WO2022001449A1

WO2022001449A1 - Metal wire grid polarizer and manufacturing method therefor, and display device

Info

Publication number: WO2022001449A1
Application number: PCT/CN2021/094596
Authority: WO
Inventors: 王国强
Original assignee: 京东方科技集团股份有限公司
Priority date: 2020-06-29
Filing date: 2021-05-19
Publication date: 2022-01-06
Also published as: CN113933924A

Abstract

A metal wire grid polarizer and a manufacturing method therefor. The metal wire grid polarizer comprises: a substrate (1); a first sub-wire grid structure located on the substrate (1), the first sub-wire grid structure comprising a plurality of first sub-wire grids (2) parallel to each other, and the first sub-wire grids (2) being made of a metal material; and a second sub-wire grid structure comprising a plurality of second sub-wire grids (3), the second sub-wire grids (3) corresponding one-to-one to the first sub-wire grids (2), each second sub-wire grid (3) being located at the side of the corresponding first sub-wire grid (2) away from the substrate (1), and the second sub-wire grids (3) and the corresponding first sub-wire grids (2) forming a wire grid of the metal wire grid polarizer. The metal wire grid polarizer features a high polarization degree.

Description

Wire grid polarizer, method for making the same, and display device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202010607618.X filed in China on Jun. 29, 2020, the entire contents of which are hereby incorporated by reference.

technical field

The present disclosure relates to the field of display technology, and in particular, to a metal wire grid polarizer, a manufacturing method thereof, and a display device.

Background technique

Polarizing devices play a pivotal role in modern optical systems. In display products, polarizers are used to reduce the impact of ambient reflected light on the display, and polarizers are added in front of photographic lenses to eliminate reflected light.

However, traditional polarizers, such as crystal polarizers, are large in size, expensive and have poor angular incidence performance. Metal gratings are based on the fact that electrons on the surface of metal gratings freely oscillate along the direction of the gratings under the action of incident light, and are restricted in the direction perpendicular to the gratings, thus exhibiting strong polarization characteristics and can be used as polarizers or polarization beam splitters. Compared with traditional polarizing devices, such as polarizers, wire grid polarizers also have good polarization effects when the angle of incident light changes greatly. They are cheap, have good temperature adaptability, and are small in size, making them easy to use in microsystems. . Therefore, wire grid polarizers have advantages that traditional polarizers cannot match.

At present, the main methods of making metal wire grid polarizers include: nano-imprint technology, electron beam direct writing exposure technology, X-ray lithography technology and holographic lithography technology. However, the minimum separation distance between the adjacent two wire grids of the metal wire grid polarizer produced by the above method is relatively large, resulting in a small degree of polarization, which cannot meet the requirements for the degree of polarization of some products.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present disclosure is to provide a metal wire grid polarizer, a manufacturing method thereof, and a display device, which can manufacture a metal wire grid polarizer with a high degree of polarization.

In order to solve the above-mentioned technical problems, the embodiments of the present disclosure provide the following technical solutions:

In one aspect, embodiments of the present disclosure provide a method for fabricating a metal wire grid polarizer, including:

preparing a first sub-wire grid structure on a substrate, the first sub-wire grid structure includes a plurality of first sub-wire grids parallel to each other, and the first sub-wire grid adopts a metal material;

A metal thin film with a thickness smaller than a first threshold is deposited on the substrate on which the first sub-wire grid structure is formed, and the metal thin film is deposited on the side of the first sub-wire grid away from the substrate to form a plurality of first Two sub-wire grids, the second sub-wire grid and the corresponding first sub-wire grid form a wire grid of the metal wire grid polarizer.

In some embodiments, after the metal thin film is deposited, a part of the metal thin film is located in the spaced region between the first sub-wire grids, and the method further includes:

The metal thin film on the substrate is etched as a whole, and the metal thin film in the spaced region between the first sub-wire grids is removed, and the etching thickness is smaller than the deposition thickness of the metal thin film.

In some embodiments, the metal thin film includes: Al, Ag, Cu or Ir thin film.

In some embodiments, the thickness of the metal thin film is greater than a second threshold, the first threshold is 500 nm, and the second threshold is 30 nm.

In some embodiments, the deposited thickness of the metal thin film is 40-50 nm.

In some embodiments, the etch thickness is 25-30 nm.

In some embodiments, the longitudinal section of the first sub-wire grid perpendicular to its own extension direction is rectangular;

The profile of the longitudinal section of the second sub-wire grid perpendicular to its own extension direction is a part of an ellipse.

In some embodiments, the preparing the first sub-wire grid structure on the substrate includes:

The first sub-wire grid structure is prepared by using nano-imprinting technology.

In some embodiments, the depositing a metal thin film with a thickness smaller than a first threshold on the substrate on which the first sub-wire grid structure is formed includes:

A layer of metal thin film is covered on the first sub-wire grid structure by sputtering.

Embodiments of the present disclosure provide a metal wire grid polarizer comprising:

base;

a first sub-wire grid structure located on the substrate, the first sub-wire grid structure includes a plurality of first sub-wire grids parallel to each other, and the first sub-wire grid adopts a metal material;

a second sub-wire grid structure, the second sub-wire grid structure includes a plurality of second sub-wire grids, the second sub-wire grids are in one-to-one correspondence with the first sub-wire grids, each of the second sub-wire grids The wire grid is located on a side of the corresponding first sub-wire grid away from the substrate, and the second sub-wire grid and the corresponding first sub-wire grid form a wire grid of the metal wire grid polarizer.

In some embodiments, the distance between two adjacent first sub-grids is equal to D1; the minimum distance between two adjacent wire grids is equal to D2, and D2 is smaller than D1.

In some embodiments, the value range of D1 is 50-500 nm, and the value range of D2 is 20-450 nm.

An embodiment of the present disclosure is a display device including the metal wire grid polarizer as described above.

Description of drawings

FIG. 1 is a schematic diagram of forming a first wire grid structure on a substrate according to an embodiment of the present disclosure;

Fig. 2 is the sectional schematic diagram of Fig. 1 in AA' direction;

3 is a schematic diagram of forming a second wire grid structure on a substrate according to an embodiment of the present disclosure;

Fig. 4 is a schematic cross-sectional view in the direction AA' of Fig. 3 .

reference number

1 base

2 The first sub-wire grid

3 Second sub-wire grid

detailed description

In order to make the technical problems, technical solutions and advantages to be solved by the embodiments of the present disclosure more clear, the following detailed description will be given in conjunction with the accompanying drawings and specific embodiments.

Some display products require the polarization degree of the wire grid polarizer to be greater than 99.986% to meet the contrast requirement. However, the existing process capability is temporarily unable to achieve the polarization degree of the metal wire grid polarizer greater than 99.986%, and the polarization degree uniformity is poor. Some wire grid polarizers have a degree of polarization of only 99%. For example, in the related art, when a metal wire grid polarizer is fabricated by a nano-imprinting process, an embossing glue is formed on a substrate, nano-imprinting is performed to form an embossing glue pattern, a metal film is deposited on the imprinting glue pattern, and the pressure is removed. The rubber pattern is printed to obtain a metal wire grid polarizer. In this solution, the polarization degree of the metal wire grid polarizer can only reach about 99%.

In order to improve the polarization degree of the metal wire grid polarizer, a double-layer WGP (wire grid polarizer) process can be used, that is, a first layer of metal wire grid is formed on the first surface of the substrate, and then a second layer is formed on the second surface of the substrate. The metal wire grid, double-layer WGP process can increase the polarization degree of the metal wire grid polarizer to more than 99.99%, but the double-layer WGP (wire grid polarizer) process is complicated, the efficiency is low, and the first layer of metal wire The alignment requirements of the grid and the second-layer wire grid are high. If there is an angle difference between the wire grid directions of the first-layer wire grid and the second-layer wire grid, it will seriously affect the transmittance of the wire grid polarizer. Since the metal wire grids of the first layer and the metal wire grids of the second layer are formed on different surfaces of the substrate, deviations in alignment are inevitable.

Another way to increase the degree of polarization is the stacked WGP process. The preparation process includes: cleaning the substrate; depositing a metal film, such as an aluminum film, on the substrate; patterning the aluminum film; depositing a layer of SiO; Coating tackifier, IPA isopropyl alcohol and embossing glue in sequence; embossing the embossing glue to form an embossing glue pattern; etching the aluminum film with the embossing glue as a pattern to form the first layer of metal wire grid ; forming a flat layer; forming a buffer layer; depositing a metal film, such as an aluminum film; patterning the aluminum film; depositing a layer of SiO; The embossing glue is embossed to form an embossing glue pattern; the aluminum film is etched with the embossing glue as a pattern to form a second layer of metal wire grids. It can be seen that the process of the stacked WGP process is complex, the efficiency is low, and the polarization degree improvement of the metal wire grid polarizer is limited.

Embodiments of the present disclosure provide a metal wire grid polarizer, a manufacturing method thereof, and a display device, which can manufacture a metal wire grid polarizer with a high degree of polarization.

Embodiments of the present disclosure provide a method for fabricating a metal wire grid polarizer, including:

For wire grid polarizers, the degree of polarization is determined by the duty cycle of the wire grid polarizer and the height of the wire grid, where the duty cycle is the ratio of the wire width of the wire grid to the spacing between the wire grids, the wire grid The greater the duty cycle of the polarizer, the greater the degree of polarization of the wire grid polarizer; the greater the height of the wire grid, the greater the degree of polarization of the wire grid polarizer.

In this embodiment, the first sub-wire grid structure and the second sub-wire grid structure constitute a metal wire grid polarizer, and the second sub-wire grid structure is formed on the basis of the first sub-wire grid structure, which increases the height of the wire grid, Therefore, the degree of polarization of the wire grid polarizer can be improved; in this embodiment, the first sub-wire grid structure and the second sub-wire grid structure are fabricated on the same side of the substrate to avoid alignment deviation and ensure the wire grid polarizer. In addition, the manufacturing process of this embodiment is simple, the production efficiency is high, and the cost of the metal wire grid polarizer is reduced. Furthermore, when a metal film is deposited on the first sub-wire grid structure in this embodiment, part of the metal will be deposited on the sidewall of the first sub-wire grid, so that the width of the wire grid can be increased, and the duty ratio of the wire grid can be improved. The degree of polarization of the wire grid polarizer is further improved. Through the technical solution of this embodiment, the degree of polarization of the wire grid polarizer can be increased to more than 99.986%, or even more than 99.998%.

When a metal thin film is deposited on the first sub-wire grid structure, a small amount of metal may be deposited in the spaced area between the first sub-wire grids, which affects the transmittance of the metal wire grid polarizer. After the metal thin film, part of the metal thin film is located in the spaced area between the first sub-wire grids. After the metal thin film is deposited, the metal thin film on the substrate needs to be etched as a whole to remove the first sub-wire grid. The metal film in the spaced area between the wire grids can be completely removed by controlling the etching time; since only a small part of the metal is deposited between the first sub-wire grids. Therefore, the thickness of the etching is smaller than the thickness of the metal film. After etching, the side of the first sub-wire grid away from the substrate still retains most of the metal film to form the second sub-wire grid. The degree of polarization of the wire grid polarizer is improved under the condition of ensuring the transmittance of the wire grid polarizer.

In addition, the deposition thickness of the metal film can also be controlled to avoid deposition of the metal film in the spacer regions between the first sub-wire grids, or to reduce the thickness of the metal film deposition in the spacer regions between the first sub-wire grids.

In a specific embodiment, as shown in FIG. 1 to FIG. 4 , the manufacturing method of the metal wire grid polarizer of this embodiment includes the following steps:

Step 1. As shown in FIG. 1 and FIG. 2, a first sub-wire grid structure is formed on the substrate 1, and the first sub-wire grid structure includes a plurality of first sub-wire grids 2 parallel to each other;

Specifically, the first sub-wire grid structure may be prepared by using a nanoimprint technology. When the first sub-wire grid structure is fabricated by the nano-imprinting process, an imprinting glue is formed on the substrate 1, nano-imprinting is performed to form an imprinting glue pattern, a metal film is deposited on the imprinting glue pattern, and the imprinting glue pattern is removed, A first sub-wire grid structure is obtained.

Since the wire grid made of Al has a good degree of polarization, the metal film in this step can be made of Al film. Of course, the metal film in this step is not limited to the use of Al film, and Ag, Cu or Ir film can also be used .

It can be seen from FIG. 2 that the manufactured first sub-wire grid 2 has a rectangular longitudinal section perpendicular to its own extending direction. The distances between adjacent first sub-grids 2 are all equal to D1.

Step 2: As shown in FIG. 3 and FIG. 4 , a metal film is deposited on the first sub-wire grid 2 to form a second sub-wire grid 3 .

In this embodiment, a metal thin film can be deposited on the first sub-wire grid 2 by a sputtering method, and the sputtering method includes atomic layer deposition technology and magnetron sputtering technology.

Due to the special self-limiting reaction characteristics of atomic layer deposition technology, only one layer of atoms is deposited in each deposition cycle, and the thickness of the deposited film (0.05nm level) can be extremely precisely controlled by controlling the deposition cycle, and the three-dimensional coverage ability is very good. . Therefore, based on the excellent three-dimensional coverage and precise thickness control capability of the atomic layer deposition technology, in this embodiment, the first sub-wire grid structure can be covered with a layer of metal thin film by the atomic layer deposition method. Of course, this embodiment is not limited to the use of atomic layer deposition to form metal thin films, and magnetron sputtering can also be used to form metal thin films. In magnetron sputtering, by controlling the electric field and the magnetic field, the metal thin films can be made It is only formed on the first sub-wire grid 2, and will not be deposited on the spaced regions between adjacent first sub-wire grids 2; Deposited to the spacer regions between adjacent first sub-wire grids 2 .

In a specific example, as shown in FIG. 4 , a metal film with a thickness of H may be deposited on the substrate 1 on which the first sub-wire grid structure is formed; when the metal film is deposited by magnetron sputtering, the By controlling the electric and magnetic fields, the metal thin film can be formed only on the first sub-wire grid 2, as shown in FIG. In the space area between the sub-wire grids 2, in order to ensure the transmittance of the metal wire grid polarizer, the metal film on the substrate 1 needs to be etched as a whole to remove the space area between the adjacent first sub-wire grids 2. At the same time, part of the metal film on the top of the first sub-wire grid 2 is also removed, and the etching thickness K is less than H. After etching, a second sub-wire grid structure is formed on the side away from the substrate. A sub-wire grid structure, the second sub-wire grid structure includes a plurality of second sub-wire grids 3 parallel to each other, the second sub-wire grids 3 are in one-to-one correspondence with the first sub-wire grids 2, and each second sub-wire grid 2 3 is located on the side of the corresponding first sub-wire grid 2 away from the substrate 1. Each second sub-wire grid 3 and the corresponding first sub-wire grid 2 form a wire grid of a metal wire grid polarizer. The sub-wire grid structure and the second sub-wire grid structure constitute a metal wire grid polarizer. It can be seen from FIG. 4 that the longitudinal section of the first sub-wire grid 2 perpendicular to its own extension direction is rectangular, and the profile of the longitudinal section of the second sub-wire grid 3 perpendicular to its own extension direction is elliptical. part

It can be seen from FIG. 4 that the minimum distance between adjacent second sub-grids 3 is D2, and D2 is smaller than D1. The minimum spacing between adjacent second sub-wire grids 3 also determines the minimum spacing between the wire grids of the metal wire grid polarizer.

The degree of polarization of the wire grid polarizer is proportional to the height of the wire grid, and increasing the thickness of the deposited metal film will also increase the degree of polarization of the wire grid polarizer, but if the thickness of the deposited metal film is too large, the adjacent The distance between the two sub-wire grids will be reduced to 0. Therefore, the thickness H of the metal film should be less than 500 nm, which can ensure that there is a certain gap between the adjacent second sub-wire grids. A threshold, the thickness of the metal film is greater than the second threshold, the first threshold may be 500 nm, and the second threshold may be 30 nm.

In some embodiments, the deposition thickness H of the metal film may be 40-50 nm, and the etching thickness K may be 25-30 nm. Under these parameters, the height of the wire grid structure of the metal wire grid polarizer is higher than that of the first sub-wire grid. The height of the wire grid polarizer is about 25nm larger, which can increase the polarization degree of the metal wire grid polarizer to 99.999%.

An embodiment of the present disclosure also provides a metal wire grid polarizer, as shown in FIG. 3 and FIG. 4 , including:

base 1;

a first sub-wire grid structure located on the substrate 1, the first sub-wire grid structure includes a plurality of first sub-wire grids 2 parallel to each other, and the first sub-wire grid 2 adopts a metal material;

A second sub-wire grid structure, the second sub-wire grid structure includes a plurality of second sub-wire grids 3, the second sub-wire grids 3 are in one-to-one correspondence with the first sub-wire grids 2, each of the The second sub-wire grid 3 is located on the side of the corresponding first sub-wire grid 2 away from the substrate 1 , and the second sub-wire grid 3 and the corresponding first sub-wire grid 2 constitute the metal wire grid polarizer. wire grid.

In this embodiment, the first sub-wire grid structure and the second sub-wire grid structure constitute a metal wire grid polarizer, and the second sub-wire grid structure is formed on the basis of the first sub-wire grid structure, which increases the height of the wire grid, Therefore, the degree of polarization of the wire grid polarizer can be improved; in this embodiment, the first sub-wire grid structure and the second sub-wire grid structure are fabricated on the same side of the substrate to avoid alignment deviation and ensure the wire grid polarizer. In addition, the manufacturing process of this embodiment is simple, the production efficiency is high, and the cost of the metal wire grid polarizer is reduced.

When fabricating the metal wire grid polarizer of this embodiment, a first sub-wire grid structure may be prepared on a substrate, and the first sub-wire grid structure includes a plurality of first sub-wire grids parallel to each other; A metal thin film with a thickness smaller than a first threshold is deposited on the substrate of the first sub-wire grid structure, and the metal thin film is deposited on the side of the first sub-wire grid away from the substrate to form a plurality of second sub-wire grids, The second sub-wire grid and the corresponding first sub-wire grid form a wire grid of the metal wire grid polarizer.

In this embodiment, when a metal thin film is deposited on the first sub-wire grid structure, part of the metal will be deposited on the sidewall of the first sub-wire grid, which can increase the width of the wire grid and reduce the distance between two adjacent wire grids , for example, the distance between two adjacent first sub-grids is equal to D1; the minimum distance D2 between two adjacent grids is smaller than D1. In this way, this embodiment improves the duty cycle of the wire grid, and further improves the polarization degree of the metal wire grid polarizer. Through the technical solution of this embodiment, the polarization degree of the metal wire grid polarizer can be increased to more than 99.986%, or even It can reach more than 99.998%.

Since the wire grid made of Al has a good degree of polarization, the first sub-wire grid 2 can be made of Al. Of course, the first sub-wire grid 2 is not limited to using Al, but also Ag, Cu or Ir; The two sub-wire grids 3 can be made of Al. Of course, the second sub-wire grid 3 is not limited to be made of Al, and can also be made of Ag, Cu or Ir.

In some embodiments, as shown in FIG. 4 , the longitudinal section of the first sub-wire grid 2 in the direction perpendicular to its own extension may be rectangular; the longitudinal section of the second sub-wire grid 3 in the direction perpendicular to its own extension The profile of the cross-section can be a part of an ellipse, a part of the second sub-wire grid 3 is located on the surface of the first sub-wire grid 2 away from the substrate 1, and the other part extends to the sidewall of the first sub-wire grid 2, which is the same as the first sub-wire grid 2. The sub-wire grids together constitute the wire grid of the metal wire grid polarizer.

In some embodiments, the minimum distance D2 between two adjacent second sub-wire grids 3 is 20-450 nm, that is, the minimum distance between two adjacent wire grids of the metal wire grid polarizer is 20-450 nm. The value range of the distance D1 between the adjacent first sub-wire grids 2 is 50-500 nm. It can be seen that the minimum distance between two adjacent wire grids of the metal wire grid polarizer is smaller than the adjacent first sub-wires The distance D1 between the grids 2 can effectively improve the polarization degree of the wire grid polarizer.

In this embodiment, the height of the wire grid of the wire grid polarizer can be about 25 nm larger than the height of the first sub-wire grid, and the polarization degree of the wire grid polarizer can be increased to 99.999%, which can meet the needs of various products .

Embodiments of the present disclosure also provide a display device including the metal wire grid polarizer as described above.

The display device includes but is not limited to: a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply and other components. Those skilled in the art can understand that the structure of the above-mentioned display device does not constitute a limitation on the display device, and the display device may include more or less components described above, or combine some components, or arrange different components. In the embodiments of the present disclosure, the display device includes, but is not limited to, a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, and the like.

The display device can be any product or component with display function, such as LCD TV, LCD, digital photo frame, mobile phone, tablet computer, etc., wherein the display device also includes a flexible circuit board, a printed circuit board and a backplane.

In the method embodiments of the present disclosure, the sequence numbers of the steps are not used to limit the sequence of the steps. For those of ordinary skill in the art, the sequence of the steps can be changed without creative work. Also within the scope of protection of the present disclosure.

It should be noted that each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. Especially, for the embodiment, since it is basically similar to the product embodiment, the description is relatively simple, and the relevant part may refer to the partial description of the product embodiment.

Unless otherwise defined, technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. As used in this disclosure, "first," "second," and similar terms do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right", etc. are only used to represent the relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element, Or intermediate elements may be present.

In the foregoing description of the embodiments, the particular features, structures, materials or characteristics may be combined in any suitable manner in any one or more of the embodiments or examples.

The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited to this. should be included within the scope of protection of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

A method for making a wire grid polarizer, comprising:

preparing a first sub-wire grid structure on a substrate, the first sub-wire grid structure includes a plurality of first sub-wire grids parallel to each other, and the first sub-wire grid adopts a metal material;

A metal thin film with a thickness smaller than a first threshold is deposited on the substrate on which the first sub-wire grid structure is formed, and the metal thin film is deposited on the side of the first sub-wire grid away from the substrate to form a plurality of first Two sub-wire grids, the second sub-wire grid and the corresponding first sub-wire grid form a wire grid of the metal wire grid polarizer.
The method for fabricating a metal wire grid polarizer according to claim 1, wherein after depositing the metal thin film, part of the metal thin film is located in a spaced region between the first sub-wire grids, and the method further comprises:

The metal thin film on the substrate is etched as a whole, and the metal thin film in the spaced region between the first sub-wire grids is removed, and the etching thickness is smaller than the deposition thickness of the metal thin film.
The method for manufacturing a metal wire grid polarizer according to claim 1, wherein the metal thin film comprises: Al, Ag, Cu or Ir thin film.
The method for manufacturing a metal wire grid polarizer according to claim 1, wherein the thickness of the metal thin film is greater than a second threshold, the first threshold is 500 nm, and the second threshold is 30 nm.
The method for manufacturing a metal wire grid polarizer according to claim 2, wherein the deposition thickness of the metal thin film is 40-50 nm.
The method for manufacturing a metal wire grid polarizer according to claim 5, wherein the etching thickness is 25-30 nm.
The method for manufacturing a wire grid polarizer according to claim 1, wherein,

The longitudinal section of the first sub-wire grid perpendicular to its own extension direction is rectangular;

The profile of the longitudinal section of the second sub-wire grid perpendicular to its own extension direction is a part of an ellipse.
The method for making a metal wire grid polarizer according to claim 1, wherein the preparing the first sub-wire grid structure on the substrate comprises:

The first sub-wire grid structure is prepared by using nano-imprinting technology.
The method for manufacturing a metal wire grid polarizer according to claim 1, wherein the depositing a metal thin film with a thickness smaller than a first threshold on the substrate on which the first sub-wire grid structure is formed comprises:

A layer of metal thin film is covered on the first sub-wire grid structure by sputtering.
A metal wire grid polarizer, comprising:

base;

a first sub-wire grid structure located on the substrate, the first sub-wire grid structure includes a plurality of first sub-wire grids parallel to each other, and the first sub-wire grid adopts a metal material;

a second sub-wire grid structure, the second sub-wire grid structure includes a plurality of second sub-wire grids, the second sub-wire grids are in one-to-one correspondence with the first sub-wire grids, each of the second sub-wire grids The wire grid is located on a side of the corresponding first sub-wire grid away from the substrate, and the second sub-wire grid and the corresponding first sub-wire grid form a wire grid of the metal wire grid polarizer.
The metal wire grid polarizer according to claim 10, wherein the distance between two adjacent first sub-wire grids is equal to D1; the minimum distance between two adjacent wire grids is equal to D2, and D2 is less than D1.
The wire grid polarizer of claim 10, wherein:

The longitudinal section of the first sub-wire grid perpendicular to its own extension direction is rectangular;

The profile of the longitudinal section of the second sub-wire grid perpendicular to its own extension direction is a part of an ellipse.
The metal wire grid polarizer according to claim 11, wherein the value range of D1 is 50-500 nm, and the value range of D2 is 20-450 nm.
A display device, characterized by comprising the metal wire grid polarizer according to any one of claims 10-13.