METHOD FOR MANUFACTURING DIFFRACTIVE OPTICAL WAVEGUIDE, DIFFRACTIVE OPTICAL WAVEGUIDE AND IMPRINT TEMPLATE

Abstract

The present invention provides a method for manufacturing a diffractive optical waveguide and an imprint template (104), and the method for manufacturing a diffractive optical waveguide includes the steps of: providing a waveguide substrate (101); forming a patterned imprint resist layer (103) on the surface of the waveguide substrate (101); and using the patterned imprint resist layer (103) as a first mask to perform a first-stage etching on the waveguide substrate (101) to form a coupling-in structure (1011) in a first region, forming the patterned imprint resist layer remaining in a second region as a second mask, and using the second mask as a mask etching the waveguide substrate (101) to form coupling-out structures (1012, 1013), wherein the depths of the coupling-out structures (1012, 1013) are greater than the depth of the coupling-in structure (1011). The imprint template (104) includes a substrate (1041) and a second template pattern structure (1042) and a first template pattern structure (1043) formed on the substrate (1041), where the thickness of the substrate (1041) at the second template pattern structure (1042) is smaller than the thickness of the substrate (1041) at the first template pattern structure (1043). This solves the problem of how to form coupling-in structures (1011) and coupling-out structures (1012, 1013) with asymmetric depths on the waveguide substrate (101) while ensuring that the requirement of no obvious deviation in the relative positions of the coupling-in structure (1011) and the coupling-out structures (1012, 1013) is met.

Description

[Technical Field]

[0001] The present invention relates to the field of diffractive optical waveguides, and in particular to a method for manufacturing a diffractive optical waveguide, a diffractive optical waveguide, and an imprint template. [Background technology]

[0002] Generally, a diffractive optical waveguide can be divided into two parts, a coupling-in diffraction grating region and a coupling-out diffraction grating region, according to the functional regions. According to the performance requirements of the different functional regions, different types of diffraction grating structures are generally used for the coupling-in diffraction grating region and the coupling-out diffraction grating region. For example, since the coupling-in region requires efficient coupling-in performance, it is common to select a blazed diffraction grating for the coupling-in diffraction grating region, and since the coupling-out region requires uniform coupling-out performance, it is common to select a laminar diffraction grating for the coupling-out diffraction grating region.

[0003] According to the design requirements of the diffractive waveguide sheet, it is necessary to realize a structure in which the coupling-in depth and the coupling-out depth are not uniform on the target material, and the waveguide sheet is required to have good transmission efficiency and certain optical properties. Generally speaking, manufacturing a blazed diffraction grating is difficult and the process is complicated. In particular, when forming the diffraction grating by etching, the longer the etching time (or the deeper the etching depth), the greater the impact on the surface morphology of the diffraction grating. When a blazed diffraction grating and a laminar diffraction grating are formed by simultaneous etching, the etching conditions for the blazed diffraction grating significantly limit the etching of the laminar diffraction grating. This impact is particularly pronounced when there is a difference in the grating depth between the blazed diffraction grating and the laminar diffraction grating. The depth of the laminar diffraction grating is generally deeper than the depth of the blazed diffraction grating, which results in the performance of both the blazed diffraction grating and the laminar diffraction grating being incompatible, and the resulting diffractive optical waveguide does not achieve the expected results.

[0004] In the prior art, when the blazed diffraction grating and the laminar diffraction grating are respectively etched by overlay, the relative positions of the coupling-in and coupling-out are easily misaligned, which affects the overall performance of the diffractive optical waveguide.

[0005] Therefore, developing a manufacturing process for a waveguide that can form a structure in which the coupling-in depth and the coupling-out depth of a diffractive optical waveguide are not aligned and that can ensure that the relative positions of the coupling-in and coupling-out are not misaligned has become a technically important issue that must be resolved by those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a method for manufacturing a diffractive optical waveguide, a diffractive optical waveguide, and an imprint template to solve the problem of how to form coupling-in structures and coupling-out structures with uneven depths on a waveguide substrate while ensuring that the requirement of no obvious deviation in the relative positions of the coupling-in structures and the coupling-out structures is met. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided a method for manufacturing a diffractive optical waveguide, said method comprising the steps of: providing a waveguide substrate; forming a patterned imprint resist layer on a surface of the waveguide substrate, the patterned imprint resist layer including a first patterned imprint structure formed in a first region of the surface and a second patterned imprint structure formed in a second region of the surface, the second patterned imprint structure having a thickness greater than a thickness of the first patterned imprint structure; performing a first stage of etching on the waveguide substrate using the patterned imprint resist layer as a first mask to form a coupling-in structure on the waveguide substrate in the first region, and maintaining a pattern of the second patterned imprint structure with the remaining patterned imprint resist layer on the waveguide substrate in the second region; forming a second mask using the remaining patterned imprint resist layer, and performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region; However, the second mask covers the coupling-in structure to protect the coupling-in structure from being etched during the etching of the second step, and the coupling-in structure and the coupling-out structure have different structural forms, and the depth of the coupling-out structure is greater than the depth of the coupling-in structure.

[0008] Optionally, the etching depth of the coupling-out structure is uniform, or the etching depth of different regions of the coupling-out structure is non-uniform.

[0009] Optionally, the step of forming a second mask using the remaining patterned imprint resist layer, and performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region includes: forming a first hard mask layer, the first hard mask layer being formed on the surface of the waveguide substrate and covering the coupling-in structure and the remaining patterned imprint resist layer; removing the remaining patterned imprint resist layer and the first hard mask layer covering the remaining patterned imprint resist layer to form the second mask; and performing a second stage of etching on the waveguide substrate using the second mask as a mask to form a coupling-out structure in the second region.

[0010] Optionally, the step of performing a second stage of etching on the waveguide substrate using the second mask as a mask to form a coupling-out structure in the second region includes the steps of performing a first etching of a second stage on the waveguide substrate using the second mask as a mask to form a coupling-out structure with a uniform etching depth; forming a photoresist layer in N steps, each of which covers a portion of the coupling-out structure, where N is an integer greater than or equal to 1; every time a photoresist layer is formed, a part of the coupling-out structure that is not covered by the photoresist layer this time is etched using the photoresist layer formed this time and the remaining patterned imprint resist as a mask, and after the Nth etching, the coupling-out structure of N+1 different etching areas is formed; and removing the photoresist and the second mask.

[0011] Optionally, the step of forming a second mask using the remaining patterned imprint resist layer, and performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region includes: forming a coupling-in protection layer on the surface of the coupling-in structure; and using the coupling-in protection layer and the remaining patterned imprint resist layer as a second mask, performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region.

[0012] Optionally, the step of forming a coupling-in protection layer on the surface of the coupling-in structure comprises: Dropping a predetermined amount of photoresist onto the area where the coupling-in structure is located; uniformly flowing the photoresist under vacuum and negative pressure conditions to cover the surface of the coupling-in structure; and curing the photoresist to form the photoresist layer.

[0013] Optionally, the thickness of the coupling-in protection layer is greater than the thickness of the remaining patterned imprint resist layer.

[0014] Optionally, the step of forming a patterned imprint resist layer on the surface of the waveguide substrate specifically comprises: providing an imprint template, the imprint template being provided with a first template pattern structure corresponding to the coupling-in structure and a second template pattern structure corresponding to the coupling-out structure; applying an imprint resist to the waveguide substrate; imprinting the imprint template into the imprint resist layer to form the patterned imprint resist layer, wherein a pattern in the patterned imprint resist layer corresponds to a pattern of the first template pattern structure and a second template pattern structure; separating the imprint template and the patterned imprint resist layer.

[0015] Optionally, the step of imprinting the imprint template into the imprint resist layer to form the patterned imprint resist layer specifically comprises: imprinting the imprint template into the imprint resist; and curing the imprint resist to form the patterned imprint resist layer.

[0016] Optionally, the thickness of the imprint resist is adapted to a maximum depth of patterns in the first template pattern structure and the second template pattern structure.

[0017] According to a second aspect of the present invention, there is provided a diffractive optical waveguide manufactured by the method for manufacturing a diffractive optical waveguide according to any one of the first aspects of the present invention.

[0018] According to a third aspect of the present invention there is provided an imprint template comprising: A substrate; a second template pattern structure and a first template pattern structure formed on the substrate, wherein a thickness of the substrate in the second template pattern structure is smaller than a thickness of the substrate in the first template pattern structure; The imprint template is used to manufacture a diffractive optical waveguide, and the pattern of the second template pattern structure matches the pattern of the coupling-out structure of the diffractive optical waveguide, and the pattern of the first template pattern structure matches the pattern of the coupling-in structure of the diffractive optical waveguide.

[0019] Optionally, the second template pattern structure includes several recessed groove structures or several raised structures.

[0020] Optionally, the depths of the groove structures included in the second template pattern structure are the same.

[0021] Optionally, the second template pattern structure is a laminar structure.

[0022] Optionally, the position of the groove structure included in the second template pattern structure coincides with the position of the groove of the coupling-out structure of the diffractive optical waveguide, and the width of the groove structure included in the second template pattern structure coincides with the width of the groove of the coupling-out structure of the diffractive optical waveguide.

[0023] Optionally, the first template pattern structure is a blazed structure.

[0024] Optionally, the material of the imprint template is SiO2, Si, quartz glass or high refractive index glass.

[0025] Optionally, the shape of the second template pattern structure and / or the first template pattern structure is a closed shape surrounded by curved and / or rectilinear lines.

[0026] Optionally, the pattern of the first template pattern structure is complementary to the pattern of the coupling-in structure of the diffractive optical waveguide.

[0027] The method for manufacturing a diffractive optical waveguide provided by the present invention utilizes a patterned imprint resist layer formed on a waveguide substrate, and firstly, a first-stage etching is performed on the waveguide substrate using the patterned imprint resist layer as a first mask to form a coupling-in structure in a first region and a remaining patterned imprint resist layer in a second region; next, the technical solution provided by the present invention includes a sub-step of forming a second mask using the remaining patterned imprint resist layer to protect the coupling-in structure; and a sub-step of performing a second-stage etching on the waveguide substrate using the second mask as a mask to form a coupling-out structure in the second region. The present invention creatively proposes a sub-step of forming a structure, and through these two sub-steps, coupling-in structures and coupling-out structures with different depths can be finally formed, and the relative positions of the formed coupling-out structures and the coupling-in structures do not significantly deviate from the predetermined relative positions. As can be seen, the technical solution provided by the present invention solves the problem of how to form coupling-in structures and coupling-out structures with unequal depths on a waveguide substrate while ensuring that the requirement of no significant deviation in the relative positions of the coupling-in structures and the coupling-out structures is met, and is suitable for mass production.Furthermore, the imprint template provided by the present invention is designed to include a second template pattern structure and a first template pattern structure, with the substrate thickness in the second template pattern structure being smaller than that in the first template pattern structure. When the imprint template is used to manufacture a diffractive optical waveguide, the patterns of the second template pattern structure and the first template pattern structure can be simultaneously transferred to the diffractive optical waveguide, with the second template pattern structure and the first template pattern structure corresponding to a coupling-in structure and a coupling-out structure, respectively. This solves the problem of misalignment between the coupling-out structure and the coupling-in structure. When transferring the patterns, the resist thicknesses of the coupling-in structure and the coupling-out structure are different, which provides greater design freedom in the manufacturing method for forming coupling-out structures and coupling-in structures with different shapes without affecting each other, thereby improving the overall performance of the diffractive optical waveguide. [Brief explanation of the drawings]

[0028] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. However, the drawings in the following description are only some embodiments of the present invention, and it is obvious that those skilled in the art can obtain other drawings based on these drawings without creative work. [Figure 1] 1 is a schematic flow chart of a method for manufacturing a diffractive optical waveguide provided in an embodiment of the present invention. [Figure 2] 1 is a schematic diagram of the structure of an imprint template provided in a specific embodiment of the present invention; [Figure 3] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 4]2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 5] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 6] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 7] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 8] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 9] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 10] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 11] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 12] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 13] 2A to 2C are schematic diagrams illustrating the structure of a device at different process stages manufactured by the method for manufacturing a diffractive optical waveguide provided in a specific embodiment of the present invention; [Figure 14] 5A to 5C are schematic diagrams of device structures at different process stages manufactured by a method for manufacturing a diffractive optical waveguide provided in another specific embodiment of the present invention. [Figure 15]5A to 5C are schematic diagrams of device structures at different process stages manufactured by a method for manufacturing a diffractive optical waveguide provided in another specific embodiment of the present invention. [Figure 16] 1 is a schematic diagram of the structure of a vacuum dish provided in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] The technical solutions of the embodiments of the present invention will be described more clearly and completely below with reference to the drawings of the embodiments of the present invention, but it is clear that the described embodiments are only some of the embodiments of the present invention, and do not represent all of the embodiments. Based on the embodiments of the present invention, any other embodiments that those skilled in the art can obtain without creative efforts fall within the scope of protection of the present invention.

[0030] The terms "first," "second," "third," "fourth," etc. (if any) in the present specification and claims and in the above drawings are intended to distinguish between similar objects and need not be used to describe a particular order or chronology. It should be understood that such terms, when used, may be interchanged, where appropriate, such that the embodiments of the present invention described herein may be performed in orders other than those illustrated or described herein. Furthermore, the terms "comprise" and "have," and any variations thereof, are intended to be non-exclusive inclusive; for example, a process, method, system, product, or apparatus comprising a series of steps or units need not be limited to the explicitly recited steps or units, but may include steps or units not explicitly recited, or other steps or units inherent to such process, method, system, product, or apparatus.

[0031] Generally, a diffractive optical waveguide can be divided into two parts, a coupling-in diffraction grating region and a coupling-out diffraction grating region, according to the functional regions. According to the performance requirements of the different functional regions, different types of diffraction grating structures are generally used for the coupling-in diffraction grating region and the coupling-out diffraction grating region. For example, since the coupling-in region requires efficient coupling-in performance, it is common to select a blazed diffraction grating for the coupling-in diffraction grating region, and since the coupling-out region requires uniform coupling-out performance, it is common to select a laminar diffraction grating for the coupling-out diffraction grating region.

[0032] According to the design requirements of the diffractive waveguide sheet, it is necessary to realize a structure in which the coupling-in depth and the coupling-out depth are not uniform on the target material, and the waveguide sheet is required to have good transmission efficiency and certain optical properties. Generally speaking, manufacturing a blazed diffraction grating is difficult and the process is complicated. In particular, when forming the diffraction grating by etching, the longer the etching time (or the deeper the etching depth), the greater the impact on the surface morphology of the diffraction grating. When a blazed diffraction grating and a laminar diffraction grating are formed by simultaneous etching, the etching conditions for the blazed diffraction grating significantly limit the etching of the laminar diffraction grating. This impact is particularly pronounced when there is a difference in the grating depth between the blazed diffraction grating and the laminar diffraction grating. The depth of the laminar diffraction grating is generally deeper than the depth of the blazed diffraction grating, which results in the performance of both the blazed diffraction grating and the laminar diffraction grating being incompatible, and the resulting diffractive optical waveguide does not achieve the expected results.

[0033] In the prior art, when the blazed diffraction grating and the laminar diffraction grating are respectively etched by overlay, the relative positions of the coupling-in and coupling-out are easily misaligned, which affects the overall performance of the diffractive optical waveguide.

[0034] In view of this, in order to meet the requirement that there is basically no deviation in the relative positions of the coupling-in and coupling-out, the present application simultaneously forms patterns corresponding to a predetermined coupling-in structure and a predetermined coupling-out structure on the surface of the waveguide substrate in a single imprint, and by cleverly providing a mask, etching is performed in two stages to form the coupling-in structure and the coupling-out structure, respectively, thereby realizing a structure in which the coupling-in depth and the coupling-out depth are not aligned.

[0035] Furthermore, the present application provides a method for forming a coupling-in structure in a first etching step, controlling the remaining resist layer at the position of a predetermined coupling-out structure to still maintain a pattern that reflects the coupling-out structure, and then using the remaining resist layer to form a second mask, and performing a second etching step on the waveguide substrate based on the second mask to form the coupling-out structure, and the second mask covers the coupling-in structure to protect the shape of the coupling-in structure from being affected during the second etching step. As can be seen, the method provided herein can form a structure in which the coupling-in structure and the coupling-out structure of a diffractive optical waveguide have asymmetric depths, while ensuring that the requirement of no deviation in the relative positions of the coupling-in structure and the coupling-out structure is met, and is suitable for mass production.

[0036] Furthermore, the present invention cleverly utilizes a dissolution process to form a hard mask on the waveguide substrate, and then uses the hard mask as a mask to etch the waveguide substrate in the coupling-out region to form a coupling-out structure in the coupling-out region, which has a different depth from the coupling-in structure. Compared with the prior art, there is no obvious error in the relative positions of the coupling-out structure and the coupling-in structure formed using this solution. And by using the hard mask as a mask to etch the coupling-out structure, different etching depths can be achieved in different regions.

[0037] In addition, in the present application, the coupling-in structure can be protected by applying photoresist to the top of the already formed coupling-in structure, and the remaining imprint resist formed by imprinting can be used as a mask to etch the waveguide substrate in the coupling-out region to form the coupling-out structure, which can achieve the same effect. Furthermore, conventional imprint templates usually have only one type of structure, and when manufacturing a diffractive optical waveguide using an imprint template, it is usually formed in a single imprint. That is, when the diffraction grating structure of the imprint template and the diffraction grating structure of the diffractive optical waveguide are bonded face to face, the protrusions of the diffraction grating structure of the imprint template fill and adhere to the grooves of the diffraction grating structure of the diffractive optical waveguide, and similarly, the protrusions of the diffraction grating structure of the diffractive optical waveguide fill and adhere to the grooves of the diffraction grating structure of the imprint template. Therefore, the structure of the imprint template in the prior art cannot manufacture coupling-out structures and coupling-in structures with different shapes, which is disadvantageous for improving the performance of the diffractive optical waveguide. Existing methods of forming coupling-out structures and coupling-in structures with different shapes by etching, respectively, due to overlay, tend to cause misalignment of the relative positions of the coupling-in and coupling-out, which also affects the overall performance of the diffractive optical waveguide.

[0038] In view of this, the present application proposes a new imprint template structure, which is designed as follows: A second template pattern structure and a first template pattern structure are formed on a substrate, and the relative positions of the two are fixed, so that, in the process of manufacturing a diffractive optical waveguide using the imprint template, when a patterned imprint resist is formed by transferring the pattern of the imprint template to an imprint resist, the patterns of the second template pattern structure and the first template pattern structure can be transferred to the resist layer at one time, thereby solving the problem of misalignment of the relative positions of the coupling-out structure and the coupling-in structure. The thickness of the substrate in the second template pattern structure is smaller than the thickness of the substrate in the first template pattern structure. In this way, the patterned imprint resist is used as a first mask to etch the waveguide substrate, and after the first template pattern structure with a larger thickness is formed on the waveguide substrate, the pattern of the patterned imprint resist remaining in the corresponding position of the second template pattern structure with a smaller thickness maintains the pattern of the patterned imprint resist. This provides greater freedom in designing how to protect the already formed coupling-in portion (the portion corresponding to the second template pattern structure) and how to subsequently form the coupling-out portion to be formed (the portion corresponding to the first template pattern structure). Finally, coupling-out structures and coupling-in structures with different shapes can be etched, and the shapes of both of these two structures meet expectations.

[0039] As can be seen from this, the technical solution provided in this application solves the problem of how to etch coupling-out structures and coupling-in structures with different shapes and eliminate the misalignment of the relative positions of the coupling-out structures and coupling-in structures, thereby improving the overall performance of the diffractive optical waveguide.

[0040] The technical solutions of the present invention are described in detail in the following specific embodiments. Some of the following specific embodiments can be combined, and the detailed description of the same or similar concepts or processes may be omitted in some embodiments.

[0041] According to an embodiment of the present invention, there is provided a method for manufacturing a diffractive optical waveguide, the flow chart of which is shown in FIG. 1, and includes steps S11 to S14.

[0042] In S11, a waveguide substrate 101 is provided.

[0043] In S12, a patterned imprint resist layer is formed on one surface of the waveguide substrate 101, the patterned imprint resist layer including a first patterned imprint structure 1031 formed in a first region of the surface and a second patterned imprint structure 1032 formed in a second region of the surface, the thickness of the second patterned imprint structure 1032 being greater than the thickness of the first patterned imprint structure 1031, and the structure of the device after the patterned imprint resist layer is formed is as shown in FIG.

[0044] In one embodiment, in step S12, the step of forming the patterned imprint resist layer 103 on one surface of the waveguide substrate 101 specifically includes the following steps S121 to S124.

[0045] In S121, an imprint template 104 is provided, and the imprint template is provided with a first template pattern structure 1043 and a second template pattern structure 1042. However, the first template pattern structure 1043 corresponds to the coupling-in structure 1011, and the second template pattern structure 1042 corresponds to the coupling-out structure 1012, and the structure of the imprint template 104 is as shown by 104 in Figure 2 or Figure 5.

[0046] Specifically, the first template pattern structure 1043 corresponds to the coupling-in structure 1011 and the second template pattern structure 1042 corresponds to the coupling-out structure 1012 includes that the pattern of the first template pattern structure 1043 corresponds to the pattern of the predetermined coupling-in structure 1011 and that the pattern of the second template pattern structure 1042 corresponds to the pattern of the predetermined coupling-out structure 1012. However, the correspondence of the patterns may be that the patterns are identical or complementary, etc.

[0047] Furthermore, the correspondence of the first template pattern structure 1043 to the coupling-in structure 1011 further includes that the pattern depth of the first template pattern structure 1043 matches the pattern depth of the coupling-in structure 1011.

[0048] Here, in a preferred embodiment, the thickness of the first template pattern structure 1043 is 100 to 500 nm, and the thickness of the second template pattern structure 1042 is 100 to 300 nm.

[0049] In one embodiment, the material of the imprint template 104 is SiO2, but may also be SiO2, TiO2, Nb2O5, high refractive index glass, etc., and of course other materials, and the invention is not limited thereto.

[0050] In one embodiment, the cross section of the first template pattern structure 1043 and / or the second template pattern structure 1042 is a square or a triangle, and in other embodiments, it may be other shapes that can achieve the purpose of the present invention, and the present invention is not limited thereto, and any implementation form is within the protection scope of the present invention.

[0051] 3, an imprint resist 102 is applied to the waveguide substrate 101. Preferably, the imprint resist 102 has properties such as good fluidity and photosensitivity, as well as good dry etching resistance. Considering that semiconductor etching gases commonly used for dry etching are F-based, Cl-based gases, etc., the imprint resist 102 can be selected based on these etching gases when considering dry etching resistance.

[0052] In one embodiment, the thickness of the applied imprint resist 102 matches the maximum thickness of the patterns in the first template pattern structure 1043 and the second template pattern structure 1042, where matching means that the thickness of the imprint resist 102 is equal to or greater than the maximum thickness of the patterns in the first template pattern structure 1043 and the second template pattern structure 1042 to provide a sufficient thickness of imprint resist 102 so that the depth of the ultimately formed first patterned imprint structure 1031 and second patterned imprint structure 1032 matches the thickness of the first template pattern structure 1043 and the second template pattern structure 1042. In practice, the thickness of the imprint resist 102 is typically between 100 and 1000 nm.

[0053] In one embodiment, the method used to apply the imprint resist 102 to the waveguide substrate 101 is spin coating or spray coating, but in other embodiments, other implementation methods may be used, and the present invention is not limited thereto.

[0054] In S123, the imprint template 104 is imprinted into the imprint resist 102 to form a patterned imprint resist layer 103. However, the pattern of the patterned imprint resist layer 103 corresponds to the patterns of the first template pattern structure 1043 and the second template pattern structure 1042, and the structure of the device after imprinting the imprint template 104 into the imprint resist 102 is as shown in Figure 5.

[0055] In one embodiment, step S123 of imprinting the imprint template 104 into the imprint resist 102 to form the patterned imprint resist layer 103 specifically includes steps S1231 to S1232.

[0056] In S1231, the imprint template 104 is imprinted onto the imprint resist 102.

[0057] In one embodiment, the method used to imprint the imprint template 104 into the imprint resist 102 is an integrated nanoimprint process, which ensures good contact between the imprint template 104 and the imprint resist 102 to ensure a perfect transfer of the structure of the imprint template 104 into the imprint resist to form the patterned imprint resist layer 103 (as shown in FIG. 5 ).

[0058] In S1232, the imprint resist 102 is cured to form a patterned imprint resist layer 103.

[0059] In one embodiment, the method used to harden the imprint resist 102 is an ultraviolet lamp exposure method or a thermal hardening technique method, but in other embodiments, other implementation methods may be used, and the present invention is not limited thereto.

[0060] In S124, the imprint template 104 is separated from the patterned imprint resist layer 103. The structure of the device after the imprint template 104 is separated from the patterned imprint resist layer 103 is as shown in FIG.

[0061] In one embodiment, the process used to separate the imprint template 104 and the patterned imprint resist layer 103 is a stamping process, but in other embodiments, other implementations may be used, and the present invention is not limited thereto. After stamping, structural information corresponding to the template is obtained on the patterned imprint resist layer 103, which can be used as a mask for subsequent dry etching.

[0062] In S13, the patterned imprint resist layer 103 is used as a first mask to perform a first stage of etching on the waveguide substrate 101, to form a coupling-in structure 1011 on the waveguide substrate 101 in the first region, and the remaining patterned imprint resist 102 on the waveguide substrate 101 in the second region maintains the pattern of the second patterned imprint structure 1032, and the device structure after step S13 is as shown in Figure 6.

[0063] In one embodiment, dry etching is used in the first stage etching, but the etching gas used is a commonly used semiconductor etching gas, such as an F-based gas or a Cl-based gas.

[0064] In S14, a second mask 107 is formed using the remaining patterned imprint resist layer 105, and a second stage of etching is performed on the waveguide substrate 101 based on the second mask 107 to form a coupling-out structure 1012 or 1013 in the second region. The device after the coupling-out structure 1012 or 1013 is formed is as shown in FIG. 10 or FIG. 13 (please note that the structure of the device in FIG. 9 is a schematic diagram of the structure of the device before the second mask is removed).

[0065] Here, the second mask 107 covers the coupling-in structure 1011 to protect the coupling-in structure 1011 from being etched during the second-stage etching, and the coupling-in structure 1011 and the coupling-out structures 1012 and 1013 have different structural forms, and the depth of the coupling-out structures 1012 and 1013 is greater than the depth of the coupling-in structure 1011.

[0066] Here, the etching depth of the coupling-out structure 1012 is uniform, but the etching depths of different regions of the coupling-out structure 1013 are not uniform. In the present application, based on the fact that the etching resistance of the hard mask material is better than that of the photoresist material, by using a hard mask and a photoresist mask in combination, it is possible to achieve etching to different depths depending on the region of the coupling-out structure.

[0067] In one embodiment, the cross section of the coupling-in structure 1011 and / or the coupling-out structure 1012, 1013 is rectangular or triangular, and in other embodiments, it may be other shapes that can achieve the purpose of the present invention, and the present invention is not limited thereto, and any implementation form is within the protection scope of the present invention.

[0068] The method for manufacturing a diffractive optical waveguide provided by the present invention is divided into two substeps after forming a patterned imprint resist layer 103 on a waveguide substrate 101. In the first step, a coupling-in structure 1011 is formed in a first region. Specifically, the first step includes using the patterned imprint resist layer 103 as a first mask to perform a first-stage etching on the first region of the waveguide substrate 101 and controlling the etching time to etch and form the coupling-in structure 1011, while forming a remaining patterned imprint resist in the second region. In the second step, a second mask is formed using the remaining patterned imprint resist layer 105, and the second mask is used to protect the coupling-in structure 1011, and the waveguide substrate 101 in the second region is etched to form a coupling-out structure 1012 or 1013.

[0069] The technical solution provided by the present invention is to form the coupling-in structure 1011 and the remaining patterned imprint resist layer 105 in the first step, and then use the remaining patterned imprint resist layer 105 to form a second mask, and use the second mask as a mask to perform a second etching step on the waveguide substrate 101 in the second region to form the coupling-out structure 1012 or 1013. Therefore, as can be seen from this, under the protection of the second mask, when there is a difference in etching depth between the coupling-out structure 1012 or 1013 and the coupling-in structure 1011, especially when the depth of the formed coupling-out structure 1012 or 1013 is greater than the depth of the coupling-in structure 1011. If a larger etching depth is required, the etching of a deep diffraction grating structure is not limited to a shallow diffraction grating structure. In this way, the etching depths of the coupling-in structure 1011 and the coupling-out structure 1012 or 1013, which have different depths, can be made compatible, thereby achieving the effect of combining the performance of the coupling-in structure 1011 and the coupling-out structure 1012 or 1013. In addition, the depth of the finally formed coupling-out structure 1012 or 1013 is different from the depth of the coupling-in structure 1011, and the relative position of the obtained coupling-out structure 1012 or 1013 and the coupling-in structure 1011 does not significantly deviate from the predetermined relative position.

[0070] Therefore, the technical solution provided by the present invention solves the problem of how to form the coupling-in structure 1011 and the coupling-out structure 1012 or 1013 with uneven depths on the waveguide substrate 101 while ensuring that the requirement of no obvious deviation in the relative positions of the coupling-in structure 1011 and the coupling-out structure 1012 or 1013 is met, thereby achieving the technical effect of improving the overall performance of the diffractive optical waveguide and being suitable for mass production.

[0071] Referring to Figures 1 to 13, the following will be divided into two specific examples to specifically describe the specific steps of performing a second stage of etching on the waveguide substrate 101 based on the second mask 107 to form coupling-out structures 1012, 1013 in the second region.

[0072] In a specific embodiment, step S14 of forming a second mask 107 using the remaining patterned imprint resist layer 105 and performing a second stage of etching on the waveguide substrate 101 based on the second mask 107 to form coupling-out structures 1012, 1013 in the second region specifically includes the following steps S141 to S143.

[0073] In S141, a first hard mask layer 106 is formed, the first hard mask layer 106 is formed on the surface of the waveguide substrate 101 and covers the coupling-in structure 1011 and the remaining patterned imprint resist layer 105.

[0074] Specifically, the material of the first hard mask layer 106 is Cr, Al, SiO2, or Si3N4. Naturally, other materials may be used. Any method for realizing the first hard mask layer 106 that can achieve the objectives of the present invention is within the protection scope of the present invention, and the present invention is not limited thereto. Preferably, in one embodiment, the first hard mask layer 106 is an Al metal film, which can well cover the surface of the waveguide substrate 101 and minimize deposition on the sidewalls of the remaining patterned imprint resist layer 105, thereby avoiding defects in the shape of the etched coupling-out structures 1012, 1013, thereby manufacturing coupling-out structures 1012, 1013 with ideal performance. The device structure after the first hard mask layer 106 is formed is as shown in FIG.

[0075] Here, the etching rate of the dry etching of the first hard mask layer 106 is much lower than the etching rate of the imprint resist 102 .

[0076] In one embodiment, the semiconductor deposition technique used to form the first hard mask layer 106 is a PVD coating process, specifically using a sputtering or evaporation method.

[0077] In one embodiment, to effectively protect the coupling-in structure 1011, the thickness of the first hard mask layer 106 is preferably 50 nm.

[0078] In S142, the remaining patterned imprint resist layer 105 and the first hard mask layer 106 covering the remaining patterned imprint resist layer 105 are removed to form a second mask 107, exposing the substrate 1041 of the coupling-out structure 1012, and the remaining hard mask layer is the second mask 107, and the structure of the device after the second mask 107 is formed is as shown in Figure 8.

[0079] In one embodiment, a dissolution process is used to remove the remaining patterned imprint resist layer 105, and of course there may be other implementations, and any implementations of removing the remaining patterned imprint resist layer 105 that can achieve the objectives of the present invention are within the protection scope of the present invention, and the present invention is not limited thereto.

[0080] Here, the elution process specifically includes the following steps: first, the device including the remaining patterned imprint resist layer 105 obtained in step S141 is placed in an ultrasonic bath; then, a highly polar organic solution is added into the ultrasonic bath; then, ultrasound is turned on to assist in expanding the remaining patterned imprint resist layer 105 with the organic solution until the remaining patterned imprint resist layer 105 is completely peeled off; finally, the device including the remaining patterned imprint resist layer 105 obtained in step S141 is washed and dried by spin rinse drying to obtain the device after the remaining patterned imprint resist layer 105 is removed in step S142.

[0081] Here, the organic solvent must have essentially no corrosive or swelling effect on the hard mask material. In a specific embodiment, the organic solvent is generally acetone or dimethyl sulfoxide, etc.

[0082] In S143, a second stage of etching is performed on the waveguide substrate 101 using the second mask 107 as a mask to form coupling-out structures 1012, 1013 in the second region, and the structure of the device after the coupling-out structures 1012, 1013 are formed is as shown in Figure 10 or 13.

[0083] In one embodiment, the method used for the second stage etching is a dry etching method. In the second stage etching, a single etching step can etch the coupling-out structure 1012 with a uniform etching depth. Multiple etching steps can etch the coupling-out structure 1013 with different regions having non-uniform etching depths.

[0084] Here, each etching depth region in the coupling-out structure 1013 may include several grating units, and the etching depth within this region is the same. The present invention does not limit the number of the grating units.

[0085] In one embodiment, step S143 of performing a second stage of etching on the waveguide substrate 101 using the second mask 107 as a mask to form the coupling-out structure 1012 in the second region includes: The second mask 107 is used as a mask to perform a second etching step on the waveguide substrate 101, stopping the etching when the target depth is reached, and removing the remaining second mask layer from the etched waveguide substrate 101 to form a coupling-out structure 1012 with a uniform etching depth. A final diffractive optical waveguide structure is obtained in which the coupling-in and coupling-out structures have different shapes and are not misaligned, and the shapes of the obtained coupling-in and coupling-out structures are also as expected.

[0086] In one embodiment, step S143 of performing a second stage of etching on the waveguide substrate 101 using the second mask 107 as a mask to form the coupling-out structure 1013 in the second region includes: performing a first etching of the second stage on the waveguide substrate 101 using the second mask 107 as a mask to form a coupling-out structure 1012 with a uniform etching depth; forming a photoresist layer 108 in N steps, each of which covers a portion of the coupling-out structure, where N is an integer greater than or equal to 1 (as shown in FIG. 11); Each time the photoresist layer 108 is formed, the method includes the steps of etching a portion of the waveguide substrate 101 of the coupling-out structure that is not currently covered by the photoresist layer 108 using the currently formed photoresist layer 108 and the remaining patterned imprint resist of the second mask 107 as a mask (as shown in FIG. 12); after the Nth etching, forming coupling-out structures 1013 of N+1 different etching areas; and removing the photoresist and the second mask 107 (as shown in FIG. 13).

[0087] However, the material of the second mask 107 can refer to the material of the first hard mask layer 106, and detailed description thereof will be omitted in this application.

[0088] In the above specific embodiment, after forming the coupling-in structure 1011 on the waveguide substrate 101 by the first-stage etching and forming the remaining patterned imprint resist layer 105 on the waveguide substrate 101 in the second region, the first hard mask layer 106 is strategically formed on the surface of the waveguide substrate 101 and the surface of the remaining patterned imprint resist layer 105, and then the remaining patterned imprint resist layer 105 is removed using an elution process, and the second hard mask layer can protect the coupling-in structure 1011, so that the expected coupling-out structures 1012, 1013 can be etched. When etching the coupling-out structures 1012 and 1013 in the second region, the coupling-in structure 1011 in the first region is not affected, so that the etching of the coupling-in structure 1011 and the coupling-out structures 1012 and 1013 can be achieved in separate steps, and the coupling-in structure 1011 and the coupling-out structures 1012 and 1013 with uneven depths of the diffractive optical waveguides can be formed, and the requirement that the relative positions of the coupling-in structure 1011 and the coupling-out structures 1012 and 1013 are consistent can be ensured, and the method is suitable for mass production.

[0089] 1, 3 to 6, 14 to 16, according to another specific embodiment of the present invention, step S14 of forming a second mask 107 using the remaining patterned imprint resist layer 105, and performing a second stage of etching on the waveguide substrate 101 based on the second mask 107 to form a coupling-out structure 1012 in the second region specifically includes the following steps S141 to S142:

[0090] In step S141, a coupling-in protection layer 109 is formed on the surface of the coupling-in structure 1011. In a specific embodiment, the coupling-in protection layer 109 is a photoresist layer 108. After the coupling-in protection layer 109 is formed, the structure of the device is as shown in FIG. 14.

[0091] In one embodiment, step S141 of forming the coupling-in protective layer 109 on the surface of the coupling-in structure 1011 specifically includes the following steps S1411 to S1413.

[0092] In step S1411, a predetermined amount of photoresist is dropped onto the area where the coupling-in structure 1011 is to be located.

[0093] In step S1412, the photoresist is made to flow uniformly under vacuum and negative pressure conditions to cover the surface of the coupling-in structure 1011.

[0094] In step S1413, the photoresist is subjected to a hardening process to form a photoresist layer 108.

[0095] In one embodiment, when the formed coupling-in protection layer 109 is a photoresist layer 108, the method used to form the coupling-in protection layer 109 is a photoresist vacuum coating method.

[0096] The step of performing step S141 using a photoresist vacuum coating method to form the coupling-in protection layer 109 specifically includes the following steps: First, apply a drop of photoresist to the top of the coupling-in structure 1011. Depending on the size of the coupling-in structure 1011, the amount of photoresist applied is generally in the range of 0.1 to 10 ml. Place the coupling-in structure 1011 horizontally for several minutes. The entire device structure is placed in a dedicated vacuum dish 110 placed horizontally, and a constant negative pressure is applied inside the vacuum dish 110 to ensure that the photoresist flows evenly to the top of the coupling-in structure 1011 and no bubbles are generated throughout the entire process. Specifically, the target material substrate after the resist is dropped is placed horizontally on the vacuum dish 110, and the first evacuation is started at a vacuum pressure of less than 100 Pa. After leaving it horizontally and standing for several minutes, an inert gas (e.g., GN2, Ar, etc.) is slowly passed through to return to atmospheric pressure; the second evacuation is performed at a vacuum pressure of less than 100 Pa, and after leaving it horizontally and standing for several minutes, an inert gas (e.g., GN2, Ar, etc.) is slowly passed through to return to atmospheric pressure; and the third evacuation is performed at a vacuum pressure of less than 100 Pa, and after leaving it horizontally and standing for several minutes, an inert gas (e.g., GN2, Ar, etc.) is slowly passed through to return to atmospheric pressure. Generally speaking, after three vacuum pumpings, the protective photoresist in the area of ​​the coupling-in structure 1011 will be bubble-free, and if there are still bubbles, vacuum pumping can be performed again until there are no bubbles; Finally, the device is removed and baked horizontally in an oven or hotplate until the photoresist is hardened; The vacuum dish 110 is made of organic glass, and specifically includes a vacuum dish lid 1102, a vacuum dish base 1101, a sealing ring 11011, and a vacuum port 11012. The structure of the vacuum dish 110 is as shown in FIG.

[0097] In step S142, the coupling-in protection layer 109 and the remaining patterned imprint resist layer 105 are used as a second mask 107, and a second stage of etching is performed on the waveguide substrate 101 based on the second mask 107 to form a coupling-out structure 1012 in the second region.

[0098] When the coupling-in protective layer 109 is a photoresist layer 108, it is preferable that the thickness of the coupling-in protective layer 109 is greater than the thickness of the remaining patterned imprint resist layer 105, and the difference in thickness between the two is usually controlled to 1 to 2 um.

[0099] After step S142, the method further includes step S143 of removing the remaining coupling-in protective layer 109 to form a diffractive optical waveguide, and the structure of the device with the diffractive optical waveguide formed therein is as shown in FIG.

[0100] In yet another embodiment, when etching the coupling-out structure using the hard mask 107 as a mask, a coupling-in protection layer 109 can also be formed on the surface of the coupling-in structure 1011, and the specific steps are the same as S1411 to S1413.

[0101] Next, according to one embodiment of the present invention, there is further provided a diffractive optical waveguide manufactured by the method for manufacturing a diffractive optical waveguide according to any one of the above embodiments of the present invention.

[0102] Furthermore, according to one embodiment of the present invention, there is provided an AR device including the diffractive optical waveguide provided in the above embodiment of the present invention.

[0103] 2, 4 to 10 and 13, according to one embodiment of the present invention, there is provided an imprint template 104. Note that FIG. 2 only shows the structure of the imprint template 104 provided in one specific embodiment of the present invention, and the present application is not limited thereto. Any imprint template structure that falls within the scope of the present application and can achieve the purpose of the present application is within the scope of protection of the present application. As shown in FIG. 2, the imprint template 104 has: A substrate 1041, which is typically made of SiO2, Si, quartz glass, high refractive index glass, or the like, but is not limited thereto; A second template pattern structure 1042 and a first template pattern structure 1043 are formed on a substrate 1041, wherein the thickness of the substrate 1041 at the second template pattern structure 1042 is smaller than the thickness of the substrate 1041 at the first template pattern structure 1043, and in one specific embodiment, the application of the imprint template 104 is as shown in Figure 2, wherein the patterns of the second template pattern structure 1042 and the first template pattern structure 1043 are different.

[0104] Since the thickness of the substrate 1041 in the second template pattern structure 1042 is smaller than the thickness of the substrate 1041 in the first template pattern structure 1043, as can be seen from FIGS. 4 to 10 together, in the patterned imprint resist layer 103 formed by imprinting with the imprint template 104 provided in the present invention, the thickness of the imprint resist formed by imprinting on the second template pattern structure 1042 is greater than the thickness of the imprint resist formed by imprinting on the first template pattern structure 1043. As a result, when the coupling-in structure 1012 is etched on the waveguide substrate 101 using the patterned imprint resist layer 103 as a first mask, the imprint resist remaining on the coupling-out structure 1012 is patterned. While maintaining the pattern of the imprint resist layer 103, the coupling-out structure 1012 is then etched using the second mask 107, and the etching depth of the manufactured coupling-out structure 1012 is greater than the etching depth of the coupling-in structure 1011. As can be seen, the diffractive optical waveguide manufactured using the imprint template 104 provided in the present application can be used to etch the coupling-out structure 1012 and the coupling-in structure 1011, which have different shapes, thereby achieving a balance between the etching depths of the coupling-in structure 1011 and the coupling-out structure 1012 and solving the problem of the relative positional deviation between the coupling-in structure and the coupling-out structure manufactured using the imprint template 104 of the prior art, and improving the overall performance of the diffractive optical waveguide.

[0105] The technical solution provided by the present invention is to design an imprint template that includes a second template pattern structure and a first template pattern structure, with the substrate thickness of the second template pattern structure being smaller than that of the first template pattern structure. When the imprint template is used to manufacture a diffractive optical waveguide, the patterns of the second template pattern structure and the first template pattern structure can be simultaneously transferred to the diffractive optical waveguide, with the second template pattern structure and the first template pattern structure corresponding to a coupling-in structure and a coupling-out structure, respectively, thereby solving the problem of misalignment of the coupling-out structure and the coupling-in structure relative to each other. Furthermore, when transferring the patterns, the resist thicknesses of the coupling-in structure and the coupling-out structure are different, which increases the design freedom of the manufacturing method for forming the coupling-out structure and the coupling-in structure with different shapes without affecting each other, thereby improving the overall performance of the diffractive optical waveguide.

[0106] In one embodiment, the shape of the second template pattern structure 1042 and / or the first template pattern structure 1043 is a closed shape surrounded by curves and / or straight lines, where the shape refers to the shape of the area in which the second template pattern structure 1042 and / or the first template pattern structure 1043 is located.

[0107] In one embodiment, the imprint template 104 is used to fabricate a diffractive optical waveguide, and the pattern of the second template pattern features 1042 matches the pattern of the coupling-out features 1012 of the diffractive optical waveguide.

[0108] Implementably, the pattern of the second template pattern structure 1042 matching with the pattern of the diffractive optical waveguide coupling-out structure 1012 may mean that the pattern of the second template pattern structure 1042 is complementary to the pattern of the diffractive optical waveguide coupling-out structure 1012, or that the pattern of the second template pattern structure 1042 matches the pattern of the diffractive optical waveguide coupling-out structure 1012, i.e., the groove positions and widths of the second template pattern structure 1042 and the diffractive optical waveguide coupling-out structure 1012 match.

[0109] In one embodiment, the second template pattern structure 1042 is a laminar structure, which is a structure recessed relative to the surface of the substrate 1041. The coupling-out structure of the diffractive optical waveguide also has a laminar structure, and specifically, may be a structure raised relative to the surface of the diffractive optical waveguide, or a structure recessed relative to the surface of the diffractive optical waveguide.

[0110] In one embodiment, the pattern of the first template pattern structure 1043 matches the pattern of the diffractive optical waveguide coupling-in structure 1011. Operable, the pattern of the first template pattern structure 1043 is complementary to the pattern of the diffractive optical waveguide coupling-in structure 1011.

[0111] In one embodiment, the first template pattern structure 1043 is a blazed structure, the diffractive optical waveguide coupling-in structure 1011 is a blazed structure, and the two blazed structures are complementary.

[0112] In one embodiment, the second template pattern structure 1042 includes several recessed groove structures or several raised structures, and FIG. 2 shows the second template pattern structure 1042 as a recessed groove structure.

[0113] When the second template pattern structure 1042 includes several groove structures, in one embodiment, the width of the groove structures included in the second template pattern structure 1042 is designed to match the width of the grooves of the coupling-out structure 1012 of the diffractive optical waveguide.

[0114] Specifically, the method for manufacturing the imprint template 104 provided by the present invention includes the following steps: Step 1: forming an imprint template 104 using a micro-nano patterning process or dry etching technique; and step 2 of cleaning the imprint template 104.

[0115] Specifically, the method includes a first step of immersing the imprint template 104 in a cleaning solution, heating to 125°C, and immersion cleaning for 10 minutes, and a second step of formulating an NHOH:H2O2:H2O solution, heating to 70°C, and immersion cleaning for 10 minutes, thereby finally forming the imprint template 104. However, in one specific embodiment, the cleaning solution used to clean the imprint template 104 is an H2SO4:H2O2:H2O solution.

[0116] In one example, when the size of the groove structure included in the second template pattern structure 1042 is designed to match the size of the groove of the coupling-out structure 1012 of a predetermined diffractive optical waveguide, and the position of the groove is also designed to match, the pattern size of the patterned imprint resist layer 103 remaining after the first-stage etching matches the size of the groove structure of the second template pattern structure 1042, and when using an elution process to remove the patterned imprint resist layer 105 remaining on the surface of the coupling-out structure 1012 and the hard mask layer on its surface, the exposed substrate 1041 of the coupling-out structure 1012 can be The size of the groove of the coupling-out structure 1012 formed by etching on the waveguide substrate 101 using the second mask 107 of the hard mask layer is made to match the size and position of the groove structure included in the second template pattern structure 1042 on the imprint template 104, and is made to match the size of the groove of the specified coupling-out structure 1012. The size of the groove structure included in the second template pattern structure 1042 matching the size of the groove of the coupling-out structure 1012 of the diffractive optical waveguide means that the width of the groove structure matches the width of the groove of the coupling-out structure 1012.

[0117] In one example, the depths of the recessed groove structures included in the second template pattern structure 1042 are the same.

[0118] The imprint template 104 provided by the present invention can be used not only to manufacture diffractive optical waveguides with coupling-out structures 1012 having the same etching depth (as shown in FIG. 10), but also to manufacture diffractive optical waveguides with coupling-out structures 1012 having different etching depths (as shown in FIG. 13). Specifically, as described in the previous section of this application, starting from the diffractive optical waveguide coupling-out structures 1012 with the same etching depth, a local position of the deeper coupling-out structure 1012 is subsequently etched using a photoresist as a mask to form diffractive optical waveguide coupling-out structures 1013 with different etching depths.

[0119] As can be seen from this, the imprint template 104 provided in the present invention can not only be used to manufacture coupling-out structures 1012 and coupling-in structures 1011 with different shapes, but can also be used to manufacture coupling-out structures 1012 and 1013 with different etching depths, so the imprint template 104 provided in the present invention can be widely used and facilitates batch manufacturing of optical waveguide substrates 101.

[0120] Finally, it should be noted that the above-mentioned embodiments are only used to explain the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or equivalently replaced with part or all of the technical features therein, and these modifications or replacements will not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention. [Explanation of symbols]

[0121] 101-waveguide substrate 1011-coupling structure 1012, 1013 - Coupling-out structure 102-Imprint Resist 103-Patterned imprint resist layer 1031—First patterned imprint structure 1032—Second patterned imprint structure 104-Imprint Template 1041-Substrate 1042-Second template pattern structure 1043-First template pattern structure 105—Remaining patterned imprint resist layer 106 - First hard mask layer 107-Second Mask 108-Photoresist layer 109-Coupling-in protective layer 110-Vacuum dish 1101-Vacuum Dish Base 11011-Seal Ring 11012-Vacuum port 1102-Vacuum dish lid

Claims

1. providing a waveguide substrate; forming a patterned imprint resist layer on a surface of the waveguide substrate, the patterned imprint resist layer including a first patterned imprint structure formed in a first region of the surface and a second patterned imprint structure formed in a second region of the surface, the second patterned imprint structure having a thickness greater than a thickness of the first patterned imprint structure; performing a first stage of etching on the waveguide substrate using the patterned imprint resist layer as a first mask to form a coupling-in structure on the waveguide substrate in the first region, and maintaining a pattern of the second patterned imprint structure with the remaining patterned imprint resist layer on the waveguide substrate in the second region; forming a second mask using the remaining patterned imprint resist layer, and performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region; wherein the second mask covers the coupling-in structure to protect the coupling-in structure from being etched during the etching of the second step, the coupling-in structure and the coupling-out structure have different structural forms, and the depth of the coupling-out structure is greater than the depth of the coupling-in structure; 2. A method for manufacturing a diffractive optical waveguide, comprising:

2. The etching depth of the coupling-out structure is uniform, or the etching depth of different regions of the coupling-out structure is not uniform; 2. The method for manufacturing a diffractive optical waveguide according to claim 1.

3. The step of forming a coupling-out structure in the second region by forming a second mask using the remaining patterned imprint resist layer and performing a second stage of etching on the waveguide substrate based on the second mask includes: forming a first hard mask layer, the first hard mask layer being formed on the surface of the waveguide substrate and covering the coupling-in structure and the remaining patterned imprint resist layer; forming the second mask by removing the remaining patterned imprint resist layer and the first hard mask layer covering the remaining patterned imprint resist layer; performing a second stage of etching on the waveguide substrate using the second mask as a mask to form a coupling-out structure in the second region; 2. The method for manufacturing a diffractive optical waveguide according to claim 1.

4. The step of forming a coupling-out structure in the second region by performing a second stage of etching on the waveguide substrate using the second mask as a mask includes: performing a first etching of a second stage on the waveguide substrate using the second mask as a mask to form a coupling-out structure with a uniform etching depth; forming a photoresist layer N times, each time the photoresist layer is formed covering a portion of the coupling-out structure, where N is an integer greater than or equal to 1; every time a photoresist layer is formed, a part of the coupling-out structure that is not covered by the photoresist layer this time is etched using the photoresist layer formed this time and the remaining patterned imprint resist as a mask, and after the Nth etching, the coupling-out structure of N+1 different etching areas is formed; removing the photoresist layer and the second mask.

4. The method for manufacturing a diffractive optical waveguide according to claim 3.

5. The step of forming a coupling-out structure in the second region by forming a second mask using the remaining patterned imprint resist layer and performing a second stage of etching on the waveguide substrate based on the second mask includes: forming a coupling-in protection layer on the surface of the coupling-in structure; and using the coupling-in protection layer and the remaining patterned imprint resist layer as a second mask, performing a second stage of etching on the waveguide substrate based on the second mask to form a coupling-out structure in the second region.

2. The method for manufacturing a diffractive optical waveguide according to claim 1.

6. The step of forming a coupling-in protection layer on the surface of the coupling-in structure includes: Dropping a predetermined amount of photoresist onto the area where the coupling-in structure is located; uniformly flowing the photoresist under vacuum and negative pressure conditions to cover the surface of the coupling-in structure; and curing the photoresist to form a photoresist layer.

6. The method for manufacturing a diffractive optical waveguide according to claim 5.

7. the thickness of the coupling-in protection layer is greater than the thickness of the remaining patterned imprint resist layer; 6. The method for manufacturing a diffractive optical waveguide according to claim 5.

8. The step of forming a patterned imprint resist layer on the surface of the waveguide substrate specifically includes: providing an imprint template, the imprint template being provided with first template pattern structures corresponding to the coupling-in structures and second template pattern structures corresponding to the coupling-out structures; applying an imprint resist to the waveguide substrate; imprinting the imprint template into the imprint resist layer to form the patterned imprint resist layer, wherein a pattern in the patterned imprint resist layer corresponds to patterns of the first template pattern structure and the second template pattern structure; separating the imprint template and the patterned imprint resist layer; 2. The method for manufacturing a diffractive optical waveguide according to claim 1.

9. The step of imprinting the imprint template into the imprint resist layer to form the patterned imprint resist layer specifically includes: imprinting the imprint template into the imprint resist layer; and curing the imprint resist layer to form the patterned imprint resist layer.

9. The method for manufacturing a diffractive optical waveguide according to claim 8.

10. a thickness of the imprint resist layer that matches a maximum depth of patterns in the first template pattern structure and the second template pattern structure; 9. The method for manufacturing a diffractive optical waveguide according to claim 8.

11. Manufactured by the manufacturing method of a diffractive optical waveguide according to claim 1. A diffractive optical waveguide characterized by:

12. 1. An imprint template comprising: A substrate; a first template pattern structure and a second template pattern structure formed on the substrate, wherein a thickness of the substrate at the second template pattern structure is smaller than a thickness of the substrate at the first template pattern structure; the imprint template is used to manufacture a diffractive optical waveguide, and a pattern of the second template pattern structure matches a pattern of a coupling-out structure of the diffractive optical waveguide, and a pattern of the first template pattern structure matches a pattern of a coupling-in structure of the diffractive optical waveguide; 1. An imprint template comprising:

13. The second template pattern structure includes several recessed groove structures or several raised structures; The imprint template of claim 12 .

14. the depths of the groove structures included in the second template pattern structure are the same; An imprint template according to claim 13.

15. the second template pattern structure is a laminar structure; An imprint template according to claim 13.

16. a position of a groove structure included in the second template pattern structure coincides with a position of a groove of a coupling-out structure of the diffractive optical waveguide, and a width of the groove structure included in the second template pattern structure coincides with a width of the groove of the coupling-out structure of the diffractive optical waveguide; An imprint template according to claim 13.

17. the first template pattern structure is a blazed structure; The imprint template of claim 12 .

18. The material of the imprint template is SiO ２ , Si, quartz glass or high refractive index glass; The imprint template of claim 12 .

19. a shape of the second template pattern structure and / or the first template pattern structure is a closed shape surrounded by curves and / or straight lines; The imprint template of claim 12 .

20. a pattern of the first template pattern structure is complementary to a pattern of a coupling-in structure of the diffractive optical waveguide; The imprint template of claim 12 .

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