CN-122018072-A - Processing technology of optical waveguide structure and preparation method of optical waveguide sheet

CN122018072ACN 122018072 ACN122018072 ACN 122018072ACN-122018072-A

Abstract

The application relates to a processing technology of an optical waveguide structure and a preparation method of an optical waveguide sheet, wherein the processing technology of the optical waveguide structure comprises the steps of treating a substrate, and cleaning and preprocessing the substrate layer; depositing a transition layer, wherein the transition layer is deposited on the surface of the pretreated substrate layer and comprises at least one first bonding element bonded with the substrate layer and at least one second bonding element bonded with the optical waveguide layer; and depositing an optical waveguide layer on one side of the transition layer away from the substrate layer, so that the refractive index of the optical waveguide layer is larger than that of the transition layer. The optical waveguide sheet is formed by overlapping three layers, so that the technical effect of reducing the processing difficulty of the optical waveguide sheet is achieved.

Inventors

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Assignees

浙江求是半导体设备有限公司

Dates

Publication Date: 20260512
Application Date: 20260414
Priority Date: 20260209

Claims (10)

1. A process for fabricating an optical waveguide structure, comprising: a substrate treatment for performing a cleaning pretreatment on the substrate layer (110); Depositing a transition layer (120), and depositing the transition layer (120) on the surface of the pretreated substrate layer (110), wherein the transition layer (120) comprises at least one first bonding element forming a bond with the substrate layer (110) and at least one second bonding element forming a bond with the optical waveguide layer (130); An optical waveguide layer (130) is deposited, the optical waveguide layer (130) being deposited on a side of the transition layer (120) remote from the substrate layer (110) such that the refractive index of the optical waveguide layer (130) is greater than the refractive index of the transition layer (120).
2. The process for fabricating an optical waveguide structure according to claim 1, wherein the depositing of the transition layer (120) further comprises: The content of the first bonding element is gradually reduced and the content of the second bonding element is gradually increased in a first direction, wherein the first direction is from the substrate layer (110) to the optical waveguide layer (130).
3. The process for fabricating an optical waveguide structure according to claim 2, wherein the optical waveguide layer (130) deposition further comprises: The optical waveguide layer (130) is silicon carbide, and the silicon carbide is deposited by a low-pressure chemical vapor deposition method or a plasma enhanced chemical vapor deposition method, so that the deposition thickness of the silicon carbide is 400-600 nm.
4. A process for fabricating an optical waveguide structure according to claim 3, wherein, The basal layer (110) is a sapphire single crystal, and the transition layer (120) is XN, wherein X is Al or Ga; The transition layer (120) is deposited by adopting a metal organic chemical vapor deposition method, the X content is gradually reduced along a first direction by adjusting the flow of an X source and an N source, and the N content is gradually increased along the first direction until the atomic ratio of the X to the N is 1:1, wherein the first direction is the direction from a substrate layer (110) to an optical waveguide layer (130).
5. The process for manufacturing an optical waveguide structure according to claim 4, wherein, Introducing hydrogen and trimethylaluminum into an MOCVD reaction chamber at the temperature of 40-60 mbar and 800-850 ℃ on a pretreated substrate to pre-spread an Al layer; introducing hydrogen, ammonia and trimethylaluminum at the temperature of 60-65 mbar and 1005-1255 ℃ to grow an aluminum nitride layer; When the aluminum nitride layer grows, the gradient of the content of the Al element is reduced by regulating and controlling the temperature of the reaction chamber, the flow rate of trimethyl aluminum and the proportion of the air inlet, and the gradient of the content of the N element is increased by regulating and controlling the flow rate of ammonia and the proportion of the air inlet, so that the atomic ratio of Al to N at one side of the aluminum nitride transition layer (120) close to the optical waveguide layer (130) reaches 1:1.
6. The process of claim 5, further comprising epitaxially growing a silicon carbide optical waveguide layer (130) on a surface of the aluminum nitride transition layer (120) after depositing the aluminum nitride transition layer (120), comprising: introducing hydrogen into the reaction cavity as carrier gas, and carrying out in-situ etching on the surface of the aluminum nitride transition layer (120) at the constant temperature of 1500-1700 ℃ under the pressure of 60-150 mbar for 10-30 min; the method comprises the steps of keeping the pressure and the temperature of a reaction cavity unchanged, introducing a Si source, a C source and an optional doping source, controlling the carbon-silicon ratio to be 0.6-1.2, and growing a silicon carbide layer with the thickness of 400-600 nm, wherein the doping source enters the reaction cavity after being diluted by at least one-stage dilution pipeline, and controlling the doping concentration by regulating and controlling the flow of the dilution gas of the doping source; Closing an air source, gradually cooling the reaction cavity to 600-1000 ℃, boosting the temperature to 900-1100 mbar, introducing inert gas, purging, and cooling and taking out.
7. A process for fabricating an optical waveguide structure according to claim 3, wherein, The substrate layer (110) is a sapphire single crystal, and the transition layer (120) is Al i Ga (1-i) N, wherein i is E (0, 1); The depositing of the transition layer (120) further comprises depositing the transition layer (120) by adopting a metal organic chemical vapor deposition method, and gradually reducing the i value along the first direction by adjusting the flow rates of an Al source, a Ga source and an N source.
8. A process for fabricating an optical waveguide structure according to claim 1 or 2, wherein, The substrate layer (110) is a quartz monocrystal, the optical waveguide layer (130) is silicon carbide, the transition layer (120) is made of Si 3 N 4 or an AlN-SiO x N y composite layer, wherein in the first direction of the transition layer (120), the content of Si element in the Si 3 N 4 layer is gradually increased, the content of N element is gradually reduced to an atomic ratio of 3:4, the AlN duty ratio in the AlN-SiO x N y composite layer is gradually increased, the SiO x N y duty ratio is gradually reduced, the Al content of AlN is gradually reduced, the N content is gradually increased to an atomic ratio of 1:1, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); or the substrate layer (110) is magnesium oxide single crystal, the optical waveguide layer (130) is silicon carbide, the material of the transition layer (120) is MgAl 2 O 4 or MgAl 2 O 4 -AlN composite layer, wherein in the first direction of the transition layer (120), the MgAl 2 O 4 ratio in the MgAl 2 O 4 -AlN composite layer is gradually reduced, the AlN ratio is gradually increased, the Al content of AlN is gradually reduced, the N content is gradually increased until the atomic ratio of Al to N is 1:1, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); Or the substrate layer (110) is high alumina silicon optical glass, the optical waveguide layer (130) is silicon carbide, the material of the transition layer (120) is amorphous AlO x N y or SiO x N y; , wherein in the first direction of the transition layer (120), the oxygen ratio of Al in the AlO x N y layer is gradually reduced, the nitrogen ratio is gradually increased, the oxygen ratio of Si in the SiO x N y layer is gradually reduced, and the nitrogen ratio is gradually increased, wherein the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); Or the substrate layer (110) is borosilicate glass, the optical waveguide layer (130) is silicon carbide, the material of the transition layer (120) is an amorphous SiO 2 -TiO 2 composite layer or SiO x N y , wherein in the first direction of the transition layer (120), the ratio of TiO 2 in the SiO 2 -TiO 2 composite layer gradually increases, the ratio of SiO 2 gradually decreases, the ratio of Si in the SiO x N y layer gradually decreases and the ratio of N gradually increases, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); Or the substrate layer (110) is sapphire, the optical waveguide layer (130) is GaN, and the material of the transition layer (120) is Al i Ga (1-i) N, wherein in the first direction of the transition layer (120), the i value gradually decreases, and the atomic ratio of Al/Ga to N gradually transits to 1:1, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); or the substrate layer (110) is quartz glass, the optical waveguide layer (130) is TiO 2 , the material of the transition layer (120) is Si 3 N 4 or TiO x N y , wherein in the first direction of the transition layer (120), the atomic ratio of Si element to N element in the Si 3 N 4 layer is gradually reduced until reaching 3:4, the oxygen ratio of Ti in the TiO x N y layer is gradually reduced, the nitrogen ratio is gradually increased until reaching 1:2 of the atomic ratio of Ti to O, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130); Or the substrate layer (110) is soda lime glass or high alumina silica optical glass, the optical waveguide layer (130) is ZnO, the material of the transition layer (120) is ZnO x AlN or AlO x N y , the Zn proportion in the ZnO x AlN layer is gradually increased, the Al proportion is gradually decreased, the Al proportion in the AlO x N y layer is gradually decreased, the nitrogen proportion is gradually increased, and the first direction is the direction from the substrate layer (110) to the optical waveguide layer (130).
9. A method for producing an optical waveguide sheet, characterized in that a coupling element (140) is produced on the surface of the optical waveguide layer (130) of the optical waveguide structure according to any one of claims 1 to 8, the producing of the coupling element (140) comprising: photoetching, namely coating photoresist on the surface of the optical waveguide layer (130), and manufacturing a photoresist mask through an electron beam photoetching process; And etching the optical waveguide layer (130) by using the photoresist mask as a mask and adopting a dry etching process to form a coupling-in unit (141) and a coupling-out unit (142), wherein the coupling-in unit (141) is used for coupling virtual imaging light into the optical waveguide layer (130) so that the virtual imaging light meets the total reflection condition and is conducted in the optical waveguide layer (130), and the coupling-out unit (142) is used for coupling and emitting the virtual imaging light in the optical waveguide layer (130) at one side of the optical waveguide layer (130) far away from the transition layer (120).
10. The method of manufacturing an optical waveguide sheet according to claim 9, further comprising: manufacturing a plurality of groups of photoresist masks; And etching to form a plurality of groups of coupling elements (140) in the direction perpendicular to the thickness direction of the waveguide sheet, wherein in each group of coupling elements (140), the coupling-in units (141) and the coupling-out units (142) are matched in a one-to-one correspondence manner, so that an eye box array (210) is formed on one side of the optical waveguide layer (130) away from the transition layer (120), and the eye box array (210) is arranged in the direction perpendicular to the thickness direction of the waveguide sheet.

Description

Processing technology of optical waveguide structure and preparation method of optical waveguide sheet Technical Field The application relates to the technical field of optical elements, in particular to a processing technology of an optical waveguide structure and a preparation method of an optical waveguide sheet. Background Augmented Reality (AR) glasses are used as new-generation intelligent wearing equipment, the core function realization of the AR glasses depends on a waveguide sheet, the waveguide sheet is a key optical component in the AR glasses, the key optical component is responsible for conducting virtual imaging light and superposing real natural light, the view angle, imaging definition and wearing comfort of the AR glasses are directly determined, and the AR glasses are core carriers for realizing 'virtual-real fusion' visual effects and are widely applied to multiple fields of consumer electronics, industrial assistance, medical mapping and the like. In the prior art, silicon carbide (SiC) is mostly used as a core substrate material for the AR glasses waveguide sheet, and the reason is that the silicon carbide has excellent optical and mechanical characteristics such as high refractive index, high thermal stability and high hardness, and can meet the core requirements of the waveguide sheet on efficient transmission of virtual light and dispersion inhibition, however, the thickness of the silicon carbide waveguide sheet is generally about 650 mu m, the silicon carbide waveguide sheet with the thickness has obvious processing problems, the silicon carbide is extremely brittle and low in fracture toughness, and defects such as edge breakage, cracking and breakage easily occur in the processing processes such as ultra-precise polishing, cutting and edge chamfering, and meanwhile, the thick silicon carbide substrate needs to be processed by a semiconductor-grade ultra-precise processing technology, so that the processing difficulty is high, the period is long, the yield of the waveguide sheet in mass production is low, and the production cost is high, and the large-scale mass production and popularization and application of the AR glasses are seriously restricted. Therefore, the technical problem of the prior art is that the processing difficulty of the optical waveguide sheet is high. Disclosure of Invention The application provides a processing technology of an optical waveguide structure and a preparation method of an optical waveguide sheet, wherein the optical waveguide sheet is formed by superposing three layers of structures, so that the technical effect of reducing the processing difficulty of the optical waveguide sheet is achieved. In a first aspect, the present application provides an optical waveguide structure, which adopts the following technical scheme: An optical waveguide structure comprising: The base layer is made of a light-transmitting material; a transition layer, the transition layer being disposed on the base layer; An optical waveguide layer, the optical waveguide layer being disposed on the transition layer; The light-transmitting optical fiber comprises a substrate layer, a transition layer, an optical waveguide layer, a light-transmitting layer and a light-transmitting layer, wherein the substrate layer, the transition layer and the optical waveguide layer are made of light-transmitting materials, the substrate layer is connected with the optical waveguide layer through the transition layer, the refractive index of the optical waveguide layer is larger than that of the transition layer, and the transition layer comprises at least one first bonding element bonded with the substrate layer and at least one second bonding element bonded with the optical waveguide layer. Preferably, in the transition layer, the content of the first bonding element gradually decreases in a first direction, and the content of the second bonding element gradually increases in a first direction, wherein the first direction is a direction from the base layer to the optical waveguide layer. Preferably, the optical waveguide layer is silicon carbide. Preferably, the thickness of the optical waveguide layer is 400-600 nm. Preferably, the base layer is sapphire, and the material of the transition layer is XN, where X is Al or Ga. Preferably, in the transition layer, the X content gradually decreases along a first direction, and the N content gradually increases along the first direction until the atomic ratio of X to N is 1:1, where the first direction is a direction from the substrate layer to the optical waveguide layer. Preferably, the substrate layer is sapphire, and the material of the transition layer is Al iGa(1-i) N, where i is (0, 1). Preferably, in the transition layer, the i gradually decreases along a first direction, wherein the first direction is a direction from the base layer to the optical waveguide layer. Preferably, the substrate layer is a quartz single crystal, the optical wav