Mask and preparation method thereof, and preparation method of semiconductor device

Abstract

The invention provides a mask plate which comprises a light-transmitting substrate, a light shielding layer and at least one first opening, the light shielding layer is located on the light-transmitting substrate, the center area of the first opening penetrates through the light shielding layer, and the edge area of the first opening penetrates through the light shielding layer and extends into the light-transmitting substrate. According to the mask plate, the first grooves with the larger inclination angles of the side walls can be formed in the semiconductor front layer structure, the problem that the first grooves are prone to being closed up in advance or the closing-up difference between the first grooves is large is avoided, parameters of the photoetching technology do not need to be adjusted, and other performance of a device cannot be affected. Correspondingly, the invention also provides a preparation method of the mask and a preparation method of the semiconductor device.

Description

Technical Field

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

[0002] A photomask, also known as a photomask, photomask, or photolithography mask, is a graphic master used in the photolithography process in the manufacture of microelectronics and integrated optoelectronics. The mask pattern is formed on a transparent substrate by an opaque shading layer, and the pattern is transferred to the wafer through exposure.

[0003] Typically, there are several openings in the light-shielding layer, and patterns are formed in the light-shielding layer through the openings. The openings penetrate the light-shielding layer and expose the light-transmitting substrate. The patterns are transferred to the wafer through exposure, so that grooves corresponding to the openings can be generated in the wafer. Due to process limitations, the side walls of the grooves may not be vertical, but have a certain inclination angle. In some cases, the inclination angles of the side walls of some grooves need to be designed to be larger, so as to avoid problems such as premature closing of the grooves or large differences in closing between grooves when certain material layers are subsequently formed in the grooves. Although the inclination angle of the side walls of the grooves can be adjusted by adjusting the lithography parameters, this will simultaneously adjust the inclination angles of the side walls of all grooves, which may affect other performance of the device. Summary of the invention

[0004] The purpose of the present application is to provide a mask and a method for preparing the same, as well as a method for preparing a semiconductor device, so as to solve the problem of affecting other performances of the device when adjusting the sidewall morphology of a portion of a groove.

[0005] In order to achieve the above object, the present application provides a mask, comprising:

[0006] Light-transmitting substrate;

[0007] A light shielding layer, located on the light-transmitting substrate;

[0008] At least one first opening, wherein a central area of ​​the first opening penetrates the light shielding layer, and an edge area of ​​the first opening penetrates the light shielding layer and extends into the light-transmitting substrate.

[0009] Optionally, the lateral width of the edge region of the first opening is equal to tanθ*h / k, wherein θ is a predetermined adjustment angle, h is an etching depth, and k is a ratio of a graphic size of the mask to an etching product.

[0010] Optionally, the edge region of the first opening extends into the light-transmitting substrate to a depth equal to λ / 2(n-1), wherein λ is a photolithography wavelength and n is a refractive index of the light-transmitting substrate.

[0011] Optionally, also include:

[0012] At least one second opening, the second switch passes through the light shielding layer.

[0013] Optionally, the first opening and the second opening are used to form a first groove and a second groove on a semiconductor front layer structure, respectively, and the inclination angle of the side wall of the first groove is greater than the inclination angle of the side wall of the second groove.

[0014] Optionally, the first groove and the second groove are respectively located in a scribing area and a normal unit area of ​​the semiconductor front layer structure, and the first groove is an alignment groove in the scribing area.

[0015] Optionally, a lateral width of the first groove is greater than a lateral width of the second groove.

[0016] Optionally, the first groove and the second groove are both located in the scribe area or are both located in the normal cell area.

[0017] The present application also provides a method for preparing a mask, comprising:

[0018] providing a light-transmitting substrate;

[0019] forming a light shielding layer on the light-transmitting substrate;

[0020] Etching a portion of the depth of the light shielding layer and the light-transmitting substrate to form at least one annular etching area;

[0021] The light shielding layer in the annular etched area is removed by etching to form at least one first opening, wherein a central area of ​​the first opening penetrates the light shielding layer, and an edge area of ​​the first opening penetrates the light shielding layer and extends into the light-transmitting substrate.

[0022] Optionally, the lateral width of the annular surface of the annular etching area is equal to tanθ*h / k, wherein θ is a predetermined adjustment angle, h is an etching depth, and k is a ratio of a graphic size of the mask to an etching product.

[0023] Optionally, the etching depth of the light-transmitting substrate is equal to λ / 2(n-1), wherein λ is the photolithography wavelength and n is the refractive index of the light-transmitting substrate.

[0024] Optionally, when etching is performed to remove the light shielding layer in the annular etching area, the light shielding layer outside the annular etching area is also etched to form at least one second opening, wherein the second opening penetrates the light shielding layer.

[0025] The present application also provides a method for preparing a semiconductor device, comprising:

[0026] Providing a semiconductor front layer structure;

[0027] forming a first photoresist layer on the semiconductor front layer structure;

[0028] Using the mask to expose and develop the first photoresist layer to form at least one third opening in the first photoresist layer, wherein the central area of ​​the third opening penetrates the first photoresist layer, and the edge area of ​​the third opening extends from the surface of the first photoresist layer to the inside of the first photoresist layer;

[0029] The semiconductor front layer structure is etched downward along the third opening to form a first groove in the semiconductor front layer structure.

[0030] Optionally, when the first photoresist layer is exposed and developed using the mask, at least one fourth opening is formed in the first photoresist layer, and the fourth opening penetrates the first photoresist layer;

[0031] When the semiconductor front layer structure is etched downward along the third opening, the semiconductor front layer structure is also etched downward along the fourth opening to form a second groove in the semiconductor front layer structure.

[0032] Optionally, an inclination angle of the side wall of the first groove is greater than an inclination angle of the side wall of the second groove; and / or a lateral width of the first groove is greater than a lateral width of the second groove.

[0033] The present application provides a mask, including a light-transmitting substrate, a light-shielding layer and at least one first opening, wherein the light-shielding layer is located on the light-transmitting substrate, the central area of ​​the first opening penetrates the light-shielding layer, and the edge area of ​​the first opening penetrates the light-shielding layer and extends into the light-transmitting substrate. The mask in the present application can form a first groove with a larger sidewall inclination angle in the semiconductor front layer structure, avoiding the problem that the first groove is easy to close prematurely or the closing difference between the first grooves is large, without adjusting the parameters of the photolithography process, and will not affect other performances of the device. Accordingly, the present application also provides a method for preparing a mask and a method for preparing a semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart of a method for preparing a mask provided in an embodiment of the present application;

[0035] Figure 2 to Figure 7 A schematic diagram of the structures corresponding to the corresponding steps of the method for preparing a mask provided in an embodiment of the present application;

[0036] Figure 8 A light intensity distribution diagram of the mask provided in an embodiment of the present application on a focal plane during exposure;

[0037] Fig. 9 A flowchart of a method for preparing a semiconductor device provided in an embodiment of the present application;

[0038] Figure 10 to Figure 13 A schematic diagram of structures corresponding to corresponding steps of a method for preparing a semiconductor device provided in an embodiment of the present application;

[0039] Wherein, the accompanying drawings are marked as follows:

[0040] 100 - light-transmitting substrate; 200 - light-shielding layer; 300 - second photoresist layer; 300a - annular etching area; 300b - conventional etching area; 310 - first opening; 320 - second opening; 400 - semiconductor front layer structure; 500 - first photoresist layer; 510 - third opening; 520 - fourth opening; 610 - first groove; 620 - second groove. DETAILED DESCRIPTION

[0041] The specific implementation of the present application will be described in more detail below in conjunction with the schematic diagram. Based on the following description, the advantages and features of the present application will become clearer. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present application.

[0042] Figure 7 The schematic diagram of the structure of the mask provided in this embodiment. Figure 7 As shown, the mask includes a light-transmitting substrate 100 , a light-shielding layer 200 , at least one first opening 310 and at least one second opening 320 . Figure 7 Schematically showing a first opening 310 and a second opening 320. Fig.13 As shown, when a semiconductor front layer structure 400 is exposed using the mask, the first opening 310 and the second opening 320 are used to form a first groove 610 and a second groove 620 in the semiconductor front layer structure 400, respectively. The semiconductor front layer structure 400 may be a substrate, or a substrate and a single-layer film or a multi-layer film formed on the substrate. The semiconductor front layer structure 400 may also include various functional structures. In short, the semiconductor front layer structure 400 is the sum of all device structures before the first groove 610 is formed. In different devices, the specific composition of the semiconductor front layer structure 400 is different, and will not be described one by one here.

[0043] The light-transmitting substrate 100 may be a resin substrate or a glass substrate. The material of the resin substrate may be film, etc., and the material of the glass substrate may be quartz glass, borosilicate glass, soda-lime glass, etc. The light transmittance of the light-transmitting substrate 100 may be greater than 80%. Generally speaking, the greater the light transmittance of the light-transmitting substrate 100, the better.

[0044] The light shielding layer 200 is located on the light-transmitting substrate 100 and covers part of the surface of the light-transmitting substrate 100. The material of the light shielding layer 200 can generally be a metal material or other opaque material, such as chromium, silicon, tantalum silicide, etc. The light transmittance of the light shielding layer 200 can be less than 10%. Generally speaking, the lower the light transmittance of the light shielding layer 200, the better.

[0045] The first opening 310 has a central area and an edge area surrounding the central area, the central area of ​​the first opening 310 penetrates the light shielding layer 200 and exposes the surface of the light-transmitting substrate 100, and the edge area of ​​the first opening 310 penetrates the light shielding layer 200 and extends into the light-transmitting substrate 100. Alternatively, it can also be considered that the first opening 310 has two parts with different depths, the first part is located in its central area, and the second part is located in its edge area, and the depth of the second part located in the edge area is greater than the depth of the first part located in the central area.

[0046] In some embodiments, the lateral width CD of the edge region of the first opening 310 is equal to tanθ*h / k, where θ is a predetermined adjustment angle, h is an etching depth, and k is a graphic size ratio between the mask and the etching product (such as a wafer). It should be noted that θ can be measured experimentally. For example, a test opening with the same lateral width as the first opening 310 is opened on a test mask, and the test opening only penetrates the light shielding layer 200 of the test mask and exposes the surface of the transparent substrate of the test mask. The test mask is used to form a test groove in a test wafer, and the inclination angle of the side wall of the test groove is measured. θ is the difference between the measured inclination angle and the ideal inclination angle. Of course, the inclination angle can also be actually measured during the production process of the device. That is to say, the value of the lateral width CD of the edge region of the first opening 310 can be obtained by calculating θ. In this way, the inclination angle of the side wall of the first groove 610 can be controlled by controlling the size of the lateral width CD of the edge region of the first opening 310.

[0047] The edge area of ​​the first opening 310 extends into the transparent substrate 100 at a depth t equal to λ / 2(n-1), wherein λ is the photolithography wavelength and n is the refractive index of the transparent substrate 100. At this time, the optical path difference between the edge area and the central area of ​​the first opening 310 is 180°, which can ensure that the light passing through the first opening 310 during exposure is focused on the same focal plane, and the edge of the pattern formed after development is clearer and less rough.

[0048] Furthermore, the second opening 320 penetrates the light shielding layer 200 and exposes the surface of the light-transmitting substrate 100. In this embodiment, the lateral width of the first opening 310 is greater than the lateral width of the second opening 320, so that the lateral width of the first groove 610 is also greater than the lateral width of the second groove 620, but it should not be limited to this. In some embodiments, the lateral width of the first opening 310 can also be smaller than the lateral width of the second opening 320. In this case, the lateral width of the first groove 610 is also less than or equal to the lateral width of the second groove 620.

[0049] In this embodiment, the first groove 610 and the second groove 620 are respectively located in the scribe area and the normal unit area of ​​the semiconductor front layer structure, the first groove 610 is an alignment groove in the scribe area, and the second groove 620 can be a groove for accommodating an isolation structure or a groove for accommodating a plug in the normal unit area. It can be understood that when the first groove 610 is an alignment groove in the scribe area, and the second groove 620 is a groove for accommodating an isolation structure in the normal unit area, after the first groove 610 and the second groove 620 are formed, it is necessary to deposit an isolation material (such as silicon oxide) in the second groove 620, and at this time, the isolation material will be deposited in the first groove 610 synchronously; when the first groove 610 is an alignment groove in the scribe area (a mark for alignment), and the second groove 620 is a groove for accommodating a plug in the normal unit area, after the first groove 610 and the second groove 620 are formed, it is necessary to deposit a conductive material (such as a metal material) in the second groove 620, and at this time, the conductive material will be deposited in the first groove 610 synchronously. Conductive material is deposited in the groove 610; since the lateral width of the first groove 610 is greater than the lateral width of the second groove 620, when the second groove 620 is filled with isolation material or conductive material, the first groove 610 will not be filled with isolation material or conductive material, but if the side wall inclination angle of the first groove 610 is small (relatively vertical), due to the limitation of the deposition process, the first groove 610 is easy to close prematurely, and the difference in closing between the first grooves 610 may also be large, which makes the first groove 610 difficult to identify, and then leads to reduced overlay accuracy. If the lithography parameters are adjusted, the inclination angles of the side walls of the first groove 610 and the second groove 620 will be adjusted together, which may affect other performances of the device.

[0050] Figure 8 The light intensity distribution diagram of the mask provided in this embodiment on the focal plane during exposure. Figure 8As shown, when the semiconductor front layer structure is exposed using the mask, the depth of the second opening 320 is the same everywhere. After the light passes through the second opening 320 to reach the focal plane, the light intensity is Gaussian distributed, and the corresponding position of the focal plane is completely exposed; while the edge area and the central area of ​​the first opening 310 have different depths. During the exposure process, after the light passes through the first opening 310, the edge area and the central area of ​​the first opening 310 have a certain optical path difference. When it finally reaches the focal plane, the light intensity distribution at the corresponding position of the focal plane changes, so that the central area at the corresponding position of the focal plane is completely exposed, while the position of the edge area can only be partially exposed. That is, when the first groove 610 and the second groove 620 are formed in the semiconductor front layer structure 400 using the mask, the inclination angle of the side wall of the first groove 610 will be greater than the inclination angle of the side wall of the first groove 610. When the isolation material or the conductive material is subsequently formed in the first groove 610 and the second groove 620, the problem of the first groove 610 being easily closed in advance or the first grooves 610 having large differences in closing can be avoided, thereby avoiding the first groove 610 from being unrecognizable, without adjusting the parameters of the photolithography process, and without affecting other performance of the device.

[0051] Of course, the first opening 310 and the second opening 320 may also be both located in the scribe area or both located in the normal unit area. In this case, the first groove 610 and the second groove 620 may both be grooves for accommodating plugs or grooves for accommodating isolation structures in the normal unit area, except that the inclination angle of the side wall of the first groove 610 is required to be larger.

[0052] Based on this, this embodiment also provides a method for preparing a mask. Figure 1 The flowchart of the method for preparing the mask provided in this embodiment is as follows: Figure 1 As shown, the method for preparing the mask includes:

[0053] Step S100: providing a light-transmitting substrate 100;

[0054] Step S200: forming a light shielding layer 200 on the light-transmitting substrate 100;

[0055] Step S300: etching a portion of the light shielding layer 200 and the light-transmitting substrate 100 to form at least one annular etched area 300 a;

[0056] Step S400: Etching to remove the light-shielding layer 200 in the annular etching area 300a to form at least one first opening 310, wherein the central area of ​​the first opening 310 penetrates the light-shielding layer 200, and the edge area of ​​the first opening 310 penetrates the light-shielding layer 200 and extends into the transparent substrate 100.

[0057] Figure 2 to Figure 7 The following is a schematic diagram of the structure corresponding to the corresponding steps of the method for preparing the mask provided in this embodiment. Figure 2 to Figure 7 The method for preparing the mask provided in this embodiment is described in detail.

[0058] like Figure 2 As shown, step S100 is performed to provide a light-transmitting substrate 100. The light-transmitting substrate 100 may be a resin substrate or a glass substrate. The material of the resin substrate may be film, etc., and the material of the glass substrate may be quartz glass, borosilicate glass, soda-lime glass, etc. The light transmittance of the light-transmitting substrate 100 may be greater than 80%. Generally speaking, the greater the light transmittance of the light-transmitting substrate 100, the better.

[0059] Please continue reading Figure 2 , perform step S200 to sequentially form a light shielding layer 200 and a second photoresist layer 300 on the light-transmitting substrate 100 , wherein the light shielding layer 200 covers the surface of the light-transmitting substrate 100 , and the second photoresist layer 300 covers the light shielding layer 200 .

[0060] The material of the light shielding layer 200 can generally be a metal material or other opaque material, such as chromium, silicon, tantalum silicide, etc. The light transmittance of the light shielding layer 200 can be less than 10%. Generally speaking, the lower the light transmittance of the light shielding layer 200, the better. In this embodiment, the material of the light shielding layer 200 is chromium, which can be formed on the transparent substrate 100 by evaporation or other processes.

[0061] like Figure 3 As shown, step S300 is performed to expose and develop the second photoresist layer 300, so as to pattern the second photoresist layer 300 to form at least one annular etched area 300a in the second photoresist layer 300, wherein the annular etched area 300a penetrates the second photoresist layer 300 and exposes the light shielding layer 200. Figure 3 Only one annular etched area 300a is schematically shown. In this embodiment, the lateral width of the annular surface of the annular etched area 300a is equal to tanθ*h / k, but it should not be limited thereto.

[0062] like Figure 4As shown, the patterned second photoresist layer 300 is used as a mask to etch the light shielding layer 200 and a portion of the light-transmitting substrate 100 to a depth such that the annular etched area 300a penetrates downward through the light shielding layer 200 and extends into the light-transmitting substrate 100. In this step, the depth of etching the light-transmitting substrate 100 is equal to λ / 2(n-1), but this should not be limited thereto.

[0063] like Figure 5 As shown, the second photoresist layer 300 is exposed and developed again, so as to pattern the second photoresist layer 300 again, remove the second photoresist layer 300 in the annular etching area 300a, and at least one conventional etching area 300b is formed in the second photoresist layer 300, and the conventional etching area 300b can be rectangular or circular. The conventional etching area 300b penetrates the second photoresist layer 300 and exposes the light shielding layer 200, Figure 5 Only one conventional etching area 300b is schematically shown.

[0064] like Figure 6 and Figure 7 As shown, step S400 is performed to etch to remove the light shielding layer 200 in the annular etching area 300a, and at the same time, to remove the light shielding layer 200 exposed in the conventional etching area 300b, and to remove the patterned second photoresist layer 300, and finally form at least one first opening 310 and at least one second opening 320. The edge area of ​​the first opening 310 is the area where the annular etching area 300a is located, the center area of ​​the first opening 310 is the area defined within the inner annular surface of the annular etching area 300a, and the second opening 320 is the area where the conventional etching area 300b is located. Figure 7 It can be seen from the figure that the central area of ​​the first opening 310 penetrates the light shielding layer 200 and exposes the surface of the light-transmitting substrate 100, the edge area of ​​the first opening 310 penetrates the light shielding layer 200 and extends into the light-transmitting substrate 100, and the second opening 320 penetrates the light shielding layer 200 and exposes the surface of the light-transmitting substrate 100. In addition, the lateral width CD of the edge area of ​​the first opening 310 is equal to the lateral width of the annular surface of the annular etched area 300a, CD=tanθ*h / k, and the depth t of the edge area of ​​the first opening 310 extending into the light-transmitting substrate 100 is equal to the etching depth of the light-transmitting substrate 100, t=λ / 2(n-1).

[0065] Based on this, this embodiment also provides a method for preparing a semiconductor device. Fig. 9 A flow chart of a method for preparing a semiconductor device provided in this embodiment, such as Fig. 9As shown, the method for preparing the semiconductor device includes:

[0066] Step S500: providing a semiconductor front layer structure 400;

[0067] Step S600: forming a first photoresist layer 500 on the semiconductor front layer structure 400;

[0068] Step S700: using the mask to expose and develop the first photoresist layer 500 to form at least one third opening 510 in the first photoresist layer 500, wherein the central area of ​​the third opening 510 penetrates the first photoresist layer 500, and the edge area of ​​the third opening 510 extends from the surface of the first photoresist layer 500 to the inside of the first photoresist layer 500;

[0069] Step S800 : etching the semiconductor front layer structure 400 downward along the third opening 510 to form a first groove 610 in the semiconductor front layer structure 400 .

[0070] Figure 10 to Figure 13 The following is a schematic diagram of the structure corresponding to the corresponding steps of the method for preparing a semiconductor device provided in this embodiment. Figure 10 to Figure 13 The method for preparing the semiconductor device provided in this embodiment is described in detail.

[0071] like Fig. 9 As shown, step S500 is performed to provide a semiconductor front layer structure 400. The semiconductor front layer structure 400 may be a substrate, or may be a substrate and a single-layer film or a multi-layer film formed on the substrate. The semiconductor front layer structure 400 may also include various functional structures. In short, the semiconductor front layer structure 400 is the sum of all device structures before the first groove 610 is formed. In different devices, the specific composition of the semiconductor front layer structure 400 is different, and will not be described one by one here.

[0072] Please continue reading Fig. 9 , perform step S600 to form a first photoresist layer 500 on the semiconductor front layer structure 400 , wherein the first photoresist layer 500 covers the surface of the semiconductor front layer structure 400 .

[0073] like Fig.11 As shown, step S700 is executed, using Figure 7The mask shown in the figure exposes and develops the first photoresist layer 500 to form at least one third opening 510 and at least one fourth opening 520 on the first photoresist layer 500. As described above, after the light passes through the first opening 310, the edge area and the central area of ​​the first opening 310 have a certain optical path difference. When the light finally reaches the focal plane, the light intensity distribution at the corresponding position of the focal plane changes, so that the central area at the corresponding position of the focal plane is fully exposed, while the position of the edge area can only be partially exposed. Therefore, the central area of ​​the third opening 510 is fully exposed, while the edge area of ​​the third opening 510 is partially exposed, so that a certain amount of photoresist remains, so that the central area of ​​the third opening 510 penetrates the first photoresist layer 500 and exposes the surface of the semiconductor front layer structure 400, while the edge area of ​​the third opening 510 does not penetrate the first photoresist layer 500, but extends from the surface of the first photoresist layer 500 to the inside of the first photoresist layer 500. Correspondingly, after the light passes through the second opening 320 and reaches the focal plane, the light intensity is Gaussian distributed and the corresponding position of the focal plane is fully exposed, so the second opening 320 penetrates the first photoresist layer 500 and exposes the surface of the semiconductor front layer structure 400 .

[0074] like Fig.12 As shown, the semiconductor front layer structure 400 is etched downward along the third opening 510 and the fourth opening 520 to form the first groove 610 and the second groove 620 in the semiconductor front layer structure 400. It can be understood that, since there is residual photoresist in the edge area of ​​the third opening 510, when etching the semiconductor front layer structure 400 downward along the third opening 510, it is necessary to first etch the residual photoresist and then etch the semiconductor front layer structure 400 below, so that the inclination angle of the side wall of the first groove 610 formed in the end is larger (greater than the inclination angle of the side wall of the second groove 620).

[0075] like Fig.13 As shown, the first photoresist layer 500 is removed. Subsequently, an isolation material or a conductive material can be formed in the first groove 610 and the second groove 620. Since the inclination angle of the side wall of the first groove 610 is larger, the problem that the first groove 610 is easily closed in advance or the closing difference between the first grooves 610 is large can be avoided, and there is no need to adjust the parameters of the photolithography process, and other performances of the device will not be affected.

[0076] In summary, the mask and its preparation method, and the semiconductor device preparation method provided in the embodiments of the present application include a light-transmitting substrate 100, a light-shielding layer 200, and at least one first opening 310. The light-shielding layer 200 is located on the light-transmitting substrate 100. The central area of ​​the first opening 310 penetrates the light-shielding layer 200, and the edge area of ​​the first opening 310 penetrates the light-shielding layer 200 and extends into the light-transmitting substrate 100. The mask in the present application can form a first groove 610 with a larger sidewall inclination angle in the semiconductor front layer structure 400, avoiding the problem that the first groove 610 is easy to close in advance or the closing difference between the first grooves 610 is large, without adjusting the parameters of the photolithography process, and will not affect other performances of the device.

[0077] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0078] It should also be noted that, although the present application has been disclosed as above with preferred embodiments, the above embodiments are not intended to limit the present application. For any technician familiar with the art, without departing from the scope of the technical solution of the present application, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present application, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

[0079] It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are merely used to distinguish between the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0080] It should also be recognized that the terms described herein are only used to describe specific embodiments and are not used to limit the scope of the present application. It should be noted that the singular forms "one" and "a kind" used herein and in the appended claims include plural references unless the context clearly indicates the opposite meaning. For example, a reference to "a step" or "a device" means a reference to one or more steps or devices, and may include secondary steps and secondary devices. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood to have a definition of logical "or", rather than a definition of logical "exclusive or", unless the context clearly indicates the opposite meaning. In addition, the implementation of the method and / or device in the embodiment of the present application may include performing the selected task manually, automatically, or in combination.

Claims

1. A mask, characterized in that: include: Light-transmitting substrate; A light shielding layer, located on the light-transmitting substrate; At least one first opening, wherein a central area of ​​the first opening penetrates the light shielding layer, and an edge area of ​​the first opening penetrates the light shielding layer and extends into the light-transmitting substrate.

2. The mask according to claim 1, wherein: The lateral width of the edge region of the first opening is equal to tanθ*h / k, wherein θ is a predetermined adjustment angle, h is an etching depth, and k is a ratio of the pattern size of the mask to the etching product.

3. The mask according to claim 1, wherein: The edge region of the first opening extends into the transparent substrate to a depth equal to λ / 2(n-1), where λ is the photolithography wavelength and n is the refractive index of the transparent substrate.

4. The mask according to any one of claims 1 to 3, characterized in that: Also includes: At least one second opening, the second switch passes through the light shielding layer.

5. The mask according to claim 4, characterized in that: The first opening and the second opening are used to form a first groove and a second groove on a semiconductor front layer structure, respectively. The inclination angle of the side wall of the first groove is greater than the inclination angle of the side wall of the second groove.

6. The mask according to claim 5, characterized in that: The first groove and the second groove are respectively located in a scribing area and a normal unit area of ​​the semiconductor front layer structure, and the first groove is an alignment groove in the scribing area.

7. The mask according to claim 6, wherein: A lateral width of the first groove is greater than a lateral width of the second groove.

8. The mask according to claim 6, wherein: The first groove and the second groove are both located in the scribe area or in the normal cell area.

9. A method for preparing a mask, characterized in that: include: providing a light-transmitting substrate; forming a light shielding layer on the light-transmitting substrate; Etching a portion of the depth of the light shielding layer and the light-transmitting substrate to form at least one annular etching area; The light shielding layer in the annular etched area is removed by etching to form at least one first opening, wherein a central area of ​​the first opening penetrates the light shielding layer, and an edge area of ​​the first opening penetrates the light shielding layer and extends into the light-transmitting substrate.

10. The method for preparing a mask according to claim 9, characterized in that: The lateral width of the annular surface of the annular etching area is equal to tanθ*h / k, wherein θ is a predetermined adjustment angle, h is an etching depth, and k is a ratio of the graphic dimensions of the mask to the etching product.

11. The method for preparing a mask according to claim 9, wherein: The depth of etching the light-transmitting substrate is equal to λ / 2(n-1), wherein λ is the photolithography wavelength and n is the refractive index of the light-transmitting substrate.

12. The method for preparing a mask according to any one of claims 9 to 11, characterized in that: When etching is performed to remove the light shielding layer in the annular etching area, the light shielding layer outside the annular etching area is also etched to form at least one second opening, wherein the second opening penetrates the light shielding layer.

13. A method for preparing a semiconductor device, characterized in that: include: Providing a semiconductor front layer structure; forming a first photoresist layer on the semiconductor front layer structure; Using the mask according to any one of claims 1 to 8 to expose and develop the first photoresist layer, so as to form at least one third opening in the first photoresist layer, wherein the central area of ​​the third opening penetrates the first photoresist layer, and the edge area of ​​the third opening extends from the surface of the first photoresist layer into the first photoresist layer; The semiconductor front layer structure is etched downward along the third opening to form a first groove in the semiconductor front layer structure.

14. The method for preparing a semiconductor device according to claim 13, wherein: When the first photoresist layer is exposed and developed by using the mask, at least one fourth opening is formed in the first photoresist layer, and the fourth opening penetrates the first photoresist layer; When the semiconductor front layer structure is etched downward along the third opening, the semiconductor front layer structure is also etched downward along the fourth opening to form a second groove in the semiconductor front layer structure.

15. The method for preparing a semiconductor device according to claim 14, characterized in that: The inclination angle of the side wall of the first groove is greater than the inclination angle of the side wall of the second groove; and / or the lateral width of the first groove is greater than the lateral width of the second groove.

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