore, in some embodiments, before controlling the clamping mechanism to place the wafer in the immersion tank for the third predetermined time, the third predetermined time corresponding to the predetermined threshold range can be checked from the second predetermined database based on the predetermined threshold range. In this way, by checking the third predetermined time corresponding to the predetermined threshold range from the second predetermined database based on the predetermined threshold range, the third predetermined time corresponding to the immersion in the immersion tank can be accurately determined depending on the predetermined threshold range to which the total residual amount of photoresist falls, and adaptive adjustment of the third predetermined time can be further realized, thereby improving the efficiency of subsequent megasonic photoresist removal.

[0041] In some embodiments, the photoresist removal method in the chip-on-wafer process of the present application can also be used in combination with a prior art photoresist removal method, which is as follows. Method 1: First, a preliminary photoresist strip, cleaning, and drying process is performed on the wafer using a conventional single-wafer photoresist stripping method. In this process, there is no need to spin dry the wafer. The wafer is removed and the photoresist stripping method for the chip-on-wafer process of the present application is carried out. In this process, megasonic waves are used in the photoresist removal and cleaning process, and the rotation speed is 30 RPM to 200 RPM. Method 2: First, use a conventional tank to strip and remove the photoresist by immersion, then remove the wafer and perform the photoresist stripping method according to the present invention for the chip-on-wafer process. This process uses megasonic waves in the photoresist removal and cleaning process and is performed at rotation speeds of 30 RPM to 200 RPM. Method 3: First, use a conventional tank to strip and remove the photoresist by immersion, then perform the conventional single-wafer photoresist removal method, and then perform the photoresist stripping method corresponding to the chip-on-wafer process according to the present application. This process uses megasonic waves in the photoresist removal and cleaning process and is performed at rotation speeds of 30 RPM to 200 RPM.

[0042] Through the above-described method, the photoresist removal method for chip-on-wafer processing proposed in this application combines a low rotation speed of 30 RPM to 200 RPM with megasonic photoresist removal, thereby overcoming the shortcomings of conventional photoresist removal techniques, improving photoresist removal efficiency and removal quality. Megasonic technology is also used to remove and clean wafer photoresist. While improving photoresist removal and cleaning capabilities and simultaneously increasing production capacity, the application's low rotation speed of 30 RPM to 200 RPM effectively prevents liquid splashing, ensuring complete processing of chips at the wafer edge and preventing them from moving or flying off the wafer.

[0043] The embodiments of the present application also provide a photoresist stripping system compatible with chip-on-wafer processes, which is used to implement the above-described embodiments and preferred embodiments, and the details already described will be omitted. Terms such as "module," "unit," and "subunit" used below may refer to a combination of software and / or hardware that performs a specific function. While the systems described in the following embodiments are preferably implemented by software, implementation by hardware or a combination of software and hardware is also possible and envisioned.

[0044] 7 is a block diagram of a photoresist stripping system compatible with a chip-on-wafer process according to an embodiment of the present invention. As shown in FIG. 7, the system includes the following components: A wafer holding device 76 is a device for holding a wafer 75 from which photoresist is to be removed. A nozzle 71 is disposed above a wafer holding device 76 and sprays a photoresist stripping liquid onto a wafer 75 . A megasonic device 72 is a device for performing megasonic photoresist removal on a wafer 75 . A rotation drive device 73 is connected to the wafer holding device 76 and rotates the wafer 75 by driving the wafer holding device 76 to rotate. a controller 74 electrically connected to the nozzle 71, the megasonic device 72, and the rotary drive device 73, the controller 74 controlling the nozzle 71 to spray a photoresist stripper solution to wet the wafer 75, controlling the rotary drive device 73 to rotate the wafer 75 at a rotational speed of 30 RPM to 200 RPM, and controlling the megasonic device 72 to apply megasonic waves to the wet wafer 75 for a first predetermined time period to remove the photoresist.

[0045] In this embodiment, based on a photoresist stripping system compatible with chip-on-wafer processes, photoresist can be removed at a rotation speed of less than 200 RPM, which avoids the problem in the prior art that excessively high rotation speed of the wafer causes liquid to splash, and the splashed liquid adheres to the inner wall of the chamber and drips onto the wafer surface, affecting the next process and ultimately reducing the production yield, thereby improving the production yield.

[0046] In some embodiments, the controller 74 is used to control the rotary drive 72 to rotate the wafer 75 at a rotational speed of 30 RPM to 200 RPM and to control the megasonic device 72 to apply a second predetermined time of megasonic cleaning to the wafer 75 after photoresist removal.

[0047] In some embodiments, the nozzles 71 are also used to spray cleaning fluid to wet and clean the wafer.

[0048] In some embodiments, the megasonic frequency is in the range of 15 MHz to 40 MHz.

[0049] In some embodiments, the system further includes the following components: a detector for detecting the total amount of photoresist remaining on the surface of the wafer 75 from which the photoresist is to be removed, a calculator for determining a predetermined threshold range to which the total amount of photoresist falls, and a collator for collating a first predetermined time corresponding to the threshold range from a first predetermined database based on the predetermined threshold range.

[0050] In this embodiment, the detector may be a camera or other conventional hardware device capable of detecting the total amount of photoresist remaining on the wafer surface from which the photoresist is to be removed. The calculator and verifier in this embodiment may be implemented by software in the controller 74. In some embodiments, the calculator and verifier may be hardware devices with corresponding functionality.

[0051] In some embodiments, the system further includes a clamping mechanism, and the controller is electrically connected to the clamping mechanism and controls the clamping mechanism to immerse the wafer from which the photoresist is to be removed in the immersion tank for a third set time if the total residual amount of photoresist exceeds a predetermined total residual amount.

[0052] In some embodiments, the matcher may be used to match a third predetermined time corresponding to the third predetermined time from the second predetermined database based on a predetermined threshold range.

[0053] Those skilled in the art will understand that the technical features described in the above embodiments can be combined in any way, and all possible combinations of the technical features described in the above embodiments have not been described for the sake of brevity, but as long as there is no contradiction in the combination of these technical features, the technical features shall be deemed to be within the scope of this specification.

[0054] The above embodiments represent some embodiments of the present application, and although the description is relatively specific and detailed, it should not be construed as limiting the scope of the invention patent. It is noted that a person skilled in the art can make some modifications and improvements without departing from the concept of the present application, and all of these modifications and improvements fall within the protection scope of the present application. Therefore, the protection scope of the present patent application should be defined by the appended claims.

Claims

1. wetting a wafer to be photoresist stripped; and controlling a rotation speed of the wafer within a range of 30 RPM to 200 RPM and applying megasonic waves to the wetted wafer for a first predetermined time to remove the photoresist.

2. controlling the rotation speed of the wafer within a range of 30 RPM to 200 RPM and applying megasonic waves to the wetted wafer for a first predetermined time to remove the photoresist, and then further 2. The photoresist stripping method for chip-on-wafer process according to claim 1, further comprising the step of controlling the rotation speed of the wafer within a range of 30 RPM to 200 RPM and applying megasonic waves to the wafer for a second predetermined time to remove the photoresist, thereby cleaning the wafer.

3. and controlling the rotation speed of the wafer to be within a range of 30 RPM to 200 RPM and applying megasonic waves to the wafer for a second predetermined time period before cleaning the wafer.

3. The photoresist stripping method for chip-on-wafer processing according to claim 2, further comprising the step of wetting the wafer.

4. 3. The photoresist stripping method for chip-on-wafer processing according to claim 1, wherein the frequency of the megasonic waves is 15 MHz to 40 MHz.

5. controlling the rotation speed of the wafer within a range of 30 RPM to 200 RPM and applying megasonic waves to the wetted wafer for a first predetermined time period to remove the photoresist, and further detecting the total amount of photoresist remaining on the wafer surface; determining a predetermined threshold range within which the total amount of photoresist remaining falls; 2. The photoresist stripping method for chip-on-wafer processing according to claim 1, further comprising: a step of collating a first predetermined time corresponding to the predetermined threshold range from a first predetermined database based on the predetermined threshold range.

6. After detecting the total amount of photoresist remaining on the wafer surface, 6. The photoresist stripping method for chip-on-wafer processes according to claim 5, further comprising the step of placing the wafer in an immersion tank and immersing it for a third predetermined time period when the total remaining amount of the photoresist exceeds a predetermined total remaining amount.

7. and, prior to placing the wafer in the immersion tank and immersing for a third predetermined period of time, further 7. The photoresist stripping method for chip-on-wafer processing according to claim 6, further comprising the step of: collating the third predetermined time corresponding to the predetermined threshold range from a second predetermined database based on the predetermined threshold range.

8. a wafer holding device for holding a wafer from which photoresist is to be removed; a nozzle for spraying a photoresist stripper onto the wafer; a megasonic apparatus for performing megasonic photoresist removal on the wafer; a rotation drive device that rotates the wafer holding device and the wafer; a controller that controls the nozzle to spray a photoresist stripping solution onto the wafer to wet the wafer, controls the rotary drive device to rotate the wafer at a rotation speed of 30 RPM to 200 RPM, and controls the megasonic device to apply megasonic waves to the wetted wafer for a first predetermined time to remove the photoresist.

9. 10. The photoresist stripping system for chip-on-wafer processing of claim 8, wherein the controller is further configured to control the rotational drive to rotate the wafer at a rotational speed of 30 RPM to 200 RPM, and to control the megasonic device to apply a megasonic clean to the wafer for a second predetermined time period after photoresist removal.

10. 9. The photoresist stripping system for chip-on-wafer processing according to claim 8, wherein the nozzle is further used to spray a cleaning liquid to wet and clean the wafer.

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