Preparation method of optical chip with graphene as substrate and optical chip

Abstract

The invention provides a preparation method of an optical chip with graphene as a substrate and the optical chip, and the preparation method comprises the steps: selecting a semiconductor substrate, and preparing a graphene film through a water phase method; combining the prepared graphene film with a transfer medium to transfer the graphene film to a semiconductor substrate, and removing the transfer medium to obtain a graphene substrate layer; performing microstructure treatment on the obtained graphene substrate layer, and growing a semiconductor layer; and removing the traditional semiconductor substrate by chemical corrosion to obtain the prepared optical chip. According to the invention, the problem of insufficient chip heat dissipation capability and performance of the traditional substrate growth optical chip technology can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and particularly to a method for preparing an optical chip with graphene as a substrate and the optical chip. Background Art

[0002] At present, the development speed in the field of optoelectronic devices has been gradually increasing. The selection of substrates has become diversified, and the growth technology has gradually matured. The technology for growing optical chips on substrates has also been improved.

[0003] However, the current technology for growing optical chips using traditional substrates in the market has deficiencies in the heat dissipation ability and performance of the chips, posing potential risks. The thermal conductivity of the traditional material GaAs is approximately 46 - 50 W / mk, and the maximum can only reach 55 W / mk, with poor heat dissipation. While the thermal conductivity of graphene is usually 3000 - 5000 W / mk, and the maximum can reach 5300 W / mk, having good thermal conductivity. Moreover, graphene is a two-dimensional material composed of a single layer of carbon atoms and has extremely excellent electrical conductivity. Growing an optical chip with graphene as a substrate greatly improves the heat dissipation and working performance.

[0004] Therefore, it is necessary to design an optical chip with graphene as a substrate to solve the above problems. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing an optical chip with graphene as a substrate and the optical chip, so as to solve the problems of insufficient heat dissipation ability and performance of the chips in the traditional substrate-based optical chip growth technology.

[0006] To achieve the above purpose, the present invention provides the following solutions: A method for preparing an optical chip with graphene as a substrate, comprising: Selecting a semiconductor substrate and preparing a graphene film by the aqueous phase method; Combining the prepared graphene thin film with a transfer medium to transfer it onto the semiconductor substrate, and removing the transfer medium to obtain a graphene substrate layer; Performing microstructure treatment on the obtained graphene substrate layer and growing a semiconductor layer; Removing the traditional semiconductor substrate by chemical etching to obtain the prepared optical chip.

[0007] Preferably, the semiconductor substrate is any one of silicon, silicon nitride, gallium arsenide, gallium nitride, indium phosphide, indium selenide, and zinc selenide. To provide the matching of bandgap and crystal orientation.

[0008] Preferably, the transfer medium is methyl methacrylate.

[0009] Preferably, it further comprises: Perform solvent cleaning on the semiconductor substrate; use any one of acetone, isopropyl alcohol, methanol, chloroform, and dimethyl carbonate as the solvent to remove any residual organic matter; Clean the semiconductor substrate using an acidic or alkaline solution; use any one of a mixture of hydrofluoric acid and hydrogen peroxide, hydrochloric acid, and hydrofluoric acid as the solution to remove oxides.

[0010] Preferably, prepare the graphene film by the aqueous phase method, including: Add a surfactant to the graphene solution and ultrasonically treat the resulting graphene suspension; the surfactant includes sodium dodecyl sulfate and polyvinylpyrrolidone; Prepare a water tank, pour the graphene suspension solution into the water tank, and control the quality and uniformity of the film by adjusting the adding speed and method of the solution; When the film reaches the preset thickness, use a hot air oven or other drying equipment to remove moisture, or let the film dry naturally in the air to obtain the prepared graphene film.

[0011] Optionally, grow a graphene buffer layer on a traditional semiconductor substrate, including: precisely controlling the temperature, gas flow rate, and pressure in the reaction chamber, controlling the growth time to control the thickness of the graphene layer, and growing the graphene layer on the (111) crystal orientation in the lattice structure of the traditional semiconductor substrate.

[0012] Optionally, select appropriate natural graphite as the raw material, such as natural graphite powder or graphite flakes. Perform an oxidation reaction, usually using methods such as sulfuric acid oxidation or nitric acid oxidation. After forming graphene oxide, perform cleaning and dispersion.

[0013] Optionally, prepare the graphene film by the aqueous phase method, including: reacting graphene oxide with a reducing agent under appropriate conditions, such as in an alkaline or neutral environment, and performing the reaction by means of heating or stirring. During this process, graphene oxide gradually loses oxygen atoms and is reduced to a graphene structure. The obtained reduced graphene needs to be cleaned and dispersed to remove residual reducing agents and other impurities.

[0014] Optionally, prepare the graphene film by the aqueous phase method, including: improving the stability and dispersion of graphene in the solution, adding surfactants such as sodium dodecyl sulfate and polyvinylpyrrolidone. Ultrasonically treat the resulting graphene suspension to make its dispersion more uniform.

[0015] Optionally, the preparation of the graphene film by the aqueous phase method includes: preparing a water tank, pouring the graphene suspension solution into the water tank, controlling the quality and uniformity of the film by adjusting the adding speed and method of the solution, and once the film reaches the required thickness, gently remove the moisture with a hot air oven or other drying equipment, or let it dry naturally in the air.

[0016] Preferably, the prepared graphene film is combined with a transfer medium to be transferred onto a semiconductor substrate, and the transfer medium is removed to obtain a graphene substrate layer, including: Transfer the prepared graphene film onto a copper sheet, then spin-coat a transfer medium on the graphene film and cure the transfer medium. Remove the copper by immersing the whole composed of the graphene film and the transfer medium into a ferrous chloride solution to obtain a combination of the transfer medium and the graphene film; Transfer the prepared combination onto a semiconductor substrate, and ensure that the graphene film is in uniform contact with the substrate and has no bubbles; gently flatten the graphene film to ensure its flatness and adhesion on the substrate.

[0017] Immerse the transferred semiconductor substrate into acetone or other appropriate solvents to remove the transfer medium layer, and obtain a graphene substrate layer.

[0018] Optionally, after the prepared graphene film is transferred onto a copper sheet, spin-coat PMMA on the graphene film and cure it. PMMA can be coated using a spin coater to ensure the uniformity of the coating. The coating thickness is usually in the range of several hundred nanometers. The PMMA coating needs to be cured in an oven, usually at a curing temperature of 80 °C for about 30 minutes to 1 hour. Then, remove the copper by immersing the whole into a ferrous chloride solution to obtain a combination of PMMA and the graphene film.

[0019] Optionally, microstructural processing is performed on the obtained graphene substrate layer, including: performing microstructural processing on the obtained graphene substrate layer by photolithography.

[0020] Optionally, a semiconductor layer is grown on the obtained graphene substrate layer, including: placing the obtained graphene substrate layer into a MOCVD reaction chamber, depositing semiconductor materials on the surface of the graphene substrate by thermal decomposition of metal organic compounds, and controlling the reaction conditions to ensure the uniformity and quality of the semiconductor layer.

[0021] Preferably, the traditional semiconductor substrate is removed by chemical etching to obtain a prepared optical chip, including: Use a chemical etchant to dissolve the semiconductor substrate to obtain a prepared optical chip.

[0022] Preferably, the chemical etchant is one of a mixture of hydrochloric acid and nitric acid, hydrochloric acid - hydrogen peroxide etching solution, citric acid hydrogen peroxide, hydrofluoric acid, sodium hydroxide, a mixed solution of ammonium hydroxide and hydrogen peroxide.

[0023] Optionally, a suitable chemical etchant can be used to dissolve the semiconductor substrate. The etchant is one of a mixture of hydrochloric acid and nitric acid, hydrochloric acid - hydrogen peroxide etchant, citric acid hydrogen peroxide, hydrofluoric acid, sodium hydroxide, and a mixed solution of ammonium hydroxide and hydrogen peroxide. The semiconductor substrate is removed under appropriate conditions to maintain the integrity of the graphene. A small-scale test is conducted before the experiment to ensure the minimum impact on the graphene.

[0024] The present invention also provides an optical chip prepared based on the above method.

[0025] According to the specific embodiments provided by the present invention, the following technical effects are disclosed: The present invention provides a method for preparing an optical chip with graphene as a substrate and the optical chip. The thermal conductivity of graphene is usually 3000 - 5000 W / mk, and can reach up to 5300 W / mk, which has good thermal conductivity compared with traditional materials. Moreover, it is a two-dimensional material composed of a single layer of carbon atoms and has extremely excellent electrical conductivity. When growing graphene on a semiconductor substrate, the (111) crystal orientation in its lattice structure is selected to grow graphene, with a highly matched structure, which promotes the growth of high-quality graphene, has excellent electrical properties, and reduces the formation of defects and distortions. The graphene layer is connected to the semiconductor layer, increasing the heat conduction, improving the heat dissipation function, forming a heterojunction, enhancing the optical amplification effect, and enhancing the optoelectronic characteristics. By lithography patterning on the graphene, the loss is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a flowchart of the method provided by the embodiment of the present invention; Figure 2 It is a traditional semiconductor substrate provided by the embodiment of the present invention; Figure 3 It is graphene coated with PMMA (polymethyl methacrylate) provided by the embodiment of the present invention; Figure 4 It is a graphene layer transferred to a traditional semiconductor substrate provided by the embodiment of the present invention; Figure 5 It is graphene and a traditional semiconductor substrate after removing PMMA provided by the embodiment of the present invention; Figure 6 It is the structure after forming a semiconductor layer provided by the embodiment of the present invention; Figure 7 The structure after etching the semiconductor substrate provided by the embodiment of the present invention.

[0028] Explanation of reference numerals: (1) Semiconductor substrate, (2) PMMA, (3) Graphene, (4) Semiconductor layer. Specific implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] The object of the present invention is to provide a method for preparing an optical chip with graphene as a substrate and the optical chip, which increases the heat conduction, improves the heat dissipation function, forms a heterojunction, improves the optical amplification effect, and enhances the optoelectronic characteristics. By lithography patterning on graphene, the loss is reduced.

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0032] Figure 1 The method flow chart provided by the embodiment of the present invention is as Figure 1 shown. The present invention provides a method for preparing an optical chip with graphene as a substrate, including: Step 100: Select a semiconductor substrate and prepare a graphene film by the aqueous phase method; Step 200: Combine the prepared graphene thin film with a transfer medium to transfer it onto the semiconductor substrate, and remove the transfer medium to obtain a graphene substrate layer; Step 300: Perform microstructure processing on the obtained graphene substrate layer and grow a semiconductor layer; Step 400: Use chemical etching to remove the traditional semiconductor substrate to obtain the prepared optical chip.

[0033] Refer to Figures 2-7 , an optical chip with graphene as a substrate in this embodiment, the structure of which includes: a graphene substrate layer (2), a semiconductor layer (3). The preparation method thereof includes the following steps: S1: Select a suitable material for the traditional semiconductor substrate (1) and prepare a graphene film (3) by the aqueous phase method; Specifically: Select a 20-μm GaAs substrate and ensure that its surface flatness and purity are high enough to provide a good growth platform. Chemically clean the substrate using acetone solvent to remove any residual organic matter; Select natural graphite powder as the raw material, perform an oxidation reaction with sulfuric acid, form graphene oxide, then clean and disperse it. React graphene oxide with a reducing agent under neutral conditions and carry out the reaction by heating means. Clean and disperse the obtained reduced graphene to remove residual reducing agent and other impurities. Add a surfactant to the obtained graphene solution and then perform ultrasonic treatment to improve the stability and dispersibility of the suspension. Select a large enough water tank to accommodate the required amount of solution, ensure that there are no contaminants in the water tank, add deionized water to ensure the purity of the water, carefully pour the graphene suspension solution into the water tank, and control the quality and uniformity of the film by adjusting the addition speed and method of the solution. Control the thickness of the graphene layer to be 20 μm. Once the film reaches the required thickness, let it dry naturally in the air to remove moisture.

[0034] S2: Combine the prepared graphene film (3) with PMMA (polymethyl methacrylate) (2), transfer it onto a traditional semiconductor substrate (1), and remove the transfer medium PMMA (2); Specifically: Uniformly coat a layer of PMMA (polymethyl methacrylate) on the prepared graphene film using copper as the medium. A spin coater can be used for coating to ensure the uniformity of the coating; Gently flatten the graphene film to ensure its flatness and adhesion on the substrate. Immerse the transferred substrate in acetone or other appropriate solvents to remove the PMMA layer. After removing the PMMA, the graphene film will be retained on the substrate.

[0035] S3: Perform microstructural processing on the obtained graphene substrate layer (3) and grow a semiconductor layer (4); Specifically: First, perform microstructural processing on the obtained graphene substrate layer (3) by photolithography, then place the obtained graphene substrate layer (3) into a MOCVD reaction chamber, introduce the inert gas nitrogen (N 2 ), control the reaction chamber temperature at 700 °C, control the gas flow rate of trimethylgallium (TMGa) at 50 μmol / min and the gas flow rate of arsine (AsH 3 ) at 50 μmol / min to adjust the growth rate and film quality, ensure the uniform growth of GaAs material on the surface of the graphene substrate (3), and ensure the uniformity and quality of the GaAs layer S4: Use chemical etching to remove the traditional semiconductor substrate (1).

[0036] Specifically: Use a mixed solution of hydrochloric acid and hydrogen peroxide, with a mixing ratio of 3:1 (volume ratio). Prepare the mixed solution in a fume hood. First pour in HCl, and then slowly add H 2 O 2 , avoiding violent reactions. Immerse the GaAs substrate completely in the etching solution. Once the required etching depth is reached, remove the material from the etching solution. Then use a large amount of deionized water to thoroughly wash it to remove the residual etching solution and etching products.

[0037] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same and similar parts among the embodiments, reference can be made to each other.

[0038] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for preparing an optical chip with graphene as a substrate, characterized in that: include: Selecting a semiconductor substrate and preparing a graphene film by an aqueous phase method; combining the prepared graphene film with a transfer medium to transfer it to a semiconductor substrate, and removing the transfer medium to obtain a graphene substrate layer; Performing microstructural processing on the obtained graphene substrate layer and growing a semiconductor layer; The traditional semiconductor substrate is removed by chemical etching to obtain the prepared optical chip.

2. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: The semiconductor substrate is any one of silicon, silicon nitride, gallium arsenide, gallium nitride, indium phosphide, indium selenide, and zinc selenide.

3. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: The transfer medium is methyl methacrylate.

4. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: Also includes: performing solvent cleaning on the semiconductor substrate; The solvent used was any one of acetone, isopropanol, methanol, chloroform, and dimethyl carbonate to remove any residual organic matter; The semiconductor substrate is cleaned using an acid or alkaline solution; the solution uses any one of a mixture of hydrofluoric acid and hydrogen peroxide, hydrochloric acid, and hydrofluoric acid to remove oxides.

5. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: The graphene film is prepared by an aqueous phase method, comprising: Adding a surfactant to the graphene solution and subjecting the obtained graphene suspension to ultrasonic treatment; the surfactant comprises sodium dodecyl sulfate and polyvinyl pyrrolidone; Prepare a water tank, pour the graphene suspension solution into the water tank, and control the quality and uniformity of the film by adjusting the speed and method of adding the solution; When the film reaches a preset thickness, a hot air oven or other drying equipment is used to remove moisture, or the film is allowed to dry naturally in the air to obtain a prepared graphene film.

6. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: The prepared graphene film is combined with a transfer medium to transfer to a semiconductor substrate, and the transfer medium is removed to obtain a graphene substrate layer, including: The prepared graphene film is transferred onto a copper sheet, a transfer medium is spin-coated onto the graphene film and the transfer medium is solidified, and the copper is removed by placing the whole composed of the graphene film and the transfer medium into a ferrous chloride solution to obtain a combination of the transfer medium and the graphene film; Transferring the prepared composite onto a semiconductor substrate and ensuring that the graphene film is in uniform contact with the substrate and that there are no bubbles; The transferred semiconductor substrate is immersed in an acetone solvent to remove the transfer medium layer and obtain a graphene substrate layer.

7. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: Performing microstructural processing on the obtained graphene substrate layer and growing a semiconductor layer, including: The obtained graphene substrate layer is subjected to microstructural processing by photolithography; The obtained graphene substrate layer is placed in an MOCVD reaction chamber, and the semiconductor material is deposited on the surface of the graphene substrate by thermally decomposing metal organic compounds, and the reaction conditions are controlled to ensure the uniformity and quality of the semiconductor layer.

8. The method for preparing an optical chip with graphene as a substrate according to claim 1, characterized in that: The conventional semiconductor substrate is removed by chemical etching to obtain a prepared optical chip, including: A chemical etchant is used to dissolve the semiconductor substrate to obtain a prepared optical chip.

9. The method for preparing an optical chip with graphene as a substrate according to claim 8, characterized in that: The chemical corrosive agent is one of a mixture of hydrochloric acid and nitric acid, a hydrochloric acid-hydrogen peroxide corrosive solution, a citric acid hydrogen peroxide solution, hydrofluoric acid, sodium hydroxide, ammonium hydroxide and a hydrogen peroxide mixed solution.

10. An optical chip, characterized in that: It is prepared based on the method according to any one of claims 1 to 9.

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