A photolithography alignment method

Abstract

The application provides a photolithography alignment method and relates to the technical field of semiconductor processes. Based on a first groove and a second groove of a mask layer, a metal layer is formed with a similar conformal topography as the second groove in a preparation process of the metal layer; in a preparation process of a first non-light-transmitting film layer, the first non-light-transmitting film layer is also formed with a similar conformal topography as the second groove; then a photoresist layer and a second non-light-transmitting film layer are formed in sequence, and the surface of the photoresist layer and the second non-light-transmitting film layer away from the substrate side is parallel to the plane where the substrate is located; at this time, the thickness of the photoresist layer corresponding to the core area pattern is smaller than the thickness of the photoresist layer corresponding to the alignment mark pattern; in a measurement process of diffraction light efficiency, the photoresist layers with different thicknesses have different signal responses, so that the purpose of accurately positioning the position of the alignment mark pattern is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor process, in particular to a photolithography alignment method. BACKGROUND

[0002] In the process of manufacturing integrated circuits, as the core structure becomes smaller and thinner, and the chemical mechanical polishing technology is widely used, it is difficult to transfer the pattern features in the manufacturing process through the thin film.

[0003] When there is an opaque material between the alignment mark pattern of the previous layer and the photoresist, it is difficult to detect the alignment mark pattern of the previous layer during the photolithography alignment detection process, and thus the photolithography machine cannot perform alignment operation and subsequent exposure operation. SUMMARY

[0004] In view of the above problems, the present application provides a photolithography alignment method to achieve the purpose of accurately positioning the alignment mark pattern. The specific scheme is as follows:

[0005] The first aspect of the present application provides a photolithography alignment method, which comprises:

[0006] A to-be-processed structure is provided, which comprises a substrate and a mask layer located on one side of the substrate; the mask layer has a core area pattern and an alignment mark pattern; the core area pattern has a first groove, and the alignment mark pattern has a second groove;

[0007] A metal layer is formed, which fills the first groove and covers the sidewall and bottom of the second groove; the thickness of the metal layer at the bottom of the second groove is less than the depth of the second groove;

[0008] A first non-opaque film layer is formed, which comprises a first recessed area recessed towards one side of the substrate; the orthographic projection of the first recessed area on the substrate is located within the orthographic projection of the second groove on the substrate;

[0009] A photoresist layer is formed on the side of the first non-opaque film layer away from the substrate, and the surface of the photoresist layer on the side away from the substrate is parallel to the plane on which the substrate is located;

[0010] A second non-opaque film layer is formed on the side of the photoresist layer away from the substrate, and the surface of the second non-opaque film layer on the side away from the substrate is parallel to the plane on which the substrate is located;

[0011] The diffraction light efficiency is measured on the side of the second non-opaque film layer away from the substrate to determine the position of the alignment mark pattern.

[0012] Preferably, in the photolithography alignment method, the width of the first groove is less than or equal to 200 nanometers.

[0013] Preferably, in the photolithography alignment method, the width of the second groove is greater than or equal to 1 micrometer.

[0014] Preferably, in the photolithography alignment method, the thickness of the mask layer is in the range of 50 nanometers to 500 nanometers.

[0015] Preferably, in the photolithography alignment method, the forming of the metal layer comprises:

[0016] forming a metal layer on the side of the mask layer away from the substrate, the metal layer comprising a second recessed region recessed toward the substrate; the orthographic projection of the second recessed region on the substrate is within the orthographic projection of the second groove on the substrate;

[0017] processing the metal layer based on a CMP process, so that the metal layer fills the first groove, and the metal layer covers the sidewall and the bottom of the second groove; the thickness of the metal layer at the bottom of the second groove is less than the depth of the second groove.

[0018] Preferably, in the photolithography alignment method, the structure to be processed further comprises:

[0019] a first protective layer between the substrate and the mask layer.

[0020] Preferably, in the photolithography alignment method, before the forming of the first non-transparent film layer, the photolithography alignment method further comprises:

[0021] forming a second protective layer, the second protective layer comprising a third recessed region recessed toward the substrate; the orthographic projection of the third recessed region on the substrate is within the orthographic projection of the second groove on the substrate.

[0022] Preferably, in the photolithography alignment method, before the forming of the photoresist layer, the photolithography alignment method further comprises:

[0023] forming a dielectric material layer, the dielectric material layer comprising a fourth recessed region recessed toward the substrate; the orthographic projection of the fourth recessed region on the substrate is within the orthographic projection of the second groove on the substrate.

[0024] wherein the refractive index of the dielectric material layer is different from the refractive index of the first non-transparent film layer.

[0025] Preferably, in the photolithography alignment method, the material of the metal layer is Cu material or Al material.

[0026] Preferably, in the above photolithography alignment method, the material of the first non-transparent film layer is Ag or Al.

[0027] The material of the second opaque film layer is Ag or Al.

[0028] By means of the above technical solution, this application provides a photolithographic alignment method. Based on the first and second grooves of the mask layer, the first groove is filled during the preparation of the metal layer, and the sidewalls and bottom of the second groove are covered. The thickness of the metal layer at the bottom of the second groove is less than the depth of the second groove, forming a morphology similar to the second groove. During the preparation of the first opaque film layer, the orthographic projection of the first recessed area of ​​the first opaque film layer on the substrate is located within the orthographic projection of the second groove on the substrate, also forming a morphology similar to the second groove. Then, a photoresist layer and a second opaque film layer are formed sequentially. The surfaces of the photoresist layer and the second opaque film layer facing away from the substrate are parallel to the plane of the substrate. At this time, the thickness of the photoresist layer corresponding to the core region pattern will be less than the thickness of the photoresist layer corresponding to the alignment mark pattern. During the measurement of diffraction light efficiency, photoresist layers of different thicknesses have different signal responses, thereby achieving the purpose of accurately locating the alignment mark pattern. Attached Figure Description

[0029] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0030] Figure 1 A schematic flowchart of a photolithographic alignment method provided in an embodiment of the present invention;

[0031] Figures 2-9 for Figure 1 A schematic diagram of a portion of the structure corresponding to the photolithography alignment method shown;

[0032] Figure 10 This is a schematic diagram illustrating the relationship between mask layer thickness and normalized diffraction efficiency, provided in an embodiment of the present invention.

[0033] Figure 11 This is a schematic diagram of another structure corresponding to a photolithography alignment method provided in an embodiment of the present invention. Detailed Implementation

[0034] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is only for explaining specific embodiments and is not intended to limit the application. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should be noted that the directional terms appearing in this invention are based on the relative positional relationships shown in the accompanying drawings and should not be taken as absolute limitations on this application.

[0037] refer to Figure 1 , Figure 1 This is a schematic flowchart illustrating a photolithographic alignment method provided in an embodiment of the present invention. The photolithographic alignment method provided in this embodiment of the present invention includes:

[0038] S101: As Figure 2 As shown, a structure to be processed is provided, the structure to be processed includes a substrate 11 and a mask layer 12 located on one side of the substrate 11; the mask layer has a core region pattern and an alignment mark pattern; the core region pattern has a first groove 13 and the alignment mark pattern has a second groove 14.

[0039] Specifically, in this embodiment of the invention, the mask layer 12 includes, but is not limited to, a hard mask layer, and the thickness of the mask layer 12 is 50 nanometers to 500 nanometers; for example, the thickness of the mask layer 12 is 50 nanometers, 78 nanometers, 200 nanometers, 264 nanometers, or 500 nanometers, etc. The width WO1 of the first groove 13 is less than or equal to 200 nanometers; for example, the width WO1 of the first groove 13 is 200 nanometers, 146 nanometers, or 75 nanometers, etc. The width WO2 of the second groove 14 is greater than or equal to 1 micrometer; for example, the width WO2 of the second groove 14 is 1 micrometer, 3.5 micrometers, or 8 micrometers, etc.

[0040] It should be noted that for the alignment mark pattern, when there is a gap with a width greater than 1 micrometer, the corresponding part of the mask layer 12 can be further subdivided according to the size of the core area pattern. That is, the pattern in the alignment mark pattern other than the second groove 14 can be further subdivided according to the width of the first groove 13.

[0041] The material of the mask layer 12 includes, but is not limited to, dielectric materials such as silicon oxide and silicon nitride, and must have good electrical insulation properties. This mask layer 12 serves as a subsequent metal isolation layer.

[0042] In an optional embodiment of the present application, as shown in Figure 3 The structure to be processed further comprises:

[0043] A first protective layer 15 is arranged between the substrate 11 and the mask layer 12.

[0044] Since a metal layer will be formed in the subsequent process, in order to avoid the diffusion of metal elements in the metal layer and ensure the film quality of the metal layer, a protective layer, i.e. the first protective layer 15, is arranged between the substrate 11 and the mask layer 12 to protect the bottom of the metal layer.

[0045] S102: As shown in Figure 4 and Figure 5 A metal layer 16 is formed, which fills the first recess 13 and covers the sidewall and bottom of the second recess 14; the thickness of the metal layer 16 at the bottom of the second recess 14 is less than the depth of the second recess 14.

[0046] Optionally, in the embodiment of the present application, one implementation of forming the metal layer 16 is as follows:

[0047] As shown in Figure 4 The metal layer 16 is formed on the side of the mask layer 12 away from the substrate 11, and the metal layer 16 comprises a second recessed area 17 recessed toward the substrate 11; the orthographic projection of the second recessed area 17 on the substrate 11 is within the orthographic projection of the second recess 14 on the substrate 11.

[0048] As shown in Figure 5 The metal layer 16 is processed based on the CMP process, so that the metal layer 16 fills the first recess 13 and covers the sidewall and bottom of the second recess 14; the thickness of the metal layer 16 at the bottom of the second recess 14 is less than the depth of the second recess 14.

[0049] Specifically, the material of the metal layer 16 comprises but is not limited to Cu material or Al material, and the metal layer 16 is formed by electroplating process, but is not limited thereto. The thickness of the metal layer 16 in different areas is controlled by controlling the parameters in the electroplating process. As shown in Figure 4 The cutoff time of the metal layer 16 covering the structure can be accurately controlled according to the time of the electroplating process of the metal layer 16, so that it presents as shown in Figure 4The conformal effect is shown. That is, the core area pattern is well filled, and the alignment mark pattern is provided with a conformal feature. In an ideal case, the cross-sectional pattern of the second recessed area 17 is the same as that of the second recess 14, but the size of the cross-sectional pattern of the second recessed area 17 is smaller than that of the second recess 14.

[0050] In order to ensure that the metal layer 16 can completely fill the area where the first recess 13 is located, as shown in the process of electroplating the metal layer 16, a part of the metal layer 16 is deposited, and at this time, the metal layer 16 completely covers the surface exposed by the mask layer 12. Figure 4

[0051] Then, as shown in the process of processing the metal layer 16, for example, but not limited to, the CMP process is used to remove the metal layer 16 above the mask layer 12, so that the metal layer 16 fills the first recess 13, and the metal layer 16 covers the sidewall and bottom of the second recess 14, and the thickness of the metal layer 16 at the bottom of the second recess 14 is smaller than the depth of the second recess 14, thereby obtaining a film layer structure with different features. Figure 5

[0052] The film layer structure with different features means that the metal layer 16 of the core area pattern can be well filled into the first recess 13, and the thickness of the metal layer 16 in the first recess 13 is the same as the depth of the first recess 13; the metal layer 16 of the alignment mark pattern covers the sidewall and bottom of the second recess 14, and the thickness of the metal layer 16 at the bottom of the second recess 14 is smaller than the depth of the second recess 14, thereby forming a structure conformal to the second recess 14, and a step morphology appears.

[0053] In an optional embodiment of the present application, as shown in the process of forming the first non-light-transmitting film layer, the photolithography alignment method further comprises: Figure 6

[0054] A second protective layer 18 is formed, the second protective layer 18 comprises a third recessed area 19 recessed to one side of the substrate 11; the orthographic projection of the third recessed area 19 on the substrate 11 is located in the orthographic projection of the second recess 14 on the substrate 11.

[0055] In order to avoid the diffusion of metal elements in the metal layer 16 and ensure the film layer quality of the metal layer 16, after the metal layer 16 is prepared, a protective layer, that is, a second protective layer 18, is further arranged above the metal layer 16, thereby protecting the top of the metal layer 16.

[0056] ​​​Based on the arrangement of the first protective layer 15 and the second protective layer 18, in combination with the mask layer 12, the metal layer 16 can be protected in all directions, thereby maximizing the film layer quality of the metal layer 16.

[0057] Based on Figure 5 The prepared second protective layer 18 also has a third recessed area 19 recessed toward the substrate 11, as shown in the morphology of the film layer, so that it presents a conformal effect as shown in Figure 6 That is, the core area pattern realizes good planar film layer characteristics, and the alignment mark pattern realizes conformal characteristics. In an ideal case, the cross-sectional pattern of the third recessed area 19 is the same as that of the second groove 14, but the size of the cross-sectional pattern of the third recessed area 19 is smaller than that of the second groove 14 and smaller than that of the second recessed area 17.

[0058] The thickness of the second protective layer 18 ranges from 5 nanometers to 200 nanometers. For example, the thickness of the second protective layer 18 is 5 nanometers, 60 nanometers, 124 nanometers, or 200 nanometers, etc.

[0059] S103: As shown in Figure 7 A first non-light-transmitting film layer 20 is formed, which includes a first recessed area 21 recessed toward the substrate 11; the orthographic projection of the first recessed area 21 on the substrate 11 is within the orthographic projection of the second groove 14 on the substrate 11.

[0060] Specifically, the material of the first non-light-transmitting film layer 20 includes but is not limited to Ag material or Al material, and the first non-light-transmitting film layer 20 is formed by metal sputtering, for example. The thickness of the first non-light-transmitting film layer 20 is less than or equal to 50 nanometers.

[0061] Based on Figure 6 The prepared first non-light-transmitting film layer 20 also has a first recessed area 21 recessed toward the substrate 11, as shown in the morphology of the film layer, so that it presents a conformal effect as shown in Figure 7 That is, the core area pattern realizes good planar film layer characteristics, and the alignment mark pattern realizes conformal characteristics. In an ideal case, the cross-sectional pattern of the first recessed area 21 is the same as that of the second groove 14, but the size of the cross-sectional pattern of the first recessed area 21 is smaller than that of the second groove 14, smaller than that of the second recessed area 17, and smaller than that of the third recessed area 19.

[0062] S104: As shown in Figure 8As shown, a photoresist layer 22 is formed on the side of the first non-transparent film layer 20 away from the substrate 11, and the surface of the photoresist layer 22 away from the substrate 11 is parallel to the plane of the substrate 11.

[0063] Specifically, the photoresist layer 22 is prepared using a spin coater, but not limited to this method, and the top height of the prepared photoresist layer 22 is uniform. It is understood that the surface of the photoresist layer 22 facing away from the substrate 11 is parallel to the plane of the substrate 11. In this case, the thickness of the photoresist layer 22 corresponding to the core region pattern will be less than the thickness of the photoresist layer 22 corresponding to the alignment mark pattern.

[0064] S105: As Figure 9 As shown, a second opaque film layer 23 is formed on the side of the photoresist layer 22 away from the substrate 11, and the surface of the second opaque film layer 23 away from the substrate 11 is parallel to the plane of the substrate 11.

[0065] Specifically, the material of the second opaque film layer 23 includes, but is not limited to, Ag or Al materials, and includes, but is not limited to, forming the second opaque film layer 23 by metal sputtering. The thickness of the second opaque film layer 23 is less than or equal to 50 nanometers.

[0066] In an optional embodiment of the present invention, the thickness of the first opaque film layer 20 and the second opaque film layer 23 is 30 nanometers, and the thickness of the photoresist layer 22 is 50 nanometers.

[0067] based on Figure 9 In the structure shown, the sandwich-like stacked structure consisting of the first opaque film layer 20, the photoresist layer 22, and the second opaque film layer 23 has different thickness characteristics for the photoresist layers 22 corresponding to the core region pattern and the alignment mark pattern. Specifically, the thickness of the photoresist layer 22 corresponding to the core region pattern is less than the thickness of the photoresist layer 22 corresponding to the alignment mark pattern. During subsequent diffraction efficiency measurements, photoresist layers 22 of different thicknesses exhibit different signal responses, thereby achieving the purpose of accurately locating the alignment mark pattern.

[0068] S106: The diffraction efficiency is measured on the side of the second opaque film layer 23 away from the substrate 11 to determine the position of the alignment mark pattern.

[0069] Specifically, in the embodiments of the present invention, reference is made to Figure 10 , Figure 10This is a schematic diagram illustrating the relationship between mask layer thickness and normalized diffraction efficiency, provided in an embodiment of the present invention. In the sandwich-like stacked structure consisting of the first opaque film layer 20, the photoresist layer 22, and the second opaque film layer 23, the photoresist layers 22 corresponding to the core region pattern and the alignment mark pattern have different thickness characteristics. Specifically, the thickness of the photoresist layer 22 corresponding to the core region pattern is less than the thickness of the photoresist layer 22 corresponding to the alignment mark pattern. During subsequent diffraction efficiency measurements, photoresist layers 22 of different thicknesses exhibit different signal responses. Further optimization of the mask layer 12 thickness allows for signal modulation, thereby achieving the goal of precisely locating the alignment mark pattern.

[0070] The measurement of diffraction efficiency refers to measuring the efficiency of diffracted light, particularly the first-order diffraction efficiency. Normalized diffraction efficiency is used for evaluation, and a diffraction efficiency exceeding 0.1% is typically required. Figure 10 As shown, variations in the thickness of the mask layer 12 cause changes in the diffraction efficiency. The maximum diffraction efficiency, 115%, is achieved when the thickness of the mask layer 12 is 210 nanometers. In this embodiment, the diffraction detection wavelength is 633 nanometers. Optionally, light of any wavelength from 400 nanometers to 900 nanometers can be used for detection. Specifically, when changing the detection wavelength, the thickness of the mask layer 12 should be optimized.

[0071] When the thickness of the mask layer 12 exceeds 147 nm and is less than 268 nm, the first-order diffraction efficiency exceeds 0.1%; when the thickness of the mask layer 12 exceeds 184 nm and is less than 236 nm, the first-order diffraction efficiency exceeds 1%.

[0072] During feedback, the thickness of the mask layer 12 should be controlled within the range of [147, 268] nanometers to achieve a normalized diffraction efficiency of 0.1%; controlling the thickness of the mask layer 12 within the range of [184, 236] nanometers can achieve a normalized diffraction efficiency of 1%.

[0073] When it is difficult to detect the alignment mark pattern in the alignment detection process, the technical solution of this application can be used to ensure that the photoresist layer 22 corresponding to the core area pattern and the alignment mark pattern has different thickness characteristics. With the optimization of the mask layer 12 thickness, excellent alignment efficiency can be achieved.

[0074] Furthermore, the technical solution of this application ensures the filling quality of the metal layer 16 of the core area pattern, and also ensures the conformal characteristics of the alignment mark pattern of some film layers. That is, it does not affect the imaging quality requirements of the core area, and does not require additional processes in the area of ​​the alignment mark pattern, such as additional photolithography processes to etch and remove the opaque film layer.

[0075] In an optional embodiment of the present application, referring to Figure 11 , Figure 11 Another structure diagram corresponding to the photoetching alignment method provided by the embodiment of the present application is shown. Since the size of the second groove 14 of the alignment mark pattern is in the order of microns, after the photoresist layer 22 is prepared, a feature conforming to the second groove 14 will also appear, and after the second non-light-transmitting film layer 23 is prepared, a feature conforming to the second groove 14 will also appear. If this feature can be extracted obviously, the thickness of the mask layer 12 does not need to be controlled additionally, and the position of the alignment mark pattern can be recognized intuitively.

[0076] In an optional embodiment of the present application, before the photoresist layer 22 is formed, the photoetching alignment method further comprises:

[0077] forming a dielectric material layer, the dielectric material layer comprising a fourth recessed area recessed to one side of the substrate 11; the orthographic projection of the fourth recessed area on the substrate 11 is located within the orthographic projection of the second groove 14 on the substrate 11; wherein the refractive index of the dielectric material layer is different from the refractive index of the first non-light-transmitting film layer 20.

[0078] Specifically, in the embodiment of the present application, after the first non-light-transmitting film layer 20 is prepared, other materials can be deposited and chemical mechanical polishing is performed to realize the flat surface feature, and then the photoresist layer 22 and the second non-light-transmitting film layer 23 are prepared. The refractive index of the dielectric material layer is different from the refractive index of the first non-light-transmitting film layer 20 to realize the optical signal difference, and in the measurement process of the diffraction light efficiency, the position of the alignment mark pattern can be determined more accurately.

[0079] The photoetching alignment method provided by the present application is described in detail above, and the principles and implementation manners of the present application are described by applying specific examples in this paper. The above embodiment description is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and the above description should not be understood as the limitation of the present application.

[0080] It should be noted that each embodiment in the present specification adopts a progressive description manner, and each embodiment focuses on the difference from other embodiments. The same and similar parts of each embodiment can be referred to each other. For the device disclosed by the embodiment, since it corresponds to the method disclosed by the embodiment, the description is relatively simple, and the related parts can be referred to the method part.

[0081] It is also to be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Furthermore, to the extent that the terms "including," "includes," "having," "has," "with," or "contains" are used in either the detailed description and the claims section below, these terms are intended to be inclusive in a manner similar to the term "comprising" as an open transition term without precluding any additional or other elements.

[0082] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Numerous modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of the innovation falling outside the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lithographic alignment method characterized by, The photoetching alignment method comprises: providing a structure to be processed, the structure to be processed comprising a substrate and a mask layer on one side of the substrate; the mask layer having a core area pattern and an alignment mark pattern; the core area pattern having a first groove, and the alignment mark pattern having a second groove; forming a metal layer, the metal layer filling the first groove, and the metal layer covering the sidewall and the bottom of the second groove; the thickness of the metal layer at the bottom of the second groove being less than the depth of the second groove; forming a first non-light-transmitting film layer, the first non-light-transmitting film layer comprising a first recessed area recessed towards the substrate; the orthographic projection of the first recessed area on the substrate being within the orthographic projection of the second groove on the substrate; forming a photoresist layer on the side of the first non-light-transmitting film layer away from the substrate, the surface of the photoresist layer on the side away from the substrate being parallel to the plane of the substrate; forming a second non-light-transmitting film layer on the side of the photoresist layer away from the substrate, the surface of the second non-light-transmitting film layer on the side away from the substrate being parallel to the plane of the substrate; measuring the diffraction light efficiency on the side of the second non-light-transmitting film layer away from the substrate to determine the position of the alignment mark pattern.

2. The photolithography alignment method of claim 1, wherein, The width of the first groove is less than or equal to 200 nanometers.

3. The photolithography alignment method of claim 1, wherein, The width of the second groove is greater than or equal to 1 micrometer.

4. The photolithography alignment method of claim 1, wherein, The thickness of the mask layer ranges from 50 nanometers to 500 nanometers.

5. The photolithography alignment method of claim 1, wherein, The forming of the metal layer comprises: forming a metal layer on the side of the mask layer away from the substrate, the metal layer comprising a second recessed area recessed towards the substrate; the orthographic projection of the second recessed area on the substrate being within the orthographic projection of the second groove on the substrate; processing the metal layer based on a CMP process, so that the metal layer fills the first groove, and the metal layer covers the sidewall and the bottom of the second groove; the thickness of the metal layer at the bottom of the second groove being less than the depth of the second groove.

6. The photolithography alignment method of claim 1, wherein, The structure to be processed further comprises: a first protective layer between the substrate and the mask layer.

7. The photolithography alignment method of claim 1, wherein, Before forming the first non-light-transmitting film layer, the photoetching alignment method further comprises: forming a second protective layer, the second protective layer comprising a third recessed area recessed towards the substrate; the orthographic projection of the third recessed area on the substrate being within the orthographic projection of the second groove on the substrate.

8. The photolithography alignment method of claim 1, wherein, Before forming the photoresist layer, the photoetching alignment method further comprises: forming a dielectric material layer, the dielectric material layer comprising a fourth recessed area recessed towards the substrate; the orthographic projection of the fourth recessed area on the substrate being within the orthographic projection of the second groove on the substrate; wherein the refractive index of the dielectric material layer is different from the refractive index of the first non-light-transmitting film layer.

9. The photolithography alignment method according to any one of claims 1-8, wherein, The material of the metal layer is Cu material or Al material.

10. The photolithography alignment method according to any one of claims 1-8, wherein, The material of the first non-light-transmitting film layer is Ag material or Al material; The material of the second non-light-transmitting film layer is Ag material or Al material.

Images