Grating preparation device
By using grating mask and interference exposure technology in the grating preparation device, the problem of difficulty in preparing high-precision toothed grating structures in the prior art is solved, and higher process accuracy and optical performance are achieved.
Patent Information
- Application Number
- CN202420087520.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-01-12
AI Technical Summary
The existing semiconductor manufacturing and processing technology is difficult to prepare a toothed grating structure with high process accuracy, resulting in poor optical performance of diffraction optical waveguides.
A grating preparation device is adopted, which includes a light source module and a grating mask. A diffraction beam of order 0, positive, and negative, minus 1 diffraction beam is generated on the grating mask by collimating the light beam, and these beams interfere with each other on the substrate to form an interference exposure field, and finally a grating structure with tooth-shaped depressions is superimposed on the substrate.
The process accuracy of grating preparation is improved, the process complexity is reduced, and the grating structures with different tooth shapes can be accurately prepared, which improves the optical performance of diffraction optical waveguides.
Smart Images
Figure CN222580280U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical technology, and in particular to a grating preparation device. Background Art
[0002] As a mainstream display optical solution for virtual display devices, diffraction waveguides couple the light emitted by the image source into the waveguide for propagation through an in-coupling grating. When the light propagates to the out-coupling grating area, it is coupled out by the out-coupling grating and enters the human eye, and the human eye can see the light on the image source. However, in the existing semiconductor manufacturing process, when processing and preparing a grating structure with a toothed structure, it is difficult to obtain a toothed grating structure with high process accuracy using conventional grating preparation methods, resulting in poor optical performance of the diffraction waveguide. Utility Model Content
[0003] The present application proposes a grating preparation device, comprising: a light source module, the light source module is used to emit a collimated light beam; a grating mask, arranged in the output direction of the collimated light beam, the grating mask is used to diffract the collimated light beam incident thereon to form a 0th order diffraction beam, a positive 1st order diffraction beam and a negative 1st order diffraction beam, the 0th order diffraction beam, the positive 1st order diffraction beam and the negative 1st order diffraction beam are used to emit onto a substrate, and form two different patterned interference exposure fields on the substrate, so as to superimpose on the substrate to form a grating structure with toothed depressions.
[0004] Optionally, the 0th order diffraction beam is vertically incident on the substrate, and the positive first order diffraction beam and the negative first order diffraction beam are incident on the substrate at a set angle θ d The incident angle is incident on the substrate, and the setting angle θ d for:
[0005]
[0006] Wherein, λ0 is the wavelength of the collimated light beam, Λ g is the period of the grating mask.
[0007] Optionally, the positive first-order diffraction beam interferes with the negative first-order diffraction beam on the substrate, and forms an interference exposure field having interference fringes with an interference period of Λ1 on the substrate, wherein Λ1 is:
[0008]
[0009] Optionally, the 0th order diffraction beam interferes with the positive first order diffraction beam on the substrate, and forms an interference exposure field having interference fringes with an interference period of Λ2 on the substrate; the 0th order diffraction beam interferes with the negative first order diffraction beam on the substrate, and forms an interference exposure field having interference fringes with an interference period of Λ2 on the substrate, wherein Λ2 is:
[0010]
[0011] Optionally, a photoresist is plated on the surface of the substrate, and the photoresist is used to be exposed by the two interference exposure fields. The photoresist forms a grating with tooth-shaped depressions after development.
[0012] Optionally, the light source module includes a laser light source and a collimating lens; the laser light source is used to emit a light beam; the collimating lens is arranged in an output direction of the light beam, and the collimating lens is used to collimate the light beam to form the collimated light beam and emit the collimated light beam.
[0013] Optionally, the light source module also includes a spatial light filter; the spatial light filter is arranged at the light output of the laser light source, and the spatial light filter is used to filter stray light in the light beam emitted by the laser light source, and output the filtered light beam to the collimating lens.
[0014] Optionally, the spatial light filter includes an input lens and a filtering pinhole; the input lens is arranged at the light output of the laser light source, and the input lens is used to converge the light beam and output the converged light beam; the filtering pinhole is arranged between the input lens and the collimating lens, and the filtering pinhole is used to transmit a target light beam in the output light beam to the collimating lens, and filter other light beams in the light beam except the target light beam, the aperture center of the filtering pinhole coincides with the beam focus of the target light beam, and the target light beam includes a light beam in the light beam whose wavelength is within a set wavelength range.
[0015] Optionally, the light source module also includes an iris, the aperture size of which matches the size of the grating mask; the iris is arranged at the light exit of the collimating lens, and the iris is used to adjust the spot size of the collimated light beam so that the spot size of the collimated light beam projected onto the grating mask matches the size of the grating mask.
[0016] Optionally, the grating mask includes at least one of a relief grating, a volume holographic grating and a polarization volume grating.
[0017] The grating preparation device provided by the present application includes: a light source module, the light source module is used to emit a collimated light beam; a grating mask, which is arranged in the output direction of the collimated light beam, and the grating mask is used to diffract the collimated light beam incident thereon to form a 0th order diffraction light beam, a positive 1st order diffraction light beam and a negative 1st order diffraction light beam, and the 0th order diffraction light beam, the positive 1st order diffraction light beam and the negative 1st order diffraction light beam are used to emit to a substrate, and form two different patterned interference exposure fields on the substrate, so as to form a grating structure with tooth-shaped depressions by superposition on the substrate. In this embodiment, the grating mask forms a 0th order diffraction light beam, a positive 1st order diffraction light beam and a negative 1st order diffraction light beam based on the diffraction of the vertically incident collimated light beam, and the three diffraction light beams interfere with each other on the substrate to form two different patterned interference exposure fields, and the two interference exposure fields are superimposed on the substrate, so that the grating structure with tooth-shaped depressions can be easily obtained by interference exposure, and while improving the process accuracy of grating preparation, the preparation method of three diffraction light beams interference exposure reduces the process complexity of grating preparation.
[0018] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0020] Figure 1 A schematic structural diagram of a grating preparation device provided in one embodiment of the present application is shown.
[0021] Figure 2 Shows this application Figure 1 Schematic diagram of the diffracted beams from the provided grating mask.
[0022] Figure 3 A schematic structural diagram of a first grating structure provided in an embodiment of the present application is shown.
[0023] Figure 4 A schematic structural diagram of a second grating structure provided in an embodiment of the present application is shown.
[0024] Figure 5 A schematic diagram of a target interference exposure field provided by an embodiment of the present application is shown.
[0025] Figure 6 A schematic structural diagram of a third grating structure provided in an embodiment of the present application is shown.
[0026] Figure 7A schematic structural diagram of a grating preparation device provided in another embodiment of the present application is shown. DETAILED DESCRIPTION
[0027] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.
[0028] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.
[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0030] Please refer to Figure 1 , Figure 1 FIG. 1 is a schematic diagram showing the structure of a grating preparation device 1 provided in an embodiment of the present application. The grating preparation device 1 provided in an embodiment of the present application will be described in detail below in conjunction with the figure. Figure 1 As shown, the grating preparation device 1 of the present application includes a light source module 10 and a grating mask 20 .
[0031] In this embodiment, the light source module 10 is used to emit a collimated light beam and project the collimated light beam onto the grating mask 20, and the collimated light beam emitted by the light source module 10 is vertically projected onto the grating mask 20. The grating mask 20 includes at least one of a relief grating, a volume holographic grating, and a polarization volume grating, which is not limited here.
[0032] Optionally, the grating mask 20 disposed in the output direction of the collimated light beam is used to diffract the collimated light beam incident thereon, that is, the collimated light beam vertically incident on the grating mask 20 is diffracted to form a 0th order diffraction light beam, a positive 1st order diffraction light beam, and a negative 1st order diffraction light beam. The 0th order diffraction light beam, the positive 1st order diffraction light beam, and the negative 1st order diffraction light beam diffracted and output by the grating mask 20 are projected onto the substrate 30, and the overlapping area of the 0th order diffraction light beam, the positive 1st order diffraction light beam, and the negative 1st order diffraction light beam interferes, thereby forming two different patterned interference exposure fields on the substrate 30.
[0033] Specifically, Figure 2 As shown, Figure 2 Shows this application Figure 1 A schematic diagram of the diffraction beam of the grating mask 20 is provided. In this embodiment, when the collimated beam is vertically incident on the grating mask 20, the 0th order diffraction beam output by the grating mask 20 is vertically incident on the substrate 30, and the positive 1st order diffraction beam and the negative 1st order diffraction beam output by the grating mask 20 are diffracted at a set angle θ. d The incident angle is incident on the substrate 30, and the positive first-order diffraction beam and the negative first-order diffraction beam are symmetrical with respect to the 0th-order diffraction beam. The angle θ is set d for:
[0034]
[0035] Where λ0 is the wavelength of the collimated beam, Λ g is the period of the grating mask 20.
[0036] Optionally, the grating mask 20 diffracts the output at a set angle θ d The positive first-order diffraction beam incident on the substrate 30 at an incident angle of 1 interferes with the negative first-order diffraction beam on the substrate 30, and forms an interference exposure field with interference fringes with an interference period of Λ1 on the substrate 30, where Λ1 is:
[0037]
[0038] Optionally, when the positive first-order diffraction beam and the negative first-order diffraction beam are symmetrical with respect to the 0th-order diffraction beam, the interference exposure field formed by the interference of the 0th-order diffraction beam and the positive first-order diffraction beam and the interference exposure field formed by the interference of the 0th-order diffraction beam and the negative first-order diffraction beam have the same interference fringes. Specifically, the 0th-order diffraction beam diffracted by the grating mask 20 and the 0th-order diffraction beam incident vertically on the substrate 30 are diffracted at a set angle θ. d The first-order diffraction beam incident on the substrate 30 at an incident angle of θ interferes on the substrate 30 and forms an interference exposure field with interference fringes with an interference period of Λ2 on the substrate 30; the 0th-order diffraction beam diffracted by the grating mask 20 and incident on the substrate 30 at a set angle θd The minus first-order diffraction beam incident on the substrate 30 at an incident angle of , interferes on the substrate 30 and forms an interference exposure field having interference fringes with an interference period of Λ2 on the substrate 30, where Λ2 is:
[0039]
[0040] In this embodiment, the period length of the interference period Λ2 is N times the period length of the interference period Λ1, that is, Λ2=N*Λ1, where N is an integer greater than or equal to 2. Based on this, after the interference exposure field with interference fringes with an interference period of Λ1 formed by the 0th order diffraction beam, the positive 1st order diffraction beam, and the negative 1st order diffraction beam and the interference exposure field with interference fringes with an interference period of Λ2 are superimposed on the substrate 30, the two different patterned interference exposure fields can be superimposed to form a target interference exposure field with periodic interference fringes. Therefore, when the photoresist is coated on the surface of the substrate 30, based on the interference exposure of the target interference exposure field formed by the interference superposition, the photoresist can form a grating structure with toothed depressions after development.
[0041] In an embodiment of the present application, a grating preparation device 1 includes: a light source module 10, which is used to emit a collimated light beam; a grating mask 20, which is arranged in the output direction of the collimated light beam, and the grating mask 20 is used to diffract the collimated light beam incident thereon to form a 0th-order diffraction beam, a positive 1st-order diffraction beam, and a negative 1st-order diffraction beam, and the 0th-order diffraction beam, the positive 1st-order diffraction beam, and the negative 1st-order diffraction beam are used to be emitted onto a substrate 30, and two different patterned interference exposure fields are formed on the substrate 30, so as to form a grating structure with toothed depressions on the substrate 30 in an overlapping manner. In this embodiment, the grating mask 20 forms a 0th order diffraction beam, a positive 1st order diffraction beam and a negative 1st order diffraction beam based on the diffraction of the vertically incident collimated light beam. The three diffraction light beams interfere with each other on the substrate 30 to form two different patterned interference exposure fields. By superimposing the two interference exposure fields on the substrate 30, it is easy to obtain a grating structure with toothed depressions by interference exposure. While improving the process accuracy of grating preparation, the preparation method of three-beam diffraction beam interference exposure reduces the process complexity of grating preparation.
[0042] In this embodiment, the positive first-order diffraction beam and the negative first-order diffraction beam emitted by the grating mask 20 interfere with each other on the substrate 30. When the photoresist on the surface of the substrate 30 is interference exposed based on the interference exposure field having interference fringes with an interference period of Λ1, the photoresist can form a first grating structure after development.
[0043] like Figure 3 As shown, Figure 3The first grating structure 40 provided in one embodiment of the present application is shown in FIG. The first grating structure 40 includes a plurality of first recesses 41 spaced evenly apart, and in the first grating structure 40, the grating period is Λ1, the grating depth is H1, that is, the depth of the first recess 41 is H1.
[0044] In this embodiment, when the 0th-order diffraction beam emitted by the grating mask interferes with the positive 1st-order diffraction beam on the substrate, and the 0th-order diffraction beam interferes with the negative 1st-order diffraction beam on the substrate, and the interference exposure field formed by the interference of the 0th-order diffraction beam and the positive 1st-order diffraction beam and the interference exposure field formed by the interference of the 0th-order diffraction beam and the negative 1st-order diffraction beam have the same interference fringes, when the photoresist on the surface of the substrate is interference exposed based on the interference exposure field with interference fringes having an interference period of Λ2, the photoresist can form a second grating structure after development.
[0045] like Figure 4 As shown, Figure 4 The schematic diagram of the structure of the second grating structure 50 provided by an embodiment of the present application is shown. The second grating structure 50 includes a plurality of second recessed portions 51 that are evenly spaced. In the second grating structure 50, the grating period is Λ2, and the grating depth is H2, that is, the depth of the second recessed portion 51 is H2. The grating depth H2 of the second grating structure 50 is greater than the grating depth H1 of the first grating structure, and the period length of the grating period Λ2 of the second grating structure 50 is N times the period length of the grating period Λ1 of the first grating structure.
[0046] Exemplarily, if N is 2, that is, the period length of the interference period Λ2 is twice the period length of the interference period Λ1, the interference exposure field of the interference fringes with the interference period Λ1 is superimposed with the interference exposure field of the interference fringes with the interference period Λ2 to form the target interference exposure field.
[0047] like Figure 5 As shown, Figure 5 A schematic diagram of a target interference exposure field 60 provided in an embodiment of the present application is shown. The period length of the interference period of the interference fringes in the target interference exposure field 60 is equal to the interference period length of the interference exposure field having interference fringes with an interference period of Λ2, which is Λ2.
[0048] Optionally, when the photoresist on the substrate surface is subjected to interference exposure based on the target interference exposure field, the photoresist can form a third grating structure after development. Figure 6 As shown, Figure 6The schematic diagram of the structure of the third grating structure 70 provided by an embodiment of the present application is shown. The first grating structure and the second grating structure are superimposed to form the third grating structure 70, and the third grating structure 70 includes a plurality of evenly distributed third recessed portions 71 and a fourth recessed portion 72, and the grating period of the third grating structure 70 is equal to the grating period of the second grating structure, that is, the grating period Λ3 of the third grating structure 70 is equal to Λ2. In addition, in the third grating structure 70, the depth H3 of the third recessed portion 71 is equal to H1+H2, and the depth H4 of the fourth recessed portion 72 is equal to H1, thereby forming a grating structure with a middle recessed feature.
[0049] In some embodiments, if N is greater than 2, the third grating structure 70 will include a plurality of evenly distributed third recesses 71 and a fourth recess 72, and the fourth recess 72 includes a plurality of sub-recesses, the depth H3 of the third recess 71 is H1+H2, and the depth H4 of each sub-recess is H1, thereby forming a grating structure with toothed recesses.
[0050] It should be noted that when the diffracted light beams are interferometrically exposed on the photoresist, the greater the beam energy of the diffracted light beams, the deeper the grating depth of the grating structure formed after the photoresist is interferometrically exposed and developed. Figure 3 The deeper the depth H1 of the first recessed portion 41 in the first grating structure 40, the greater the interference exposure field formed after superposition. Figure 6 In the third grating structure 70, the depth H4 of the fourth recessed portion 72 is deeper.
[0051] In this embodiment, by adjusting the grating tooth shape, grating depth and one or more grating structures in the grating period of the grating mask, the beam energy and spot size of the 0th order diffraction beam, the positive 1st order diffraction beam and the negative 1st order diffraction beam formed by the grating mask based on the diffraction of the vertically incident collimated light beam can be adjusted to adjust the tooth depth and tooth width of the grating structure formed by the interference exposure, so that the embodiment of the present application can achieve precise preparation of grating structures with different tooth shapes.
[0052] Please refer to Figure 7 , Figure 7 FIG. 2 shows a schematic diagram of the structure of a grating preparation device provided by another embodiment of the present application. The grating preparation device provided by the embodiment of the present application will be described in detail below in conjunction with the figure. Figure 7 As shown, the grating preparation device of the present application includes a light source module and a grating mask 20 .
[0053] In this embodiment, a photoresist 31 is plated on the surface of the substrate 30. The photoresist 31 is used to be exposed to an interference exposure field having interference fringes with an interference period of Λ1 and an interference exposure field having interference fringes with an interference period of Λ2, and forms a grating with tooth-shaped depressions after development. The photoresist 31 includes at least one of silver halide emulsion, dichromate gelatin, and photorefractive crystal, which is not limited here.
[0054] Specifically, when the photoresist 31 on the surface of the substrate 30 is interfered and superimposed by the 0th order diffraction beam, the positive 1st order diffraction beam and the negative 1st order diffraction beam diffracted and output by the grating mask 20, the two different patterned interference exposure fields formed by the 0th order diffraction beam, the positive 1st order diffraction beam and the negative 1st order diffraction beam are superimposed to form a target interference exposure field, which will interfere with the exposure of the photoresist 31, so that the interference exposed photoresist 31 can form a grating structure with toothed depressions after development.
[0055] In other embodiments, the surface of the substrate 30 may also be coated with a holographic recording material. After the holographic recording material is interference-exposed to two different patterned interference exposure fields formed by the 0th-order diffraction beam, the positive 1st-order diffraction beam and the negative 1st-order diffraction beam diffracted and output by the grating mask 20, the holographic recording material can form a grating structure with toothed depressions without the need for further development operations.
[0056] In this embodiment, the light source module includes a laser light source 11 and a collimating lens 12. The laser light source 11 is used to emit a light beam. In some embodiments, the grating preparation device can perform interference exposure of the photoresist 31 by an ultraviolet light beam to prepare a grating. In this case, the laser light source 11 is an ultraviolet laser, and the ultraviolet laser is used to emit a laser beam in the ultraviolet band to the collimating lens 12.
[0057] Optionally, the collimating lens 12 is disposed in the output direction of the light beam emitted by the laser light source 11 , and the collimating lens 12 is used to collimate the divergent light beam emitted by the laser light source 11 , and emit a collimated light beam formed after the collimation process.
[0058] Furthermore, the light source module further includes a spatial light filter 13 disposed at the light exit of the laser light source 11 and a lens 14 disposed at the light exit of the collimating lens 12 .
[0059] Optionally, the spatial light filter 13 provided at the light output of the laser light source 11 is used to filter stray light in the light beam emitted by the laser light source 11, and output the filtered light beam to the collimating lens 12, so as to avoid the presence of stray light with a wavelength outside the set wavelength range in the collimated light beam finally projected onto the grating mask 20. When the grating mask 20 diffracts the stray light, the diffracted light beam output by the grating mask 20 based on the diffraction of the stray light with a wavelength outside the set wavelength range is projected onto the substrate 30, and the 0th order diffracted light beam, the positive first order diffracted light beam, and the negative first order diffracted light beam output by the grating mask 20 based on the diffraction of the target light beam with a wavelength within the set wavelength range are superimposed on the 0th order diffracted light beam, the positive first order diffracted light beam, and the negative first order diffracted light beam, which are output by the grating mask 20 based on the diffraction of the target light beam with a wavelength within the set wavelength range, are affected, thereby affecting the interference exposure effect of the photoresist 31 on the surface of the substrate 30, so that the photoresist 31 cannot form a grating structure with regular tooth-shaped depressions after development.
[0060] Specifically, the spatial light filter 13 includes an input lens 131 and a filter aperture 132. The input lens 131 in the spatial light filter 13 is arranged at the light output of the laser light source 11, and the input lens 131 is used to converge the divergent light beam emitted by the laser light source 11, and output the converged light beam to the filter aperture 132. When the light beam emitted by the laser light source 11 is projected onto the input lens 131, the stray light in the light beam and the target light beam are converged by the input lens 131, and the beam foci of the stray light and the target light beam do not overlap. Among them, the target light beam includes the light beam whose wavelength is within the set wavelength range in the light beam, and the stray light includes the light beam whose wavelength is outside the set wavelength range in the light beam.
[0061] Optionally, in this embodiment, the filter aperture 132 is disposed between the input lens 131 and the collimating lens 12, and the aperture center of the filter aperture 132 is set to coincide with the beam focus of the target beam, so that the filter aperture 132 can transmit the target beam in the output beam to the collimating lens 12, and filter other beams in the beam except the target beam. That is, the beam focus of stray light with a wavelength outside the set wavelength range does not coincide with the aperture center of the filter aperture 132, so that the stray light converged by the input lens 131 cannot pass through the filter aperture 132, and is thus filtered out by the filter aperture 132.
[0062] In this embodiment, 14 provided at the light outlet of the collimating lens 12 is used to adjust the spot size of the collimated light beam, and the aperture size of 14 matches the size of the grating mask 20, so that the spot size of the collimated light beam projected onto the grating mask 20 after adjustment by 14 matches the size of the grating mask 20, and a grating structure is provided on the grating mask 20, and the collimated light beam can be diffracted in the grating structure on the grating mask 20.
[0063] In some embodiments, the spot size of the collimated light beam projected onto the grating mask 20 matches the size of the diffraction region of the grating mask 20 having the grating structure after adjustment 14, and the other regions of the grating mask 20 except the diffraction region are made of transparent light-transmitting material. If the collimated light beam is not adjusted in the spot size 14 and is directly projected onto the grating mask 20, the collimated light beam projected onto the other regions of the grating mask 20 will be directly transmitted and output to the photoresist 31 on the surface of the substrate 30. Since the other regions without the grating structure cannot diffract the collimated light beam, the photoresist 31 cannot form a grating structure after being exposed by the light beam emitted from the other regions. Based on this, by setting an aperture size 14 that matches the size of the diffraction area of the grating structure at the light exit of the collimating lens 12, the spot size of the collimated light beam projected onto the grating mask 20 matches the size of the diffraction area on the grating mask 20, which can ensure that the light beam emitted from the grating mask 20 can form two different patterned interference exposure fields on the substrate 30, thereby forming a grating structure with toothed depressions on the substrate 30.
[0064] In this embodiment, a spatial light filter 13 is provided to filter the light beam emitted by the laser light source 11, and a spot size of the collimated light beam incident on the grating mask 20 is adjusted by providing 14, so that it can be ensured that the diffraction area on the grating mask 20 only emits a light beam with a wavelength within a set wavelength range to the substrate 30, so as to form two different patterned interference exposure fields on the substrate 30, so that after interference exposure of the photoresist 31 on the surface of the substrate 30, the photoresist 31 can form a grating structure with toothed depressions after development, thereby improving the process accuracy of grating preparation.
[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A grating preparation device, characterized in that: The grating preparation device comprises: A light source module, the light source module is used to emit a collimated light beam; A grating mask is arranged in the output direction of the collimated light beam, and the grating mask is used to diffract the collimated light beam incident thereon to form a 0th order diffraction beam, a positive 1st order diffraction beam, and a negative 1st order diffraction beam. The 0th order diffraction beam, the positive 1st order diffraction beam, and the negative 1st order diffraction beam are used to be emitted onto a substrate, and form two different patterned interference exposure fields on the substrate, so as to form a grating structure with toothed depressions on the substrate by superposition.
2. The grating preparation device according to claim 1, characterized in that: The 0th order diffraction beam is vertically incident on the substrate, and the positive first order diffraction beam and the negative first order diffraction beam are incident on the substrate at a set angle θ. d The incident angle is incident on the substrate, and the setting angle θ d for: Wherein, λ0 is the wavelength of the collimated light beam, Λ g is the period of the grating mask.
3. The grating preparation device according to claim 2, characterized in that: The positive first-order diffraction beam and the negative first-order diffraction beam interfere with each other on the substrate, and form an interference exposure field having interference fringes with an interference period of Λ1 on the substrate, where Λ1 is:
4. The grating preparation device according to claim 2, characterized in that: The 0th-order diffraction beam interferes with the positive 1st-order diffraction beam on the substrate, and forms an interference exposure field having interference fringes with an interference period of Λ2 on the substrate; The 0th order diffraction beam and the negative 1st order diffraction beam interfere with each other on the substrate, and form an interference exposure field having interference fringes with an interference period of Λ2 on the substrate, where Λ2 is:
5. The grating preparation device according to any one of claims 1 to 4, characterized in that: The substrate surface is plated with photoresist, the photoresist is used to be exposed by the two interference exposure fields, and the photoresist forms a grating with tooth-shaped depressions after development.
6. The grating preparation device according to any one of claims 1 to 4, characterized in that: The light source module includes a laser light source and a collimating lens; The laser light source is used to emit a light beam; The collimating lens is arranged in the output direction of the light beam, and is used to collimate the light beam to form the collimated light beam, and emit the collimated light beam.
7. The grating preparation device according to claim 6, characterized in that: The light source module also includes a spatial light filter; The spatial light filter is arranged at the light output of the laser light source, and is used to filter stray light in the light beam emitted by the laser light source, and output the filtered light beam to the collimating lens.
8. The grating preparation device according to claim 7, characterized in that: The spatial light filter comprises an input lens and a filtering aperture; The input lens is arranged at the light output position of the laser light source, and is used to converge the light beam and output the converged light beam; The filter pinhole is arranged between the input lens and the collimating lens. The filter pinhole is used to transmit the target light beam in the output light beam to the collimating lens and filter other light beams in the light beam except the target light beam. The aperture center of the filter pinhole coincides with the beam focus of the target light beam. The target light beam includes the light beam in the light beam whose wavelength is within the set wavelength range.
9. The grating preparation device according to claim 6, characterized in that: The light source module further comprises an aperture, the aperture size of which matches the size of the grating mask; The aperture is arranged at the light exit of the collimating lens, and is used to adjust the spot size of the collimated light beam so that the spot size of the collimated light beam projected onto the grating mask matches the size of the grating mask.
10. The grating preparation device according to any one of claims 1 to 4, characterized in that: The grating mask includes at least one of a relief grating, a volume holographic grating and a polarization volume grating.