CN119439324A

CN119439324A - Preparation process of super-surface optical device

Info

Publication number: CN119439324A
Application number: CN202310966685.4A
Authority: CN
Inventors: 吴贤丰; 延宇豪; 邱山峰; 孙磊
Original assignee: Suzhou Shanhe Photoelectric Technology Co ltd
Current assignee: Suzhou Shanhe Photoelectric Technology Co ltd
Priority date: 2023-08-02
Filing date: 2023-08-02
Publication date: 2025-02-14

Abstract

The present invention provides a preparation process of a metasurface optical device, including an optical film forming process for 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: 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 outwardly; 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; by arranging a metasurface having multiple materials on the same substrate, the metasurface structure has a high degree of freedom in design, and the working band of the metasurface is wider, so that different preset functions can be realized, and the processing of large-area, cross-scale metasurface optical devices can be realized.

Description

Preparation process of super-surface optical device

Technical Field

The invention relates to the technical field of optical imaging, in particular to a preparation process of a super-surface optical device.

Background

The super-surface optical device is composed of sub-wavelength unit structures which have high freedom degree, aperiodicity and dense arrangement on a two-dimensional plane. The super-surface optical device is widely applied in the field of optical design, and can realize lenses, polarization devices, optical calculation, laser radars and the like through super-surface design, and the super-surface optical device can replace almost all the existing optical devices.

Super-surface optics in the optical band (from ultraviolet, visible to infrared) place extreme parameter demands on the micro-nano machining process of the shaped super-surface. For example, in the optical frequency band, the structure of the sub-wavelength unit requires a very small scale (for example, in the visible light band, the structure size of the sub-wavelength unit is l 5-400 nm), the optical field regulation is realized by regulating the structure size of the sub-wavelength unit in a plane, extremely high precision is required (for example, the 16-order phase of the visible light band requires about 5nm regulation precision), the sub-wavelength unit structure is generally composed of dielectric materials with high refractive index which are difficult to process, such as TiO2, gaN, si3N4, hfO2, si and the like, in order to realize high working efficiency, the processing of dielectric materials with extremely high depth-to-width ratio is required for realizing multifunctional integration, such as a single-chip broadband achromatic lens and the like, and a processing method with cross scale (nanometer to meter), high efficiency (TB data amount) and low cost is required for realizing the processing of the ultra-structured surface element with large area. The super surface of the single material has the defects of narrow working wave band, small design freedom degree, large depth-to-width ratio, difficult processing and the like, namely, when the super surface optical device is prepared by adopting the single material, the super surface optical device meeting the requirements cannot be prepared by the actual preparation process because the sub-wavelength unit structure in the super surface has too large size span, the depth-to-width ratio is designed too large and the like in the design of the wider working wave band.

Disclosure of Invention

The invention aims to provide a preparation process of a multi-material super-surface optical device.

In order to achieve the above object, the present invention adopts the following technical scheme that the preparation process of the super surface optical device comprises an optical film forming process for forming an optical film layer with at least two optical films of different materials arranged in parallel on a light receiving surface of a substrate, wherein the optical film forming process of each optical film comprises:

forming a first photoresist layer on the whole surface of the 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 outwards;

plating a material corresponding to the optical film to be formed at the preset area of the light receiving surface to form the optical film;

And removing the first photoresist layer.

In order to achieve the above object, the present invention further provides a process for preparing a super-surface optical device, comprising an optical film forming process for forming an optical film layer having at least two optical films of different materials arranged in parallel on a light receiving surface of a substrate, each optical film forming process comprising:

plating a material corresponding to the optical film to be formed on the whole light receiving surface to form an initial film layer;

forming a second photoresist layer on the whole surface of the initial film layer;

exposing and developing the second photoresist layer to expose other areas except the area corresponding to the optical film to be formed on the initial film layer;

etching to remove the initial film layer at the other areas;

And removing the second photoresist layer.

In order to achieve the above object, the present invention also provides a process for preparing a super surface optical device, comprising an optical film forming process for forming an optical film layer having at least two optical films of different materials arranged in parallel on a light receiving surface of a substrate, the optical film forming process comprising a first optical film forming process, a second optical film forming process, a part of the at least two optical films being prepared by the first optical film forming process, and the other part of the at least two optical films being prepared by the second optical film forming process, wherein the first optical film forming process comprises the steps of:

Removing the first photoresist layer;

The second optical film forming process comprises the following steps:

etching to remove the initial film layer at the other areas;

And removing the second photoresist layer.

As a further improved technical scheme of the invention, after the optical film is formed on the light receiving surface, the preparation process further comprises a super-surface forming process for patterning the optical film layer to form a super-surface.

As a further improved technical scheme of the invention, the super surface forming process comprises the following steps:

a third photoresist layer is formed on the whole 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;

Etching the optical film layer by taking the patterned third photoresist layer as an etching mask, and copying the super-surface pattern onto the optical film layer;

And removing the third photoresist 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;

coating the patterned third photoresist layer to form a first mask layer;

Removing the third photoresist layer and the first mask layer positioned on the surface of the third photoresist layer to obtain a patterned first super-surface mask;

etching the optical film layer by using a patterned first super-surface mask, and copying a super-surface pattern onto the optical film layer;

the first subsurface mask is removed.

As a further improved technical scheme of the invention, the step of patterning the optical film layer is to pattern each optical film in turn.

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

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;

Etching the optical film to be patterned by taking the patterned third photoresist layer as an etching mask, and copying the super-surface pattern corresponding to the optical film to be patterned onto the optical film to be patterned;

And removing the third photoresist 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 outwards 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 positioned on the surface of the third photoresist layer to obtain a patterned second super-surface mask;

etching the optical film to be patterned by using the second super-surface mask to be patterned, and copying the super-surface pattern corresponding to the optical film to be patterned onto the optical film;

And removing the second super-surface mask.

As a further improved technical scheme of the invention, the super-surface molding process comprises a first super-surface molding process and a second super-surface molding process, wherein part of the optical films are subjected to super-surface molding by the first super-surface molding process, the other part of the optical films are subjected to super-surface molding by the second super-surface molding process, and each optical film patterned in the first super-surface molding process comprises the following steps of

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

removing the second super-surface mask;

patterning each optical film in the second supersurface forming process comprises the steps of

And removing the third photoresist layer.

As a further improved technical scheme of the invention, after the second super-surface mask is removed, patterning each optical film further comprises the step of filling a protective material on the patterned optical film to form a protective layer, wherein the thickness of the protective layer is larger than that of the patterned optical film.

As a further improved technical scheme of the invention, the light refractive index of the protective material is smaller than 1.5.

The preparation process of the super-surface optical device has the beneficial effects that the super-surface with various materials is arranged on the same substrate, so that the design freedom degree of the super-surface structure is high, the working wave band of the super-surface is wider, different preset functions can be realized, and the processing of the large-area and cross-scale super-surface optical device can be realized.

Drawings

Fig. 1 (a) -1 (h) are step diagrams of a first embodiment of an optical film forming process;

fig. 2 (a) -2 (i) are step diagrams of a second embodiment of the optical film forming process;

Fig. 3 (a) to 3 (i) are step diagrams of a third embodiment of the optical film forming process;

FIGS. 4 (a) -4 (e) are step diagrams of a first embodiment of a subsurface formation process;

FIGS. 5 (a) -5 (f) are step diagrams of a second embodiment of a subsurface molding process;

FIGS. 6 (a) -6 (j) are step diagrams of a third embodiment of a subsurface formation process;

FIGS. 7 (a) -7 (l) are step diagrams of a fourth embodiment of a subsurface molding process;

FIGS. 8 (a) -8 (r) are step diagrams of a fifth embodiment of a subsurface molding process;

Fig. 9 (a) to 9 (k) are step diagrams of a sixth embodiment of the super surface molding process.

Detailed Description

The present invention will be described in detail with reference to the embodiments shown in the drawings, and reference is made to fig. 1 to 9, which are preferred embodiments of the present invention. It should be understood that these embodiments are not intended to limit the present invention, and that functional, method, or structural equivalents and alternatives falling within the scope of the present invention may be modified by any person skilled in the art to include such embodiments.

Referring to fig. 1 to 9, the present invention provides a process for preparing a super-surface optical device 100, which includes an optical film forming process for forming an optical film layer 20 having at least two optical films of different materials arranged in parallel on a light receiving surface of a substrate 10, and a super-surface forming process for patterning the optical film layer 20 to form a super-surface 30. In the present invention, by providing the super surface 30 having a plurality of materials on the same substrate 10, the degree of freedom of structural design of the super surface 30 is high, and the working band of the super surface 30 is made wider, so that different preset functions can be realized, and the processing of the large-area and cross-scale super surface optical device 100 can be realized.

In particular, the material and thickness of the substrate 10 may be adaptively selected according to the application of the super surface optical device 100. The material of the substrate 10 may be silicon wafer or optical glass, which is not limited to this.

Specifically, the material, thickness, etc. of each of the optical films may be selected according to specific requirements, such as the operating band, structure, function, etc. of the supersurface 30. Materials for the optical film include, but are not limited to, tiO2, A-SI, hfO2, SI3N4, taO2, mgF2, znS, H4, SIO2.

Further, the fabrication process may further include processing the substrate 10 to form a plurality of fiducial points prior to the optical film formation process. The datum point is used as a reference point in the subsequent optical film forming process and the super-surface forming process, and can ensure the process precision.

Referring to fig. 1 (a) to 1 (h), in a first embodiment of the optical film forming process according to the present invention, each optical film forming process includes:

And removing the first photoresist layer.

It is known that after forming an optical film to remove the first photoresist layer, the optical film is formed only in a predetermined region of the substrate. And when other optical films are formed later, repeating the steps to form the optical film layer on the light receiving surface, wherein the optical film layer is provided with at least two optical films with different materials which are arranged on the light receiving surface in parallel.

It can be seen that the exposure and development of the first photoresist layer specifically includes:

Covering a first mask plate on the first photoresist layer, and then exposing;

Developing with TMAH solution;

after development, deionized water was used for fixing.

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

When a first mask is covered on the first photoresist layer, the first mask is aligned by taking a datum point positioned on the substrate as a reference point.

In this embodiment, the step of plating the material corresponding to the optical film to be formed on the light receiving surface in the preset area to form the optical film includes plating a film by physical vapor deposition technology to form the optical film, and forming the optical film on the first photoresist layer in the preset area after plating. It is known that the optical film on the first photoresist layer is simultaneously removed when the first photoresist layer is subsequently removed, and finally, only the optical film at a predetermined area is remained. Of course, the present invention is not limited thereto, and in other embodiments, the optical film may be coated only at the predetermined area, so that the optical film is formed only at the predetermined area.

In the following, taking two optical films of different materials arranged in parallel on the light receiving surface as an example, the first embodiment of the optical film forming process in the present invention is specifically described below, but it is of course not limited thereto, and it is understood that when three or more optical films of different materials arranged in parallel on the light receiving surface are formed, the forming process of each corresponding optical film need only be repeated.

Specifically, as shown in fig. 1 (a) to 1 (h), two optical films of different materials arranged in parallel are defined as a first optical film 201 and a second optical film 202, a region of the light receiving surface corresponding to the first optical film 201 is a first region 101, and a region of the light receiving surface corresponding to the second optical film 202 is a second region 102. 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.

Referring to fig. 1 (a) -1 (h), in one embodiment, the optical film forming process is to form the second optical film 202 first and then form the first optical film 201. Of course, this is not a limitation.

Specifically, referring to fig. 1 (a) to 1 (d), the optical film forming process for forming the second optical film 202 includes the following steps:

as shown in fig. 1 (a), a first photoresist layer 1 is formed on the entire light-receiving surface of the substrate 10, and the light-receiving surface is a flat light-receiving surface;

As shown in fig. 1 (b), exposing and developing the first photoresist layer 1, and removing the first photoresist layer 1 at the second region 102, so that the second region 102 is exposed outwards;

As shown in fig. 1 (c), plating a second material at the second region 102 to form an optical film;

as shown in fig. 1 (d), the first photoresist layer 1 is removed.

In the optical film forming process for forming the second optical film 202, after the first photoresist layer 1 is removed, the first photoresist layer 1 and the optical film formed of the second material on the first photoresist layer 1 are simultaneously removed, and at this time, only the optical film in the second area 102 remains, that is, the second optical film 202.

Referring to fig. 1 (e) to 1 (h), the optical film forming process for forming the first optical film 201 includes the following steps:

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, and at this time, the first photoresist layer 1' covers the first region 101 of the light receiving surface and the second optical film 202;

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, and at this time, the first photoresist layer 1' covers only the second optical film 202;

as shown in fig. 1 (g), plating a first material at the first region 101 to form an optical film;

As shown in fig. 1 (h), the first photoresist layer 1' is removed.

In the optical film forming process for forming the first optical film 201, after the first photoresist layer 1' is removed, the first photoresist layer 1' and the optical film formed of the first material on the first photoresist layer 1' are simultaneously removed, and only the optical film of the first region 101, that is, the first optical film 201, is remained, and at this time, the first optical film 201 and the second optical film 202 are arranged in parallel on the light receiving surface to form the optical film layer 20.

Referring to fig. 2 (a) -2 (i), in a second embodiment of the optical film forming process according to the present invention, each optical film forming process includes:

etching to remove the initial film layer at the other areas;

And removing the second photoresist layer.

It is known that after forming an optical film to remove the second photoresist layer, the optical film is formed only in a predetermined region of the substrate. And when other optical films are formed later, repeating the steps to form the optical film layer on the light receiving surface, wherein the optical film layer is provided with at least two optical films with different materials which are arranged on the light receiving surface in parallel.

Specifically, the molding sequence of the optical film may be according to the thickness of the optical film, such as molding a thinner optical film first and molding a thicker optical film second, so that the initial film layer formed later can completely cover the previously molded optical film. Of course, this is not a limitation.

It can be seen that the exposure and development of the second photoresist layer specifically includes:

covering a second mask plate on the second photoresist layer, and then exposing;

Developing with TMAH solution;

after development, deionized water was used for fixing.

And when a second mask is covered on the second photoresist layer, aligning the second mask by taking a datum point positioned on the substrate as a reference point.

It is known that after the second photoresist layer is exposed and developed, the second photoresist layer covers an initial film layer in a preset area corresponding to the optical film to be formed, during subsequent etching, the initial film layer not covered by the second photoresist layer is etched and removed, the initial film layer covered by the second photoresist layer is protected by the second photoresist layer and is reserved, and after the second photoresist layer on the reserved initial film layer is removed after etching is completed, the optical film of the preset material is formed on the light receiving surface.

In the following, taking two optical films of different materials arranged in parallel on the light receiving surface as an example, the second embodiment of the optical film forming process in the present invention is specifically described below, but it is of course not limited thereto, and it is understood that when three or more optical films of different materials arranged in parallel on the light receiving surface are formed, the forming process of each corresponding optical film need only be repeated.

Specifically, as shown in fig. 2 (a) to 2 (i), two optical films of different materials arranged in parallel are defined as a first optical film 201 and a second optical film 202, a region of the light receiving surface corresponding to the first optical film 201 is a first region 101, and a region of the light receiving surface corresponding to the second optical film 202 is a second region 102. 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.

In one embodiment, the optical film forming process is to form the first optical film 201 and then form the second optical film 202.

Specifically, as shown in fig. 2 (a) to 2 (d), the optical film forming process for forming the first optical film 201 includes the following steps:

as shown in fig. 2 (a), an initial film layer 2 is formed by plating a first material on the entire light-receiving surface of the substrate 10, where the light-receiving surface is a flat light-receiving surface;

Forming a second photoresist layer 3 on the whole surface of the initial film layer 2;

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 outwards, that is, the second photoresist layer 3 located in the second region 102 is removed;

as shown in fig. 2 (c), the initial film layer 2 at the second region 102 is etched away;

as shown in fig. 2 (d), the second photoresist layer 3 is removed.

In the optical film forming process for forming the first optical film 201, after the second photoresist layer 3 is removed, the initial film layer 2 located in the first region 101 is exposed, so as to form the first optical film 201 located in the first region 101.

Referring to fig. 2 (e) to 2 (i), the optical film forming process for forming the second optical film 202 includes the following steps:

As shown in fig. 2 (e), an initial film layer 2 'is formed by plating a second material on the entire light receiving surface having the first optical film 201, and at this time, the initial film layer 2' covers the second region 102 of the light receiving surface and the first optical film 201;

As shown in fig. 2 (f), a second photoresist layer3 'is formed on the entire surface of the initial film layer 2';

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 upwards in the first region 101, and the second photoresist layer 3' covers the initial film layer 2' at the second region 102;

as shown in fig. 2 (h), the initial film layer 2' at the first region 101 is etched away, leaving the first optical film 201 of the first region 101;

as shown in fig. 2 (i), the second photoresist layer 3' is removed.

In the optical film forming process for forming the second optical film 202, after the second photoresist layer 3' is removed, the first optical film 201 and the second optical film 202 are arranged in parallel on the light receiving surface to form the optical film layer 20.

Referring to fig. 3 (a) to 3 (i), in a third embodiment of the optical film forming process according to the present invention, the optical film forming process includes a first optical film forming process and a second optical film forming process, wherein at least part of the 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 is the first embodiment described above with respect to the optical film forming process, and the second optical film forming process is the second embodiment described above with respect to the optical film forming process.

The first and second embodiments of the optical film forming process are described above, and are not described herein.

In the following, referring to fig. 3 (a) to 3 (i), taking two optical films of different materials arranged in parallel on the light receiving surface as an example, a third embodiment of the optical film forming process in the present invention is specifically described below, but of course, it is not limited thereto, and it is understood that only one optical film forming process needs to be selected for forming when three or more optical films of different materials arranged in parallel on the light receiving surface are formed.

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 region of the light receiving surface corresponding to the first optical film 201 is a first region 101, and the region of the light receiving surface corresponding to the second optical film 202 is a second region 102. 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.

Specifically, the optical film forming process is to form the second optical film 202 first and then form the first optical film 201. The second optical film 202 is molded by the optical film molding process according to the first embodiment, and the first optical film 201 is molded by the optical film molding process according to the second embodiment. Of course, the present invention is not limited to this, and in other examples, the first optical film 201 may be formed by the optical film forming process in the first embodiment, and the second optical film 202 may be formed by the optical film forming process in the second embodiment, and the specific process may be selected according to specific requirements.

Specifically, with reference to fig. 3 (a) -3 (d), the optical film forming process for forming the second optical film 202 includes the following steps:

As shown in fig. 3 (a), a first photoresist layer 1 is formed on the entire light-receiving surface of the substrate 10, and the light-receiving surface is a flat light-receiving surface;

As shown in fig. 3 (b), the first photoresist layer 1 is exposed and developed, and the first photoresist layer 1 at the second region 102 is removed, so that the second region 102 is exposed outwards;

As shown in fig. 3 (c), plating a second material at the second region 102 to form an optical film;

As shown in fig. 3 (d), the first photoresist layer 1 is removed.

In the optical film forming process for forming the second optical film 202, after the first photoresist layer 1 is removed, the first photoresist layer 1 and the optical film formed of the second material on the first photoresist layer 1 are simultaneously removed, and at this time, only the optical film of the second region 102, that is, the second optical film 202 remains.

Referring to fig. 3 (e) to 3 (i), the optical film forming process for forming the first optical film 201 includes the following steps:

As shown in fig. 3 (e), an initial film layer 2 is formed by plating a first material on the entire light-receiving surface having the second optical film 202, and at this time, the initial film layer 2 covers the first region 101 of the light-receiving surface and the second optical film 202;

As shown in fig. 3 (f), a second photoresist layer 3 is formed on the whole surface of the initial film layer 2;

As shown in fig. 3 (g), the second photoresist layer 3 is exposed and developed, the second photoresist layer 3 located in the second area 102 is removed, so that the initial film layer 2 located in the second area 102 is exposed outwards, and at this time, the second optical film 202 and the initial film layer 2 are sequentially stacked upwards in the second area 102;

As shown in fig. 3 (h), the initial film layer 2 at the second region 102 is etched away, leaving the second optical film 202 of the second region 102;

As shown in fig. 3 (i), the second photoresist layer 3 is removed.

In the optical film forming process for forming the first optical film 201, after the second photoresist layer 3 is removed, the first optical film 201 and the second optical film 202 are arranged in parallel on the light receiving surface to form the optical film layer 20.

Referring to fig. 4 (a) to fig. 4 (e), in a first embodiment of the present invention, the super surface forming process includes:

as shown in fig. 4 (a), a third photoresist layer4 is formed on the entire surface of the optical film layer 20;

As shown in fig. 4 (b), exposing and developing the third photoresist layer 4 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;

As shown in fig. 4 (d), the optical film layer 20 is etched with the patterned third photoresist layer 4 as an etching mask, and the pattern of the super surface 30 is copied to the optical film layer 20;

As shown in fig. 4 (e), the third photoresist layer 4 is removed.

After the third photoresist layer 4 is removed, a super surface 30 is formed on the light receiving surface of the substrate 10.

Specifically, the third photoresist layer 4 is formed on the whole surface of the optical film layer 20, specifically, photoresist is spin-coated on the surface of the optical film layer 20 away from the substrate 10, and then the photoresist is baked to form the third photoresist layer 4.

The "exposing and developing the third photoresist layer 4 to form the patterned third photoresist layer 4" is specifically:

Covering a third mask plate on the third photoresist layer 4, and then exposing;

Developing with TMAH solution;

after development, deionized water was used for fixing.

When the third photoresist layer 4 is 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 identical to the pattern of the super surface 30. When the third photoresist layer 4 is negative photoresist, the third mask is a negative photoresist mask, and the pattern of the opening 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 which is the same as the pattern of the super surface 30.

In this embodiment, the third photoresist layer 4 is exposed and developed by a high-precision ultraviolet lithography process to form a patterned third photoresist layer 4. Of course, the present invention is not limited thereto, and in other embodiments, the patterned third photoresist layer 4 may be formed by exposing and developing the third photoresist layer 4 by using an electron beam lithography process.

When a third mask is covered on the third photoresist layer 4, the third mask is aligned with the reference point of the substrate 10 as a reference point.

Further, as shown in fig. 4 (c), after the patterned third photoresist layer 4 is formed by exposing and developing the third photoresist layer 4 and before the etching of the optical film layer 20, the super surface forming process further includes a step of PEB baking the substrate 10 having the patterned third photoresist layer 4. The patterned third photoresist layer 4 is further subjected to a crosslinking reaction and is more resistant to subsequent etching.

Specifically, the third photoresist layer 4 may be removed by a wet photoresist removing process. For example, the removal can be performed using a heated NMP solvent. Of course, this is not a limitation.

Referring to fig. 5 (a) to 5 (f), in a second embodiment of the present invention, the super surface forming process includes:

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

As shown in fig. 5 (b), exposing and developing the third photoresist layer 4a to form a patterned third photoresist layer 4a, wherein the pattern in the third photoresist layer 4a is opposite to the pattern of the super surface 30;

As shown in fig. 5 (c), the patterned third photoresist layer 4a is coated to form a first mask layer 5;

As shown in fig. 5 (d), removing the third photoresist layer 4 and the first mask layer 5 on the surface of the third photoresist layer 4 to obtain a patterned first super surface mask 6;

as shown in fig. 5 (e), the optical film layer 20 is etched with the patterned first super surface mask 6, and the super surface 30 pattern is copied onto the optical film layer 20;

as shown in fig. 5 (f), the first super surface mask 6 is removed, and the super surface 30 is formed on the light receiving surface.

In comparison with the first embodiment, in this embodiment, when etching the optical film layer 20, the first mask layer 5 is additionally provided, so that the situation of insufficient etching selectivity is avoided.

Specifically, the first mask layer made of a metal material such as Cr or Al or the first mask layer 5 made of a non-metal material such as SIO ₂ may be used.

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 filled back in the groove in the patterned third photoresist layer 4, i.e. the pattern of the first mask layer 5 is 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 on the surface of the third photoresist layer 4, the patterned first super surface mask 6 is the same as the pattern of the super surface 30. The optical film layer 20 is etched under the mask action of the remaining patterned first super surface mask 6, so that the pattern of the first super surface mask 6 can be transferred to the optical film layer 20 to form a super surface 30 on the light receiving surface of the substrate 10.

In this embodiment, the third photoresist layer 4 is also subjected to exposure and development by using a high-precision ultraviolet lithography process to form a patterned third photoresist layer 4. Of course, the present invention is not limited thereto, and in other embodiments, the patterned third photoresist layer 4 may be formed by exposing and developing the third photoresist layer 4 by using an electron beam lithography process.

Specifically, "exposing and developing the third photoresist layer 4 to form a patterned third photoresist layer 4" is specifically:

Developing with TMAH solution;

after development, deionized water was used for fixing.

When the third photoresist layer 4 is 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 negative photoresist, the third mask is a negative photoresist mask, and the pattern of the opening 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.

Further, "the third patterned photoresist layer 4 is coated to form the first mask layer 5", specifically, the first mask layer 5 may be formed by electron beam evaporation or sputtering a metal material such as Cr, al, or a non-metal material such as SIO2 to form the first mask layer 5.

The removing mode of the first super surface mask 6 may be a dry method or a wet method, for example, when the first super surface mask 6 is chromium, ammonium cerium nitrate is used for wet removal, or cl2+o2 is used for dry removal, when the first super surface mask 6 is SIO2, hydrofluoric acid is used for wet removal, CHF3 is used for dry removal, CF4 is used for dry removal, and the like, so long as the substrate 10 and the optical film are not damaged when the first super surface mask 6 is removed, and the removing is fast and simple, and no other reactions with parameters remain.

Referring to fig. 6 (a) - (6 (j)), which are a third embodiment of the present invention related to the super surface molding process, the difference between the present embodiment and the first and second embodiments related to the super surface molding process is that the "patterning the optical film layer 20" in the super surface molding process is to pattern each optical film in turn. It is known that, when etching a certain optical film, other optical films are protected by the corresponding masks, and thus, are not affected. The simultaneous etching of a plurality of optical films can be avoided from affecting each other so as to affect the final etching effect, and the film thickness of each optical film is not affected by the etching selection ratio, so that the film thickness of each optical film can be set according to specific requirements.

In this embodiment, patterning each optical film includes the steps of:

And removing the third photoresist layer.

It can be seen that, in this embodiment, the patterned third photoresist layer shields other optical films except the optical film to be patterned, and when etching the optical film to be patterned, the third photoresist layer protects the other optical films from being etched, and at the same time, the pattern on the patterned third photoresist layer can be copied to the optical film to be patterned, so as to form the patterned optical film.

Further, after forming the patterned third photoresist layer and before etching the optical films to be patterned, patterning each optical film further comprises the step of PEB baking the patterned third photoresist layer. The patterned third photoresist layer is further subjected to a crosslinking reaction, and is more resistant to subsequent etching.

The forming method, the exposing developing method, the removing method, etc. of the third photoresist layer in the present embodiment may be similar to those of the first embodiment, and the details thereof will not be repeated.

Next, taking an example in which the light receiving surface has two optical films of different materials arranged in parallel, the super surface molding process in this embodiment will be described. Specifically, the two optical films with 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, and the first material is different from the second material. The light receiving surface is provided with a first region 101 of the first optical film 201 and a second region 102 of the second optical film 202. Of course, this is not a limitation.

Referring to fig. 6 (a) - (6 (j), the super surface forming process is to pattern the first optical film 201 and then pattern the second optical film 202.

Specifically, referring to fig. 6 (a) to 6 (e), patterning the first optical film 201 includes the steps of:

as shown in fig. 6 (a), a third photoresist layer 4b is formed on the entire surface of the optical film layer 20, and at this time, the third photoresist layer 4b covers the first optical film 201 and the second optical film 202;

As shown in fig. 6 (b), exposing and developing the third photoresist layer 4b 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;

As shown in fig. 6 (c), the patterned third photoresist layer 4b is PEB baked;

As shown in fig. 6 (d), the first optical film 201 is etched by using the patterned third photoresist layer 4b as an etching mask, and the pattern of the super surface 30 corresponding to the first optical film 201 is copied onto the first optical film 201, so as to form a patterned first optical film 201;

as shown in fig. 6 (e), the third photoresist layer 4b is removed.

When the first optical film 201 is patterned, the third photoresist layer 4b is used as an etching mask, and when the first optical film 201 is etched, the third photoresist layer 4b shields the second optical film 202 and protects the second optical film 202, so that only the first optical film 201 is etched. After the third photoresist layer 4b is removed, the second optical film 202 and the patterned first optical film 201 are exposed, so that the second optical film 202 is patterned later.

Referring to fig. 6 (f) to 6 (j), the patterning of the second optical film 202 includes the following steps:

As shown in fig. 6 (f), a third photoresist layer 4b 'is formed on the patterned first optical film 201 and the second optical film 202, and at this time, the third photoresist layer 4b' covers the second optical film 202 and the patterned first optical film 201;

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;

As shown in fig. 6 (h), the patterned third photoresist layer 4b' is PEB baked;

As shown in fig. 6 (i), the second optical film 202 is etched with the patterned third photoresist layer 4b' as an etching mask, and the super surface 30 pattern corresponding to the second optical film 202 is copied onto the second optical film 202, forming a patterned second optical film 202;

as shown in fig. 6 (j), the third photoresist layer 4b' is removed.

When the second optical film 202 is patterned, the third photoresist layer 4b 'is used as an etching mask, and when the second optical film 202 is etched, the third photoresist layer 4b' covers the patterned first optical film 201 and protects the first optical film 201, so that only the second optical film 202 is etched. After the third photoresist layer 4b' is removed, the patterned second optical film 202 and the patterned first optical film 201 are exposed to form the super surface 30.

Referring to fig. 7 (a) - (7 (l)), in a fourth embodiment of the present invention, the difference between the present embodiment and the third embodiment of the present invention is that the mask is different when etching the optical film to be patterned, so as to avoid the situation of insufficient etching selectivity.

In this embodiment, patterning each optical film includes the steps of:

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

And removing the second super-surface mask.

When the optical film to be patterned is patterned, the second super surface mask covers the optical film other than the optical film to be patterned, and can protect the optical film other than the optical film to be patterned, and only the optical film to be patterned is etched.

The forming method, the exposing, the developing and the removing method of the third photoresist layer in the present embodiment may be the corresponding method in the second embodiment, and the material, the forming method, the removing method and the like of the second mask layer in the present embodiment may be the corresponding material and the method of the first mask layer in the second embodiment, which are not described herein again.

Referring to fig. 7 (a) - (7 (l)), the super surface molding process is to pattern the first optical film 201 and then pattern the second optical film 202.

Specifically, referring to fig. 7 (a) to 7 (f), patterning the first optical film 201 includes the steps of:

as shown in fig. 7 (a), a third photoresist layer 4c is formed on the entire surface of the optical film layer 20, and at this time, the third photoresist layer 4c covers the first optical film 201 and the second optical film 202;

As shown in fig. 7 (b), exposing and developing the third photoresist layer 4c 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 outwards;

As shown in fig. 7 (c), the patterned third photoresist layer 4c is coated to form a second mask layer 7, and the second mask layer 7 covers the second optical film 202 and the third photoresist layer 4c on the first optical film 201;

as shown in fig. 7 (d), removing the third photoresist layer 4c and the second mask layer 7 on the surface of the third photoresist layer 4c to obtain a patterned second super surface mask 8, where the pattern of the second super surface mask 8 on the first optical film 201 is the same as the pattern of the super surface 30 corresponding to the first optical film 201, and the second super surface mask 8 covers the second optical film 202;

As shown in fig. 7 (e), etching the first optical film 201 with the patterned second super surface mask 8, and copying the super surface 30 pattern corresponding to the first optical film 201 onto the first optical film 201 to form a patterned first optical film 201;

as shown in fig. 7 (f), the second super surface mask 8 is removed, at this time, the second optical film 202 is exposed to the outside, and the first optical film 201 is the patterned first optical film 201.

When the first optical film 201 is patterned, the second super surface mask 8 is used as an etching mask, and when the first optical film 201 is etched, the second super surface 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 the second super surface mask 8 is removed, the second optical film 202 and the patterned first optical film 201 are exposed, so that the second optical film 202 is patterned later.

As shown in fig. 7 (g) to 7 (l), the patterned second optical film 202 includes the steps of:

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, and at this time, the third photoresist layer 4c' covers the second optical film 202 and the patterned first optical film 201;

As shown in fig. 7 (h), the third photoresist layer 4c ' is exposed and developed to form a patterned third photoresist layer 4c ', where the pattern of the third photoresist layer 4c ' is opposite to the pattern of the super surface 30 corresponding to the second optical film 202, and at this time, the patterned first optical film 201 is exposed outwards;

As shown in fig. 7 (i), the patterned third photoresist layer 4c 'is coated to form a second mask layer 7', and the second mask layer 7 'covers the first optical film 201 and the third photoresist layer 4c' on the second optical film 202;

as shown in fig. 7 (j), removing the third photoresist layer 4c 'and the second mask layer 7' on the surface of the third photoresist layer 4c 'to obtain a patterned second super surface mask 8', where the pattern of the second super surface mask 8 'on the second optical film 202 is the same as the pattern of the super surface 30 corresponding to the second optical film 202, and the second super surface mask 8' covers the patterned first optical film 201;

As shown in fig. 7 (k), the second optical film 202 is etched with the patterned second super surface mask 8', and the super surface 30 pattern corresponding to the second optical film 202 is copied onto the second optical film 202, forming the patterned second optical film 202;

as shown in fig. 7 (l), the second super surface mask 8' is removed.

When the second optical film 202 is patterned, the second super surface mask 8 'is used as an etching mask, and when the second optical film 202 is etched, the second super surface mask 8' covers the patterned first optical film 201 to protect the first optical film 201, thereby only etching the second optical film 202. After the second super surface mask 8' is removed, the patterned second optical film 202 and the patterned first optical film 201 are exposed to form the super surface 30.

It is known that the thickness of the second mask layer 7 is greater than the thickness of the first optical film 201, so that the first optical film 201 can be better protected.

Referring to fig. 8 (a) -8 (r), which are a fifth embodiment of the present invention related to the super surface forming process, the difference between the present embodiment and the fourth embodiment related to the super surface forming process is that after removing the second super surface masks 8, 8', patterning each optical film further comprises the step of filling a protective material on the patterned optical film to form a protective layer 9, wherein the thickness of the protective layer 9 is greater than the thickness of the patterned optical film. By adding the protective layer 9 for protecting the patterned optical film, the etching selectivity, the thickness of each optical film, and the like are not limited, and the thickness of the mask layer is not required to be larger than the thickness of the patterned optical film, thereby saving the cost.

Further, the protective material has a light refractive index of less than 1.5.

Specifically, the protective material may be silicon dioxide, which is not limited thereto.

Specifically, when there is still the optical film that is not patterned, filling the protective material on the patterned optical film to form the protective layer 9 specifically includes the steps of:

covering the entire surface of the optical film layer 20 with a fourth photoresist layer 11, wherein the fourth photoresist layer 11 covers the optical film which is patterned and the optical film which is not patterned;

Exposing and developing the fourth photoresist layer 11 to expose the patterned optical film outwards, and simultaneously, covering the unpatterned optical film by the fourth photoresist layer 11;

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;

the fourth photoresist layer 11 is removed.

After the removal of the fourth photoresist layer 11, the initial protective layer 12 on the fourth photoresist layer 11 is simultaneously removed, leaving only the initial protective layer 12 on the patterned optical film, forming the protective layer 9.

It is known that, if the optical film is not unpatterned, i.e. after patterning the last optical film, the protective layer 9 can be directly formed by filling the protective material, and the fourth photoresist layer and the process steps corresponding to the fourth photoresist layer are not required.

Specifically, the "filling the protective material on the fourth photoresist layer 11 to form the initial protective layer 12" may specifically be performed by using FCVD, SCVD, or ALD method to fill SIO ₂.

Further, in the embodiment having 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 molding process further includes:

the surfaces of the protective layers 9 are ground so that the surfaces of adjacent protective layers 9 are flush.

Specifically, chemical polishing may be performed by CMP. Of course, this is not a limitation.

Referring to fig. 8 (a) -8 (r), the super surface molding process includes patterning the first optical film 201 and then patterning the second optical film 202.

Specifically, referring to fig. 8 (a) to 8 (j), patterning the first optical film 201 includes the following steps:

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

as shown in fig. 8 (b), exposing and developing the third photoresist layer 4d 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 outwards;

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

as shown in fig. 8 (d), removing the third photoresist layer 4d and the second mask layer 7d on the surface of the third photoresist layer 4d to obtain a patterned second super surface mask 8d, where the pattern of the second super surface mask 8d on the first optical film 201 is the same as the pattern of the super surface 30 corresponding to the first optical film 201, and the second super surface mask 8d covers the second optical film 202;

As shown in fig. 8 (e), etching the first optical film 201 with the patterned second super surface mask 8d, and copying the super surface 30 pattern corresponding to the first optical film 201 onto the first optical film 201 to form a patterned first optical film 201;

As shown in fig. 8 (f), the second super surface mask 8d is removed, at this time, the second optical film 202 is exposed outwards, and the first optical film 201 is a patterned first optical film 201;

As shown in fig. 8 (g), a fourth photoresist layer 11 is coated on the patterned first and second optical films 201 and 202;

As shown in fig. 8 (h), the fourth photoresist layer 11 is exposed and developed to expose the first optical film 201 outwards, and at the same time, the fourth photoresist layer 11 covers the second optical film 202;

as shown in fig. 8 (i), an initial protective layer 12 is formed by filling a protective material on the fourth photoresist layer 11, and the initial protective layer 12 covers the fourth photoresist layer 11 on the first optical film 201 and the second optical film 202;

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

Referring to fig. 8 (k) to 8 (r), the patterning of the second optical film 202 includes the steps of:

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

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 outwards;

As shown in fig. 8 (m), the patterned third photoresist layer 4 is coated to form a second mask layer 7d ', and the second mask layer 7d ' covers the protective layer 9 and the third photoresist layer 4d ' on the second optical film 202;

as shown in fig. 8 (n), removing the third photoresist layer 4d 'and the second mask layer 7d' on the surface of the third photoresist layer 4d 'to obtain a patterned second super surface mask 8d', where the pattern of the second super surface mask 8d 'on the second optical film 202 is the same as the pattern of the super surface 30 corresponding to the second optical film 202, and the second super surface mask 8d' covers the protective layer 9;

As shown in fig. 8 (o), the second optical film 202 is etched with the patterned second super surface mask 8d', and the super surface 30 pattern corresponding to the second optical film 202 is copied onto the second optical film 202, forming the patterned second optical film 202;

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 outward;

as shown in fig. 8 (q), a protective layer 9 is formed by filling a protective material;

As shown in fig. 8 (r), the surface of the protective layer 9 is polished to make the surfaces of the protective layers 9 on the first optical film 201 and the second optical film 202 flush, thereby forming the super-surface optical device 100 having the protective layer 9.

Referring to fig. 9 (a) to 9 (k), in a sixth embodiment of the present invention, the difference between the present embodiment and the first and second embodiments of the present invention is that in the present embodiment, the surface molding process includes a first surface molding process and a second surface molding process, a part of the optical film uses the first surface molding process to mold the surface 30, and another part of the optical film uses the second surface molding process to mold the surface 30. The first subsurface forming process is the second embodiment related to the subsurface forming process, and the second subsurface forming process is the first embodiment related to the subsurface forming process.

The first and second embodiments of the above-mentioned super surface forming process are described above, and are not described herein again.

When two kinds of super surface forming processes are selected, the mask can be selected according to specific requirements, for example, according to the thickness of an optical film to be patterned, when the thicker optical film is etched, the mask made of metal or phenanthrene metal such as silicon dioxide is adopted in the second embodiment, so that the defect of insufficient etching selection ratio can be avoided, and when the thinner optical film is etched, the photoresist is directly adopted as an etching mask in the first embodiment, so that the super surface forming process can be simplified, and the cost is reduced. Of course, the present invention is not limited thereto, and a suitable super surface molding process may be selected according to the material of the optical film to be patterned, and the like.

Next, taking an example in which the light receiving surface has two optical films of different materials arranged in parallel, the super surface molding process in this embodiment will be described. Specifically, the two optical films with 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 a first region 101 of the first optical film 201 and a second region 102 of the second optical film 202. Of course, this is not a limitation.

Referring to fig. 9 (a) to 9 (k), the super surface molding process includes patterning a first optical film 201, patterning a second optical film 202, patterning the first optical film 201 by the super surface molding process in the second embodiment, and patterning the second optical film 202 by the super surface molding process in the first embodiment.

Specifically, referring to fig. 9 (a) to 9 (f), patterning the first optical film 201 includes the steps of:

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

As shown in fig. 9 (b), exposing and developing the third photoresist layer 4e to form a patterned third photoresist layer 4e, where the pattern of the third photoresist layer 4e 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 outwards;

as shown in fig. 9 (c), the patterned third photoresist layer 4e is coated with a second mask layer 7e, where the second mask layer 7e covers the second optical film 202 and the third photoresist layer 4e on the first optical film 201;

As shown in fig. 9 (d), removing the third photoresist layer 4e and the second mask layer 7e on the surface of the third photoresist layer 4e to obtain a patterned second super surface mask 8e, where the pattern of the second super surface mask 8e on the first optical film 201 is the same as the pattern of the super surface 30 corresponding to the first optical film 201, and the second super surface mask 8e covers the second optical film 202;

As shown in fig. 9 (e), the first optical film 201 is etched with the patterned second super surface mask 8e, and the super surface 30 pattern corresponding to the first optical film 201 is copied onto the first optical film 201, so as to form a patterned first optical film 201;

As shown in fig. 9 (f), the second super surface mask 8e is removed, at this time, the second optical film 202 is exposed to the outside, and the first optical film 201 is the patterned first optical film 201.

Referring to fig. 9 (g) to 9 (k), the patterning of the second optical film 202 includes the steps of:

as shown in fig. 9 (g), a third photoresist layer 4e' is formed on the entire surface of the optical film layer 20, and at this time, the third photoresist layer 4 covers the second optical film 202 and the patterned first optical film 201;

As shown in fig. 9 (h), exposing and developing the third photoresist layer 4e '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;

As shown in fig. 9 (i), the patterned third photoresist layer 4e' is PEB baked;

as shown in fig. 9 (j), the second optical film 202 is etched with the patterned third photoresist layer 4e' as an etching mask, and the super surface 30 pattern corresponding to the second optical film 202 is copied onto the second optical film 202;

as shown in fig. 9 (k), the third photoresist layer 4e' is removed, the patterned first optical film 201 and the second optical film 202 are exposed outward, and the super surface 30 is formed.

Compared with the prior art, in the preparation process of the super-surface optical device 100, by arranging the super-surface 30 with various materials on the same substrate 10, the super-surface 30 has high freedom degree in structural design, and the working wave band of the super-surface 30 is wider, so that different preset functions can be realized, and the processing of the super-surface optical device 100 with large area and cross dimension can be realized.

It should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is for clarity only, and that the skilled artisan should recognize that the embodiments may be combined as appropriate to form other embodiments that will be understood by those skilled in the art.

The above list of detailed descriptions is only specific to practical embodiments of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent embodiments or modifications that do not depart from the spirit of the present invention should be included in the scope of the present invention.

Claims

1. A process for preparing a metasurface optical device, characterized in that: the process comprises an optical film forming process for 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 for each optical film comprises:

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 process comprises an optical film forming process for 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, and the optical film forming process for each of the optical films comprises:

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 preparation process for a metasurface optical device, characterized in that: the preparation process includes an optical film forming process for 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 films 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;

removing the first photoresist layer;

The second optical film forming process includes the following steps:

Etching and removing the initial film layer in the other regions;

The second photoresist layer is removed.

4. The preparation process of the metasurface optical device as described in any one of claims 1 to 3 is characterized in that: after the optical film is formed on the light-receiving surface, the preparation process also includes a metasurface forming process of patterning the optical film layer to form a metasurface.

5. The process for preparing a metasurface optical device according to claim 4, wherein the metasurface forming process comprises:

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

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, wherein the metasurface forming process comprises:

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 as described in claim 4, wherein: "patterning the optical film layer" means: patterning each optical film in sequence.

8. The process for preparing a metasurface optical device according to claim 7, wherein patterning each optical film comprises the following steps:

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, wherein patterning each optical film comprises the following steps:

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 preparation process of the metasurface optical device according to claim 7, characterized in that: the metasurface forming process includes a first metasurface forming process and a second metasurface forming process, part of the optical film is formed into a metasurface by the first metasurface forming process, and another part of the optical film is formed into a metasurface by the second metasurface forming process; the patterning of each optical film in the first metasurface forming process includes the following steps

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

removing the second metasurface mask;

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

The third photoresist layer is removed.

11. The process for preparing a metasurface optical device as described in claim 9 is characterized in that: after removing the second metasurface mask, patterning each optical film further comprises 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, wherein the refractive index of the protective material is less than 1.5.