High-quality directional remote epitaxy method and stripping transfer method of indium phosphide single crystal film

Abstract

The invention relates to the technical field of semiconductors, and provides a high-quality directional remote epitaxy method and a stripping transfer method of an indium phosphide single crystal film. The surface of an indium phosphide single-crystal substrate is covered with a single-layer graphene film, and then the indium phosphide single-crystal film is prepared by adopting a two-stage vapor phase epitaxy method. And then the indium phosphide single crystal film is stripped and transferred to the surface of the silicon substrate. A two-stage vapor phase epitaxy method is adopted, so that graphene can be protected from being damaged, and the crystal quality of an epitaxial film is improved; by utilizing the thin-layer characteristic and the electric penetrability of the single-layer graphene, the indium phosphide single-crystal thin film with the oriented crystal face can be prepared by replacing substrates with different crystal faces; meanwhile, the graphene / epitaxial layer interface is Van der Waals force, stripping can be achieved through mechanical force, and then transfer of the indium phosphide single crystal thin film is achieved. In conclusion, stripping transfer and silicon-based heterogeneous integration of the indium phosphide single crystal thin film, the heterojunction thin film and even the device in specific orientation can be achieved, and the application prospect is wide.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a high-quality directional remote epitaxy method and a peeling transfer method for an indium phosphide single crystal film. Background Art

[0002] Indium phosphide (InP) is a typical representative of III-V semiconductors. InP materials and devices have high electron mobility, low noise, and high gain, and are key materials for semiconductor lasers and receivers. InP single crystals match the ternary direct bandgap alloy InGaAs lattice. By adjusting the In component, the light response wavelength can be continuously changed from 0.87μm to 3.5μm to suit the wavelength required for optical fiber communication, which is the basis of optical communication. InGaAsP / InP double heterojunction lasers can perfectly meet the requirements of the on-chip optical communication wavelength range of 1.3 to 1.6μm. InGaAs / InP photodetectors have low dark current and high quantum efficiency, and are widely used in high-efficiency photoelectric conversion in the 1 to 3μm short-wave infrared optical fiber communication band.

[0003] It should be noted that InGaAs and InGaAsP alloy films can only achieve high-quality matching epitaxial growth on single-crystal InP substrates, and currently large-size InP single-crystal substrates have great problems in technology and production costs, resulting in the high prices of commercial InP-based optoelectronic devices. The integration of optoelectronic devices manufactured by InP semiconductors and Si-based platforms can effectively reduce costs while enhancing the integration capabilities of Si-based optoelectronic technology, which has significant cost advantages and bright development prospects.

[0004] The silicon-based heterogeneous integration scheme of InP is to directly package and integrate InP functional devices with Si-based CMOS platforms. The current mature wafer-level InP-Si heterogeneous integration scheme is to directly bond InP bare wafers to Si substrates, and then thin and polish the surface of the InP wafer to obtain an InP-Si composite substrate. Although the bonding technology can ignore the lattice mismatch problem of the InP-Si heterostructure, the mechanical thinning process can easily cause problems such as poor surface quality control accuracy, poor uniformity, and large lattice damage. In addition, the subsequent epitaxial growth of functional heterojunction films and superlattice structures on the composite substrate is still required to design and construct InP optoelectronic devices. The complex process flow greatly limits the flexibility of the application of the InP-Si heterogeneous platform. More importantly, this method will cause a large amount of wear and tear of InP wafers, and the actual utilization rate of materials is less than 1 / 200, which is extremely unfavorable for the cost control of commercial products.

[0005] The peeling transfer technology of thin film refers to the use of technical means to separate the thin film and even the device structure located on the surface of the substrate from the substrate relatively completely and transfer it to other substrates. This type of technology can reuse the original substrate and can flexibly integrate thin film materials with different substrates. Remote epitaxy technology uses the interlayer force of two-dimensional (2D) materials van der Waals to generate a free-standing single crystal film. This method is achieved by combining 2D material assisted transfer with thin film epitaxy technology, in which the commonly used 2D material is graphene, and the weak van der Waals bonding of graphene helps the epitaxially grown film to peel off from the substrate, leaving the original surface after peeling. MIT (Massachusetts Institute of Technology) in the United States has realized InP remote epitaxy and peeling, but the carrier gas used to protect graphene during the growth process is N2. However, in order to ensure the uniformity and repeatability of InP epitaxial thin films and superlattices in industrial production, only H2 is used as the carrier gas. Therefore, the use of N2 as the carrier gas is not conducive to large-scale industrialization of InP film epitaxy and device preparation. However, according to the mature InP epitaxial process, at 650°C in H2 atmosphere, hydrogen will destroy the CC bonds of graphene, specifically sp 2 The bonded graphene lattice is destroyed by hydrogen, forming dangling bonds and metal carbides (In-C and / or PC), which can become nucleation sites. Since the crystal information of the substrate is shielded by the damaged graphene, the growth deviates from the long-range epitaxial mode, which will make it impossible for the epitaxial film to peel off at the graphene interface. More importantly, this process only peels off the InP epitaxial film. Due to the process conditions, it is impossible to achieve controllable peeling and transfer of the InP epitaxial film, which greatly limits the integration freedom and application areas of InP devices and silicon-based CMOS platforms.

[0006] In summary, there are currently no effective technologies and methods that can achieve high-quality remote epitaxy, lift-off transfer, and silicon-based heterogeneous integration of specifically oriented InP heterojunction films and device arrays. Summary of the invention

[0007] In view of this, the present invention provides a high-quality directional remote epitaxy method and a peeling transfer method for an indium phosphide single crystal film. The high-quality directional remote epitaxy method provided by the present invention can avoid the destruction of the graphene film when performing indium phosphide epitaxial growth, does not need to use nitrogen as a protective gas, and can obtain an indium phosphide single crystal film with a specific orientation; the peeling transfer method provided by the present invention can achieve non-destructive and controllable peeling of the indium phosphide single crystal film and heterogeneous integration with a silicon substrate.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] A high-quality directional remote epitaxy method for an indium phosphide single crystal thin film comprises the following steps:

[0010] A single-layer graphene film is covered on the surface of an indium phosphide single crystal substrate to obtain an indium phosphide single crystal substrate with a single-layer graphene film;

[0011] Vapor phase epitaxy is performed on one side of a single-layer graphene film of an indium phosphide single crystal substrate with a single-layer graphene film to obtain an indium phosphide single crystal film; the vapor phase epitaxy includes sequentially growing an indium phosphide seed layer and an indium phosphide epitaxial layer, the substrate temperature for growing the indium phosphide seed layer is 400-500°C, and the carrier gas is H2; the substrate temperature for growing the indium phosphide epitaxial layer is 600-700°C, and the carrier gas is H2.

[0012] Preferably, the crystal plane of the indium phosphide single crystal substrate is (100), (110) or (111).

[0013] Preferably, the vapor phase epitaxy method is metal organic chemical vapor deposition.

[0014] Preferably, the conditions for growing the indium phosphide seed layer include: a pressure of 50 to 150 torr, a molar ratio of phosphorus in the phosphorus source to indium in the indium source of 200 to 350; and a thickness of the indium phosphide seed layer of 1 to 3 nm.

[0015] Preferably, the conditions for growing the indium phosphide epitaxial layer include: a pressure of 50 to 150 torr, a molar ratio of phosphorus in the phosphorus source to indium in the indium source of 150 to 250; and a thickness of the indium phosphide epitaxial layer of 300 to 500 nm.

[0016] Preferably, the method of covering the surface of an indium phosphide single crystal substrate with a single-layer graphene film comprises: providing a copper substrate with a single-layer graphene film, and transferring the single-layer graphene film on the surface of the copper substrate to the surface of the indium phosphide single crystal substrate.

[0017] Preferably, after obtaining the indium phosphide single crystal thin film, the method further comprises preparing other III-V group compound semiconductors on the indium phosphide single crystal thin film to obtain an indium phosphide heterojunction thin film.

[0018] Preferably, after obtaining the indium phosphide single crystal thin film or the indium phosphide heterojunction thin film, the method further comprises preparing an optoelectronic device structure on the indium phosphide single crystal thin film or the indium phosphide heterojunction thin film.

[0019] The present invention also provides an epitaxial wafer or device, wherein the epitaxial wafer comprises an indium phosphide single crystal substrate, a single-layer graphene film coated on the surface of the indium phosphide single crystal substrate, and an epitaxial structure coated on the surface of the single-layer graphene film, wherein the epitaxial structure is an indium phosphide single crystal film or an indium phosphide heterogeneous film; the indium phosphide single crystal film and the indium phosphide heterogeneous film are prepared by the method described in the above scheme;

[0020] The device comprises the epitaxial wafer and a photoelectric device structure arranged on the surface of the epitaxial wafer; the photoelectric device structure is prepared by the method described in the above scheme.

[0021] The present invention also provides a method for peeling and transferring an indium phosphide single crystal film, comprising the following steps:

[0022] Providing the epitaxial wafer or device described in the above scheme;

[0023] Depositing a metal stress layer on the surface of the epitaxial structure of the epitaxial wafer, or depositing a metal stress layer on the surface of the optoelectronic device structure of the device;

[0024] Pasting an adhesive tape on the surface of the metal stress layer, and then peeling off the adhesive tape to separate the indium phosphide single crystal film and the single-layer graphene film to obtain a separation structure; the separation structure includes an epitaxial structure, a metal stress layer and an adhesive tape stacked in sequence, or includes an epitaxial structure, an optoelectronic device structure, a metal stress layer and an adhesive tape stacked in sequence;

[0025] The separation structure is transferred to the surface of a silicon substrate so that the indium phosphide single crystal film contacts the surface of the silicon substrate, and then the adhesive tape and the metal stress layer are removed.

[0026] Preferably, the metal stress layer is a Ni metal layer, and the thickness of the metal stress layer is 1-3 μm; and the tape is a thermal release tape.

[0027] Preferably, the method for removing the tape is heating treatment, the temperature of the heating treatment is 90 to 140° C., and the time is 10 to 20 minutes;

[0028] The method for removing the metal stress layer is chemical etching; the time of the chemical etching is 1 to 3 hours.

[0029] The invention provides a high-quality directional remote epitaxy method for an indium phosphide single crystal film, comprising the following steps: covering a single-layer graphene film on the surface of an indium phosphide single crystal substrate to obtain an indium phosphide single crystal substrate with a single-layer graphene film; performing vapor phase epitaxy on one side of the single-layer graphene film of the indium phosphide single crystal substrate with the single-layer graphene film to obtain an indium phosphide single crystal film; the vapor phase epitaxy comprises sequentially growing an indium phosphide seed layer and an indium phosphide epitaxial layer, the substrate temperature for growing the indium phosphide seed layer is 400-500° C., and the carrier gas is H2; the substrate temperature for growing the indium phosphide epitaxial layer is 600-700° C., and the carrier gas is H2. The present invention adopts a two-stage vapor phase epitaxy technology, firstly grows an indium phosphide seed layer at low temperature, protects graphene and reduces the generation of defects, avoids the destruction of graphene in a H2 atmosphere, and then realizes the preparation of an indium phosphide epitaxial layer at high temperature. This method can protect the graphene lattice from being destroyed during the entire vapor phase epitaxy process, and improves the crystal quality of the indium phosphide single crystal film. In addition, the present invention adopts a single-layer graphene as an intermediate layer, so that the substrate and the indium phosphide single crystal film interact through the single-layer graphene. The single-layer graphene is thin enough and has electrical permeability, and does not affect the substrate-induced epitaxial orientation. Therefore, the present invention can realize the epitaxial growth of a specific orientation indium phosphide single crystal film by replacing substrates with different crystal planes. In addition, after obtaining the indium phosphide single crystal film, the present invention can further prepare an indium phosphide heterojunction film or a photoelectric device structure, and the film and even the device structure can be relatively completely separated from the substrate and transferred to other substrates by peeling transfer in the later stage.

[0030] The present invention also provides a method for peeling and transferring an indium phosphide single crystal film. The present invention utilizes the van der Waals force between a single-layer graphene and an indium phosphide single crystal film, and combines a metal stress layer and an adhesive tape to release the indium phosphide single crystal film from the surface of the single-layer graphene film, thereby achieving large-area non-destructive and controllable peeling of an indium phosphide single crystal film, a heterojunction film, or an optoelectronic device, thereby obtaining an independent indium phosphide single crystal film, a heterojunction film, or an optoelectronic device, and integrating it with a silicon substrate. In summary, the present invention provides high-quality remote epitaxy, peeling and transfer, and silicon-based heterogeneous integration that can achieve characteristically oriented indium phosphide single crystal films, heterojunction films, and even optoelectronic devices, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic flow chart of a high-quality directional remote epitaxy method for an indium phosphide single crystal thin film provided by the present invention;

[0032] Figure 2 A diagram showing the growth mechanism of the indium phosphide heterojunction film and device in the present invention;

[0033] Figure 3 The optical microscope image (left) and the corresponding Raman spectrum (right) of the InP single crystal substrate with a single-layer graphene film on the surface in Example 1;

[0034] Figure 4 Backscattered electron characterization and AFM characterization of InP single crystal films with different crystal orientations prepared by remote vapor phase epitaxy, where a, b, and c are respectively the SEM image, EBSD characterization, and AFM surface morphology characterization of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal face (100); d, e, and f are respectively the SEM image, EBSD characterization, and AFM surface morphology characterization of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal face (110); g, h, and i are respectively the SEM image, EBSD characterization, and AFM surface morphology characterization of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal face (111). DETAILED DESCRIPTION

[0035] The present invention provides a high-quality directional remote epitaxy method for an indium phosphide single crystal thin film, comprising the following steps:

[0036] A single-layer graphene film is covered on the surface of an indium phosphide single crystal substrate to obtain an indium phosphide single crystal substrate with a single-layer graphene film;

[0037] Vapor phase epitaxy is performed on one side of a single-layer graphene film of an indium phosphide single crystal substrate with a single-layer graphene film to obtain an indium phosphide single crystal film; the vapor phase epitaxy includes sequentially growing an indium phosphide seed layer and an indium phosphide epitaxial layer, the substrate temperature for growing the indium phosphide seed layer is 400-500°C, and the carrier gas is H2; the substrate temperature for growing the indium phosphide epitaxial layer is 600-700°C, and the carrier gas is H2.

[0038] Figure 1 The schematic diagram of the process of high-quality directional remote epitaxy of indium phosphide single crystal thin film provided by the present invention is as follows. Figure 1 Provide detailed explanation.

[0039] The present invention covers a single-layer graphene film on the surface of an indium phosphide single crystal substrate to obtain an indium phosphide single crystal substrate with a single-layer graphene film. In the present invention, the method of covering the surface of an indium phosphide single crystal substrate with a single-layer graphene film preferably includes: providing a copper substrate with a single-layer graphene film, and transferring the single-layer graphene film on the surface of the copper substrate to the surface of the indium phosphide single crystal substrate. The present invention has no special requirements on the source of the copper substrate with the single-layer graphene film grown, and it can be prepared by a method well known to those skilled in the art.

[0040] In the present invention, the crystal plane of the indium phosphide single crystal substrate is preferably (100), (110) or (111); InP single crystal films with different crystal orientations can be prepared in a controllable manner, and their heterogeneous integration with silicon-based CMOS platforms can be further realized in different application scenarios, which is very important for expanding their application fields; the single-layer graphene used in the present invention is thin enough and has electrical permeability, and does not affect the substrate-induced epitaxial orientation. Therefore, the present invention can prepare an InP epitaxial layer with a directional crystal plane by replacing substrates with different crystal planes.

[0041] In the present invention, the method for transferring a single-layer graphene film on the surface of a copper substrate to the surface of an indium phosphide single crystal substrate preferably comprises: applying a polymethyl methacrylate (PMMA) solution to the surface of the single-layer graphene film and then drying it to form a single-layer graphene-polymethyl methacrylate composite film (graphene / PMMA composite film) on the surface of the copper substrate; peeling the single-layer graphene-polymethyl methacrylate composite film from the surface of the copper substrate by an electrochemical bubbling method, transferring the obtained single-layer graphene-polymethyl methacrylate composite film to the surface of an indium phosphide single crystal substrate, making the single-layer graphene surface of the single-layer graphene-polymethyl methacrylate composite film contact with the surface of the indium phosphide single crystal substrate, and then dissolving the polymethyl methacrylate in the single-layer graphene-polymethyl methacrylate composite film. In the present invention, the coating method of the polymethyl methacrylate solution is preferably spin coating, and the coating thickness is preferably 300-600 nm; the drying method is preferably baking, and the baking temperature is preferably 80-160° C., more preferably 80-100° C., and the baking time is preferably 5-15 min, more preferably 10 min. The PMMA is specifically used as a "handle" when peeling off a single-layer graphene film.

[0042] In the present invention, the electrochemical bubbling method preferably includes: using a copper substrate with a single-layer graphene-polymethyl methacrylate composite film on the surface as a cathode, using a graphite electrode as an anode, and using a sodium hydroxide aqueous solution as an electrolyte for electrochemical bubbling; the operating conditions of the electrochemical bubbling preferably include: a DC voltage of 1.5 to 2.4 V, and an electrolyte concentration of 0.01 to 0.5 mol / L, preferably 0.05 mol / L. The copper substrate with a single-layer graphene-polymethyl methacrylate composite film on the surface is cathodically polarized under a DC voltage, and hydrogen bubbles (2H2O(l)+2e -→H2(g)+2OH-(aq)). These H2 bubbles provide a gentle but lasting force to separate the single-layer graphene film from the copper substrate at the edge, and as the edge delaminates, the electrolyte solution penetrates into the interlayer, which helps the separation process, so that the single-layer graphene-polymethyl methacrylate composite film can be easily peeled off from the copper substrate. After the peeling is completed, the obtained single-layer graphene-polymethyl methacrylate composite film is preferably rinsed with deionized water to ensure a clean surface.

[0043] In the present invention, after the single-layer graphene-polymethyl methacrylate composite film is transferred to the surface of the indium phosphide single crystal substrate, the obtained composite structure is preferably dried to make the interface of the single-layer graphene and the indium phosphide single crystal substrate adhere to each other; the drying temperature is preferably 25 to 80° C., more preferably 60 to 80° C., and the drying time is preferably 1 to 5 hours, more preferably 10 minutes.

[0044] In the present invention, the solvent for dissolving the polymethyl methacrylate is preferably acetone; the present invention preferably immerses the dried composite structure in acetone, and the present invention has no special requirements for the immersion time, as long as the polymethyl methacrylate can be completely dissolved. After the polymethyl methacrylate is dissolved, the acetone solution is preferably replaced repeatedly to ensure that the surface of the indium phosphide single crystal substrate with a single-layer graphene film is clean, and then the surface is rinsed with ethanol and deionized water respectively, and then dried to reduce the organic matter and moisture residue at the bonding interface of the indium phosphide single crystal substrate with the single-layer graphene film; the drying temperature is preferably 25 to 80°C, more preferably 60°C, and the drying time is preferably 5 to 15h, more preferably 10h.

[0045] After obtaining an indium phosphide single crystal substrate with a single-layer graphene film, the present invention performs vapor phase epitaxy on one side of the single-layer graphene film of the indium phosphide single crystal substrate with the single-layer graphene film to obtain an indium phosphide single crystal thin film; the vapor phase epitaxy includes sequentially growing an indium phosphide seed layer and an indium phosphide epitaxial layer, the substrate temperature for growing the indium phosphide seed layer is 400-500°C, preferably 450°C, and the carrier gas is H2; the substrate temperature for growing the indium phosphide epitaxial layer is 600-700°C, preferably 650°C, and the carrier gas is H2. In the present invention, the method of vapor phase epitaxy is preferably metal organic chemical vapor deposition (MOCVD); the conditions for growing the indium phosphide seed layer preferably include: a pressure of 50 to 150 torr, preferably 100 torr, a molar ratio of phosphorus in the phosphorus source to indium in the indium source of 200 to 350, preferably 300; the thickness of the indium phosphide seed layer is preferably 1 to 3 nm, more preferably 1.5 to 2 nm; the conditions for growing the indium phosphide epitaxial layer preferably include: a pressure of 50 to 150 torr, preferably 100 torr, a molar ratio of phosphorus in the phosphorus source to indium in the indium source (V / III ratio) of 150 to 250, preferably 200; the thickness of the indium phosphide epitaxial layer is preferably 300 to 500 nm, more preferably 350 to 450 nm; the phosphorus source used when growing the indium phosphide single crystal indium seed layer and the indium phosphide epitaxial layer is preferably phosphine, and the indium source is preferably trimethyl indium. In the present invention, the indium phosphide seed layer forms a transition layer between the substrate and the epitaxial layer, which helps to relieve stress and reduce defects in the epitaxial layer, such as dislocations and cracks; low-temperature growth can provide a smooth and clean surface, providing a good template for the subsequent growth of the epitaxial layer. By growing the seed layer at low temperature, the quality of the epitaxial layer can be improved, the formation of defects can be reduced, and the uniformity and crystal quality of the epitaxial layer can be improved; and in the case of a high-temperature hydrogen atmosphere, hydrogen can destroy the CC bond of graphene. After the crystal information of the substrate is shielded by the damaged graphene, the growth will deviate from the long-range epitaxial mode, so that the epitaxial film cannot be peeled off at the graphene interface. The present invention first grows the indium phosphide seed layer at low temperature, which can protect the graphene from being damaged in the epitaxial environment. In the present invention, after the two-stage vapor phase epitaxy is completed, an indium phosphide single crystal film can be obtained, and the crystal plane of the obtained indium phosphide single crystal film is the same as that of the indium phosphide single crystal substrate; the surface roughness (Ra) of the indium phosphide single crystal film is less than 1nm, which is a high-quality indium phosphide single crystal film.

[0046] In the present invention, after obtaining the indium phosphide single crystal film, it also includes preparing other III-V compound semiconductors on the indium phosphide single crystal film to obtain an indium phosphide heterojunction film; the present invention has no special requirements on the type of the other III-V compound semiconductors, and can use III-V compound semiconductors well known to those skilled in the art that can form a heterojunction with the indium phosphide film, such as InGaAs, GaAs, InPGaAs, etc.; the present invention has no special requirements on the preparation method of the other III-V compound semiconductors, and can use methods well known to those skilled in the art.

[0047] In the present invention, after obtaining the indium phosphide single crystal film or the indium phosphide heterojunction film, it also includes preparing a photoelectric device structure on the indium phosphide single crystal film or the indium phosphide heterojunction film; the present invention has no special requirements on the specific structure and preparation method of the photoelectric device structure, and those familiar to those skilled in the art can be used.

[0048] Figure 2 It is the growth mechanism diagram of the indium phosphide heterojunction film and device in the present invention. On the one hand, the thickness of the single-layer graphene is only about 0.33nm, and the single-layer graphene is thin enough and has electrical penetration, which can guide the epitaxial orientation of the capping layer. And the weak van der Waals potential field of graphene cannot completely shield the strong field of the indium phosphide single crystal substrate, which makes epitaxial growth still possible despite the presence of graphene. On the other hand, the atomic bonding characteristics of the material determine the field penetration through the graphene, and the bonding characteristics of indium phosphide are covalent bonds, but there are certain ionic bond components. The potential fluctuations from the indium phosphide single crystal substrate can be well transmitted through the single-layer graphene, and the electrostatic interaction with the indium phosphide single crystal substrate is maintained on the epitaxial surface and the indium phosphide adsorbed atoms are guided to align with the substrate. In addition, due to the accumulation of potential energy fluctuations allowed by the lattice matching between the core and the substrate, the interaction between the indium phosphide core and the indium phosphide single crystal substrate below the graphene increases with the size of the nucleation. On this basis, MOCVD can be used to grow heterojunction films and prepare devices, and thin film peeling technology can be used to transfer indium phosphide heterojunction films to silicon wafers and prepare devices.

[0049] The present invention also provides an epitaxial wafer or device, the epitaxial wafer includes an indium phosphide single crystal substrate, a single-layer graphene film coated on the surface of the indium phosphide single crystal substrate, and an epitaxial structure coated on the surface of the single-layer graphene film; the epitaxial structure is an indium phosphide single crystal film or an indium phosphide heterogeneous film; the device includes the epitaxial wafer and an optoelectronic device structure arranged on the surface of the epitaxial wafer; the indium phosphide single crystal film, indium phosphide heterogeneous film or optoelectronic device structure is prepared by the method described in the above scheme. In the present invention, the indium phosphide heterojunction is specifically composed of an indium phosphide single crystal film and other III-V compounds; the indium phosphide single crystal film includes an indium phosphide seed layer and an indium phosphide epitaxial layer arranged on the surface of the indium phosphide seed layer, and the specific thickness of the seed layer and the epitaxial layer are not repeated here.

[0050] The present invention also provides a method for peeling and transferring an indium phosphide single crystal film, comprising the following steps:

[0051] Providing the epitaxial wafer or device described in the above scheme;

[0052] Depositing a metal stress layer on the surface of the epitaxial structure of the epitaxial wafer, or depositing a metal stress layer on the surface of the optoelectronic device structure of the device;

[0053] Pasting an adhesive tape on the surface of the metal stress layer, and then peeling off the adhesive tape to separate the indium phosphide single crystal film and the single-layer graphene film to obtain a separation structure; the separation structure includes an epitaxial structure, a metal stress layer and an adhesive tape stacked in sequence, or includes an epitaxial structure, an optoelectronic device structure, a metal stress layer and an adhesive tape stacked in sequence;

[0054] The separated structure is transferred to the surface of a silicon substrate, and then the tape and the metal stress layer are removed.

[0055] The method for preparing the epitaxial wafer or device will not be described in detail here.

[0056] After obtaining the epitaxial wafer, the present invention deposits a metal stress layer on the surface of the epitaxial structure of the epitaxial wafer, or deposits a metal stress layer on the surface of the optoelectronic device structure of the device. In the present invention, the metal stress layer is specifically a nickel metal layer, and the thickness of the metal stress layer is preferably 1 to 3 μm, preferably 1.5 to 2 μm; the method for depositing the metal stress layer is preferably magnetron sputtering, and the pressure of the magnetron sputtering is preferably 0.4 Pa.

[0057] After obtaining the metal stress layer, the present invention adheres an adhesive tape on the surface of the metal stress layer, and then lifts up the adhesive tape to separate the indium phosphide single crystal film and the single-layer graphene film to obtain a separation structure. In the present invention, the adhesive tape is preferably a thermal release tape; the present invention has no special requirements for the thermal release tape, and any tape known to those skilled in the art can be used. In the present invention, the metal stress layer is used to generate stress strain at the interface of the indium phosphide single crystal substrate and the single-layer graphene film. The adhesive tape acts as a "handle" and, in combination with the metal stress layer, the indium phosphide single crystal film can be quickly released from the graphene surface, thereby achieving peeling.

[0058] After obtaining the separation structure, the present invention transfers the separation structure to the surface of the silicon substrate, and then removes the tape and the metal stress layer. In the present invention, the method of removing the tape is preferably heat treatment, the temperature of the heat treatment is preferably 90-140°C, more preferably 120-130°C, and the time of the heat treatment is preferably 10-20min, more preferably 15min; the method of removing the metal stress layer is preferably chemical etching, and the etching solution used in the chemical etching is preferably Ni etching solution, and the components of the Ni etching solution include FeCl3; the concentration of FeCl3 in the Ni etching solution is preferably 1mol / L; the temperature of the chemical etching is preferably room temperature, and the etching time is preferably 1-3h, more preferably 2h. After the chemical etching is completed, the remaining structure is preferably rinsed with deionized water to obtain a heterogeneous integrated structure of a silicon substrate and a specifically oriented InP single crystal thin film.

[0059] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Example 1

[0061] 1. Prepare the raw materials: a copper substrate with a single-layer graphene film grown on it, and an indium phosphide wafer with a (100) crystal plane (i.e., an InP single crystal substrate).

[0062] 2. Graphene transfer: Spin polymethyl methacrylate (PMMA) onto the graphene-coated copper foil and bake at 80°C for 10 minutes. Using PMMA as a "handle", the graphene / PMMA composite layer is peeled off from the copper substrate by electrochemical bubbling. In the electrochemical bubbling method, a copper substrate with a graphene / PMMA composite layer is used as the cathode, a graphite electrode is used as the anode, and an aqueous sodium hydroxide solution is used as the electrolyte. The electrolyte concentration is 0.05 mol / L and the voltage is 2.1 V. The voltage is a DC voltage; after the peeling is completed, the obtained graphene / PMMA composite layer is rinsed with deionized water to ensure the surface is clean. The graphene / PMMA composite layer is then transferred to an InP single crystal substrate. The substrate is dried at 80°C for 10 minutes to make the interface fit, and then the PMMA "handle" is dissolved in acetone to obtain an InP single crystal substrate with a single-layer graphene film on the surface.

[0063] 3. Interface cleaning: After PMMA is dissolved, the acetone solution is repeatedly replaced to ensure the surface is clean, and then the surface is rinsed with ethanol and deionized water respectively. The InP single crystal substrate with a single-layer graphene film on the surface is slowly dried at 60°C for 10 hours to reduce the organic matter and moisture residue at the bonding interface.

[0064] 4. Epitaxial growth: Using the metal organic chemical vapor deposition (MOCVD) method, two-stage vapor phase epitaxial growth of InP single crystal thin films with specific orientations was performed on InP single crystal substrates with single-layer graphene on the surface, using phosphine and trimethyl indium as P and In sources, and H2 as the carrier gas. First, a 3nm thick InP seed layer was grown at 450℃, 100torr, and V / III of 300. Then the temperature of the MOCVD reactor was raised to 650℃, and an InP epitaxial layer was grown at V / III of 200. After the growth was completed, a high-quality (100) crystal plane InP single crystal thin film was obtained.

[0065] 5. Stripping and transfer of InP single crystal film: Using magnetron sputtering at a pressure of 0.4 Pa, 1 μm of metal Ni is deposited on the surface of the InP epitaxial layer as a Ni stress layer, and a thermal release tape is pasted on the surface of the Ni stress layer. The thermal release tape is peeled off to separate the InP single crystal film and the single-layer graphene film to obtain an InP single crystal film-Ni stress layer-thermal release tape structure; the InP single crystal film-Ni stress layer-thermal release tape structure is transferred to the surface of the target silicon substrate, and then heated at 120°C for 15 min to remove the thermal release tape, and then Ni etching solution (mainly FeCl3) is used for etching at room temperature for 2 h to remove the Ni stress source layer, and then rinsed with deionized water to obtain a specific orientation independent InP single crystal film, completing the transfer process.

[0066] Example 2

[0067] The other conditions are the same as those in Example 1, except that the substrate is replaced with an indium phosphide wafer with a (110) crystal plane, and a high-quality (110) crystal plane InP single crystal film is grown and transferred to the surface of the silicon substrate.

[0068] Example 3

[0069] The other conditions are the same as those in Example 1, except that the substrate is replaced with an indium phosphide wafer with a (111) crystal plane, and a high-quality (111) crystal plane InP single crystal film is grown and transferred to the surface of the silicon substrate.

[0070] Performance Test:

[0071] Figure 3 The optical microscope image (left) and the corresponding Raman spectrum (right) of the InP single crystal substrate with a single-layer graphene film on the surface in Example 1 are shown in FIG. Figure 3 The 304 and 342 cm corresponding to InP can be clearly observed. -1 The Raman peak of graphene is also present at 2700cm -1 (2D) and 1580cm -1 (G) has a Raman peak, and 2D / G≈2, which is a single-layer graphene.

[0072] Figure 4 Backscattered electron characterization and AFM characterization of InP single crystal films with different crystal orientations prepared by remote vapor phase epitaxy, where a, b, and c are respectively the SEM images, EBSD characterizations, and AFM surface morphology characterizations of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal plane of (100), and the scale of c is 2.0μm; d, e, and f are respectively the SEM images, EBSD characterizations, and AFM surface morphology characterizations of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal plane of (110), and the scale of f is 1.0μm; g, h, and i are respectively the SEM images, EBSD characterizations, and AFM surface morphology characterizations of the surface of the InP single crystal film obtained by remote epitaxy on an InP single crystal substrate with a crystal plane of (111), and the scale of i is 2.0μm. Figure 4 It can be clearly seen that the indium phosphide film prepared by epitaxy has single crystal properties, different crystal orientations, and a surface roughness (Ra) of <1 nm, indicating that the epitaxy quality is good.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-quality directional remote epitaxy method for an indium phosphide single crystal thin film, characterized in that: The following steps are involved: A single-layer graphene film is covered on the surface of an indium phosphide single crystal substrate to obtain an indium phosphide single crystal substrate with a single-layer graphene film; Vapor phase epitaxy is performed on one side of a single-layer graphene film of an indium phosphide single crystal substrate with a single-layer graphene film to obtain an indium phosphide single crystal film; the vapor phase epitaxy includes sequentially growing an indium phosphide seed layer and an indium phosphide epitaxial layer, the substrate temperature for growing the indium phosphide seed layer is 400-500°C, and the carrier gas is H2; the substrate temperature for growing the indium phosphide epitaxial layer is 600-700°C, and the carrier gas is H2.

2. The high-quality directional remote epitaxy method according to claim 1, characterized in that: The crystal plane of the indium phosphide single crystal substrate is (100), (110) or (111).

3. The high-quality directional remote epitaxy method according to claim 1, characterized in that: The method of vapor phase epitaxy is metal organic chemical vapor deposition; The conditions for growing the indium phosphide seed layer include: a pressure of 50 to 150 torr, a molar ratio of phosphorus in the phosphorus source to indium in the indium source of 200 to 350; and a thickness of the indium phosphide seed layer of 1 to 3 nm. The conditions for growing the indium phosphide epitaxial layer include: a pressure of 50 to 150 torr, a molar ratio of phosphorus in a phosphorus source to indium in an indium source of 150 to 250; and a thickness of the indium phosphide epitaxial layer of 300 to 500 nm.

4. The high-quality directional remote epitaxy method according to claim 1, characterized in that: The method for covering a single-layer graphene film on the surface of an indium phosphide single crystal substrate comprises: providing a copper substrate with a single-layer graphene film, and transferring the single-layer graphene film on the surface of the copper substrate to the surface of the indium phosphide single crystal substrate.

5. The high-quality directional remote epitaxy method according to claim 1, characterized in that: After obtaining the indium phosphide single crystal film, the method further includes preparing other III-V group compound semiconductors on the indium phosphide single crystal film to obtain an indium phosphide heterojunction film.

6. The high-quality directional remote epitaxy method according to claim 1 or 5, characterized in that: After obtaining the indium phosphide single crystal film or the indium phosphide heterojunction film, the method further includes preparing a photoelectric device structure on the indium phosphide single crystal film or the indium phosphide heterojunction film.

7. An epitaxial wafer or device, characterized in that: The epitaxial wafer comprises an indium phosphide single crystal substrate, a single-layer graphene film coated on the surface of the indium phosphide single crystal substrate, and an epitaxial structure coated on the surface of the single-layer graphene film, wherein the epitaxial structure is an indium phosphide single crystal film or an indium phosphide heterogeneous film; the indium phosphide single crystal film is prepared by the method described in any one of claims 1 to 4; the indium phosphide heterogeneous film is prepared by the method described in claim 5; The device includes the epitaxial wafer and a photoelectric device structure arranged on the surface of the epitaxial wafer; the photoelectric device structure is prepared by the method described in claim 6.

8. A method for peeling and transferring an indium phosphide single crystal thin film, characterized in that: The following steps are involved: Providing the epitaxial wafer or device according to claim 7; Depositing a metal stress layer on the surface of the epitaxial structure of the epitaxial wafer, or depositing a metal stress layer on the surface of the optoelectronic device structure of the device; Pasting an adhesive tape on the surface of the metal stress layer, and then peeling off the adhesive tape to separate the indium phosphide single crystal film and the single-layer graphene film to obtain a separation structure; the separation structure includes an epitaxial structure, a metal stress layer and an adhesive tape stacked in sequence, or includes an epitaxial structure, an optoelectronic device structure, a metal stress layer and an adhesive tape stacked in sequence; The separation structure is transferred to the surface of a silicon substrate so that the indium phosphide single crystal film contacts the surface of the silicon substrate, and then the adhesive tape and the metal stress layer are removed.

9. The peeling transfer method according to claim 8, characterized in that: The metal stress layer is a Ni metal layer, and the thickness of the metal stress layer is 1-3 μm; the adhesive tape is a thermal release adhesive tape.

10. The peeling transfer method according to claim 9, characterized in that: The method for removing the tape is heating treatment, the temperature of the heating treatment is 90 to 140° C., and the time is 10 to 20 minutes; The method for removing the metal stress layer is chemical etching; the time of the chemical etching is 1 to 3 hours.

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