Deposition auxiliary structure, method for forming optical structure and diffraction optical waveguide

Abstract

A method for forming a deposition-assisting structure, an optical structure, and a diffractive optical waveguide includes: providing a substrate comprising one or more optical structure regions; providing a deposition-assisting structure disposed perpendicular to the substrate surface; providing a target disposed above the substrate; arranging the deposition-assisting structure between the target and the substrate, with a second auxiliary plate in contact with the substrate, the second window corresponding to the optical structure region, and the first window corresponding to the target; and forming an optical structure material layer with a thickness that sequentially increases or decreases on the optical structure region by adjusting the relative positions of the target, the first window, and the second window. This allows for precise control of the continuous variation in the thickness of the optical structure.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a deposition auxiliary structure, a method for forming an optical structure, and a diffraction optical waveguide. Background Art

[0002] In the current augmented reality (AR) field, diffractive waveguide technology is highly regarded for its wide eye movement range, compact size, and excellent mass production capabilities. To further improve field of view uniformity, color consistency, and optical transmission efficiency, the industry is continuously promoting design innovations and manufacturing process optimization for diffractive waveguides. In particular, the efficient production of high-performance diffractive waveguides has become a hot topic in industry research.

[0003] How to optimize optical structures to achieve highly continuous changes is an ongoing challenge, especially for diffraction grating structures. Improving the visual effects of optical products while ensuring the diffraction efficiency of the optical structure is a problem that continues to need to be solved. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a deposition auxiliary structure, a method for forming an optical structure and a diffraction optical waveguide, which solves the technical problem of precise control of continuous thickness change of the optical structure.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a deposition auxiliary structure, including: a first auxiliary plate, wherein the first auxiliary plate has a first window passing through the first auxiliary plate; a second auxiliary plate, wherein the second auxiliary plate has a second window passing through the second auxiliary plate, and the center lines of the first window and the second window do not coincide; there is a spacing between the first auxiliary plate and the second auxiliary plate, and the first window of the first auxiliary plate and the second window of the second auxiliary plate are used to form a material layer with increasing or decreasing thickness in the second window; the thickness of the material layer is related to the spacing.

[0006] Optionally, the material layer is used to form a turning grating and / or an outcoupling grating of a diffraction optical waveguide, and the depth of the turning grating and / or the outcoupling grating gradually increases along the direction of light transmission.

[0007] Optionally, the thickness of the material layer decreases sequentially along the direction from the center line of the first window to the center line of the second window.

[0008] Correspondingly, the technical solution of the present invention also provides a method for forming an optical structure, including: providing a substrate, the substrate including one or more optical structure areas; providing a deposition auxiliary structure, the deposition auxiliary structure being arranged perpendicular to the surface direction of the substrate; providing a target material, which is arranged above the deposition auxiliary structure; arranging the deposition auxiliary structure between the target material and the substrate, the second auxiliary plate is in contact with the substrate, the second window corresponds to the optical structure area, and the first window corresponds to the target material; by adjusting the relative positions of the target material, the first window and the second window, an optical structure material layer with a thickness increasing or decreasing successively is formed on the optical structure area.

[0009] Optionally, an optical structure material layer with a thickness that increases or decreases sequentially is formed on the optical structure area by adjusting the relative positions of the target material, the first window, and the second window, including: adjusting the relative positions of the target material, the center line of the first window, and the center line of the second window so that the relative positions of the target material relative to the first window and the second window meet preset conditions.

[0010] Optionally, the relative positions of the target material with respect to the first window and the second window satisfy preset conditions, including:

[0011]

[0012]

[0013]

[0014]

[0015] in, 、 They represent the critical coordinate values ​​of the left boundary of the target's active range respectively; 、 They represent the critical coordinate values ​​of the right boundary of the target's active range; H is the distance between the first auxiliary plate and the substrate; h is the distance from the center of the target to the substrate surface; is the critical coordinate value on the left side of the x-axis in the first window area, is the critical coordinate value on the right side of the x-axis in the first window area; is the critical coordinate value on the left side of the y-axis in the first window area, is the critical coordinate value on the right side of the y-axis in the first window area; is the critical coordinate value on the left side of the x-axis in the second window area, The critical coordinate value on the left side of the y-axis in the second window area; is the critical coordinate value on the right side of the x-axis in the second window area, is the critical coordinate value on the right side of the y-axis in the second window area.

[0016] Optionally, the method further includes: the substrate surface is flat; a turning grating and / or an outcoupling grating is formed based on the optical structure material layer on the substrate, and the depth of the turning grating and / or the outcoupling grating gradually increases along the direction of light transmission.

[0017] Optionally, the method further includes: the substrate includes: a base and a grating structure located on the base, and the optical structure material layer is formed on a surface of the grating structure away from the substrate.

[0018] Correspondingly, the technical solution of the present invention also provides a diffraction optical waveguide, which includes at least a coupling-out grating region and / or a turning grating region, and the grating structure in the coupling-out grating region or the turning grating region is prepared based on the method for forming the optical structure described in any of the aforementioned embodiments.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0020] The deposition auxiliary structure provided in the present invention includes a first auxiliary plate and a second auxiliary plate. Through the first window of the first auxiliary plate and the second window of the second auxiliary plate, a material layer with a thickness that increases or decreases in sequence is constructed in the second window area. Through this auxiliary structure, a continuous change in the thickness of the material layer can be achieved on the substrate. By carefully designing the deposition auxiliary structure, the thickness of the material layer in different areas can be accurately adjusted, thereby manufacturing an optical structure with a continuous gradient change in thickness. First, the structural design of this material layer enables the optical structure to adjust the diffraction efficiency at different positions, thereby enhancing the display uniformity of the optical structure, improving the display efficiency, and thus optimizing the display quality. Secondly, this design also helps to improve the appearance of the optical structure. By realizing continuous gradient modulation of thickness through material layers with thicknesses that increase or decrease in sequence, a sharp change in thickness in different areas is avoided. Such a design not only improves the dimensional accuracy of the optical structure, but also enhances its visual beauty to prevent visual differences caused by sudden changes in thickness at different positions.

[0021] The optical structure forming method of the present invention arranges a deposition auxiliary structure between the target material and the substrate so that the second window corresponds to the optical structure area and the first window corresponds to the target material. By controlling the relative positions of the target material, the first window, and the second window and the sputtering process, a material layer with continuously varying thickness can be formed on the substrate, such as the thickness sequentially increasing or decreasing. In this way, the formation process of the optical structure is precisely controlled and the display appearance of the optical structure is improved. In particular, abrupt stripes between different optical structure areas are avoided, so that the thickness of each area presents a continuous gradient, thereby improving the display effect of the optical structure while improving display efficiency. In addition, based on this method, a grating structure can be formed in a diffraction optical waveguide to achieve continuous gradient modulation of depth, with different grating structures having different depths of deposited material. On the one hand, this method modulates the diffraction efficiency of the grating structure at different positions, especially in areas far away from the incident light source, improving the diffraction efficiency in the distant areas so that the diffraction efficiency presents a continuous and gradual change at each position, thereby improving the display uniformity and effect of the diffraction optical waveguide; on the other hand, the grating structure depth of the formed diffraction optical waveguide at different positions continuously and gradually changes, which is different from the traditional partitioned structure, avoiding the visual difference caused by thickness mutation, thereby obtaining a better visual appearance effect. The present invention has unexpected technical effects compared with the existing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 and Figure 2 is a schematic structural diagram of a deposition auxiliary structure in an embodiment of the present invention;

[0023] Figures 3 to 14 is a structural schematic diagram of the optical structure forming process in one embodiment of the present invention;

[0024] Figure 15 and Figure 16 is a structural schematic diagram of the optical structure forming process in another embodiment of the present invention;

[0025] Figure 17 and Figure 18 It is a structural schematic diagram of the optical structure forming process in another embodiment of the present invention. DETAILED DESCRIPTION

[0026] As described in the background art, how to optimize the optical structure to ensure the diffraction efficiency of the optical structure while improving the visual effect of the optical product is a problem that continues to need to be solved.

[0027] In order to solve the above technical problems, one embodiment of the present invention proposes a technology for forming an optical structure including a deposition auxiliary structure. By controlling the deposition auxiliary structure and the deposition process, the thickness change of the material layer in different areas can be precisely manipulated, thereby creating a continuous gradient optical structure with gradually increasing or decreasing thickness; and in this way, a diffraction light waveguide structure is formed or a grating structure is deposited to form an optical structure with different thickness gradients. On the one hand, this structural design can adjust the diffraction efficiency of the optical structure in different areas, enhance its display consistency at various positions, and thus optimize the display quality. On the other hand, the design also improves the appearance of the optical structure. By achieving a continuous gradient of thickness, sudden changes in thickness are avoided, which not only improves the dimensional accuracy of the optical structure, but also enhances its visual presentation effect. In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Figure 1 and Figure 2 Schematic diagram of the structure of the deposition auxiliary structure in an embodiment of the present invention.

[0029] Please refer to Figure 1 and Figure 2 , Figure 2 for Figure 1 A top view of Figure 1 for Figure 2 A schematic structural diagram along the section line BB1, wherein the deposition auxiliary structure includes: a first auxiliary plate 101, wherein the first auxiliary plate 101 has a first window 104 extending through the first auxiliary plate 101; a second auxiliary plate 102, wherein the second auxiliary plate 102 has a second window 105 extending through the second auxiliary plate 102, wherein the center line L1 of the first window 104 does not coincide with the center line L2 of the second window 105; a gap is provided between the first auxiliary plate 101 and the second auxiliary plate 102, and the first auxiliary plate 101 and the second auxiliary plate 102 are used to form material layers with increasing or decreasing thickness in the second window 105 (such as Figure 6 As shown), the thickness of the material layer is related to the spacing.

[0030] The thickness of the material layer increases or decreases sequentially, including: the thickness in the second window 105 increases or decreases sequentially.

[0031] In this embodiment, the material layer is used to form a turning grating and / or an outcoupling grating of a diffraction optical waveguide, and the depth of the turning grating and / or the outcoupling grating gradually increases along the direction of light transmission.

[0032] In this embodiment, the deposition auxiliary structure also includes: a connecting portion 103, the connecting portion 103 connects the first auxiliary plate 101 and the second auxiliary plate 102, the first auxiliary plate 101 and the second auxiliary plate 102 are connected through the connecting portion 103 to form an integrated structure, and the second auxiliary plate 102 is bonded to the substrate.

[0033] In other embodiments, the deposition auxiliary structure may not include the connecting portion, the first auxiliary plate and the second auxiliary plate are independently formed on the substrate, and the second auxiliary plate is in contact with the substrate.

[0034] The above two embodiments of the deposition auxiliary structure are both within the scope of protection of the present invention. As long as they do not deviate from the purpose of protection claimed by the present invention, that is, to achieve a material layer with a continuously gradient thickness, no limitation is imposed on the connection method of the mask structure.

[0035] In this embodiment, the projection range of the first window 104 projected onto the second auxiliary plate 102 partially overlaps with the second window 105 , and the projection range of the first window 104 projected onto the second auxiliary plate 102 has an overlapping area with the second window 105 .

[0036] In this embodiment, the area overlap between the overlapping region of the projection of the first window 104 and the projection of the second window 105 is greater than 50%.

[0037] In this embodiment, the center line L1 of the first window 104 and the center line L2 of the second window 105 do not coincide with each other, so as to accurately control the process of forming the material layer with a continuously gradient thickness in the second window 105 .

[0038] In this embodiment, the first auxiliary plate 101 and the second auxiliary plate 102 are arranged in parallel to form a material layer with a preset thickness variation in the second window 105 .

[0039] The first auxiliary plate 101 and the second auxiliary plate 102 are arranged in parallel, which can reduce the risk of interference between the deposition auxiliary structure and the material source or the machine chamber, and facilitate the adjustment of the thickness variation trend of the material formed in the second window 105.

[0040] The shape of the first window 104 includes a circle, an ellipse, a rectangle, a trapezoid or a polygon, and the number of sides of the polygon is greater than or equal to 5.

[0041] In this embodiment, the shape of the first window 104 includes a circle.

[0042] The shape of the second window 105 includes a rectangle, a trapezoid or a polygon, and the number of sides of the polygon is greater than or equal to 5.

[0043] In one embodiment, the shape of the first window 104 is the same as the shape of the second window 105. The shape of the first window 104 and the shape of the second window 105 include a rectangle, a trapezoid, or a polygon.

[0044] In another embodiment, the shape of the first window 104 is different from the shape of the second window 105 .

[0045] The material of the deposition auxiliary structure includes metal or metal alloy, the metal alloy includes stainless steel, iron-nickel alloy, and the metal includes iron, aluminum or titanium.

[0046] The above-mentioned deposition auxiliary structure includes a first auxiliary plate and a second auxiliary plate. Through the first window of the first auxiliary plate and the second window of the second auxiliary plate, a material layer with a thickness that increases or decreases in sequence is constructed in the second window area. Through this auxiliary structure, a continuous change in the thickness of the material layer can be achieved on the substrate. By carefully designing the deposition auxiliary structure, the thickness of the material layer in different areas can be accurately adjusted, thereby manufacturing an optical structure with a continuous gradient change in thickness. First, the structural design of this material layer enables the optical structure to adjust the diffraction efficiency at different positions, thereby enhancing the display uniformity of the optical structure, improving the display efficiency, and thus optimizing the display quality. Secondly, the design also helps to improve the appearance of the optical structure. By realizing continuous gradual modulation of thickness through material layers with successively increasing or decreasing thicknesses, a sharp change in thickness in different areas is avoided. Such a design not only improves the dimensional accuracy of the optical structure, but also enhances its visual beauty to prevent visual differences caused by sudden changes in thickness at different positions.

[0047] Figures 3 to 14 It is a structural schematic diagram of the optical structure forming process in one embodiment of the present invention.

[0048] Please refer to Figure 3 and Figure 4 , Figure 3 for Figure 4 A top view of Figure 4 for Figure 3 A cross-sectional structural diagram of a substrate 200 is provided, wherein the substrate 200 includes one or more optical structure areas 201.

[0049] The optical structure region 201 is a region where a material layer is subsequently formed.

[0050] In this embodiment, the surface of the substrate 200 is flat.

[0051] like Figure 3 As shown, Figure 3A single optical structure region 201 is schematically shown, and a continuous region 20 is schematically shown, wherein the continuous region 20 includes two or more optical structure regions 201, Figure 3 The continuous area 20 in the figure schematically shows three different optical structure areas 201. The different optical structure areas 201 shown in the figure are only examples and do not constitute a limitation on the structure and position of the optical structure areas 201. If multiple optical structure areas 201 are independently separated, or divided into regions, or have other structural shapes, etc., they all belong to the optical structure areas indicated in the present invention. Figure 3 The multiple structural areas shown are for simple illustration only.

[0052] The substrate 200 may be made of an inorganic material or a semiconductor material. The inorganic material may include quartz, and the semiconductor material may include silicon, silicon carbide, titanium oxide, lithium niobate, germanium, gallium arsenide, and the like.

[0053] Please refer to Figure 5 , providing a deposition auxiliary structure, the deposition auxiliary structure comprising: a first auxiliary plate 101 and a second auxiliary plate 102 arranged in a direction perpendicular to the surface of the substrate 200.

[0054] For the detailed configuration of the deposition assist structure, please refer to Figure 1 and Figure 2 The text description in will not be repeated here.

[0055] Please continue to refer to Figure 5 There is a first distance H' between the first auxiliary plate 101 and the second auxiliary plate 102, the first window 104 has a first aperture R1, and the second window 105 has a second aperture R2.

[0056] The first aperture R1 is the maximum size of the first window 104 , and the second aperture R2 is the maximum size of the second window 105 .

[0057] In this embodiment, the first aperture R1 ranges from 6 mm to 10 mm.

[0058] In this embodiment, the second aperture R2 ranges from 10 mm to 50 mm.

[0059] In this embodiment, the first distance H' ranges from 25 mm to 35 mm.

[0060] In this embodiment, the first auxiliary plate 101 has a first thickness d1 , and the first thickness d1 ranges from 2 micrometers to 500 micrometers.

[0061] In this embodiment, the second auxiliary plate 102 has a second thickness d2 , and the second thickness d2 is in a range of 2 μm to 500 μm.

[0062] The first window 104 has a first area S1 , and the second window 105 has a second area S2 .

[0063] Please refer to Figure 6 , providing a target material 202, arranged above the substrate 200; providing Figure 1 and Figure 2 The deposition auxiliary structure is arranged perpendicular to the surface direction of the substrate; the deposition auxiliary structure is arranged between the target material 202 and the substrate 200, the second auxiliary plate 102 is adjacent to the substrate 200, the first window 104 corresponds to the target material 202, and the second window 105 corresponds to the optical structure area 201; by adjusting the relative positions of the target material 202, the first window 104 and the second window 105, an optical structure material layer is formed on the optical structure area 201, and the optical structure material layer includes a material layer 203 whose thickness increases or decreases successively.

[0064] In this embodiment, the thickness of the material layer 203 increases or decreases sequentially, including: the thickness of the material layer 203 gradually decreases along the direction from the center line L1 of the first window 104 to the center line L2 of the second window 105, or the thickness of the material layer 203 gradually increases along the direction from the center line L2 of the second window 105 to the center line L1 of the first window 104.

[0065] The thickness specified in the present invention increases or decreases sequentially, and does not require absolute continuity in the mathematical sense. The thickness change difference between adjacent positions of the material layer can be less than 1%, 3% or 5%, etc. The actual thickness change difference can be determined according to the performance requirements of the actual product.

[0066] In this embodiment, the second auxiliary plate 102 is adjacent to the substrate 200 , which includes: the second auxiliary plate 102 is disposed on the substrate 200 and in contact with the substrate 200 .

[0067] In other embodiments, the second auxiliary plate is adjacent to the substrate, including: a gap exists between the second auxiliary plate and the substrate, and the second auxiliary plate is not in direct contact with the substrate.

[0068] In this embodiment, the surface of the target 202 is disposed opposite to the surface of the substrate 200 , that is, the sputtering surface of the target 202 is opposite to the surface of the substrate 200 .

[0069] Please combine Figure 3 Continue to refer Figure 6, the second window 105 corresponds to the optical structure area 201, including: the second window 105 corresponds to a single optical structure area 201.

[0070] In this embodiment, the second window 105 corresponds to the optical structure area 201 , including: the second window 105 and the optical structure area 201 have the same shape and area.

[0071] The second window 105 corresponds to the optical structure region 201 , and the shape and area of ​​the second window 105 determine the shape and area of ​​the material layer 203 formed on the surface of the substrate 200 .

[0072] In this embodiment, the first window 104 corresponds to the target 202 , which includes: a center line of the first window 104 coincides with or does not coincide with a center line of the target 202 .

[0073] Of course, in one embodiment, the center line of the first window 104 coincides with the center line of the target material 202, that is, the target material 202 is located at the center position of the first window 104 and the second window 105, so that the thickness of the subsequently formed material layer 203 can show a continuous change trend of gradually decreasing thickness along the direction from the center line L1 of the first window 104 to the center line L2 of the second window 105.

[0074] In another embodiment, the center line of the first window 104 does not coincide with the center line of the target 202 , so as to control the thickness variation trend of the material layer 203 .

[0075] The material of the material layer 203 includes an inorganic dielectric material or a metal material. The inorganic dielectric material includes titanium oxide, niobium oxide, silicon carbide, silicon oxide, lithium niobate, silicon nitride, tantalum oxide, hafnium oxide, and aluminum oxide; the metal material includes a combination of one or more of copper, aluminum, tungsten, cobalt, nickel, and tantalum.

[0076] The target 202 may be made of titanium oxide, niobium oxide, silicon carbide, silicon oxide, lithium niobate, silicon nitride, tantalum oxide, hafnium oxide, aluminum oxide, or titanium.

[0077] There is a first distance H' between the first auxiliary plate 101 and the second auxiliary plate 102, and the first window 104 has a first area S1. By adjusting the relative positions of the first auxiliary plate 101 and the second auxiliary plate 102, a material layer 203 with increasing or decreasing thickness is formed on the optical structure area 201.

[0078] By adjusting the relative positions of the target material 202, the first auxiliary plate 101 and the second auxiliary plate 102, a material layer 203 with a thickness increasing or decreasing successively is formed on the optical structure area 201, and it also includes: by adjusting the size of the first spacing H' and the relative positions of the target material 202, the second window 105 and the first window 104, the thickness and thickness change of the material layer 203 at each position on the optical structure area 201 are adjusted.

[0079] The specific process of adjusting the thickness of the material layer 203 at each position on the optical structure area 201 by adjusting the size of the first distance H' and the relative positions of the target 202, the second window 105 and the first window 104 is referred to. Figure 7 、 Figure 8 and Figure 9 , Figure 7 Schematic diagram of establishing a coordinate system based on the material layer 203. Figure 8 A schematic diagram of establishing a coordinate system for each structure based on the material layer 203, Figure 9 Schematic diagram of the coordinates of the relative positions of the target 202 , the first window 104 and the second window 105 .

[0080] Please refer to Figure 7 , with the intersection of the thickest position of the material layer 203 and the substrate 200 as the coordinate origin O, a coordinate system (x, y) is established, where the horizontal coordinate x of the coordinate system (x, y) is the distance of the material layer 203 along the surface of the substrate 200 relative to the coordinate origin O, and the vertical coordinate y of the coordinate system (x, y) is the thickness of any point on the surface of the material layer 203 in a direction perpendicular to the surface of the substrate 200.

[0081] Please refer to Figure 8 , T(x,y) is the thickness of the material layer 203 at a certain position, let a(x,y) be a point in the target 202, m(x,y) be any point in the first window 104, H be the distance between the first auxiliary plate 101 and the substrate 200, and h be the distance between the center of the target 202 and the substrate 200.

[0082] In this embodiment, the height H between the first auxiliary plate 101 and the substrate 200 is H′+d2, where H′ is a first distance between the first auxiliary plate 101 and the second auxiliary plate 102, and d2 is a second thickness of the second auxiliary plate 102.

[0083] In this embodiment, the distance h from the center of the target 202 to the surface of the substrate 200 = H + d1 + the distance between the target and the first auxiliary plate 101 , where d1 is the first thickness of the first auxiliary plate 101 .

[0084] In other embodiments, the second auxiliary plate is not in direct contact with the substrate, and a height H between the first auxiliary plate and the substrate is H′+d2+a distance between the second auxiliary plate and the substrate.

[0085] Please refer to Figure 9 , a(x,y) is a point in the target 202, and at both ends of the target 202, the critical coordinates of the point a(x,y) in the target 202 are a(x1,y1) and a(x2,y2); m(x,y) is any point in the first window 104, and the critical coordinates of the point m(x,y) in the first window 104 area are m(x1,y1) and m(x2,y2).

[0086] The thickness and thickness variation trend of the material layer 203 in the second window 105 are controlled by adjusting the relative positions of the target 202 , the center line L1 of the first window 104 , and the center line L2 of the second window 105 .

[0087] Specifically, the thickness variation trend of the material layer 203 is that the thickness of the material layer 203 gradually decreases along the direction from the center line L1 of the first window 104 to the center line L2 of the second window 105 . Figure 6 As shown in FIG. 1 , the center line L1 of the first window 104 is located on the left side of the center line L2 of the second window 105 . Therefore, the thickness variation trend of the material layer 203 is as follows: in the second window 105 , the thickness of the material layer 203 gradually decreases from the left side to the right side.

[0088] Of course, in another embodiment, also included in the second window 105 , the thickness of the material layer 203 gradually increases from the left side to the right side.

[0089] Please refer to Figure 10 , Figure 10 For Figure 9 In the schematic diagram based on the above, a(x,y) is a point in the target 202. At the two ends of the target 202, the critical coordinates of point a(x,y) in the target 202 are a(x1,y1) and a(x2,y2). m(x,y) is any point in the first window 104. The critical coordinates of point m(x,y) in the first window 104 are m(x1,y1) and m(x2,y2). The critical coordinates of point m(x,y) in the second window 105 are u(x1,y1) and u(x2,y2).

[0090] By adjusting the relative positions of the target 202, the center line L1 of the first window 104, and the center line L2 of the second window 105, the relative positions of the target 202 relative to the first window 104 and the second window 105 meet preset conditions. The preset conditions include:

[0091]

[0092]

[0093]

[0094]

[0095] in, 、 They respectively represent the critical coordinate values ​​of the left boundary of the active range of the target 202; 、 They represent the critical coordinate values ​​of the right boundary of the target 202's range of motion; H is the distance between the first auxiliary plate 101 and the substrate 200; h is the distance from the center of the target 202 to the surface of the substrate 200; is the critical coordinate value on the left side of the x-axis in the first window 104 area, is the critical coordinate value on the right side of the x-axis in the first window 104 area; is the left critical coordinate value on the y-axis in the first window 104 area, is the right critical coordinate value on the y-axis in the first window 104 area; is the critical coordinate value on the left side of the x-axis in the second window 105 area, For the critical coordinate value on the left side of the y-axis in the second window 105 area; is the critical coordinate value on the right side of the x-axis in the second window 105 area, is the critical coordinate value on the right side of the y-axis in the second window 105 area.

[0096] In the above formula, the relative positions of the target 202 , the first window 104 , and the second window 105 meet the preset conditions, which can ensure that the required material layer 203 with increasing or decreasing thickness is formed in the second window 105 .

[0097] The thickness of the material layer 203 gradually decreases from the center line L1 of the first window 104 to the center line L2 of the second window 105. Specifically, the thickness of the material layer 203 in the second window 105 continuously changes from 15 nanometers to 400 nanometers from the center line L1 of the first window 104 to the center line L2 of the second window 105.

[0098] In this embodiment, the preset size range is 3 cm to 4 cm, or 2 cm to 3 cm, 4 cm to 5 cm, or even less than 2 cm or greater than 5 cm, etc., which are all within the scope of protection requested by the present invention. The present invention does not limit the preset size range. The specific size range can be limited according to the requirements of the optical structure during design, or the regional requirements for forming the grating structure. In this regard, what is shown in the figure is only an example, which is feasible.

[0099] Please refer to Figure 11 A filling layer 204 is formed on the substrate 200 and the material layer 203 , and the top surface of the filling layer 204 is a flat surface.

[0100] In this embodiment, the method for forming the filling layer 204 includes: forming a filling material layer on the substrate 200 and the material layer 203 ; planarizing the filling material layer, and forming the filling layer 204 on the substrate 200 and the material layer 203 .

[0101] The material of the filling layer 204 includes photoresist.

[0102] Please refer to Figure 12 , a patterned mask layer 205 is formed on the filling layer 204 .

[0103] In this embodiment, the material of the patterned mask layer 205 includes photoresist.

[0104] Please refer to Figure 13 The filling layer 204 and the material layer 203 are etched using the patterned mask layer 205 as a mask until the surface of the substrate 200 is exposed, thereby forming an optical structure 206 on the substrate 200. The thickness of the optical structures 206 varies continuously.

[0105] The thickness of the optical structures 206 changes continuously, including: in the arrangement direction of the optical structures 206 , the thickness of the optical structures 206 gradually increases or gradually decreases.

[0106] Specifically, in a direction along the surface of the substrate 200 , the thickness of the optical structure 206 continuously changes from 15 nanometers to 400 nanometers.

[0107] In this embodiment, the plurality of optical structures 206 formed by the material layer 203 are used to form turning gratings and / or outcoupling gratings, and the depths of the turning gratings and / or the outcoupling gratings gradually increase along the direction of light transmission.

[0108] In this embodiment, the material of the material layer 203 includes an inorganic dielectric material, and the inorganic dielectric material includes titanium oxide, niobium oxide, silicon carbide, silicon oxide, lithium niobate, silicon nitride, tantalum oxide, hafnium oxide, and aluminum oxide.

[0109] In this embodiment, after the optical structure 206 is formed, the filling layer 204 and the patterned mask layer 205 are removed.

[0110] In another embodiment, after removing the filling layer 204 and the patterned mask layer 205, the method further includes thinning the substrate 200 to form the optical structure. Specifically, the substrate 200 is etched by an etching process to form an optical structure with a continuously gradient thickness on the substrate.

[0111] In other embodiments, the substrate 200 may not be thinned.

[0112] In other embodiments, the filling layer and the material layer are etched at a preset etching depth using the patterned mask layer as a mask to form an optical structure on the substrate, wherein the optical structure has a plurality of grooves, and the depth of the grooves is less than the depth of the material layer.

[0113] Please refer to Figure 14 In another embodiment, after the optical structure 206 is formed, the substrate 200 is further etched using the optical structure 206 as a mask, so that the substrate 200 is formed into a base 210 and a gradient structure 208 located on the base 210 .

[0114] The thickness variation trend of the gradient structure 208 is the same as the thickness variation trend of the optical structure 206 .

[0115] In this embodiment, the material of the material layer 203 includes metal, and the metal material includes one or more combinations of copper, aluminum, tungsten, cobalt, nickel, and tantalum.

[0116] In summary, the thickness of the formed optical structure 206 gradually increases or decreases in the arrangement direction of the optical structures 206. Therefore, the thickness variation trend of the optical structure 206 can be precisely controlled, and the thickness variation trend of the optical structures 206 is a continuous variation. By designing the deposition auxiliary structure, the thickness variation of the material layer at different locations can be precisely controlled, thereby forming an optical structure 206 with a continuously gradient thickness variation. On the one hand, based on this structural design, the diffraction efficiency of the optical structure 206 at different locations can be modulated to improve the display uniformity of the optical structure 206 at different locations and improve the display effect. On the other hand, this structural design can also improve the display appearance of the optical structure 206. The design of the continuously gradient thickness can prevent sudden thickness changes at different locations, thereby improving the dimensional accuracy and visual effect of the optical structure.

[0117] The above-mentioned optical structure formation method, by setting a deposition auxiliary structure between the target material and the substrate, makes the second window correspond to the optical structure area, and the first window corresponds to the target material. By controlling the relative positions of the target material, the first window and the second window and the sputtering process, a material layer with continuously varying thickness can be formed on the substrate, such as the thickness increasing or decreasing sequentially. In this way, the formation process of the optical structure is precisely controlled and the display appearance of the optical structure is improved. In particular, abrupt stripes between different optical structure areas are avoided, so that the thickness of each area presents a continuous gradient, improving the display effect of the optical structure while improving display efficiency. In addition, based on this method, a grating structure can be formed in a diffraction optical waveguide to achieve continuous gradient modulation of depth, and different grating structures have different depths of deposited materials. On the one hand, this method modulates the diffraction efficiency of the grating structure at different positions, especially in areas far away from the incident light source, improving the diffraction efficiency in the distant areas so that the diffraction efficiency presents a continuous and gradual change at each position, thereby improving the display uniformity and effect of the diffraction optical waveguide; on the other hand, the grating structure depth of the formed diffraction optical waveguide at different positions continuously and gradually changes, which is different from the traditional partitioned structure, avoiding the visual difference caused by thickness mutation, thereby obtaining a better visual appearance effect. The present invention has unexpected technical effects compared with the existing technology.

[0118] Figure 15 and Figure 16 It is a structural schematic diagram of the optical structure forming process in another embodiment of the present invention.

[0119] Please refer to Figure 15 , providing a substrate, wherein the substrate includes a base 300 and a grating structure 301 located on the base 300.

[0120] In this embodiment, a plurality of the grating structures 301 are separated on the substrate 300 , and the heights of the plurality of the grating structures 301 are the same.

[0121] Please refer to Figure 16 , using Figures 5 to 10 The method forms a material layer 302 on a substrate, wherein the material layer 302 is located on the sidewall surface and the top surface of the grating structure 301 . Along the arrangement direction of the grating structures 301 , the thickness of the material layer 302 located on the sidewall surface and the top surface of the grating structure 301 gradually increases.

[0122] Figure 17 and Figure 18 It is a structural schematic diagram of the optical structure forming process in another embodiment of the present invention.

[0123] Please refer to Figure 17 , providing a substrate, wherein the substrate includes a substrate 400 and a grating structure 401 located in the substrate 400.

[0124] In this embodiment, a plurality of the grating structures 401 are separated in the substrate 400 , and the tops of the plurality of the grating structures 401 are flush with the top of the substrate 400 .

[0125] Please refer to Figure 18 , using Figures 5 to 10 The method described forms a material layer 402 on a substrate, and the material layer 402 is located on the side wall surface and the top surface of the grating structure 401. Along the arrangement direction of the plurality of grating structures 401, the thickness of the material layer 402 located on the side wall surface and the top surface of the grating structure 401 gradually increases.

[0126] In some other embodiments, the present invention further provides a diffraction optical waveguide, the diffraction optical waveguide comprising at least an outcoupling grating region and / or a turning grating region, wherein the grating structure in the outcoupling grating region or the turning grating region is based on any of the aforementioned embodiments ( Figures 3 to 14 Examples of Figure 15 and Figure 16 embodiment, or Figure 17 and Figure 18 It is prepared by the method for forming the optical structure described in the embodiment).

[0127] Based on the technical effects listed in the above embodiments, the diffraction optical waveguide obtained by the present invention also has corresponding technical effects. Based on this method, a grating structure can be formed in the diffraction optical waveguide to achieve continuous gradient modulation of depth, and different grating structures have different depth materials deposited. On the one hand, this method modulates the diffraction efficiency of the grating structure at different positions, especially in the area far away from the incident light source, improves the diffraction efficiency of the distant area, and makes it present a continuous gradient diffraction efficiency at each position, thereby improving the display uniformity and effect of the diffraction optical waveguide; on the other hand, the grating structure depth of the formed diffraction optical waveguide at different positions is continuously gradient, which is different from the traditional partition structure, avoiding the visual difference caused by the thickness mutation, thereby visually obtaining a better appearance effect. The present invention has unexpected technical effects compared with the prior art.

[0128] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A deposition assist structure, characterized in that: include: a first auxiliary plate, wherein the first auxiliary plate has a first window extending through the first auxiliary plate; a second auxiliary plate, wherein the second auxiliary plate has a second window extending through the second auxiliary plate, and center lines of the first window and the second window do not overlap; The second auxiliary plate is disposed on the substrate and in contact with the substrate; The first auxiliary plate and the second auxiliary plate are arranged parallel to each other with a distance therebetween; the first window of the first auxiliary plate and the second window of the second auxiliary plate are used to form material layers with increasing or decreasing thicknesses within the second window; the thickness of the material layers is related to the distance; the projection range of the first window on the second auxiliary plate partially overlaps with the second window; The material layer is used to form a turning grating and / or an outcoupling grating of a diffraction optical waveguide, and the depth of the turning grating and / or the outcoupling grating gradually increases along the direction of light transmission; the thickness of the material layer at different positions is adjusted by adjusting the size of the spacing and the relative position of the first window and the second window.

2. The deposition assist structure according to claim 1, wherein: The thickness of the material layer decreases sequentially along a direction from a center line of the first window to a center line of the second window.

3. A method for forming an optical structure, characterized in that: include: Providing a substrate, the substrate comprising one or more optical structure regions; Providing a deposition assisting structure according to any one of claims 1 to 2, wherein the deposition assisting structure is arranged perpendicular to a surface direction of a substrate; providing a target material, disposed above the deposition auxiliary structure; The deposition auxiliary structure is arranged between the target and the substrate, the second auxiliary plate is in contact with the substrate, the second window corresponds to the optical structure area, and the first window corresponds to the target; An optical structure material layer with thickness increasing or decreasing sequentially is formed on the optical structure region by adjusting the relative positions of the target material, the first window and the second window.

4. The method for forming an optical structure according to claim 3, wherein: An optical structure material layer with successively increasing or decreasing thickness is formed on the optical structure area by adjusting the relative positions of the target material, the first window, and the second window, including: adjusting the relative positions of the target material, the center line of the first window, and the center line of the second window so that the relative positions of the target material relative to the first window and the second window meet preset conditions.

5. The method for forming an optical structure according to claim 4, wherein: The relative positions of the target material with respect to the first window and the second window meet preset conditions, including: in, 、 They represent the critical coordinate values ​​of the left boundary of the target's active range respectively; 、 They represent the critical coordinate values ​​of the right boundary of the target's active range; H is the distance between the first auxiliary plate and the substrate; h is the distance from the center of the target to the substrate surface; is the critical coordinate value on the left side of the x-axis in the first window area, is the critical coordinate value on the right side of the x-axis in the first window area; is the critical coordinate value on the left side of the y-axis in the first window area, is the critical coordinate value on the right side of the y-axis in the first window area; is the critical coordinate value on the left side of the x-axis in the second window area, The critical coordinate value on the left side of the y-axis in the second window area; is the critical coordinate value on the right side of the x-axis in the second window area, is the critical coordinate value on the right side of the y-axis in the second window area.

6. The method for forming an optical structure according to claim 3, wherein: Also includes: The substrate surface is flat; A turning grating and / or an outcoupling grating is formed based on the optical structure material layer on the substrate, and the depth of the turning grating and / or the outcoupling grating gradually increases along the direction of light transmission.

7. The method for forming an optical structure according to claim 3, wherein: Also includes: The substrate comprises: a base and a grating structure located on the base, and the optical structure material layer is formed on a surface of the grating structure away from the substrate.

8. A diffraction optical waveguide, characterized in that: It at least includes an outcoupling grating region and / or a turning grating region, and the grating structure in the outcoupling grating region or the turning grating region is prepared based on the method for forming an optical structure according to any one of claims 3 to 7.

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