Boss mask and manufacturing method thereof

Abstract

The invention provides a boss mask and a manufacturing method thereof. The method comprises the following steps: providing a substrate; depositing and forming a chromium film on the substrate; patterning the chromium film to form a first mask pattern; and removing at least part of the chromium film in the marginal area, and thinning the substrate in the marginal area. Compared with a traditional mask plate manufacturing method, the mask plate designed by adopting the scheme has the advantages that a gap between the mask plate and a wafer can be effectively reduced through the innovative design of removing a chromium film in an edge region, thinning a substrate in the edge region and adding a boss on the mask plate, so that the focal length is reduced, the resolution is improved, and the imaging quality is effectively improved; besides, as the surface type difference between the wafer and the mask possibly reaches the magnitude of more than 10 microns, the resolution of the proximity contact type photoetching equipment can only be about 1.5 microns, but the problem is solved by the design through the boss, the application field of the proximity contact type photoetching equipment is greatly expanded, and the replacement cost of the equipment is reduced.

Description

Technical Field

[0001] The present application relates to the field of photolithography technology, and in particular to a boss mask and a method for manufacturing the same. Background Art

[0002] With the rapid development of Micro-Electro Mechanical System (MEMS) technology, its key physical dimensions have been reduced to sub-micron levels, which puts higher requirements on photolithography processing technology.

[0003] Although advanced ultraviolet lithography and deep ultraviolet lithography (DUV) lithography equipment can provide higher processing accuracy, their high cost, complex operation and low flexibility make these devices not advantageous in the early development stage of MEMS devices. Traditional proximity contact lithography equipment has limitations in processing capabilities and is difficult to meet the current requirements of high precision and small size of MEMS devices. Therefore, how to use existing proximity contact lithography equipment to achieve sub-micron scale processing without significantly increasing costs has become a problem that needs to be solved urgently.

[0004] In addition, the contact problem between the mask and the wafer also needs to be solved. Since the surface difference between the wafer and the mask may reach more than 10μm, the resolution of the near-contact lithography equipment can only be around 1.5μm, which directly limits the resolution of the near-contact lithography equipment. Summary of the invention

[0005] In order to at least overcome the above-mentioned deficiencies in the prior art, the object of the present application is to provide a method for manufacturing a boss mask, the method comprising:

[0006] providing a substrate;

[0007] Depositing a chromium film on the substrate;

[0008] patterning the chromium film to form a first mask pattern;

[0009] The chromium film is removed from at least a portion of the edge region, and the substrate in the edge region is thinned.

[0010] In a possible implementation manner, the step of patterning the chromium film to form a first mask pattern includes:

[0011] spin coating an electron beam gel layer on the chromium film;

[0012] Performing laser direct writing, exposure and development processing on the electron beam gel layer to form a first etching stop layer;

[0013] The chromium film is etched under the blocking of the first etch stop layer to form the first mask pattern.

[0014] In a possible implementation, the step of removing the chromium film in at least a portion of the edge region and thinning the substrate in the edge region includes:

[0015] Spin coating a negative photoresist layer on the chromium film;

[0016] Processing the negative photoresist layer using a photolithography mask to form a second etching stop layer;

[0017] etching the chromium film under the blocking of the second etching blocking layer to form a second mask pattern;

[0018] The substrate in the edge area is thinned.

[0019] In a possible implementation, the step of spin coating a negative photoresist layer on the chromium film includes:

[0020] 40 μm of negative photoresist was spin coated on the chromium film.

[0021] In a possible implementation, the step of using a photolithography mask to process the negative photoresist layer to form the second etch stop layer includes:

[0022] The chromium film is exposed, post-baked and developed to form a second etching stop layer.

[0023] In a possible implementation, the step of etching the chromium film under the blocking of the second etch stop layer to form the second mask pattern includes:

[0024] The chromium film in the unexposed area is wet-etched to form the second mask pattern.

[0025] In a possible implementation manner, the step of thinning the substrate in the edge area includes:

[0026] The substrate in the edge region is dry-etched to a depth of 10 μm to 20 μm.

[0027] In a possible implementation manner, after the step of removing the chromium film in at least a portion of the edge region and thinning the substrate in the edge region, the method further includes:

[0028] The negative photoresist is stripped using oxygen plasma.

[0029] The embodiment of the present application further provides a boss mask, which is made using any of the above-mentioned boss mask making methods, including:

[0030] A substrate, the substrate comprising a first area and a second area, the first area is higher than the second area, and the first area is surrounded by the second area;

[0031] A chromium film is covered on the first area of ​​the substrate, and a first mask pattern is arranged on the chromium film.

[0032] In a possible implementation manner, the height of the first region is a first height, the height of the second region is a second height, and the difference between the first height and the second height is 10 μm-20 μm.

[0033] Based on any of the above aspects, the boss mask and its manufacturing method provided in the embodiments of the present application, compared with the traditional mask manufacturing method, the mask designed by the present scheme removes the chrome film in the edge area and thins the substrate in the edge area, and adds a boss on the mask. This innovative design can effectively reduce the gap between the mask and the wafer, thereby reducing the focal length, improving the resolution, and effectively improving the imaging quality; in addition, since the surface difference between the wafer and the mask may reach the order of 10μm or more, the resolution of the near-contact lithography equipment can only be about 1.5μm, and the present design improves this problem through the boss, greatly expanding the application field of the near-contact lithography machine and reducing the replacement cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 One of the flow charts of the method for manufacturing a boss mask provided in this embodiment;

[0036] Figure 2 One of the structural schematic diagrams of the boss mask provided in this embodiment;

[0037] Figure 3 The second structural schematic diagram of the boss mask provided in this embodiment;

[0038] Figure 4 The third structural schematic diagram of the boss mask provided in this embodiment;

[0039] Figure 5A schematic diagram of the sub-step flow chart of step S300 provided in this embodiment;

[0040] Figure 6 The fourth structural schematic diagram of the boss mask provided in this embodiment;

[0041] Figure 7 A schematic diagram of the sub-step flow chart of step S400 provided in this embodiment;

[0042] Figure 8 A fifth structural schematic diagram of the boss mask provided in this embodiment;

[0043] Fig. 9 The sixth structural schematic diagram of the boss mask provided in this embodiment;

[0044] Fig.10 The seventh structural schematic diagram of the boss mask provided in this embodiment;

[0045] Fig.11 A second flow chart of the method for manufacturing a boss mask provided in this embodiment;

[0046] Fig.12 A top view of the boss mask provided in this embodiment;

[0047] Fig.13 A comparison diagram of the boss mask provided in this embodiment and a conventional mask when in use.

[0048] Icons: boss mask-10; conventional mask-20; substrate-100; first region-110; second region-120; chrome film-200; first mask pattern-210; second mask pattern-220; first etch stop layer-300; second etch stop layer-400; wafer-900. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0051] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0052] In the description of this application, it should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0053] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0054] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] It should be noted that, in the absence of conflict, different features in the embodiments of the present application may be combined with each other.

[0056] The inventors have found that, with regard to mask lithography technology, after rapid development in recent years, it mainly includes several categories such as near-contact lithography and step-and-projection lithography. Among them, step-and-projection lithography can have a very high resolution, up to several nanometers, depending on the light source, but its equipment structure is complex and expensive, resulting in high R&D costs for micro-electromechanical systems (MEMS) devices; near-contact lithography equipment has a relatively simple structure, convenient operation, relatively low equipment cost, and meets the investment in R&D costs of MEMS devices, and can conveniently and flexibly carry out device R&D and manufacturing, and has a large cost advantage for the application of MEMS devices. However, since the difference in the surface shape of wafer 900 and mask may reach more than 10μm, the resolution of near-contact lithography equipment can only be around 1.5μm, which directly limits the resolution of near-contact lithography equipment.

[0057] In view of this, this embodiment provides a solution that can solve the above-mentioned problem, and the solution provided by this embodiment is described in detail below.

[0058] The present application provides a method for manufacturing a convex platform mask 10, please refer to Figure 1 , the method comprising:

[0059] In step S100 , a substrate 100 is provided.

[0060] Specifically, in this step, it is first necessary to select a suitable material for the substrate 100. The substrate 100 material should have good mechanical properties, thermal stability and chemical stability so as to remain stable during subsequent processes. For example, the substrate 100 material can be quartz.

[0061] Step S200, please refer to Figure 2 , a chromium film 200 is deposited on the substrate 100 .

[0062] Specifically, in this step, a layer of chromium film 200 is deposited on the surface of the substrate 100 by using methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD).

[0063] In the mask, the chromium film 200 acts as a conductive layer, which can guide the electron beam during electron beam lithography or serve as a path for current during ion beam etching. At the same time, the chromium film 200 is also a barrier layer, which can block ultraviolet light or electron beam from penetrating the mask, thereby protecting the substrate 100 from radiation damage. Thanks to the good etching characteristics and pattern transfer ability of the chromium film 200, the chromium film 200 also acts as a pattern transfer layer, and the pattern on it will be accurately transferred to the photoresist layer below. In addition, the chromium film 200 has high chemical stability and can resist chemical corrosion during lithography and etching, ensuring that the pattern on the mask remains clear after multiple uses. The good adhesion between the chromium film 200 and the substrate 100 material ensures that the pattern on the mask will not fall off or deform in subsequent process steps.

[0064] Step S300, please refer to Figure 3 , the chromium film 200 is patterned to form a first mask pattern 210 .

[0065] Specifically, in this step, the chrome film 200 is patterned by using direct writing technology to form a first mask pattern 210. The first mask pattern 210 determines the range and shape of the pattern transfer in the subsequent process.

[0066] Step S400, please refer to Figure 4 , remove the chromium film 200 in at least a portion of the edge area, and thin the substrate 100 in the edge area.

[0067] Specifically, in this step, wet etching, dry etching or the like is used to remove the chromium film 200 in the edge region and thin the substrate 100 to form the boss required in this embodiment.

[0068] For some possible implementations, please refer to Figure 5 , the step S300 comprises:

[0069] Step S310 , spin coating an electron beam gel layer on the chromium film 200 .

[0070] Specifically, first ensure that the surface of the chromium film 200 is clean and dust-free by ultrasonic cleaning, nitrogen purging or wiping with an organic solvent. Then fix the chromium film 200 on a spin coater and select an electron beam glue suitable for electron beam lithography. Turn on the spin coater, drop an appropriate amount of electron beam glue on the center of the chromium film 200, and then spin coat at a set speed and acceleration. The choice of speed and acceleration depends on the thickness of the required glue layer. During the spin coating process, the glue layer will be evenly distributed on the surface of the chromium film 200. After spin coating, the chromium film 200 is placed in an oven and baked at a certain temperature to remove the solvent in the glue layer and solidify the glue layer. The baking time and temperature are determined according to the specific model and thickness of the glue.

[0071] Step S320, please refer to Figure 6 , the electron beam gel layer is subjected to laser direct writing and exposure and development processing to form a first etching stop layer 300.

[0072] Specifically, the cured electron beam glue layer is patterned using an electron beam lithography machine or a laser direct writer. Laser direct writing is a direct writing technology that can draw the desired pattern on the glue layer more accurately than using a photolithography mask, but it is more expensive. After laser direct writing, the chromium film 200 is exposed to ultraviolet light and the pattern is transferred through a photomask. During the exposure process, the photosensitive electron beam glue layer undergoes chemical changes in the illuminated area and becomes soluble in a developer. Finally, the exposed chromium film 200 is placed in a developer, which is usually warm water or an alkaline solution of a specific concentration. During the development process, the photosensitive glue layer in the exposed area is dissolved, and the glue layer in the unexposed area remains unchanged, thereby forming the desired pattern.

[0073] Step S330, please refer to Figure 3 , the chromium film 200 is etched under the blocking of the first etch stop layer 300 to form the first mask pattern 210 .

[0074] Specifically, the developed chromium film 200 is placed in an etcher to ensure that the sample is fixed in place. Then, the chromium film 200 is etched using a technique such as plasma etching, ion beam etching or wet etching to form a first mask pattern 210. Since the electron beam glue layer serves as the first etching barrier layer 300, it protects the area on the chromium film 200 that does not need to be etched. After etching is completed, the remaining first etching barrier layer 300 is removed by dissolving the electron beam glue in an organic solvent.

[0075] For some possible implementations, please refer to Figure 7 , the step S400 includes:

[0076] Step S410 , spin coating a negative photoresist layer on the chromium film 200 .

[0077] Specifically, first ensure that the surface of the chrome film 200 is clean and dust-free. Then fix the chrome film 200 on a spin coater and select a suitable negative photoresist. Drop an appropriate amount of photoresist on the center of the chrome film 200, start the spin coater, and rotate it at a set speed and acceleration to evenly distribute the photoresist on the surface of the chrome film 200. The parameters of the spin coating depend on the thickness of the required glue layer. After spin coating, the chrome film 200 is placed in an oven for pre-baking to remove the solvent in the photoresist and solidify the glue layer. The temperature and time of the pre-baking are determined according to the specific model and thickness of the photoresist.

[0078] Step S420, please refer to Figure 8 , a negative photoresist layer is processed using a photolithography mask to form a second etch stop layer 400 .

[0079] In this embodiment, a photolithography mask is selected to process negative photoresist because the exposure speed of the photolithography mask is fast and high precision is not required for etching the second mask pattern 220. The pattern on the selected photolithography mask includes a rectangle, and after etching, the first mask pattern 210 needs to be disposed within the second mask pattern 220 without affecting the integrity of the first mask pattern 210.

[0080] Step S430, please refer to Fig. 9 , the chromium film 200 is etched under the blocking of the second etch stop layer 400 to form a second mask pattern 220 .

[0081] In this embodiment, the second mask pattern 220 is the area of ​​the boss formed by the boss mask 10 in the present application.

[0082] Step S440, please refer to Fig.10 , the substrate 100 in the edge area is thinned.

[0083] In this embodiment, in order to form a protrusion in the boss area of ​​the boss mask 10 of the present application, the substrate 100 in the edge area is thinned.

[0084] In some possible implementations, step S410 includes:

[0085] A 40 μm negative photoresist is spin-coated on the chromium film 200 .

[0086] For example, the operator first cleans the chromium film 200 with deionized water and isopropyl alcohol, and then purges it with nitrogen to keep the surface dust-free. Next, the chromium film 200 is fixed on the spin coater, and an appropriate amount of negative photoresist is added, and spin-coated at a rotation speed of 3000 rpm and an acceleration of 400 rpm / s to form a 40 μm thick glue layer. Finally, the spin-coated chromium film 200 is placed in a 90°C oven for pre-baking for 5 minutes to remove the solvent and solidify the glue layer, in preparation for the subsequent photolithography steps.

[0087] For some possible implementations, please refer to Figure 8 , the step S420 comprises:

[0088] The chromium film 200 is exposed, post-baked and developed to form a second etching stopper layer 400 .

[0089] Specifically, the pre-baked chromium film 200 is placed in a photolithography machine, covered with a photolithography mask, and exposed using a light source of an appropriate wavelength. The desired pattern is designed on the photolithography mask. After exposure, the chromium film 200 is baked to further solidify the photoresist and improve its resistance to subsequent developer. The exposed chromium film 200 is placed in a developer, and the negative photoresist becomes insoluble in the developer in the exposed area, while the unexposed area is dissolved. Through the development process, the photoresist in the exposed area is retained to form a second etching stopper 400.

[0090] For some possible implementations, please refer to Fig. 9 , the step S430 comprises:

[0091] The chromium film 200 in the unexposed area is wet-etched to form the second mask pattern 220 .

[0092] For example, after forming the second etching stopper layer 400, the chromium film 200 is fixed in a wet etching machine, ensuring that the sample position is correct, and then wet etching is performed to form a second mask pattern 220. A suitable etching solution is selected, and the etching parameters are adjusted according to the required pattern size and depth. The chromium film 200 is immersed in the etching solution, and the solution etches away the chromium area not covered by the photoresist. Finally, the chromium film 200 in the unexposed area is etched away to form a second mask pattern 220.

[0093] For some possible implementations, please refer to Fig.10 , the step S440 comprises:

[0094] The substrate 100 in the edge region is dry-etched to a depth of 10 μm-20 μm.

[0095] Specifically, after the edge area to be thinned is determined and marked, dry etching is selected as the thinning method in this embodiment because dry etching has high precision and controllability. For example, the marked substrate 100 is placed in a plasma etcher, and the etching parameters are adjusted to match the required etching depth. During the etching process, an inert gas such as argon is used to generate plasma in a vacuum environment, and the active particles in the plasma, such as chlorine atoms or fluorine atoms, react chemically with the substrate 100 material to achieve material removal. During the etching process, the etching rate and time are strictly controlled to ensure that the etching depth is within the range of 10μm-20μm. After the etching is completed, the plasma source is turned off, and the substrate 100 is removed from the etcher for a thorough cleaning step to remove any etching byproducts or damaged layers that may remain.

[0096] For some possible implementations, please refer to Fig.11 After S400, the method further includes:

[0097] Step S500, please refer to Figure 4 , using oxygen plasma to strip the negative photoresist.

[0098] In this embodiment, in order to remove the photoresist remaining on the substrate 100 after photolithography, oxygen plasma is used to perform a degumming treatment on the second etch stop layer 400. Oxygen plasma degumming can achieve a more thorough removal process, effectively avoid residual substances, thereby ensuring the cleanliness of the mask and not affecting its subsequent use effect.

[0099] The present application also provides a convex platform mask 10, please refer to Figure 4 , made using any of the aforementioned methods for making a boss mask 10, comprising:

[0100] A substrate 100, wherein the substrate 100 includes a first area 110 and a second area 120, wherein the first area 110 is higher than the second area 120, and the first area 110 is surrounded by the second area 120; a chrome film 200 covering the first area 110 of the substrate 100, wherein a first mask pattern 210 is arranged on the chrome film 200.

[0101] In the convex platform mask 10 provided in this embodiment, please refer to Fig.12 The substrate 100 is composed of two different regions, the first region 110 is a raised central region, and the second region 120 is lower and surrounds the first region 110. The chromium film 200 is deposited and patterned on the first region 110 to ensure that the raised region where the chromium film 200 is located can be properly aligned and contact the wafer 900 or other substrates 100 during the microelectronics manufacturing process, while avoiding unnecessary contact or contamination. The formation of such a boss structure is beneficial to improving the accuracy and efficiency of the manufacturing process, reducing edge defects, and enhancing the mechanical stability of the mask.

[0102] In some possible implementations, the height of the first region 110 is a first height, the height of the second region 120 is a second height, and the difference between the first height and the second height is 10 μm-20 μm.

[0103] The convex platform mask 10 provided in this embodiment is shown in FIG. Fig.13 Compared with the conventional mask 20, when using a near-contact lithography device, the gap between the mask and the wafer 900 can be effectively reduced, thereby reducing the focal length, improving the resolution, and effectively improving the imaging quality; and there is no need to replace the equipment, thereby reducing costs.

[0104] In summary, the present application provides a boss mask 10 and a manufacturing method thereof, the method comprising: providing a substrate 100; depositing a chrome film 200 on the substrate 100; patterning the chrome film 200 to form a first mask pattern 210; removing at least part of the chrome film 200 in the edge region, and thinning the substrate 100 in the edge region. Compared with the conventional mask manufacturing method, the mask designed by the present solution, by removing the chrome film 200 in the edge region and thinning the substrate 100 in the edge region, adds a boss to the mask, which is an innovative design, can effectively reduce the gap between the mask and the wafer 900, thereby reducing the focal length, improving the resolution, and effectively improving the imaging quality; in addition, since the surface difference between the wafer 900 and the mask may reach the order of 10 μm or more, the resolution of the near-contact lithography equipment can only be about 1.5 μm, and the present design improves this problem through the boss, greatly expanding the application field of the near-contact lithography machine and reducing the replacement cost of the equipment.

[0105] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0106] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a boss mask, characterized in that: The method comprises: providing a substrate; Depositing a chromium film on the substrate; patterning the chromium film to form a first mask pattern; The chromium film is removed from at least a portion of the edge region, and the substrate in the edge region is thinned.

2. The method for manufacturing a boss mask according to claim 1, characterized in that: The step of patterning the chromium film to form a first mask pattern comprises: spin coating an electron beam gel layer on the chromium film; Performing laser direct writing, exposure and development processing on the electron beam gel layer to form a first etching stop layer; The chromium film is etched under the blocking of the first etch stop layer to form the first mask pattern.

3. The method for manufacturing a boss mask according to claim 1, characterized in that: The step of removing at least a portion of the chromium film in the edge region and thinning the substrate in the edge region comprises: Spin coating a negative photoresist layer on the chromium film; Processing the negative photoresist layer using a photolithography mask to form a second etching stop layer; etching the chromium film under the blocking of the second etching blocking layer to form a second mask pattern; The substrate in the edge area is thinned.

4. The method for manufacturing a boss mask according to claim 3, characterized in that: The step of spin coating a negative photoresist layer on the chromium film comprises: 40 μm of negative photoresist was spin coated on the chromium film.

5. The method for manufacturing a boss mask according to claim 3, characterized in that: The step of using a photolithography mask to process the negative photoresist layer to form a second etch stop layer comprises: The chromium film is exposed, post-baked and developed to form a second etching stop layer.

6. The method for manufacturing a boss mask according to claim 3, characterized in that: The step of etching the chromium film under the blocking of the second etching stop layer to form the second mask pattern comprises: The chromium film in the unexposed area is wet-etched to form the second mask pattern.

7. The method for manufacturing a boss mask according to claim 3, characterized in that: The step of thinning the substrate in the edge area comprises: The substrate in the edge region is dry-etched to a depth of 10 μm to 20 μm.

8. The method for manufacturing a boss mask according to claim 1, characterized in that: After the step of removing at least a portion of the chromium film in the edge region and thinning the substrate in the edge region, the method further comprises: The negative photoresist is stripped using oxygen plasma.

9. A boss mask, made using the boss mask manufacturing method according to any one of claims 1 to 8, characterized in that: include: A substrate, the substrate comprising a first area and a second area, the first area is higher than the second area, and the first area is surrounded by the second area; A chromium film is covered on the first area of ​​the substrate, and a first mask pattern is arranged on the chromium film.

10. The boss mask according to claim 9, characterized in that: The height of the first region is a first height, the height of the second region is a second height, and the difference between the first height and the second height is 10 μm-20 μm.

Images