Device and method for removing residual adhesive on photomask protective film

Abstract

The invention discloses a device and a method for removing residual glue on a protective film of a photomask. The method comprises the following steps of: removing the protective film on the photomask to expose the residual glue on the protective film; placing the photomask on a heating device, and heating the residual adhesive on the photomask; an auxiliary plate is provided, a hollow part is arranged on the auxiliary plate, and the shape and the size of the hollow part are matched with those of the protective film; covering the auxiliary plate on the photomask, wherein the residual adhesive on the photomask is exposed out of the hollow part; and removing the residual adhesive exposed out of the hollow part. According to the method for removing the residual adhesive provided by the embodiment of the invention, the residual adhesive is effectively removed, and meanwhile, the photoetching pattern on the photomask cannot be damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular to a device and method for removing residual glue of a pellicle of a photomask. BACKGROUND

[0002] During photolithography, a photomask is used to transfer a pattern to photoresist disposed on a substrate. Particles that enter the focal plane of the photomask can damage the mask. Particles can also be imaged and transferred as part of the pattern, which results in a misfocused or suboptimal exposure of the photomask. A pellicle is often disposed on the photomask to prevent particles from damaging and contaminating the photomask.

[0003] The pellicle is a thin, transparent film that does not affect the pattern created by light passing through the photomask. Generally, the pellicle is bonded to the photomask. Over time, the pellicle can become damaged and contaminated, and thus needs to be replaced. When the pellicle is removed from the photomask, residual glue remains on the photomask, which needs to be removed before a new pellicle is attached to the photomask.

[0004] Current methods for removing the residual glue generally use a solvent to wipe off the residual glue or a cleaning solution to clean the photomask to remove the residual glue, but both methods can damage the photolithographic pattern, and in severe cases, can cause the photomask to be scrapped.

[0005] Therefore, there is a need to improve the technology for removing residual glue from a photomask. SUMMARY

[0006] The present application solves the technical problem of providing a device and method for removing residual glue of a pellicle of a photomask, which can effectively remove the residual glue left on the photomask after the pellicle is removed, and will not damage the photolithographic pattern on the photomask.

[0007] To solve the above technical problem, an embodiment of the present application provides a device for removing residual glue of a pellicle of a photomask, comprising: an auxiliary plate, the auxiliary plate is disposed on the photomask, the auxiliary plate is provided with a hollow part, the hollow part exposes residual glue of the pellicle on the photomask; a wiping tool, the wiping tool is used to wipe off the residual glue exposed by the hollow part.

[0008] Optionally, the auxiliary plate comprises opposite first and second surfaces, the first surface is opposite to the photomask, and the hollow part penetrates the auxiliary plate in a direction from the first surface to the second surface.

[0009] Optionally, the side wall of the hollow part is perpendicular to the first and second surfaces of the auxiliary plate.

[0010] Optionally, the side wall of the hollow part has an included angle with the first surface and the second surface of the auxiliary plate, and the opening area of the hollow part on the first surface side is smaller than that on the second surface side.

[0011] Optionally, the material of the auxiliary plate comprises polytetrafluoroethylene or polypropylene fluoride.

[0012] Optionally, the thickness of the auxiliary plate is 5-10 mm.

[0013] Correspondingly, the embodiment of the present application also provides a method for removing residual glue of a photo mask protection film, comprising: removing the protection film on the photo mask to expose the residual glue of the protection film; placing the photo mask on a heating device to heat the residual glue on the photo mask; providing an auxiliary plate, the auxiliary plate being provided with a hollow part, the hollow part matching the shape and size of the protection film; covering the auxiliary plate on the photo mask, the hollow part exposing the residual glue on the photo mask; and removing the residual glue exposed by the hollow part.

[0014] Optionally, the temperature for heating the residual glue is 40-50℃, and the heating time is 5-10 min.

[0015] Optionally, the material of the auxiliary plate comprises polytetrafluoroethylene or polypropylene fluoride.

[0016] Optionally, the thickness of the auxiliary plate is 5-10 mm.

[0017] Optionally, the auxiliary plate comprises opposite first and second surfaces, when the auxiliary plate is covered on the photo mask, the first surface is opposite to the photo mask, and the hollow part penetrates through the auxiliary plate along the direction from the first surface to the second surface.

[0018] Optionally, the side wall of the hollow part is perpendicular to the first and second surfaces of the auxiliary plate.

[0019] Optionally, the side wall of the hollow part has an included angle with the first and second surfaces of the auxiliary plate, and the opening area of the hollow part on the first surface side is smaller than that on the second surface side.

[0020] Optionally, the method for removing the residual glue exposed by the hollow part comprises: using a wiping tool to dip a wiping liquid and then wiping the residual glue exposed by the hollow part.

[0021] Optionally, the wiping liquid comprises an acetone solution or a tetrahydrofuran solution.

[0022] Optionally, after wiping the residual glue exposed by the hollow part, the method further comprises: cleaning the photo mask.

[0023] Optionally, the step of cleaning the photomask comprises: using a first cleaning solution to clean the photomask for the first time; using a second cleaning solution to clean the photomask for the second time.

[0024] Optionally, the first cleaning solution comprises a sulfuric acid solution; and the second cleaning solution comprises a mixed solution of sulfuric acid and hydrogen peroxide.

[0025] Optionally, after the second cleaning, the method further comprises: removing the first cleaning solution and the second cleaning solution remaining on the photomask, and performing ultrasonic cleaning on the photomask.

[0026] Compared with the prior art, the technical scheme of the embodiment of the present application has the following beneficial effects:

[0027] The device for removing residual glue provided by the technical scheme can avoid damaging the photolithography pattern, thereby reducing damage to the photomask.

[0028] The method for removing residual glue provided by the technical scheme can soften the residual glue by heating the residual glue on the photomask after removing the protective film, which is beneficial to subsequent removal of the residual glue; then, the auxiliary plate is used, the hollow part of the auxiliary plate is matched with the shape and size of the protective film, and after the auxiliary plate is covered on the photomask, the hollow part can completely expose the residual glue left after the protective film is removed, the remaining part of the auxiliary plate covers the photolithography pattern on the photomask, and the movement range during removal of the residual glue is limited in the hollow part and does not touch the photolithography pattern in other areas, thereby avoiding damage to the photolithography pattern and reducing damage to the photomask. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a top view structural schematic diagram of the photomask with residual glue in an embodiment of the present application;

[0030] Figure 2 is a top view structural schematic diagram of the auxiliary plate in an embodiment of the present application;

[0031] Figure 3 is a structural schematic diagram of covering the auxiliary plate on the photomask shown in Figure 2

[0032] Figure 4 is a sectional view structural schematic diagram of the auxiliary plate along the AA direction in Figure 2

[0033] Figure 5 is a sectional view structural schematic diagram of the auxiliary plate in another embodiment of the present application.​​ DETAILED DESCRIPTION

[0034] As described in the background, the current method for removing the residual glue of the protective film on the photomask is generally to use a wiping tool to wipe the residual glue, but the wiping range is not easy to control, and the photoetching pattern around the residual glue is easily touched, resulting in damage to the photoetching pattern. In addition, if the residual glue is removed by cleaning the photomask with a cleaning liquid, the residual glue with a large range and deep mark needs to be cleaned for multiple times, but the photoetching pattern is also easily damaged, and even the photomask is seriously scrapped, which is not conducive to cost control, and the remanufacture of the photomask also affects the production efficiency.

[0035] In order to solve the above problems, the embodiment of the present application provides a device and a removing method for the residual glue of the protective film on the photomask, wherein the removing method comprises the following steps: first, heating the photomask by using a heating device, so that the residual glue on the photomask is softened, and the subsequent removal is facilitated; and then covering an auxiliary plate on the photomask, the auxiliary plate is provided with a hollow part, the residual glue is exposed by the hollow part, and the photoetching pattern is covered by the remaining part of the auxiliary plate, so that the residual glue can only move in the hollow part during the removal of the residual glue, and the photoetching pattern is not touched, thereby avoiding damage to the photoetching pattern. In addition, multiple cleaning of the residual glue is not required, and the situation of photomask scrapping is avoided, thereby being conducive to reducing the production cost and improving the production efficiency.

[0036] In order to make the above-mentioned purpose, characteristics and beneficial effects of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0037] Figure 1 is a top view structural schematic diagram of the photomask with residual glue in an embodiment of the present application; Figure 2 is a top view structural schematic diagram of the auxiliary plate in an embodiment of the present application; Figure 3 is a structural schematic diagram of the auxiliary plate covering the photomask shown in Figure 2 is a structural schematic diagram of the auxiliary plate covering the photomask shown in Figure 4 is a sectional view structural schematic diagram of the auxiliary plate along the AA direction in Figure 2 is a sectional view structural schematic diagram of the auxiliary plate along the AA direction in Figure 5 is a sectional view structural schematic diagram of the auxiliary plate in another embodiment of the present application.

[0038] The removing method for the residual glue provided by the present application specifically comprises the following steps:

[0039] Referring to Figure 1 , step one: removing the protective film (not shown) on the photomask 10 to expose the residual glue 11 of the protective film.

[0040] In a specific embodiment, the shape of the protective film (not shown) and the position of the photomask 10 are fixed, and after the protective film is removed, the residual glue 11 is left on the position where the protective film is originally pasted.

[0041] In the embodiment, the shape of the residual glue 11 is taken as an example of a ring shape; in other embodiments, the shapes and positions of the protective films used in different photolithography processes are different, and the shapes and positions of the residual glue are also different.

[0042] In the embodiment, the residual glue 11 is an acrylic adhesive, which can be removed by a solvent later; in other embodiments, the residual glue can also be a polyester adhesive.

[0043] Step two: placing the photomask 10 on a heating device (not shown) to heat the residual glue 11 on the photomask 10.

[0044] The residual glue 11 on the photomask 10 is heated by the heating device, which can soften the residual glue 11 and reduce the adhesion of the residual glue 11, thereby facilitating the removal of the residual glue 11 later.

[0045] In the embodiment, the heating device includes a heating platform and an electric heater for heating the heating platform, and the photomask 10 is placed on the heating platform.

[0046] The temperature for heating the residual glue 11 is 40-50°C. If the temperature is too high, the residual glue 11 can be solidified, which is more unfavorable for the removal of the residual glue 11 later; if the temperature is too low, the residual glue 11 cannot be softened sufficiently, which cannot reduce the adhesion.

[0047] The heating time for heating the residual glue 11 is 5-10 min. If the heating time is too long, the residual glue 11 can be solidified, which is more unfavorable for the removal of the residual glue 11 later; if the heating time is too short, the residual glue 11 cannot be softened sufficiently, which cannot reduce the adhesion.

[0048] In combination with the reference Figure 2 and Figure 4 Step three: providing an auxiliary plate 20, and the auxiliary plate 20 is provided with a hollow part 21, and the hollow part 21 matches the shape and size of the protective film.

[0049] In the embodiment, the material of the auxiliary plate 20 includes polytetrafluoroethylene, which has high stability and can be used repeatedly, and will not fall off and cause pollution of the photomask during use, and will not scratch the photomask and cause damage to the photomask when in contact with the photomask; the polytetrafluoroethylene material also has the characteristics of easy processing, which facilitates the processing and forming of the hollow part 21.

[0050] In other embodiments, the material of the auxiliary plate 20 can also be a material with high stability such as polypropylene fluoride.

[0051] In the embodiment, the auxiliary plate 20 comprises opposite first surface 22 and second surface 23, when the auxiliary plate 20 covers the photomask 10, the first surface 22 is opposite to the photomask 10, the hollow part 21 penetrates the auxiliary plate 20 along the direction from the first surface 22 to the second surface 23.

[0052] In the embodiment, the hollow part 21 is matched with the shape and size of the protective film, after the protective film is torn off, the residual glue 11 is left in the position of the original protective film, which can ensure that the hollow part 21 can completely expose the residual glue 11 after the auxiliary plate 20 covers the photomask 10, and facilitate the subsequent removal of the residual glue 11.

[0053] In the embodiment, the opening area of the hollow part 21 can be equal to or greater than the area of the protective film. In the embodiment, the opening area of the hollow part 21 is slightly larger than the area of the protective film, so as to better expose the residual glue 11 and facilitate the subsequent operation of removing the residual glue 11.

[0054] In the embodiment, the hollow part 21 is a ring structure consistent with the shape of the residual glue 11; in other embodiments, the hollow part 21 can be designed according to the specific shape and size of the protective film.

[0055] It should be noted that, in the embodiment, since the hollow part 21 is a ring structure, in order to prevent the first part of the auxiliary plate 24 inside the ring from being completely separated from the second part of the auxiliary plate 25 outside the ring, a plurality of connecting parts 26 are arranged on the second surface 23 of the auxiliary plate 20, and the connecting parts 26 are used to connect the first part of the auxiliary plate 24 and the second part of the auxiliary plate 25.

[0056] In the embodiment, the connecting parts 26 are arranged at four corners of the side of the hollow part 21 on the second surface 23.

[0057] The thickness of the auxiliary plate 20 ranges from 5mm to 10mm. If the thickness of the auxiliary plate 20 is too thin, it is not conducive to the processing of forming the hollow part thereon; if the thickness of the auxiliary plate 20 is too thick, it is not easy to contact the residual glue when the residual glue is removed by the hollow part, causing inconvenience in removing the residual glue.

[0058] It should be noted that the thickness of the auxiliary plate 20 in the embodiment of the application represents the vertical distance between the first surface 22 and the second surface 23.

[0059] Reference Figure 3In this embodiment, the auxiliary plate 20 further comprises a support part 27, which is arranged on the side of the first surface 22 of the auxiliary plate 20. The support part 27 can form a gap between the auxiliary plate 20 and the photomask 10 when the auxiliary plate 20 covers the photomask 10, so that the first surface 22 does not directly contact the photomask 10, thereby avoiding damage to the photolithographic pattern.

[0060] In this embodiment, the support part 27 is arranged at the four corners of the auxiliary plate 20. In other embodiments, the support part 27 can be arranged at other positions that do not affect the photolithographic pattern.

[0061] Reference Figure 4 In this embodiment, the side wall 211 of the hollow part 21 is perpendicular to the first surface 22 and the second surface 23 of the auxiliary plate 20.

[0062] Reference Figure 5 , Figure 5 With Figure 4 In another embodiment, the side wall 211 of the hollow part 21 has an included angle between the first surface 22 and the second surface 23, and the opening area of the hollow part 21 on the side of the first surface 22 is smaller than that on the side of the second surface 23.

[0063] In this embodiment, the side wall 211 of the hollow part 21 is inclined, which facilitates adjustment of the wiping angle when wiping the residual glue exposed by the hollow part 21, and makes it easier to contact the residual glue for better removal of the residual glue.

[0064] Preferably, the included angle between the side wall 211 of the hollow part 21 and the first surface 22 of the auxiliary plate 20 is 45°.

[0065] Reference Figure 3 Step 4: Cover the auxiliary plate 20 on the photomask 10, and the hollow part 21 exposes the residual glue 11 on the photomask 10.

[0066] In this embodiment, the auxiliary plate 20 completely covers the photomask 10, and the part of the auxiliary plate 20 except the hollow part 21 can cover the photomask 10 except the residual glue 11. When the residual glue 11 is removed later, the photolithographic pattern on the photomask 10 can be protected from being damaged by the solvent used to remove the residual glue 11.

[0067] In other embodiments, the area of the auxiliary plate 20 can be slightly larger than that of the photomask 10, as long as the hollow part 21 can completely expose the residual glue 11.

[0068] Step five: removing the residual glue 11 exposed by the hollow part 21.

[0069] In this embodiment, the method of removing the residual glue 11 includes using a wiping tool to wipe the residual glue 11 exposed by the hollow part 21 after the wiping tool is dipped in a wiping liquid.

[0070] In specific embodiments, the wiping tool can be a cotton swab, cotton cloth or other wiping tool. Using a cotton swab, cotton cloth or other tool can avoid causing scratches on the surface of the photomask 10.

[0071] In this embodiment, the wiping liquid can be an acetone solution. Acetone is a good organic solvent that can dissolve the residual glue 11 and other glue and will not damage the photomask 10. In other embodiments, the wiping liquid can also be a tetrahydrofuran solution or other organic solvent.

[0072] In this embodiment, due to the presence of the hollow part 21, when the wiping tool is used to wipe the residual glue 11, the wiping tool can only move within the hollow part 21 and will not touch the photolithography pattern covered by the auxiliary plate 20, thereby avoiding damage to the photolithography pattern.

[0073] In this embodiment, after the residual glue 11 exposed by the hollow part 21 is wiped, the method further includes cleaning the photomask 10.

[0074] In this embodiment, the method of cleaning the photomask 10 includes using a first cleaning liquid to clean the photomask for the first time and using a second cleaning liquid to clean the photomask for the second time.

[0075] In this embodiment, the first cleaning liquid is a sulfuric acid solution, and the first cleaning lasts for 170-180 seconds. The sulfuric acid solution is used to pre-clean the photomask 10 to remove the residual glue 11 and other contaminants.

[0076] In this embodiment, the second cleaning liquid is a mixed solution of sulfuric acid and hydrogen peroxide, and the volume ratio of sulfuric acid to hydrogen peroxide is 5:1. The second cleaning lasts for 410-430 seconds, and the second cleaning can completely remove the residual glue 11.

[0077] In this embodiment, since the residual glue 11 has been basically removed before the photomask 10 is cleaned with the cleaning liquid, the photomask 10 only needs to be cleaned once to completely remove the residual glue 11 or other contaminants on the photomask 10, and repeated cleaning with corrosive liquids such as sulfuric acid will not damage the photolithography pattern.

[0078] In this embodiment, after the second cleaning, the method further includes removing the first cleaning liquid and the second cleaning liquid remaining on the photomask 10 and ultrasonic cleaning the photomask 10.

[0079] In the embodiment, the photomask 10 is flushed by the deionized water with CO2 to remove the first cleaning solution and the second cleaning solution remaining on the photomask 10, and the deionized water with CO2 can eliminate the electrostatic effect to avoid the electrostatic effect from affecting the patterns on the photomask 10.

[0080] In the embodiment, the photomask 10 is ultrasonically cleaned by the deionized water with CO2 and H2 and the tetramethylammonium hydroxide solution to remove the particles, dust and other impurities on the photomask 10, and the ultrasonic cleaning time is 530-550 seconds.

[0081] In the embodiment, the photomask 10 is flushed by the deionized water with CO2 to remove the first cleaning solution and the second cleaning solution remaining on the photomask 10, and the deionized water with CO2 can eliminate the electrostatic effect to avoid the electrostatic effect from affecting the patterns on the photomask 10.

[0082] Correspondingly, the application also provides a device for removing the residual glue of the protective film of a photomask.

[0083] In combination with reference Figures 1 to 3 , the device comprises an auxiliary plate 20, the auxiliary plate 20 is arranged on the photomask 10, the auxiliary plate 20 is provided with a hollow part 21, and the hollow part 21 exposes the residual glue 11 on the photomask 10; and a wiping tool (not shown in the figure) is arranged for wiping the residual glue 11 exposed on the photomask 10.

[0084] The wiping tool comprises a cotton swab, cotton cloth and other wiping tools, and the cotton swab, cotton cloth and other tools can avoid scratches on the surface of the photomask 10.

[0085] In combination with reference Figure 4 , in the embodiment, the auxiliary plate 20 comprises opposite first and second surfaces 22 and 23, the first surface 22 is opposite to the photomask 10 when the auxiliary plate 20 covers the photomask 10, and the hollow part 21 penetrates the auxiliary plate 20 along the direction from the first surface 22 to the second surface 23.

[0086] In the embodiment, the side wall 211 of the hollow part 21 is perpendicular to the first and second surfaces 22 and 23 of the auxiliary plate 20.

[0087] In combination with reference Figure 5 , Figure 5 and Figure 4 , in another embodiment, the side wall 211 of the hollow part 21 has an included angle between the first and second surfaces 22 and 23 of the auxiliary plate 20, and the opening area of the hollow part 21 on the first surface 22 side is smaller than the opening area on the second surface 23 side.

[0088] Preferably, the included angle between the side wall 211 of the hollow part 21 and the first surface 22 of the auxiliary plate 20 is 45°.

[0089] In the embodiment, the auxiliary plate 20 further comprises a connecting part 26, which is arranged at the four corners of the hollow part 21 on the side of the second surface 23.

[0090] In the embodiment, the auxiliary plate 20 further comprises a supporting part 27, which is arranged on the side of the first surface 22 of the auxiliary plate 20. The supporting part 27 can make the auxiliary plate 20 and the photomask 10 have a gap when the auxiliary plate 20 covers the photomask 10, so as to avoid the direct contact between the first surface 22 and the photomask 10, and prevent the damage to the photolithography pattern.

[0091] In the embodiment, the supporting part 27 is arranged at the four corners of the auxiliary plate 20. In other embodiments, the supporting part 27 can also be arranged at other positions which do not affect the photolithography pattern.

[0092] In the embodiment, the material of the auxiliary plate 20 comprises polytetrafluoroethylene. The polytetrafluoroethylene material has high stability, can be repeatedly used, and will not fall off and cause the pollution of the photomask during use. When the polytetrafluoroethylene material contacts the photomask, no scratch or other damage will be formed on the photomask. The polytetrafluoroethylene material also has the characteristics of easy processing, which facilitates the processing and forming of the hollow part 21.

[0093] In other embodiments, the material of the auxiliary plate 20 can also be polypropylene fluoride and other materials with high stability.

[0094] The thickness of the auxiliary plate 20 ranges from 5mm to 10mm. If the thickness of the auxiliary plate 20 is too thin, it is not conducive to the processing of the hollow part on the auxiliary plate 20. If the thickness of the auxiliary plate 20 is too thick, it is not easy to contact the residual glue when the residual glue is removed by using the hollow part, which causes the inconvenience of removing the residual glue.

[0095] It should be noted that the thickness of the auxiliary plate 20 in the embodiment of the present application is represented as the vertical distance between the first surface 22 and the second surface 23.

[0096] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be defined by the scope defined in the claims.

Claims

1. An apparatus for removing residual adhesive from a photomask protective film, characterized in that, include: An auxiliary plate is disposed on a photomask and has a cutout portion that exposes residual adhesive from the protective film on the photomask. A wiping tool for wiping away the residual adhesive exposed in the cutout.

2. The apparatus for removing residual adhesive from photomask protective film as described in claim 1, characterized in that, The auxiliary plate includes a first surface and a second surface opposite to each other, the first surface being opposite to the photomask, and the cutout portion penetrating the auxiliary plate along the direction from the first surface to the second surface.

3. The apparatus for removing residual adhesive from photomask protective film as described in claim 2, characterized in that, The sidewall of the hollowed-out portion is perpendicular to the first and second surfaces of the auxiliary plate.

4. The apparatus for removing residual adhesive from photomask protective film as described in claim 2, characterized in that, The sidewall of the hollow part has an angle with the first and second surfaces of the auxiliary plate, and the opening area of ​​the hollow part on the first surface is smaller than the opening area on the second surface.

5. The apparatus for removing residual adhesive from photomask protective film as described in claim 1, characterized in that, The auxiliary plate is made of polytetrafluoroethylene or polypropylene fluoroethylene.

6. The apparatus for removing residual adhesive from photomask protective film as described in claim 1, characterized in that, The thickness of the auxiliary plate is 5mm to 10mm.

7. A method for removing residual adhesive from a photomask protective film, characterized in that, include: Remove the protective film on the photomask to expose the residual adhesive of the protective film; The photomask is placed on a heating device to heat the residual adhesive on the photomask; An auxiliary plate is provided, wherein the auxiliary plate is provided with a cutout portion, the cutout portion being matched with the shape and size of the protective film; The auxiliary plate is placed over the photomask, and the cutouts expose the residual adhesive on the photomask. Remove the residual adhesive exposed in the cutout.

8. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, The residual adhesive is heated at a temperature of 40℃ to 50℃ for a duration of 5 min to 10 min.

9. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, The auxiliary plate is made of polytetrafluoroethylene or polypropylene fluoroethylene.

10. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, The thickness of the auxiliary plate is 5mm to 10mm.

11. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, The auxiliary plate includes a first surface and a second surface opposite to each other. When the auxiliary plate covers the photomask, the first surface is opposite to the photomask, and the cutout portion penetrates the auxiliary plate along the direction from the first surface to the second surface.

12. The method for removing residual adhesive from a photomask protective film as described in claim 11, characterized in that, The sidewall of the hollowed-out portion is perpendicular to the first and second surfaces of the auxiliary plate.

13. The method for removing residual adhesive from a photomask protective film as described in claim 11, characterized in that, The sidewall of the hollow part has an angle with the first and second surfaces of the auxiliary plate, and the opening area of ​​the hollow part on the first surface is smaller than the opening area on the second surface.

14. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, The method for removing the residual adhesive exposed in the cutout portion includes: using a wiping tool dipped in wiping liquid to wipe away the residual adhesive exposed in the cutout portion.

15. The method for removing residual adhesive from a photomask protective film as described in claim 14, characterized in that, The wiping solution includes acetone solution or tetrahydrofuran solution.

16. The method for removing residual adhesive from a photomask protective film as described in claim 7, characterized in that, After wiping away the residual adhesive exposed by the cutout, the process also includes cleaning the photomask.

17. The method for removing residual adhesive from a photomask protective film as described in claim 16, characterized in that, The step of cleaning the photomask includes: cleaning the photomask for the first time with a first cleaning solution; and cleaning the photomask for the second time with a second cleaning solution.

18. The method for removing residual adhesive from a photomask protective film as described in claim 17, characterized in that, The first cleaning solution includes a sulfuric acid solution; the second cleaning solution includes a mixed solution of sulfuric acid and hydrogen peroxide.

19. The method for removing residual adhesive from a photomask protective film as described in claim 17, characterized in that, After the second cleaning, the process also includes: removing the first cleaning solution and the second cleaning solution remaining on the photomask, and performing ultrasonic cleaning on the photomask.

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