A self-excited photolithography method with self-alignment effect

Abstract

The present invention provides a self-excited photolithography method with a self-alignment effect, relating to the field of semiconductor process technology. A first mask is used during the first photolithography process only to define the effective photolithography area during the second photolithography process. Therefore, a larger mask can be used for the first mask, greatly reducing the manufacturing difficulty of the first mask. Because both the first metal layer and the second metal layer are layers of negative refractive index material, and there is a thickness difference between the second photoresist layer and the first metal layer, after optimizing the film thickness and the width of the raised structure based on parallel light wavelength simulation, resolution enhancement can be achieved within the region corresponding to the raised structure, achieving a self-aligned photolithography pattern imaging effect with a self-excited effect only for the region corresponding to the raised structure. Furthermore, no mask is used during the second photolithography process, further reducing the process difficulty.

Description

Technical Field

[0001] The present application relates to the field of semiconductor process technology, and in particular to a self-excited photolithography method with a self-alignment effect. Background Art

[0002] Photolithography technology is a technology that can achieve accurate imaging of the target pattern on the substrate. Existing mature photolithography technologies include deep ultraviolet lithography technology, extreme ultraviolet lithography technology, and optical lithography technology.

[0003] From an optical perspective, the maximum resolution of these lithography techniques is limited by the optical diffraction limit. For deep ultraviolet (DUV) lithography, the current single-pass resolution limit for immersion lithography is 38 nanometers (with a minimum period of 76 nanometers), while the commercial high-volume resolution limit is 40 nanometers (with a period of 80 nanometers). Using a 193nm wavelength and water immersion lithography, the resolution limit is approximately 20% of the wavelength.

[0004] Existing photolithography technology makes it difficult to achieve resolution enhancement performance beyond the diffraction limit; for existing super-diffraction imaging technology, the existing method uses proportional masks, which makes mask manufacturing extremely difficult; for imaging methods that achieve self-excitation through features such as single holes, it is difficult to achieve selective area imaging. Summary of the Invention

[0005] In view of the above problems, this application provides a self-excited photolithography method with a self-alignment effect. The mask used is larger in size, which reduces its manufacturing difficulty and can achieve selective imaging. The specific solution is as follows:

[0006] A first aspect of the present application provides a self-excited photolithography method with a self-alignment effect, the self-excited photolithography method with a self-alignment effect comprising: providing a structure to be processed, the structure to be processed comprising a substrate, and a first photoresist layer located on one side of the substrate;

[0007] Performing a first photolithography process and a pattern transfer process on the first photoresist layer based on a first mask to form a plurality of groove structures on the substrate, with a convex structure between two adjacent groove structures;

[0008] Sequentially preparing a thin film layer and a first metal layer, wherein the thin film layer and the first metal layer located at the bottom of the groove structure have a height difference from the thin film layer and the first metal layer located on the surface of the protrusion structure;

[0009] forming a second photoresist layer on a side of the first metal layer facing away from the substrate, wherein a surface of the second photoresist layer facing away from the substrate is parallel to a plane where the substrate is located;

[0010] forming a second metal layer on a side of the second photoresist layer facing away from the substrate, wherein a surface of the second metal layer facing away from the substrate is parallel to a plane where the substrate is located; the first metal layer and the second metal layer are negative refractive index material layers;

[0011] Determining the wavelength of parallel light having interference properties, and optimizing the film thickness and the width of the protruding structure based on the wavelength of the parallel light, and then performing self-excited selective photolithography on the second photoresist layer located on the surface of the protruding structure while irradiating the second metal layer with the parallel light from a side facing away from the substrate for a second photolithography process to form a target pattern;

[0012] The target pattern is transferred onto the substrate.

[0013] Preferably, in the above-mentioned self-excited photolithography method with a self-alignment effect, after optimizing the film thickness and the width of the protruding structure based on the wavelength simulation of the parallel light, when the parallel light is irradiated from the side of the second metal layer facing away from the substrate for a second photolithography process, the second photoresist layer located on the surface of the protruding structure is subjected to self-excited selective photolithography to form a target pattern, comprising:

[0014] The thickness of the thin film layer, the thickness of the first metal layer, the thickness of the photoresist layer, the thickness of the second metal layer and the width of the protruding structure are optimized based on the wavelength simulation of the parallel light. When the parallel light is irradiated from the side of the second metal layer away from the substrate for a second photolithography process, the second photoresist layer located on the surface of the protruding structure is subjected to self-excited selective photolithography to form a target pattern.

[0015] Preferably, in the above-mentioned self-excited lithography method with self-alignment effect, the simulation optimization method is a finite-difference time-domain method, a finite element method or a rigorous coupled wave theory.

[0016] Preferably, in the above self-excited photolithography method with self-alignment effect,

[0017] The wavelength of the parallel light is 193 nanometers, 248 nanometers, 365 nanometers, 436 nanometers, 532 nanometers or 633 nanometers.

[0018] Preferably, in the above self-excited photolithography method with self-alignment effect, after the target pattern is transferred onto the substrate, the region of the substrate corresponding to the protruding structure has a nanoscale structure.

[0019] Preferably, in the self-excited photolithography method with a self-alignment effect, the first photoresist layer is subjected to a first photolithography process and a pattern transfer process based on a first mask to form a plurality of groove structures on the substrate, with a protrusion structure between two adjacent groove structures, including:

[0020] performing a first photolithography process on the first photoresist layer based on the first mask;

[0021] The substrate is etched based on the first photoresist layer after the first photolithography process, so as to form a plurality of groove structures on the substrate, with a convex structure between two adjacent groove structures.

[0022] Preferably, in the above self-excited photolithography method with self-alignment effect, the material of the first metal layer is the same as the material of the second metal layer.

[0023] Preferably, in the above-mentioned self-excited photolithography method with self-alignment effect, transferring the target pattern onto the substrate comprises:

[0024] removing the second metal layer;

[0025] performing an etching process on the first metal layer based on the second photoresist layer, and removing the second photoresist layer;

[0026] performing etching on the thin film layer based on the etched first metal layer, and removing the first metal layer;

[0027] The substrate is etched based on the etched thin film layer, and the thin film layer is removed.

[0028] Preferably, in the self-excited photolithography method with a self-alignment effect, the parallel light is incident vertically, or the parallel light is modulated by a light source and incident obliquely at a specific angle, to irradiate the second metal layer from the side facing away from the substrate for the second photolithography process;

[0029] The incident light includes two or more parallel light beams incident at opposite oblique angles.

[0030] Preferably, in the above-mentioned self-excited photolithography method with self-alignment effect, the width of the protruding structure is on the order of micrometers or nanometers of one hundred nanometers or above.

[0031] By means of the above technical solution, the present application provides a self-excited photolithography method with a self-alignment effect. The first mask is used in the first photolithography process only to define the effective photolithography area in the second photolithography process. Therefore, the first mask can use a larger mask, which greatly reduces the manufacturing difficulty of the first mask. Since the first metal layer and the second metal layer are both negative refractive index material layers, and there is a thickness difference between the second photoresist layer and the first metal layer, after optimizing the film thickness and the width of the protruding structure based on the wavelength simulation of parallel light, the resolution in the area corresponding to the protruding structure can be enhanced, and a self-aligned photolithography pattern imaging effect with a self-excited effect only in the area corresponding to the protruding structure is achieved. In addition, no mask is used in the second photolithography process, which further reduces the process difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0033] Figure 1 A schematic flow chart of a self-excited photolithography method with a self-alignment effect provided by an embodiment of the present invention;

[0034] Figure 2-Figure 9 for Figure 1 A schematic diagram of a portion of the structure corresponding to the self-excited photolithography method shown;

[0035] Figure 10 A schematic diagram of the self-excited resolution enhancement imaging effect corresponding to different widths of a protrusion structure provided by an embodiment of the present invention;

[0036] Figure 11-14 for Figure 1 A schematic diagram of a portion of the structure corresponding to the self-excited photolithography method shown;

[0037] Figure 15 A schematic diagram of the structure and imaging effect corresponding to the technical solution provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application. It is known to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] It should be noted that the directional words appearing in the present invention are based on the relative position relationship shown in the drawings and cannot be used as an absolute limitation to the present application.

[0041] refer to Figure 1 , Figure 1 A schematic flow chart of a self-excited lithography method with a self-alignment effect provided by an embodiment of the present invention. The self-excited lithography method with a self-alignment effect provided by an embodiment of the present invention includes:

[0042] S101: If Figure 2 As shown, a structure to be processed is provided, which includes a substrate 11 and a first photoresist layer 12 located on one side of the substrate 11 .

[0043] Specifically, the substrate 11 includes but is not limited to a silicon substrate, a quartz substrate or other III-V substrates.

[0044] In an optional embodiment of the present invention, Figure 3 As shown, the structure to be processed may further include an anti-reflection film layer 13 located between the substrate 11 and the first photoresist layer 12 . The provision of the anti-reflection film layer 13 may improve the quality of the photolithography effect of the first photoresist layer 12 in subsequent processes.

[0045] S102: Figure 4 and Figure 5 As shown, the first photoresist layer 12 is subjected to a first photolithography process and a pattern transfer process based on a first mask, so as to form a plurality of groove structures 14 on the substrate 11 , with a protrusion structure 15 between two adjacent groove structures 14 .

[0046] The first photoresist layer 12 is subjected to a first photolithography process and a pattern transfer process based on a first mask, so as to form a plurality of groove structures 14 on the substrate 11, with a protrusion structure 15 between two adjacent groove structures 14. One implementation method is as follows:

[0047] like Figure 4 As shown, the first photoresist layer 12 is subjected to a first photolithography process based on the first mask.

[0048] like Figure 5 As shown, the substrate 11 is etched based on the first photoresist layer 12 after the first photolithography process, so as to form a plurality of groove structures 14 on the substrate 11 , with a protrusion structure 15 between two adjacent groove structures 14 .

[0049] The first reticle used in the first photolithography process is solely for defining the effective photolithography area for the second photolithography process. Therefore, a larger reticle can be used. The minimum dimensions of the first reticle are micrometers or hundreds of nanometers or larger, and can be achieved using conventional photolithography. The dimensions on the first reticle can include uniform widths or uniform intervals, depending on the target photolithography process and material properties, and are not specifically limited in this embodiment of the present invention.

[0050] like Figure 4 As shown, the first photolithography process may adopt optical photolithography or other photolithography techniques, and then form an image on the first photoresist layer 12 after passing through the first mask.

[0051] like Figure 5 As shown, the pattern after the first photolithography process is transferred to the substrate 11 using a process including, but not limited to, etching. In an optional embodiment of the present invention, after the pattern transfer process, the pattern on the substrate 11 is realized with a structure having a micron-scale width. It is understood that the width of the protrusion structure 15 is on the micron scale. That is, the width of the protrusion structure 15 is on the order of microns or nanometers of 100 nanometers or more.

[0052] That is, in the embodiment of the present invention, a first photolithography process is performed using a first mask of a larger size to define a specific area. The specific area is described in the embodiment of the present invention by taking the area where the protrusion structure 15 is located as an example.

[0053] S103: If Figure 6 As shown, a thin film layer 16 and a first metal layer 17 are prepared in sequence. The thin film layer 16 and the first metal layer 17 at the bottom of the groove structure 14 have a height difference with the thin film layer 16 and the first metal layer 17 at the surface of the protrusion structure 15 .

[0054] Specifically, including but not limited to, using a deposition process to form the thin film layer 16 and the first metal layer 17, when the deposition process is used to form the thin film layer 16 and the first metal layer 17, the film layer can be grown conformally to the surface of the substrate 11. That is, the height of the thin film layer 16 and the first metal layer 17 in the area corresponding to the protrusion structure 15 is higher than the height of the area corresponding to the groove structure 14.

[0055] In the embodiment of the present invention, the material of the thin film layer 16 includes but is not limited to silicon oxide, and the material of the first metal layer 17 includes but is not limited to silver.

[0056] S104: Figure 7 As shown, a second photoresist layer 18 is formed on the side of the first metal layer 17 facing away from the substrate 11 , and the surface of the second photoresist layer 18 facing away from the substrate 11 is parallel to the plane where the substrate 11 is located.

[0057] Specifically, the second photoresist layer 18 is prepared by a spin coating process, including but not limited to the spin coating process. Figure 6 The surface of the structure shown is spin-coated with photoresist to achieve a smooth surface of the second photoresist layer 18. It is understood that the surface of the prepared second photoresist layer 18 facing away from the substrate 11 is parallel to the plane of the substrate 11.

[0058] S105: If Figure 8 As shown, a second metal layer 19 is formed on the side of the second photoresist layer 18 facing away from the substrate 11, and the surface of the second metal layer 19 facing away from the substrate 11 is parallel to the plane of the substrate 11; the first metal layer 17 and the second metal layer 19 are negative refractive index material layers.

[0059] Specifically, the second metal layer 19 may be formed using a deposition process, but is not limited thereto. Since the second photoresist layer 18 has a flat surface, the second metal layer 19 may also have a flat surface after it is formed. It is understood that the surface of the second metal layer 19 facing away from the substrate 11 is parallel to the plane of the substrate 11.

[0060] like Figure 8 As shown, the thickness of the second photoresist layer 18 in the area corresponding to the groove structure 14 is greater than the thickness of the second photoresist layer 18 in the area corresponding to the protrusion structure 15. It can be understood that the distance between the first metal layer 17 and the second metal layer 19 in the area corresponding to the groove structure 14 is greater than the distance between the first metal layer 17 and the second metal layer 19 in the area corresponding to the protrusion structure 15.

[0061] The first metal layer 17 and the second metal layer 19 are negative refractive index material layers, ensuring that the present technical solution can implement self-excited photolithography technology based on negative refractive index materials. The material of the second metal layer 19 includes but is not limited to silver.

[0062] In an optional embodiment of the present invention, the material of the first metal layer 17 is the same as the material of the second metal layer 19 . For example, the materials of the first metal layer 17 and the second metal layer 19 are both silver.

[0063] S106: If Figure 9 As shown, the wavelength of the parallel light with interference properties is determined, and after the film thickness and the width of the protruding structure 15 are optimized based on the wavelength simulation of the parallel light, when the parallel light is irradiated from the side of the second metal layer 19 away from the substrate 11 for a second photolithography process, the second photoresist layer 18 located on the surface of the protruding structure 15 is self-excited selectively photolithographically to form a target pattern.

[0064] Specifically, after optimizing the film thickness and the width of the protruding structure 15 based on the wavelength simulation of the parallel light, when the parallel light is irradiated from the side of the second metal layer 19 facing away from the substrate 11 for a second photolithography process, the second photoresist layer 18 located on the surface of the protruding structure 15 is subjected to self-excited selective photolithography to form a target pattern. One possible implementation method is:

[0065] Based on the wavelength simulation of the parallel light, the thickness of the thin film layer 16, the thickness of the first metal layer 17, the thickness of the photoresist layer 18, the thickness of the second metal layer 19 and the width of the protruding structure 15 are optimized. When the parallel light is irradiated from the side of the second metal layer 19 away from the substrate 11 for a second photolithography process, the second photoresist layer 18 located on the surface of the protruding structure 15 is self-excited selectively photolithographically to form a target pattern.

[0066] The simulation optimization method is a time-domain finite difference method, a finite element method or a rigorous coupled wave theory.

[0067] The wavelength of the parallel light is 193 nanometers, 248 nanometers, 365 nanometers, 436 nanometers, 532 nanometers, 633 nanometers or any wavelength in the visible light to ultraviolet light band.

[0068] The parallel light with interference properties can be modulated by a light source to illuminate the entire surface or a specific area of ​​the structure to be processed (the area where the protruding structure 15 is located is used as an example for illustration in the embodiment of the present invention) to perform a second photolithography process.

[0069] like Figure 9 As shown, after the second photolithography process, the second photoresist layer 18 in a specific area has a light intensity equidistant distribution feature (ie, the target pattern described above), which means that a self-excitation effect of resolution enhancement is achieved.

[0070] After optimizing the thickness of the thin film layer 16, the thickness of the first metal layer 17, the thickness of the photoresist layer 18, the thickness of the second metal layer 19 and the width of the protruding structure 15 based on the wavelength simulation of the parallel light, the division of specific areas can be achieved first, that is, the selective area lithography technology can be realized; and its structure will form a self-excitation effect between the wavelength of the parallel light in the second lithography process, which can form a nano-sized structure with enhanced resolution through interference excitation.

[0071] In summary, because both first metal layer 17 and second metal layer 19 are made of negative refractive index materials, and because there is a thickness difference between the second photoresist layer 18 and the first metal layer 17, the thickness of the layers and the width of the protruding structures 15 are optimized based on wavelength simulation of parallel light. This allows for enhanced resolution within the region corresponding to the protruding structures 15, resulting in a self-aligned photolithographic patterning effect with a self-excitation effect specific to the region corresponding to the protruding structures 15. Furthermore, the second photolithographic process does not require a mask, further reducing the process complexity.

[0072] In an optional embodiment of the present invention, the parallel light is incident vertically, or the parallel light is modulated by a light source and incident obliquely at a specific angle, and is irradiated from the side of the second metal layer 19 away from the substrate 11 for a second photolithography process.

[0073] The incident light includes two or more parallel light beams incident at opposite oblique angles.

[0074] Since self-excitation has a very high constraint on the size of the pattern, the scope of its application is generally very narrow. The structure in the technical solution of the present invention can greatly expand the scope of the area where the protrusion structure is located. Figure 10 , Figure 10 A schematic diagram of the self-excited resolution enhancement imaging effect corresponding to different widths of a protrusion structure provided by an embodiment of the present invention. Figure 10 In the figure, the widths of the protruding structures 15 are 0.2μm, 0.4μm, 0.6μm, 0.8μm, 1.2μm and 1.4μm as examples, i.e., Space=0.2μm, Space=0.4μm, Space=0.6μm, Space=0.8μm, Space=1.2μm and Space=1.4μm. Figure 10 The results shown show that when patterns of protrusion structures 15 with different widths are used, better self-excitation resolution enhancement imaging effects can be achieved.

[0075] S107: Figure 11-14 As shown, the target pattern is transferred onto the substrate 11.

[0076] Specifically, one possible way to transfer the target pattern onto the substrate 11 is:

[0077] like Figure 11 As shown, the second metal layer 19 is removed, and the second photoresist layer 18 is exposed and developed.

[0078] like Figure 12 As shown, the first metal layer 17 is etched based on the second photoresist layer 18 , and the second photoresist layer 18 is removed.

[0079] like Figure 13 As shown, the thin film layer 16 is etched based on the etched first metal layer 17 , and the first metal layer 17 is removed.

[0080] like Figure 14 As shown, the substrate 11 is etched based on the thin film layer 16 after the etching process, and the thin film layer 16 is removed.

[0081] In general, the process of transferring the target pattern to the substrate 11 includes the removal of the top second metal layer 19, the development and post-baking of the second photoresist layer 18, and the transfer etching of the multi-layer material. Figure 14 As shown in the effect, only the specific area defined in the first photolithography process has the nanoscale structure, that is, after the target pattern is transferred to the substrate 11, only the area of ​​the substrate 11 corresponding to the protruding structure 15 has the nanoscale structure.

[0082] refer to Figure 15 , Figure 15 A schematic diagram of the structure and imaging effect corresponding to the technical solution provided in an embodiment of the present invention. Figure 15 The results show that, given a specific film structure and multiple parameter simulation optimizations, after optimizing the film thickness and the width of the protruding structure 15 based on parallel light wavelength simulation, resolution enhancement can be achieved within the region corresponding to the protruding structure 15. This structure forms a sandwich structure comprising a second metal layer 19, a second photoresist layer 18, and a first metal layer 17 of varying thicknesses, and by optimizing parameters such as film thickness in different regions, a self-aligned photolithographic patterning effect is achieved, with a self-excitation effect specific to the region corresponding to the protruding structure 15.

[0083] The technical solution of the present application realizes self-aligned lithography at the graphic position after the first lithography process, and there is no need to consider the overlay alignment error problem caused by the two lithography processes; compared with traditional self-excitation, the second lithography process only performs self-excitation in a specific area after the first lithography process, achieving a selection effect; and it can also perform lithography on variable period graphics, expanding the complexity of the design rules of the lithography process.

[0084] The above is a detailed introduction to the self-excited lithography method with self-alignment effect provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0085] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0086] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that the process, method, article, or apparatus comprising a series of elements inherent to the elements, or also including elements inherent to these processes, methods, articles, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0087] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-excited photolithography method with a self-alignment effect, characterized in that: The self-excited photolithography method with self-alignment effect includes: Providing a structure to be processed, the structure to be processed comprising a substrate and a first photoresist layer located on one side of the substrate; Performing a first photolithography process and a pattern transfer process on the first photoresist layer based on a first mask to form a plurality of groove structures on the substrate, with a convex structure between two adjacent groove structures; Sequentially preparing a thin film layer and a first metal layer, wherein the thin film layer and the first metal layer located at the bottom of the groove structure have a height difference from the thin film layer and the first metal layer located on the surface of the protrusion structure; forming a second photoresist layer on a side of the first metal layer facing away from the substrate, wherein a surface of the second photoresist layer facing away from the substrate is parallel to a plane where the substrate is located; forming a second metal layer on a side of the second photoresist layer facing away from the substrate, wherein a surface of the second metal layer facing away from the substrate is parallel to a plane where the substrate is located; the first metal layer and the second metal layer are negative refractive index material layers; Determining the wavelength of parallel light having interference properties, and optimizing the film thickness and the width of the protruding structure based on the wavelength of the parallel light, and then performing self-excited selective photolithography on the second photoresist layer located on the surface of the protruding structure while irradiating the second metal layer with the parallel light from a side facing away from the substrate for a second photolithography process to form a target pattern; The target pattern is transferred onto the substrate.

2. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: After optimizing the film thickness and the width of the protruding structure based on the wavelength simulation of the parallel light, when the parallel light is irradiated from the side of the second metal layer facing away from the substrate for a second photolithography process, self-excited selective photolithography is performed on the second photoresist layer located on the surface of the protruding structure to form a target pattern, comprising: The thickness of the thin film layer, the thickness of the first metal layer, the thickness of the photoresist layer, the thickness of the second metal layer and the width of the protruding structure are optimized based on the wavelength simulation of the parallel light. When the parallel light is irradiated from the side of the second metal layer away from the substrate for a second photolithography process, the second photoresist layer located on the surface of the protruding structure is subjected to self-excited selective photolithography to form a target pattern.

3. The self-excited photolithography method with self-alignment effect according to claim 2, characterized in that: The simulation optimization method is a time-domain finite difference method, a finite element method or a rigorous coupled wave theory.

4. The self-excited photolithography method with self-alignment effect according to any one of claims 1 to 3, characterized in that: The wavelength of the parallel light is 193 nanometers, 248 nanometers, 365 nanometers, 436 nanometers, 532 nanometers or 633 nanometers.

5. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: After the target pattern is transferred onto the substrate, the region of the substrate corresponding to the protruding structure has a nanoscale structure.

6. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: The first photoresist layer is subjected to a first photolithography process and a pattern transfer process based on a first mask to form a plurality of groove structures on the substrate, with a convex structure between two adjacent groove structures, including: performing a first photolithography process on the first photoresist layer based on the first mask; The substrate is etched based on the first photoresist layer after the first photolithography process to form a plurality of groove structures on the substrate, with a convex structure between two adjacent groove structures.

7. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: The material of the first metal layer is the same as that of the second metal layer.

8. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: The step of transferring the target pattern onto the substrate comprises: removing the second metal layer; performing an etching process on the first metal layer based on the second photoresist layer, and removing the second photoresist layer; performing etching on the thin film layer based on the etched first metal layer, and removing the first metal layer; The substrate is etched based on the etched thin film layer, and the thin film layer is removed.

9. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: The parallel light is incident vertically, or the parallel light is modulated by a light source and incident obliquely at a specific angle, to irradiate the second metal layer from a side away from the substrate for a second photolithography process; The incident light includes two or more parallel light beams incident at opposite oblique angles.

10. The self-excited photolithography method with self-alignment effect according to claim 1, characterized in that: The width of the protruding structure is on the order of micrometers or nanometers or above.

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