Preparation process of metasurface optical device

Abstract

The invention provides a preparation process of a metasurface optical device, which comprises an optical film forming process of forming an optical film layer which is provided with at least two optical films which are arranged on a light receiving surface in parallel and are made of different materials on the light receiving surface of a substrate, the optical film forming process of each optical film comprises the following steps: forming a first photoresist layer on the whole light receiving surface; the first photoresist layer is exposed and developed, so that a light receiving surface at a preset area corresponding to the to-be-formed optical film is exposed outwards; the preset area of the light receiving surface is plated with a material corresponding to a to-be-formed optical film to form the optical film; the first photoresist layer is removed; the metasurface made of various materials is arranged on the same substrate, the structural design freedom degree of the metasurface is high, the working wave band of the metasurface is wider, different preset functions can be achieved, and machining of large-area and cross-scale metasurface optical devices can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a preparation process of a super-surface optical device. Background Art

[0002] Metasurface optical devices are composed of high-degree-of-freedom, non-periodic, densely arranged sub-wavelength unit structures on a two-dimensional plane. Metasurface optical devices are widely used in the field of optical design. Through metasurface design, lenses, polarization devices, optical computing, laser radar, etc. can be realized. Metasurface optical devices can almost replace all existing optical devices.

[0003] However, metasurface optical devices in the optical band (from ultraviolet, visible light to infrared light band) have put forward many extreme parameter requirements for the micro-nano processing technology of forming metasurfaces. For example, in the optical frequency band, the subwavelength unit structure requires an extremely small scale (for example, in the visible light band, the subwavelength unit structure size is required to be 15 to 400nm); in order to control the subwavelength unit structure size in the plane to achieve light field control, extremely high precision is required (for example, the 16th order phase in the visible light band requires a control precision of about 5nm); in order to achieve sufficiently high working efficiency, the subwavelength unit structure is generally composed of difficult-to-process high-refractive index dielectric materials, such as TiO2, GaN, Si3N4, HfO2, Si, etc.; in order to achieve multifunctional integration, such as monolithic broadband achromatic lenses, etc., it is necessary to process dielectric materials with extremely high aspect ratios; in order to realize large-area metasurface element processing, cross-scale (nanometers to meters), high-efficiency (TB data volume), and low-cost processing methods are required. However, the metasurface made of a single material has defects such as narrow working band, small design freedom, large aspect ratio and difficult processing. That is, when a single material is used to prepare metasurface optical devices, in the design of a wider working band, the sub-wavelength unit structure in the metasurface has a too large size span and the aspect ratio is too large. The actual preparation process cannot meet the processing requirements, that is, it is impossible to prepare a metasurface optical device that meets the requirements. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation process of a multi-material metasurface optical device.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a preparation process of a metasurface optical device, including an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of a substrate, wherein the optical film forming process of each optical film includes:

[0006] forming a first photoresist layer on the entire light-receiving surface;

[0007] Exposing and developing the first photoresist layer to expose the light-receiving surface at a preset area corresponding to the optical film to be formed to the outside;

[0008] Plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film;

[0009] The first photoresist layer is removed.

[0010] To achieve the above-mentioned object of the invention, the present invention further provides a preparation process of a metasurface optical device, including an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of a substrate, wherein the optical film forming process of each of the optical films includes:

[0011] The light-receiving surface is entirely coated with a material corresponding to the optical film to be formed to form an initial film layer;

[0012] forming a second photoresist layer on the entire surface of the initial film layer;

[0013] exposing and developing the second photoresist layer to expose the other regions of the initial film layer except the region corresponding to the optical film to be formed;

[0014] Etching and removing the initial film layer in the other regions;

[0015] The second photoresist layer is removed.

[0016] To achieve the above-mentioned purpose of the invention, the present invention also provides a preparation process of a metasurface optical device, including an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of a substrate, the optical film forming process including a first optical film forming process and a second optical film forming process, part of the at least two optical films are prepared by the first optical film forming process, and the other part of the optical films are prepared by the second optical film forming process, wherein the first optical film forming process includes the following steps:

[0017] forming a first photoresist layer on the entire light-receiving surface;

[0018] Exposing and developing the first photoresist layer to expose the light-receiving surface at a preset area corresponding to the optical film to be formed to the outside;

[0019] Plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film;

[0020] removing the first photoresist layer;

[0021] The second optical film forming process includes the following steps:

[0022] The light-receiving surface is entirely coated with a material corresponding to the optical film to be formed to form an initial film layer;

[0023] forming a second photoresist layer on the entire surface of the initial film layer;

[0024] exposing and developing the second photoresist layer to expose the other regions of the initial film layer except the region corresponding to the optical film to be formed;

[0025] Etching and removing the initial film layer in the other regions;

[0026] The second photoresist layer is removed.

[0027] As a further improved technical solution of the present invention, after the optical film is formed on the light-receiving surface, the preparation process also includes a super-surface forming process of patterning the optical film layer to form a super-surface.

[0028] As a further improved technical solution of the present invention, the super surface forming process includes:

[0029] forming a third photoresist layer on the entire surface of the optical film layer;

[0030] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern in the third photoresist layer is the same as the super surface pattern;

[0031] Using the patterned third photoresist layer as an etching mask, etching the optical film layer to copy the metasurface pattern onto the optical film layer;

[0032] The third photoresist layer is removed.

[0033] As a further improved technical solution of the present invention, the super surface forming process includes:

[0034] forming a third photoresist layer on the entire surface of the optical film layer;

[0035] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern in the third photoresist layer is opposite to the super surface pattern;

[0036] Plating the patterned third photoresist layer to form a first mask layer;

[0037] Removing the third photoresist layer and the first mask layer located on the surface of the third photoresist layer to obtain a patterned first super surface mask;

[0038] Etching the optical film layer with a patterned first supersurface mask to copy the supersurface pattern onto the optical film layer;

[0039] The first metasurface mask is removed.

[0040] As a further improved technical solution of the present invention, “patterning the optical film layer” is: patterning each optical film in sequence.

[0041] As a further improved technical solution of the present invention, patterning each optical film includes the following steps:

[0042] forming a third photoresist layer on the entire surface of the optical film layer;

[0043] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is the same as the super-surface pattern corresponding to the optical film to be patterned, and the third photoresist layer covers other optical films except the optical film to be patterned;

[0044] Using the patterned third photoresist layer as an etching mask, etching the optical film to be patterned, and copying the metasurface pattern corresponding to the optical film to be patterned onto the optical film to be patterned;

[0045] The third photoresist layer is removed.

[0046] As a further improved technical solution of the present invention, patterning each optical film includes the following steps:

[0047] forming a third photoresist layer on the entire surface of the optical film layer;

[0048] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is opposite to the super-surface pattern corresponding to the optical film to be patterned, and other optical films except the optical film to be patterned are exposed outward from the third photoresist layer;

[0049] coating the patterned third photoresist layer to form a second mask layer;

[0050] Removing the third photoresist layer and the second mask layer located on the surface of the third photoresist layer to obtain a patterned second super surface mask;

[0051] Etching the optical film to be patterned with the patterned second metasurface mask to copy the metasurface pattern corresponding to the optical film to be patterned onto the optical film;

[0052] The second metasurface mask is removed.

[0053] As a further improved technical solution of the present invention, the super surface forming process includes a first super surface forming process and a second super surface forming process, part of the optical film is formed by the first super surface forming process, and the other part of the optical film is formed by the second super surface forming process; the patterning of each optical film in the first super surface forming process includes the following steps

[0054] forming a third photoresist layer on the entire surface of the optical film layer;

[0055] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is opposite to the super-surface pattern corresponding to the optical film to be patterned, and other optical films except the optical film to be patterned are exposed outward from the third photoresist layer;

[0056] coating the patterned third photoresist layer to form a second mask layer;

[0057] Removing the third photoresist layer and the second mask layer located on the surface of the third photoresist layer to obtain a patterned second super surface mask;

[0058] Etching the optical film to be patterned with the patterned second metasurface mask to copy the metasurface pattern corresponding to the optical film to be patterned onto the optical film;

[0059] removing the second metasurface mask;

[0060] The patterning of each optical film in the second super surface forming process includes the following steps

[0061] forming a third photoresist layer on the entire surface of the optical film layer;

[0062] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is the same as the super-surface pattern corresponding to the optical film to be patterned, and the third photoresist layer covers other optical films except the optical film to be patterned;

[0063] Using the patterned third photoresist layer as an etching mask, etching the optical film to be patterned, and copying the metasurface pattern corresponding to the optical film to be patterned onto the optical film to be patterned;

[0064] The third photoresist layer is removed.

[0065] As a further improved technical solution of the present invention, after removing the second supersurface mask, patterning each optical film also includes the following steps: filling a protective material on the patterned optical film to form a protective layer, wherein the thickness of the protective layer is greater than the thickness of the patterned optical film.

[0066] As a further improved technical solution of the present invention, the light refractive index of the protective material is less than 1.5.

[0067] The beneficial effects of the present invention are as follows: in the preparation process of the metasurface optical device of the present invention, by arranging a metasurface with a variety of materials on the same substrate, the metasurface structure has a high degree of freedom in design, and the working band of the metasurface is made wider, different preset functions can be realized, and large-area, cross-scale metasurface optical devices can be processed. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1(a) to Figure 1(h) is a step diagram of a first embodiment of an optical film forming process;

[0069] Figure 2(a) to Figure 2(i) is a step diagram of a second embodiment of an optical film forming process;

[0070] Figure 3(a) to Figure 3(i) is a step diagram of a third embodiment of an optical film forming process;

[0071] Figure 4(a) to Figure 4(e) is a step diagram of a first embodiment of a super surface forming process;

[0072] Figure 5(a) to Figure 5(f) is a step diagram of a second embodiment of the super surface forming process;

[0073] Figure 6(a) to Figure 6(j) is a step diagram of a third embodiment of the super surface forming process;

[0074] Figure 7(a) to Figure 7(l) is a step diagram of a fourth embodiment of the super surface forming process;

[0075] Figure 8(a) to Figure 8(r) is a step diagram of a fifth embodiment of the super surface forming process;

[0076] Figure 9(a) to Figure 9(k) This is a step diagram of the sixth implementation method of the super surface forming process. DETAILED DESCRIPTION

[0077] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings. Please refer to Figures 1 to 9, which are preferred embodiments of the present invention. However, it should be noted that these embodiments are not limitations of the present invention, and equivalent changes or substitutions in functions, methods, or structures made by ordinary technicians in the field according to these embodiments are all within the protection scope of the present invention.

[0078] In conjunction with FIGS. 1 to 9 , the present invention provides a preparation process for a metasurface optical device 100, the preparation process comprising an optical film forming process of forming an optical film layer 20 having at least two optical films of different materials arranged in parallel on the light-receiving surface of a substrate 10, and a metasurface forming process of patterning the optical film layer 20 to form a metasurface 30. In the present invention, by arranging a metasurface 30 having a plurality of materials on the same substrate 10, the structural design freedom of the metasurface 30 is high, and the working band of the metasurface 30 is made wider, so that different preset functions can be realized, and the processing of a large-area, cross-scale metasurface optical device 100 can be realized.

[0079] Specifically, the material and thickness of the substrate 10 can be selected according to the application adaptability of the metasurface optical device 100. The material of the substrate 10 can be silicon wafer or optical glass, but it is not limited thereto.

[0080] Specifically, the material and thickness of each optical film can be selected according to specific requirements, such as the working band, structure, function, etc. of the metasurface 30. The materials of the optical film include but are not limited to: TiO2, A-Si, HfO2, SI3N4, TaO2, MgF2, ZnS, H4, SIO2.

[0081] Furthermore, before the optical film forming process, the preparation process further includes: forming a plurality of reference points on the substrate 10. The reference points are used as reference points in the subsequent optical film forming process and the super surface forming process, and can ensure the process accuracy.

[0082] Please refer to Figure 1(a) to Figure 1(h) As shown, it is a first embodiment of the optical film forming process of the present invention, and the optical film forming process of each optical film includes:

[0083] forming a first photoresist layer on the entire light-receiving surface;

[0084] Exposing and developing the first photoresist layer to expose the light-receiving surface at a preset area corresponding to the optical film to be formed to the outside;

[0085] Plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film;

[0086] The first photoresist layer is removed.

[0087] It is known that after the first photoresist layer is removed after forming an optical film, the optical film is formed only in the preset area of ​​the substrate. When forming other optical films subsequently, the above steps are repeated to form the optical film layer on the light-receiving surface, and the optical film layer has at least two optical films of different materials arranged side by side on the light-receiving surface.

[0088] It is known that the exposure and development of the first photoresist layer is specifically as follows:

[0089] Covering the first photoresist layer with a first mask, and then exposing;

[0090] Development was performed using TMAH solution;

[0091] After development, rinse with deionized water to fix the image.

[0092] When the first photoresist layer is a positive photoresist, the corresponding first mask is a positive photoresist mask, and the first mask has an opening at a position corresponding to the optical film to be formed, so that after development and exposure, the light-receiving surface of the preset area corresponding to the optical film to be formed is exposed from the first photoresist layer 1. When the first photoresist layer is a negative photoresist, the first mask is a negative photoresist mask, and the first mask only shields the preset area on the first photoresist layer corresponding to the optical film to be formed, so that after development and exposure, the light-receiving surface of the preset area corresponding to the optical film to be formed is exposed from the first photoresist layer.

[0093] When the first mask is placed on the first photoresist layer, the first mask is aligned using a reference point located on the substrate as a reference point.

[0094] In this embodiment, the step of "plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film" is specifically: using physical vapor deposition technology to plate the optical film, at this time, after the coating, the optical film is formed at the preset area and on the first photoresist layer. It is known that the optical film located on the first photoresist layer is removed synchronously when the first photoresist layer is subsequently removed, and finally, only the optical film at the preset area is retained. Of course, this is not limited to this. In other embodiments, the film can also be plated only at the preset area so that the optical film is formed only at the preset area.

[0095] Below, taking two optical films made of different materials arranged side by side on the light-receiving surface as an example, the first embodiment of the optical film forming process in the present invention is specifically explained as follows. Of course, it is not limited to this. It can be understood that when three or more optical films made of different materials are formed and arranged side by side on the light-receiving surface, it is only necessary to repeat the forming process of each corresponding optical film.

[0096] Specifically, combined Figure 1(a) to Figure 1(h)As shown, two optical films of different materials arranged in parallel are defined as a first optical film 201 and a second optical film 202, the area corresponding to the light-receiving surface and the first optical film 201 is a first area 101, and the area corresponding to the light-receiving surface and the second optical film 202 is a second area 102. The material of the first optical film 201 is a first material, and the material of the second optical film 202 is a second material, and the first material and the second material are different.

[0097] Combination Figure 1(a) to Figure 1(h) As shown, in a specific embodiment, the optical film forming process is to first form the second optical film 202 and then form the first optical film 201. Of course, this is not limited to this.

[0098] Specifically, combined Figure 1(a) to Figure 1(d) As shown, the optical film forming process for forming the second optical film 202 includes the following steps:

[0099] As shown in FIG. 1( a ), a first photoresist layer 1 is formed on the entire light-receiving surface of the substrate 10 . At this time, the light-receiving surface is a flat light-receiving surface;

[0100] As shown in FIG. 1( b ), the first photoresist layer 1 is exposed and developed to remove the first photoresist layer 1 at the second region 102 , so that the second region 102 is exposed to the outside;

[0101] As shown in FIG. 1( c ), a second material is plated at the second region 102 to form an optical film;

[0102] As shown in FIG. 1( d ), the first photoresist layer 1 is removed.

[0103] In the optical film forming process of forming the second optical film 202, after removing the first photoresist layer 1, the first photoresist layer 1 and the optical film formed of the second material located on the first photoresist layer 1 are removed simultaneously. At this time, only the optical film in the second area 102 is retained, that is, the second optical film 202.

[0104] Combination Figure 1(e) to Figure 1(h) As shown, the optical film forming process for forming the first optical film 201 includes the following steps:

[0105] As shown in FIG. 1( e ), a first photoresist layer 1 ′ is formed on the entire light-receiving surface having the second optical film 202 . At this time, the first photoresist layer 1 ′ covers the first region 101 of the light-receiving surface and the second optical film 202 .

[0106] As shown in FIG. 1( f ), the first photoresist layer 1 ′ is exposed and developed to remove the first photoresist layer 1 ′ at the first region 101 . At this time, the first photoresist layer 1 ′ only covers the second optical film 202 .

[0107] As shown in FIG. 1( g ), a first material is plated at the first region 101 to form an optical film;

[0108] As shown in FIG. 1( h ), the first photoresist layer 1 ′ is removed.

[0109] In the optical film forming process of forming the first optical film 201, after removing the first photoresist layer 1', the first photoresist layer 1' and the optical film formed of the first material located on the first photoresist layer 1' are removed simultaneously, and only the optical film in the first area 101, i.e., the first optical film 201, is retained. At this time, the first optical film 201 and the second optical film 202 are arranged side by side on the light receiving surface to form the optical film layer 20.

[0110] Please refer to Figure 2(a)~2(i) As shown, it is a second embodiment of the optical film forming process of the present invention, and the optical film forming process of each optical film includes:

[0111] The light-receiving surface is entirely coated with a material corresponding to the optical film to be formed to form an initial film layer;

[0112] forming a second photoresist layer on the entire surface of the initial film layer;

[0113] exposing and developing the second photoresist layer to expose the other regions of the initial film layer except the region corresponding to the optical film to be formed;

[0114] Etching and removing the initial film layer in the other regions;

[0115] The second photoresist layer is removed.

[0116] It is known that after forming an optical film and removing the second photoresist layer, the optical film is formed only in the preset area of ​​the substrate. When forming other optical films subsequently, the above steps are repeated to form the optical film layer on the light-receiving surface, and the optical film layer has at least two optical films of different materials arranged side by side on the light-receiving surface.

[0117] Specifically, the order of forming the optical films can be based on the thickness of the optical films, such as forming a thinner optical film first and then forming a thicker optical film, so that the initial film layer formed subsequently can completely cover the previously formed optical film. Of course, this is not limited to this.

[0118] It is known that the above-mentioned exposure and development of the second photoresist layer is specifically as follows:

[0119] Covering the second photoresist layer with a second mask, and then exposing;

[0120] Development was performed using TMAH solution;

[0121] After development, rinse with deionized water to fix the image.

[0122] When the second mask is placed on the second photoresist layer, the second mask is aligned using a reference point located on the substrate as a reference point.

[0123] It is known that after the second photoresist layer is exposed and developed, the second photoresist layer covers the initial film layer in the preset area corresponding to the optical film to be formed. During the subsequent etching, the initial film layer not covered by the second photoresist layer is etched away, and the initial film layer covered by the second photoresist layer is protected by the second photoresist layer and retained. After the etching is completed and the second photoresist layer on the retained initial film layer is removed, the optical film of the preset material is formed on the light receiving surface.

[0124] Below, taking two optical films made of different materials arranged side by side on the light-receiving surface as an example, the second embodiment of the optical film forming process in the present invention is specifically explained as follows. Of course, it is not limited to this. It can be understood that when three or more optical films made of different materials are formed and arranged side by side on the light-receiving surface, it is only necessary to repeat the forming process of each corresponding optical film.

[0125] Specifically, combined Figure 2(a)~2(i) As shown, two optical films of different materials arranged in parallel are defined as a first optical film 201 and a second optical film 202, the area corresponding to the light-receiving surface and the first optical film 201 is a first area 101, and the area corresponding to the light-receiving surface and the second optical film 202 is a second area 102. The material of the first optical film 201 is a first material, and the material of the second optical film 202 is a second material, and the first material and the second material are different.

[0126] In a specific embodiment, the optical film forming process is to first form the first optical film 201 and then form the second optical film 202 .

[0127] Specifically, combined Figure 2(a) to Figure 2(d) As shown, the optical film forming process for forming the first optical film 201 includes the following steps:

[0128] As shown in FIG. 2( a ), the first material is plated on the entire light-receiving surface of the substrate 10 to form an initial film layer 2 . At this time, the light-receiving surface is a flat light-receiving surface.

[0129] forming a second photoresist layer 3 on the entire surface of the initial film layer 2;

[0130] As shown in FIG. 2( b ), the second photoresist layer 3 is exposed and developed so that the initial film layer 2 located in the second region 102 is exposed to the outside, that is, the second photoresist layer 3 located in the second region 102 is removed;

[0131] As shown in FIG. 2( c ), the initial film layer 2 at the second region 102 is etched away;

[0132] As shown in FIG. 2( d ), the second photoresist layer 3 is removed.

[0133] In the optical film forming process of forming the first optical film 201 , after removing the second photoresist layer 3 , the initial film layer 2 located in the first area 101 is exposed, thereby forming the first optical film 201 located in the first area 101 .

[0134] Combination Figure 2(e) to Figure 2(i) As shown, the optical film forming process for forming the second optical film 202 includes the following steps:

[0135] As shown in FIG. 2( e ), the light-receiving surface having the first optical film 201 is entirely coated with a second material to form an initial film layer 2 ′. At this time, the initial film layer 2 ′ covers the second region 102 of the light-receiving surface and the first optical film 201 ;

[0136] As shown in FIG. 2( f ), a second photoresist layer 3 'is formed on the entire surface of the initial film layer 2 ';

[0137] As shown in FIG. 2( g ), the second photoresist layer 3 ′ is exposed and developed, that is, the second photoresist layer 3 ′ located in the first region 101 is removed. At this time, the first optical film 201 and the initial film layer 2 ′ are sequentially stacked upward in the first region 101, and the second photoresist layer 3 ′ covers the initial film layer 2 ′ at the second region 102;

[0138] As shown in FIG. 2( h ), the initial film layer 2 ′ in the first region 101 is etched away, and the first optical film 201 in the first region 101 is retained;

[0139] As shown in FIG. 2( i ), the second photoresist layer 3 ′ is removed.

[0140] In the optical film forming process of forming the second optical film 202 , after removing the second photoresist layer 3 ′, the first optical film 201 and the second optical film 202 are arranged side by side on the light receiving surface to form the optical film layer 20 .

[0141] Please refer to Figure 3(a) to Figure 3(i)As shown, it is the third embodiment of the optical film forming process of the present invention. In this embodiment, the optical film forming process includes different first optical film forming processes and second optical film forming processes. Part of the optical films of at least two optical films are prepared by the first optical film forming process, and the other part of the optical films are prepared by the second optical film forming process. Among them, the first optical film forming process is the first embodiment of the optical film forming process mentioned above, and the second optical film forming process is the second embodiment of the optical film forming process mentioned above.

[0142] The first and second embodiments of the optical film forming process are as described above and will not be described in detail herein.

[0143] Below, in combination with Figures 3(a) to 3(i), taking two optical films made of different materials arranged in parallel on the light-receiving surface as an example, the third embodiment of the optical film forming process in the present invention is specifically described as follows. Of course, it is not limited to this. It can be understood that when three or more optical films made of different materials are arranged in parallel on the light-receiving surface, it is only necessary to select one optical film forming process for corresponding forming.

[0144] Specifically, two optical films of different materials arranged in parallel are defined as a first optical film 201 and a second optical film 202, the area corresponding to the light-receiving surface of the first optical film 201 is a first area 101, and the area corresponding to the light-receiving surface of the second optical film 202 is a second area 102. The material of the first optical film 201 is a first material, the material of the second optical film 202 is a second material, and the first material is different from the second material.

[0145] Specifically, the optical film forming process is to first form the second optical film 202, and then form the first optical film 201. Moreover, the second optical film 202 is formed by the optical film forming process in the first embodiment, and the first optical film 201 is formed by the optical film forming process in the second embodiment. Of course, this is not limited to this. In other examples, the first optical film 201 can be formed by the optical film forming process in the first embodiment, and the second optical film 202 can be formed by the optical film forming process in the second embodiment. The specific process selection can be set and selected according to specific needs.

[0146] Specifically, as shown in FIG. 3( a) to FIG. 3( d ), the optical film forming process for forming the second optical film 202 includes the following steps:

[0147] As shown in FIG. 3( a ), a first photoresist layer 1 is formed on the entire light-receiving surface of the substrate 10 . At this time, the light-receiving surface is a flat light-receiving surface;

[0148] As shown in FIG. 3( b ), the first photoresist layer 1 is exposed and developed to remove the first photoresist layer 1 at the second region 102 , so that the second region 102 is exposed to the outside;

[0149] As shown in FIG. 3( c ), a second material is plated at the second region 102 to form an optical film;

[0150] As shown in FIG. 3( d ), the first photoresist layer 1 is removed.

[0151] In the optical film forming process of forming the second optical film 202, after removing the first photoresist layer 1, the first photoresist layer 1 and the optical film formed of the second material located on the first photoresist layer 1 are removed simultaneously. At this time, only the optical film in the second area 102, that is, the second optical film 202, is retained.

[0152] Combination Figure 3(e) to Figure 3(i) As shown, the optical film forming process for forming the first optical film 201 includes the following steps:

[0153] As shown in FIG. 3( e ), the first material is plated on the entire light-receiving surface having the second optical film 202 to form an initial film layer 2 . At this time, the initial film layer 2 covers the first region 101 of the light-receiving surface and the second optical film 202 .

[0154] As shown in FIG. 3( f ), a second photoresist layer 3 is formed on the entire surface of the initial film layer 2 ;

[0155] As shown in FIG. 3( g ), the second photoresist layer 3 is exposed and developed to remove the second photoresist layer 3 located in the second region 102, so that the initial film layer 2 located in the second region 102 is exposed to the outside. At this time, the second optical film 202 and the initial film layer 2 are sequentially stacked upward in the second region 102;

[0156] As shown in FIG. 3( h ), the initial film layer 2 in the second region 102 is etched away, and the second optical film 202 in the second region 102 is retained;

[0157] As shown in FIG. 3( i ), the second photoresist layer 3 is removed.

[0158] In the optical film forming process of forming the first optical film 201 , after removing the second photoresist layer 3 , the first optical film 201 and the second optical film 202 are arranged side by side on the light receiving surface to form the optical film layer 20 .

[0159] Please refer to Figure 4(a) to Figure 4(e) As shown, it is a first embodiment of the super surface forming process of the present invention. In this embodiment, the super surface forming process includes:

[0160] As shown in FIG. 4( a ), a third photoresist layer 4 is formed on the entire surface of the optical film layer 20 ;

[0161] As shown in FIG. 4( b ), the third photoresist layer 4 is exposed and developed to form a patterned third photoresist layer 4 , wherein the pattern in the third photoresist layer 4 is the same as the pattern of the super surface 30 ;

[0162] As shown in FIG. 4( d ), the optical film layer 20 is etched using the patterned third photoresist layer 4 as an etching mask, and the pattern of the super surface 30 is copied onto the optical film layer 20 ;

[0163] As shown in FIG. 4( e ), the third photoresist layer 4 is removed.

[0164] After removing the third photoresist layer 4 , a super surface 30 is formed on the light-receiving surface of the substrate 10 .

[0165] Specifically, “forming a third photoresist layer 4 on the entire surface of the optical film layer 20 ” specifically includes: spin coating photoresist on the surface of the optical film layer 20 away from the substrate 10 , and then baking the photoresist to form the third photoresist layer 4 .

[0166] “Exposing and developing the third photoresist layer 4 to form a patterned third photoresist layer 4” specifically includes:

[0167] Covering the third photoresist layer 4 with a third mask, and then exposing;

[0168] Development was performed using TMAH solution;

[0169] After development, rinse with deionized water to fix the image.

[0170] When the third photoresist layer 4 is a positive photoresist, the corresponding third mask is a positive photoresist mask, and the opening pattern on the third mask is opposite to the pattern of the super surface 30, so that the third photoresist layer 4 after development and exposure forms a patterned third photoresist layer 4 with the same pattern as the super surface 30. When the third photoresist layer 4 is a negative photoresist, the third mask is a negative photoresist mask, and the opening pattern on the third mask is the same as the pattern of the super surface 30, so that the third photoresist layer 4 after development and exposure forms a patterned third photoresist layer 4 with the same pattern as the super surface 30.

[0171] In this embodiment, a high-precision ultraviolet lithography process is used to expose and develop the third photoresist layer 4 to form a patterned third photoresist layer 4. Of course, this is not limited to this. In other embodiments, an electron beam lithography process may also be used to expose and develop the third photoresist layer 4 to form a patterned third photoresist layer 4.

[0172] When the third mask is placed on the third photoresist layer 4 , the third mask is aligned using the reference point located on the substrate 10 as a reference point.

[0173] Further, as shown in FIG4(c), after the third photoresist layer 4 is exposed and developed to form a patterned third photoresist layer 4, and before the optical film layer 20 is etched, the super surface forming process further includes the following steps: PEB baking the substrate 10 having the patterned third photoresist layer 4. The patterned third photoresist layer 4 is further cross-linked and more resistant to subsequent etching.

[0174] Specifically, the third photoresist layer 4 can be removed by a wet stripping process, such as by using a heated NMP solvent, but this is not limiting.

[0175] Please refer to Figures 5(a) to 5(f) As shown, it is a second embodiment of the super surface forming process of the present invention. In this embodiment, the super surface forming process includes:

[0176] As shown in FIG. 5( a ), a third photoresist layer 4 a is formed on the entire surface of the optical film layer 20 ;

[0177] As shown in FIG. 5( b ), the third photoresist layer 4 a is exposed and developed to form a patterned third photoresist layer 4 a , wherein the pattern in the third photoresist layer 4 a is opposite to the pattern of the super surface 30 ;

[0178] As shown in FIG. 5( c ), the patterned third photoresist layer 4 a is plated to form a first mask layer 5 ;

[0179] As shown in FIG. 5( d ), the third photoresist layer 4 and the first mask layer 5 located on the surface of the third photoresist layer 4 are removed to obtain a patterned first supersurface mask 6 ;

[0180] As shown in FIG. 5( e ), the optical film layer 20 is etched with the patterned first supersurface mask 6 to copy the pattern of the supersurface 30 onto the optical film layer 20 ;

[0181] As shown in FIG. 5( f ), the first supersurface mask 6 is removed to form the supersurface 30 on the light-receiving surface.

[0182] Compared with the first embodiment, in this embodiment, when etching the optical film layer 20, a first mask layer 5 is additionally provided to avoid the situation where the etching selectivity ratio is insufficient.

[0183] Specifically, a first mask layer made of a metal material such as Cr, Al, or a first mask layer 5 made of a non-metal material such as SIO2 may be used.

[0184] It is known that the pattern in the third photoresist layer 4 is opposite to the pattern of the super surface 30, and the first mask layer 5 is backfilled in the groove in the patterned third photoresist layer 4, that is, the pattern of the first mask layer 5 is also opposite to the pattern of the third photoresist layer 4, so that after removing the third photoresist layer 4 and the first mask layer 5 located on the surface of the third photoresist layer 4, the obtained patterned first super surface mask 6 is the same as the pattern of the super surface 30. Under the masking action of the remaining patterned first super surface mask 6, the optical film layer 20 is etched, and the pattern of the first super surface mask 6 can be transferred to the optical film layer 20, forming a super surface 30 located on the light receiving surface of the substrate 10.

[0185] Specifically, “forming a third photoresist layer 4 on the entire surface of the optical film layer 20 ” specifically includes: spin coating photoresist on the surface of the optical film layer 20 away from the substrate 10 , and then baking the photoresist to form the third photoresist layer 4 .

[0186] In this embodiment, a high-precision ultraviolet lithography process is also used to expose and develop the third photoresist layer 4 to form a patterned third photoresist layer 4. Of course, this is not limited to this. In other embodiments, an electron beam lithography process may also be used to expose and develop the third photoresist layer 4 to form a patterned third photoresist layer 4.

[0187] Specifically, “exposing and developing the third photoresist layer 4 to form a patterned third photoresist layer 4” specifically includes:

[0188] Covering the third photoresist layer 4 with a third mask, and then exposing;

[0189] Development was performed using TMAH solution;

[0190] After development, rinse with deionized water to fix the image.

[0191] When the third photoresist layer 4 is a positive photoresist, the corresponding third mask is a positive photoresist mask, and the opening pattern on the third mask is the same as the pattern of the super surface 30, so that the third photoresist layer 4 after development and exposure forms a patterned third photoresist layer 4 opposite to the pattern of the super surface 30. When the third photoresist layer 4 is a negative photoresist, the third mask is a negative photoresist mask, and the opening pattern on the third mask is opposite to the pattern of the super surface 30, so that the third photoresist layer 4 after development and exposure forms a patterned third photoresist layer 4 opposite to the pattern of the super surface 30.

[0192] Furthermore, “coating the patterned third photoresist layer 4 to form the first mask layer 5” can specifically be performed by electron beam evaporation or sputtering of metal materials such as Cr, Al to form the first mask layer 5 or non-metallic materials such as SIO2 to form the first mask layer 5.

[0193] The removal method of the first super surface mask 6 can select a dry process or a wet process. For example, when the first super surface mask 6 is chromium, use ammonium cerium nitrate wet removal, or Cl2+O2 dry removal; when the first super surface mask 6 is SIO2, use hydrofluoric acid wet removal or CHF3, CF4 dry removal, etc., as long as the substrate 10 and the optical film are not damaged when removing the first super surface mask 6, and the removal is fast and simple, and there will be no parameters of other reactions and no residue.

[0194] Specifically, the third photoresist layer 4 can be removed by a wet stripping process, such as by using a heated NMP solvent, but this is not limiting.

[0195] Please refer to Figures 6(a) to 6(j) As shown, it is the third embodiment of the super surface forming process of the present invention. The difference between this embodiment and the first and second embodiments of the super surface forming process is that: the "patterning the optical film layer 20" in the super surface forming process is: patterning each optical film in turn. It is known that when etching a certain optical film, the other optical films are protected by the corresponding masks, so they will not be affected. It can avoid the simultaneous etching of multiple optical films affecting each other and thus affecting the final etching effect, and the film thickness of each optical film is not affected by the etching selectivity, and the film thickness of each optical film can be set according to specific needs.

[0196] In this embodiment, patterning each optical film includes the following steps:

[0197] forming a third photoresist layer on the entire surface of the optical film layer;

[0198] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is the same as the super-surface pattern corresponding to the optical film to be patterned, and the third photoresist layer covers other optical films except the optical film to be patterned;

[0199] Using the patterned third photoresist layer as an etching mask, etching the optical film to be patterned, and copying the metasurface pattern corresponding to the optical film to be patterned onto the optical film to be patterned;

[0200] The third photoresist layer is removed.

[0201] It can be known that, in this embodiment, the patterned third photoresist layer will shield other optical films except the optical film to be patterned. When the optical film to be patterned is etched, the third photoresist layer will protect other optical films from being etched. At the same time, the pattern on the patterned third photoresist layer can be copied to the optical film to be patterned to form a patterned optical film.

[0202] Furthermore, after forming the patterned third photoresist layer and before etching the optical film to be patterned, patterning each optical film further includes the following steps: PEB baking the patterned third photoresist layer, so that the patterned third photoresist layer further undergoes cross-linking reaction and is more resistant to subsequent etching.

[0203] The forming method, exposure, development and removal method of the third photoresist layer in this embodiment can follow the existing technology, or can adopt the corresponding forming method, exposure, development and removal method in the first embodiment, which will not be repeated here.

[0204] Below, the super surface forming process in this embodiment is described by taking the light receiving surface having two optical films of different materials arranged in parallel as an example. Specifically, the two optical films of different materials are a first optical film 201 and a second optical film 202, wherein the material of the first optical film 201 is a first material, and the material of the second optical film 202 is a second material, and the first material is different from the second material. The light receiving surface is provided with the first optical film 201 as the first area 101, and the light receiving surface is provided with the second optical film 202 as the second area 102. Of course, this is not limited to this.

[0205] Combination Figures 6(a) to 6(j) As shown, the super surface forming process is to pattern the first optical film 201 first, and then pattern the second optical film 202.

[0206] Specifically, combined Figure 6(a)~6(e) As shown, patterning the first optical film 201 includes the following steps:

[0207] As shown in FIG. 6 (a), a third photoresist layer 4b is formed on the entire surface of the optical film layer 20. At this time, the third photoresist layer 4b covers the first optical film 201 and the second optical film 202;

[0208] As shown in FIG. 6( b), the third photoresist layer 4b is exposed and developed to form a patterned third photoresist layer 4b, wherein the pattern of the third photoresist layer 4b is the same as the pattern of the super surface 30 corresponding to the first optical film 201, and at this time, the third photoresist layer 4b covers the second optical film 202;

[0209] As shown in FIG. 6( c ), the patterned third photoresist layer 4 b is subjected to PEB baking;

[0210] As shown in FIG. 6( d ), the first optical film 201 is etched using the patterned third photoresist layer 4 b as an etching mask, and the pattern of the supersurface 30 corresponding to the first optical film 201 is copied onto the first optical film 201 to form a patterned first optical film 201;

[0211] As shown in FIG. 6( e ), the third photoresist layer 4 b is removed.

[0212] When patterning the first optical film 201, the patterned third photoresist layer 4b is used as an etching mask to etch the first optical film 201. The third photoresist layer 4b shields the second optical film 202 to protect the second optical film 202, thereby etching only the first optical film 201. After removing the third photoresist layer 4b, the second optical film 202 and the patterned first optical film 201 are both exposed, so as to facilitate the subsequent patterning of the second optical film 202.

[0213] Combination Figure 6(f) to Figure 6(j) As shown, patterning the second optical film 202 includes the following steps:

[0214] As shown in FIG. 6( f ), a third photoresist layer 4 b ′ is formed on the patterned first optical film 201 and the second optical film 202 . At this time, the third photoresist layer 4 b ′ covers the second optical film 202 and the patterned first optical film 201 .

[0215] As shown in FIG. 6( g), the third photoresist layer 4b' is exposed and developed to form a patterned third photoresist layer 4b', wherein the pattern of the third photoresist layer 4b' is the same as the pattern of the super surface 30 corresponding to the second optical film 202, and at this time, the third photoresist layer 4b' covers the patterned first optical film 201;

[0216] As shown in FIG. 6( h ), the patterned third photoresist layer 4 b ′ is subjected to PEB baking;

[0217] As shown in FIG. 6 (i), the second optical film 202 is etched using the patterned third photoresist layer 4b' as an etching mask, and the pattern of the supersurface 30 corresponding to the second optical film 202 is copied onto the second optical film 202 to form a patterned second optical film 202;

[0218] As shown in FIG. 6( j ), the third photoresist layer 4 b ′ is removed.

[0219] When the second optical film 202 is patterned, the patterned third photoresist layer 4b' is used as an etching mask to etch the second optical film 202. The third photoresist layer 4b' covers the patterned first optical film 201 to protect the first optical film 201, thereby etching only the second optical film 202. After the third photoresist layer 4b' is removed, the patterned second optical film 202 and the patterned first optical film 201 are both exposed to form a super surface 30.

[0220] Please refer to Figures 7(a) to 7(l) As shown, this is the fourth embodiment of the super surface forming process of the present invention. The difference between this embodiment and the third embodiment of the super surface forming process is that when etching the patterned optical film, the mask is different to avoid insufficient etching selectivity.

[0221] In this embodiment, patterning each optical film includes the following steps:

[0222] forming a third photoresist layer on the entire surface of the optical film layer;

[0223] Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is opposite to the super-surface pattern corresponding to the optical film to be patterned, and other optical films except the optical film to be patterned are exposed outward from the third photoresist layer;

[0224] coating the patterned third photoresist layer to form a second mask layer;

[0225] Removing the third photoresist layer and the second mask layer located on the surface of the third photoresist layer to obtain a patterned second super surface mask;

[0226] Etching the optical film to be patterned with the patterned second metasurface mask to copy the metasurface pattern corresponding to the optical film to be patterned onto the optical film;

[0227] The second metasurface mask is removed.

[0228] When patterning the optical film to be patterned, the second supersurface mask covers the optical films other than the optical film to be patterned, and can protect the optical films other than the optical film to be patterned, and only etches the optical film to be patterned.

[0229] The forming method, exposure and development, and removal method of the third photoresist layer in this embodiment can follow the corresponding methods in the second embodiment; the material, forming method, removal method, etc. of the second mask layer in this embodiment can follow the corresponding materials and methods of the first mask layer in the second embodiment, and will not be repeated here.

[0230] Below, the super surface forming process in this embodiment is described by taking the light receiving surface having two optical films of different materials arranged in parallel as an example. Specifically, the two optical films of different materials are a first optical film 201 and a second optical film 202, wherein the material of the first optical film 201 is a first material, and the material of the second optical film 202 is a second material, and the first material is different from the second material. The light receiving surface is provided with the first optical film 201 as the first area 101, and the light receiving surface is provided with the second optical film 202 as the second area 102. Of course, this is not limited to this.

[0231] Combination Figures 7(a) to 7(l) As shown, the super surface forming process is to pattern the first optical film 201 first, and then pattern the second optical film 202.

[0232] Specifically, combined Figures 7(a) to 7(f) As shown, patterning the first optical film 201 includes the following steps:

[0233] As shown in FIG. 7 (a), a third photoresist layer 4c is formed on the entire surface of the optical film layer 20. At this time, the third photoresist layer 4c covers the first optical film 201 and the second optical film 202;

[0234] As shown in FIG. 7( b), the third photoresist layer 4c is exposed and developed to form a patterned third photoresist layer 4c, wherein the pattern of the third photoresist layer 4c is opposite to the pattern of the super surface 30 corresponding to the first optical film 201, and the second optical film 202 is exposed outwardly;

[0235] As shown in FIG. 7( c ), the patterned third photoresist layer 4 c is plated to form a second mask layer 7 , wherein the second mask layer 7 covers the second optical film 202 and the third photoresist layer 4 c located on the first optical film 201 ;

[0236] As shown in FIG. 7( d ), the third photoresist layer 4 c and the second mask layer 7 located on the surface of the third photoresist layer 4 c are removed to obtain a patterned second supersurface mask 8 , wherein the pattern of the second supersurface mask 8 located on the first optical film 201 is the same as the pattern of the supersurface 30 corresponding to the first optical film 201 , and the second supersurface mask 8 covers the second optical film 202 ;

[0237] As shown in FIG. 7( e ), the first optical film 201 is etched with the patterned second metasurface mask 8 , and the pattern of the metasurface 30 corresponding to the first optical film 201 is copied onto the first optical film 201 to form a patterned first optical film 201 ;

[0238] As shown in FIG. 7( f ), the second supersurface mask 8 is removed. At this time, the second optical film 202 is exposed outward, and the first optical film 201 is a patterned first optical film 201 .

[0239] When patterning the first optical film 201, the second supersurface mask 8 is used as an etching mask to etch the first optical film 201, and the second supersurface mask 8 covers the second optical film 202 to protect the second optical film 202, so that only the first optical film 201 is etched. After removing the second supersurface mask 8, the second optical film 202 and the patterned first optical film 201 are both exposed, so as to facilitate the subsequent patterning of the second optical film 202.

[0240] Combination Figure 7(g) to 7(l) As shown, patterning the second optical film 202 includes the following steps:

[0241] As shown in FIG. 7( g ), a third photoresist layer 4c ′ is formed on the patterned first optical film 201 and the second optical film 202 . At this time, the third photoresist layer 4c ′ covers the second optical film 202 and the patterned first optical film 201 .

[0242] As shown in FIG. 7( h), the third photoresist layer 4c' is exposed and developed to form a patterned third photoresist layer 4c', wherein the pattern of the third photoresist layer 4c' is opposite to the pattern of the supersurface 30 corresponding to the second optical film 202, and at this time, the patterned first optical film 201 is exposed outwardly;

[0243] As shown in FIG. 7( i ), the patterned third photoresist layer 4 c ′ is plated to form a second mask layer 7 ′, wherein the second mask layer 7 ′ covers the first optical film 201 and the third photoresist layer 4 c ′ on the second optical film 202 ;

[0244] As shown in FIG. 7( j), the third photoresist layer 4c' and the second mask layer 7' located on the surface of the third photoresist layer 4c' are removed to obtain a patterned second supersurface mask 8', wherein the pattern of the second supersurface mask 8' located on the second optical film 202 is the same as the pattern of the supersurface 30 corresponding to the second optical film 202, and the second supersurface mask 8' covers the patterned first optical film 201;

[0245] As shown in FIG. 7( k ), the second optical film 202 is etched with a patterned second metasurface mask 8 ′, and the pattern of the metasurface 30 corresponding to the second optical film 202 is copied onto the second optical film 202 to form a patterned second optical film 202;

[0246] As shown in FIG. 7( l ), ​​the second supersurface mask 8 ′ is removed.

[0247] When the second optical film 202 is patterned, the patterned second supersurface mask 8' is used as an etching mask, and when the second optical film 202 is etched, the second supersurface mask 8' covers the patterned first optical film 201 to protect the first optical film 201, so that only the second optical film 202 is etched. After removing the second supersurface mask 8', the patterned second optical film 202 and the patterned first optical film 201 are both exposed to form a supersurface 30.

[0248] It can be known that the thickness of the second mask layer 7 is greater than the thickness of the first optical film 201 , and can better protect the first optical film 201 .

[0249] Please refer to Figures 8(a) to 8(r) As shown, it is the fifth embodiment of the present invention related to the super surface forming process. The difference between this embodiment and the fourth embodiment of the super surface forming process is that after removing the second super surface mask 8, 8', patterning each optical film further includes the following steps: filling the patterned optical film with a protective material to form a protective layer 9, and the thickness of the protective layer 9 is greater than the thickness of the patterned optical film. By adding the protective layer 9 to protect the patterned optical film, there is no restriction on the etching selectivity, the thickness of each optical film, etc., and the thickness of the mask layer is not required to be greater than the thickness of the patterned optical film, which saves costs.

[0250] Furthermore, the refractive index of the protective material is less than 1.5.

[0251] Specifically, the protective material may be silicon dioxide, but is not limited thereto.

[0252] Specifically, when there is still an unpatterned optical film, filling the patterned optical film with a protective material to form a protective layer 9 specifically includes the following steps:

[0253] The entire surface of the optical film layer 20 is covered with a fourth photoresist layer 11, wherein the fourth photoresist layer 11 covers the patterned optical film and the unpatterned optical film;

[0254] Expose and develop the fourth photoresist layer 11 to expose the patterned optical film to the outside, and at the same time, the fourth photoresist layer 11 covers the unpatterned optical film;

[0255] Filling a protective material on the fourth photoresist layer 11 to form an initial protective layer 12, wherein the initial protective layer 12 covers the patterned optical film and the fourth photoresist layer 11 on the unpatterned optical film;

[0256] The fourth photoresist layer 11 is removed.

[0257] After the fourth photoresist layer 11 is removed, the initial protective layer 12 on the fourth photoresist layer 11 is removed simultaneously, and only the initial protective layer 12 on the patterned optical film is retained to form the protective layer 9 .

[0258] It is known that if there is no unpatterned optical film, that is, after patterning the last optical film, the protective material can be directly filled to form the protective layer 9 without providing the fourth photoresist layer and the process steps corresponding to the fourth photoresist layer.

[0259] Specifically, “filling the fourth photoresist layer 11 with a protective material to form an initial protective layer 12 ” can be performed by using FCVD, SCVD or ALD methods to perform SIO2 filling.

[0260] Furthermore, in the embodiment with the protective layer 9, after each of the optical films is a patterned optical film and is covered with the protective layer 9, the super surface forming process further includes:

[0261] The surfaces of the protective layers 9 are ground to make the surfaces of adjacent protective layers 9 flush.

[0262] Specifically, CMP chemical polishing can be used, but the invention is not limited thereto.

[0263] Below, the super surface forming process in this embodiment is described by taking the light receiving surface having two optical films of different materials arranged in parallel as an example. Specifically, the two optical films of different materials are a first optical film 201 and a second optical film 202, wherein the material of the first optical film 201 is a first material, and the material of the second optical film 202 is a second material, and the first material is different from the second material. The light receiving surface is provided with the first optical film 201 in the first area 101, and the light receiving surface is provided with the second optical film 202 in the second area 102. Of course, this is not limited to this.

[0264] Combination Figure 8(a) to Figure 8(r) As shown, the super surface forming process includes first patterning the first optical film 201 and then patterning the second optical film 202.

[0265] Specifically, combined Figure 8(a) to Figure 8(j) As shown, patterning the first optical film 201 includes the following steps:

[0266] As shown in FIG. 8( a ), a third photoresist layer 4 d is formed on the entire surface of the optical film layer 20 . At this time, the third photoresist layer 4 d covers the first optical film 201 and the second optical film 202 .

[0267] As shown in FIG. 8( b), the third photoresist layer 4d is exposed and developed to form a patterned third photoresist layer 4d, wherein the pattern of the third photoresist layer 4d is opposite to the pattern of the super surface 30 corresponding to the first optical film 201, and at this time, the second optical film 202 is exposed outwardly;

[0268] As shown in FIG. 8( c ), the patterned third photoresist layer 4 d is plated to form a second mask layer 7 d , wherein the second mask layer 7 d covers the second optical film 202 and the third photoresist layer 4 d on the first optical film 201 ;

[0269] As shown in FIG8( d ), the third photoresist layer 4d and the second mask layer 7d located on the surface of the third photoresist layer 4d are removed to obtain a patterned second supersurface mask 8d, wherein the pattern of the second supersurface mask 8d located on the first optical film 201 is the same as the pattern of the supersurface 30 corresponding to the first optical film 201, and the second supersurface mask 8d covers the second optical film 202;

[0270] As shown in FIG. 8( e ), the first optical film 201 is etched with a patterned second metasurface mask 8 d , and the metasurface 30 pattern corresponding to the first optical film 201 is copied onto the first optical film 201 to form a patterned first optical film 201 ;

[0271] As shown in FIG. 8( f ), the second supersurface mask 8 d is removed. At this time, the second optical film 202 is exposed outward, and the first optical film 201 is a patterned first optical film 201 ;

[0272] As shown in FIG. 8( g ), a fourth photoresist layer 11 is covered on the patterned first optical film 201 and the second optical film 202 ;

[0273] As shown in FIG. 8( h ), the fourth photoresist layer 11 is exposed and developed to expose the first optical film 201 to the outside. Meanwhile, the fourth photoresist layer 11 covers the second optical film 202 .

[0274] As shown in FIG. 8 (i), a protective material is filled on the fourth photoresist layer 11 to form an initial protective layer 12, and the initial protective layer 12 covers the fourth photoresist layer 11 on the first optical film 201 and the second optical film 202;

[0275] As shown in FIG. 8( j ), the fourth photoresist layer 11 is removed, and a protective layer 9 is formed on the first optical film 201 .

[0276] Combination Figure 8(k) to Figure 8(r) As shown, patterning the second optical film 202 includes the following steps:

[0277] As shown in FIG. 8( k ), a third photoresist layer 4d 'is formed on the protective layer 9 and the second optical film 202 . At this time, the third photoresist layer 4d 'covers the second optical film 202 and the protective layer 9 ;

[0278] As shown in FIG. 8( l ), ​​the third photoresist layer 4d 'is exposed and developed to form a patterned third photoresist layer 4d ', wherein the pattern of the third photoresist layer 4d 'is opposite to the pattern of the super surface 30 corresponding to the second optical film 202, and the protective layer 9 is exposed outwardly;

[0279] As shown in FIG. 8( m ), the patterned third photoresist layer 4 is plated to form a second mask layer 7d ′, and the second mask layer 7d ′ covers the protective layer 9 and the third photoresist layer 4d ′ located on the second optical film 202 ;

[0280] As shown in FIG8(n), the third photoresist layer 4d' and the second mask layer 7d' located on the surface of the third photoresist layer 4d' are removed to obtain a patterned second supersurface mask 8d', the pattern of the second supersurface mask 8d' located on the second optical film 202 is the same as the pattern of the supersurface 30 corresponding to the second optical film 202, and the second supersurface mask 8d' covers the protective layer 9;

[0281] As shown in FIG. 8( o ), the second optical film 202 is etched with a patterned second metasurface mask 8d ′, and the pattern of the metasurface 30 corresponding to the second optical film 202 is copied onto the second optical film 202 to form a patterned second optical film 202;

[0282] As shown in FIG. 8( p ), the second super-surface mask 8d ′ is removed, and at this time, the protective layer 9 on the first optical film 201 and the patterned second optical film 202 are exposed to the outside;

[0283] As shown in FIG8(q), a protective material is filled to form a protective layer 9;

[0284] As shown in FIG. 8( r ), the surface of the protective layer 9 is ground to make the surfaces of the protective layer 9 on the first optical film 201 and the second optical film 202 flush with each other, thereby forming a super-surface optical device 100 having the protective layer 9 .

[0285] Please refer to Figure 9(a) to Figure 9(k)As shown, it is the sixth embodiment of the super surface forming process of the present invention. The difference between this embodiment and the first and second embodiments of the super surface forming process is that: in this embodiment, the super surface forming process includes a first super surface forming process and a second super surface forming process. Part of the optical film adopts the first super surface forming process to form the super surface 30, and the other part of the optical film adopts the second super surface forming process to form the super surface 30. Among them, the first super surface forming process is the second embodiment of the super surface forming process mentioned above, and the second super surface forming process is the first embodiment of the super surface forming process mentioned above.

[0286] The first and second embodiments of the super surface forming process have been described above and will not be elaborated here.

[0287] When selecting the two super surface forming processes, they can be selected according to specific needs. For example, according to the thickness of the optical film to be patterned, when etching a thicker optical film, the second embodiment described above is adopted, and a mask made of metal material or phenanthrene metal material such as silicon dioxide is selected to avoid insufficient etching selectivity; when etching a thinner optical film, the first embodiment described above is adopted, and photoresist is directly used as an etching mask, which can simplify the super surface forming process and reduce costs. Of course, this is not limited to this, and a suitable super surface forming process can also be selected according to the material of the optical film to be patterned.

[0288] Below, the super surface forming process in this embodiment is described by taking the light receiving surface having two optical films of different materials arranged in parallel as an example. Specifically, the two optical films of different materials are a first optical film 201 and a second optical film 202, wherein the material of the first optical film 201 is a first material, the material of the second optical film 202 is a second material, the first material is different from the second material, and the thickness of the first optical film 201 is greater than the thickness of the second optical film 202. The light receiving surface is provided with the first optical film 201 as the first area 101, and the light receiving surface is provided with the second optical film 202 as the second area 102. Of course, this is not limited to this.

[0289] Combination Figure 9(a) to Figure 9(k) As shown, the super surface forming process includes first patterning the first optical film 201 and then patterning the second optical film 202, and the first optical film 201 is patterned by the super surface forming process in the second embodiment, and the second optical film 202 is patterned by the super surface forming process in the first embodiment.

[0290] Specifically, combined Figure 9(a) to Figure 9(f) As shown, patterning the first optical film 201 includes the following steps:

[0291] As shown in FIG. 9 (a), a third photoresist layer 4e is formed on the entire surface of the optical film layer 20. At this time, the third photoresist layer 4e covers the first optical film 201 and the second optical film 202;

[0292] As shown in FIG. 9( b), the third photoresist layer 4e is exposed and developed to form a patterned third photoresist layer 4e, wherein the pattern of the third photoresist layer 4e is opposite to the pattern of the supersurface 30 corresponding to the first optical film 201, and at this time, the second optical film 202 is exposed outwardly;

[0293] As shown in FIG. 9( c ), the patterned third photoresist layer 4 e is plated to form a second mask layer 7 e , and the second mask layer 7 e covers the second optical film 202 and the third photoresist layer 4 e on the first optical film 201 ;

[0294] As shown in FIG. 9( d ), the third photoresist layer 4e and the second mask layer 7e located on the surface of the third photoresist layer 4e are removed to obtain a patterned second supersurface mask 8e, wherein the pattern of the second supersurface mask 8e located on the first optical film 201 is the same as the pattern of the supersurface 30 corresponding to the first optical film 201, and the second supersurface mask 8e covers the second optical film 202;

[0295] As shown in FIG. 9( e ), the first optical film 201 is etched with the patterned second metasurface mask 8 e , and the pattern of the metasurface 30 corresponding to the first optical film 201 is copied onto the first optical film 201 to form a patterned first optical film 201 ;

[0296] As shown in FIG. 9( f ), the second super-surface mask 8 e is removed. At this time, the second optical film 202 is exposed outward, and the first optical film 201 is a patterned first optical film 201 .

[0297] Combination Figure 9(g) to Figure 9(k) As shown, patterning the second optical film 202 includes the following steps:

[0298] As shown in FIG. 9( g ), a third photoresist layer 4 e ′ is formed on the entire surface of the optical film layer 20 . At this time, the third photoresist layer 4 covers the second optical film 202 and the patterned first optical film 201 .

[0299] As shown in FIG. 9( h), the third photoresist layer 4e' is exposed and developed to form a patterned third photoresist layer 4e', wherein the pattern of the third photoresist layer 4e' is the same as the pattern of the super surface 30 corresponding to the second optical film 202, and the third photoresist layer 4e' covers the patterned first optical film 201;

[0300] As shown in FIG. 9( i ), the patterned third photoresist layer 4 e ′ is subjected to PEB baking;

[0301] As shown in FIG. 9( j), the second optical film 202 is etched using the patterned third photoresist layer 4e' as an etching mask, and the pattern of the supersurface 30 corresponding to the second optical film 202 is copied onto the second optical film 202;

[0302] As shown in FIG. 9( k ), the third photoresist layer 4 e ′ is removed, the patterned first optical film 201 and the second optical film 202 are exposed to the outside, and a super surface 30 is formed.

[0303] Compared with the prior art, in the preparation process of the metasurface optical device 100 of the present invention, by setting a metasurface 30 with multiple materials on the same substrate 10, the metasurface 30 has a high degree of freedom in structural design, and the working band of the metasurface 30 is wider, which can realize different preset functions and realize the processing of large-area and cross-scale metasurface optical devices 100.

[0304] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0305] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for preparing a metasurface optical device, characterized in that: The preparation process includes an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of the substrate, and the optical film forming process of each optical film includes: forming a first photoresist layer on the entire light-receiving surface; Exposing and developing the first photoresist layer to expose the light-receiving surface at a preset area corresponding to the optical film to be formed to the outside; Plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film; The first photoresist layer is removed.

2. A process for preparing a metasurface optical device, characterized in that: The preparation process includes an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of the substrate, and the optical film forming process of each optical film includes: The light-receiving surface is entirely coated with a material corresponding to the optical film to be formed to form an initial film layer; forming a second photoresist layer on the entire surface of the initial film layer; exposing and developing the second photoresist layer to expose the other regions of the initial film layer except the region corresponding to the optical film to be formed; Etching and removing the initial film layer in the other regions; The second photoresist layer is removed.

3. A process for preparing a metasurface optical device, characterized in that: The preparation process includes an optical film forming process of forming an optical film layer having at least two optical films of different materials arranged in parallel on the light-receiving surface of a substrate, the optical film forming process includes a first optical film forming process and a second optical film forming process, at least part of the two optical films is prepared by the first optical film forming process, and the other part of the optical film is prepared by the second optical film forming process, wherein the first optical film forming process includes the following steps: forming a first photoresist layer on the entire light-receiving surface; Exposing and developing the first photoresist layer to expose the light-receiving surface at a preset area corresponding to the optical film to be formed to the outside; Plating a material corresponding to the optical film to be formed at the preset area of ​​the light-receiving surface to form an optical film; removing the first photoresist layer; The second optical film forming process includes the following steps: The light-receiving surface is entirely coated with a material corresponding to the optical film to be formed to form an initial film layer; forming a second photoresist layer on the entire surface of the initial film layer; exposing and developing the second photoresist layer to expose the other regions of the initial film layer except the region corresponding to the optical film to be formed; Etching and removing the initial film layer in the other regions; The second photoresist layer is removed.

4. The process for preparing a metasurface optical device according to any one of claims 1 to 3, characterized in that: After the optical film is formed on the light-receiving surface, the preparation process further includes a super-surface forming process of patterning the optical film layer to form a super-surface.

5. The process for preparing a metasurface optical device according to claim 4, characterized in that: The super surface forming process comprises: forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern in the third photoresist layer is the same as the super surface pattern; Using the patterned third photoresist layer as an etching mask, etching the optical film layer to copy the metasurface pattern onto the optical film layer; The third photoresist layer is removed.

6. The process for preparing a metasurface optical device according to claim 4, characterized in that: The super surface forming process comprises: forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern in the third photoresist layer is opposite to the super surface pattern; Plating the patterned third photoresist layer to form a first mask layer; Removing the third photoresist layer and the first mask layer located on the surface of the third photoresist layer to obtain a patterned first super surface mask; Etching the optical film layer with a patterned first supersurface mask to copy the supersurface pattern onto the optical film layer; The first metasurface mask is removed.

7. The process for preparing a metasurface optical device according to claim 4, characterized in that: “Patterning the optical film layer” means: patterning each optical film in turn.

8. The process for preparing a metasurface optical device according to claim 7, characterized in that: Patterning each optical film includes the following steps: forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is the same as the super-surface pattern corresponding to the optical film to be patterned, and the third photoresist layer covers other optical films except the optical film to be patterned; Using the patterned third photoresist layer as an etching mask, etching the optical film to be patterned, and copying the metasurface pattern corresponding to the optical film to be patterned onto the optical film to be patterned; The third photoresist layer is removed.

9. The process for preparing a metasurface optical device according to claim 7, characterized in that: Patterning each optical film includes the following steps: forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is opposite to the super-surface pattern corresponding to the optical film to be patterned, and other optical films except the optical film to be patterned are exposed outward from the third photoresist layer; coating the patterned third photoresist layer to form a second mask layer; Removing the third photoresist layer and the second mask layer located on the surface of the third photoresist layer to obtain a patterned second super surface mask; Etching the optical film to be patterned with the patterned second metasurface mask to copy the metasurface pattern corresponding to the optical film to be patterned onto the optical film; The second metasurface mask is removed.

10. The process for preparing a metasurface optical device according to claim 7, characterized in that: The super surface forming process includes a first super surface forming process and a second super surface forming process. Part of the optical film is formed by the first super surface forming process, and the other part of the optical film is formed by the second super surface forming process. The patterning of each optical film in the first super surface forming process includes the following steps forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is opposite to the super-surface pattern corresponding to the optical film to be patterned, and other optical films except the optical film to be patterned are exposed outward from the third photoresist layer; coating the patterned third photoresist layer to form a second mask layer; Removing the third photoresist layer and the second mask layer located on the surface of the third photoresist layer to obtain a patterned second super surface mask; Etching the optical film to be patterned with the patterned second metasurface mask to copy the metasurface pattern corresponding to the optical film to be patterned onto the optical film; removing the second metasurface mask; The patterning of each optical film in the second super surface forming process includes the following steps forming a third photoresist layer on the entire surface of the optical film layer; Exposing and developing the third photoresist layer to form a patterned third photoresist layer, wherein the pattern of the third photoresist layer is the same as the super-surface pattern corresponding to the optical film to be patterned, and the third photoresist layer covers other optical films except the optical film to be patterned; Using the patterned third photoresist layer as an etching mask, etching the optical film to be patterned, and copying the metasurface pattern corresponding to the optical film to be patterned onto the optical film to be patterned; The third photoresist layer is removed.

11. The process for preparing a metasurface optical device according to claim 9, characterized in that: After removing the second supersurface mask, patterning each optical film further includes the following steps: filling a protective material on the patterned optical film to form a protective layer, wherein the thickness of the protective layer is greater than the thickness of the patterned optical film.

12. The process for preparing a metasurface optical device according to claim 11, characterized in that: The protective material has a light refractive index less than 1.5.

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