Large-size screen structure gallium oxide semiconductor thin film and preparation method thereof

Abstract

This invention provides a large-size screen-structure gallium oxide semiconductor thin film and its preparation method, belonging to the field of semiconductor materials technology. The invention provides a patterned substrate; the patterned substrate includes a substrate body and a periodic pattern, the periodic pattern having an H / L ratio of 3~15:1; gallium oxide epitaxial growth is performed on the surface of the patterned substrate, and then the patterned substrate is removed to obtain the large-size screen-structure gallium oxide semiconductor thin film. This invention uses a patterned substrate with an H / L ratio of 3~15:1 for gallium oxide semiconductor thin film epitaxy. During the epitaxial growth process, an amorphous layer is first formed on the surface of the patterned substrate to fully release the internal stress caused by the mismatch between the lattice and the coefficient of thermal expansion, thereby greatly reducing the defect density and residual stress within the gallium oxide semiconductor thin film, improving the self-supporting ability of the film, and obtaining a high-quality, complete large-size gallium oxide thin film.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and in particular to a large-size sieve structure gallium oxide semiconductor thin film and its preparation method. Background Technology

[0002] Since the 1920s, advancements in solid-state physics and quantum mechanics, along with the continuous refinement of band theory, have led to more in-depth research on semiconductor materials. From the 1950s onward, semiconductor materials have evolved through three generations: the first generation represented by silicon and germanium elemental semiconductors; the second generation represented by compound semiconductors such as gallium arsenide; and the third generation represented by wide-bandgap semiconductors such as silicon carbide and gallium nitride. Currently, in special applications requiring high frequency, high power, high temperature resistance, and radiation resistance, electronic devices made from these semiconductor materials struggle to meet these conditions. Therefore, novel ultra-wide-bandgap semiconductor materials have emerged. Among these, gallium oxide stands out due to its ease of fabrication and low cost.

[0003] Currently, apart from β-Ga₂O₃, which can be used to prepare bulk single crystals, other phases of gallium oxide can only be fabricated into thin films via heteroepitaxial growth. When using heteroepitaxial gallium oxide films for vertical structure device fabrication, the problem of difficult peeling arises. This is mainly due to the lattice difference and thermal expansion coefficient deviation between the gallium oxide film and the substrate material during the growth process, resulting in a high defect density and residual stress within the obtained gallium oxide film. These problems reduce the self-supporting capacity of the gallium oxide film, leading to fragmentation during peeling and making it difficult to obtain large-size gallium oxide films.

[0004] The related technology discloses the growth of gallium oxide thin films on the surface of patterned substrates, but there is still a problem of low quality of the obtained gallium oxide thin films. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a large-size sieve structure gallium oxide semiconductor thin film and a method for preparing the same.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing a large-size sieve-structured gallium oxide semiconductor thin film, comprising the following steps: A patterned substrate is provided; the patterned substrate includes a substrate body and a periodic pattern, wherein the H / L ratio of the periodic pattern is 3~15:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern; Gallium oxide epitaxial growth is performed on the surface of the patterned substrate, and then the patterned substrate is removed to obtain the large-size screen structure gallium oxide semiconductor thin film.

[0007] Preferably, the periodic pattern includes one or more of the following: a centripetal circular arrangement, an equidistant matrix arrangement, and a hexagonal close-packed arrangement. When the periodic pattern is a centripetal circular arrangement, the gap between two adjacent centripetal circular arrangement units is 0.05 to 0.5 times the radius of the centripetal circular arrangement unit; when the periodic pattern is an equidistant matrix arrangement, the gap between two adjacent equidistant matrix arrangement units is 0.05 to 0.5 times the length of the equidistant matrix arrangement unit; when the periodic pattern is a hexagonal close-packed arrangement, the gap between two adjacent hexagonal close-packed arrangement units is 0.05 to 0.5 times the length of the hexagonal close-packed arrangement unit.

[0008] Preferably, the height of the individual graphic is 0.3~3000μm.

[0009] Preferably, the shape of the individual graphic is a circle, triangle, rectangle, polygon, or irregular shape.

[0010] Preferably, the shape of the single graphic includes one or more of the following: a circular concave hole, a circular protrusion, a square concave hole, a square protrusion, a conical concave hole, a conical protrusion, a square concave hole, a square concave protrusion, a frustum concave hole, a frustum concave protrusion, a square frustum concave hole, a square frustum concave protrusion, a trapezoidal concave hole, a trapezoidal protrusion, a polygonal concave hole, a polygonal protrusion, a polygonal frustum concave hole, a polygonal frustum concave protrusion, an irregular graphic concave hole, and an irregular graphic protrusion.

[0011] Preferably, the angle between the hypotenuse of the conical recess, conical protrusion, square pyramidal recess, square pyramidal protrusion, truncated cone recess, truncated cone protrusion, square pyramidal recess, square pyramidal protrusion, trapezoidal recess, trapezoidal protrusion, polygonal recess, polygonal protrusion, polygonal pyramidal recess, and polygonal pyramidal protrusion and the substrate is independently 90~180°.

[0012] Preferably, the angle between the hypotenuse of the circular and square recesses and the substrate is independently 90-180°.

[0013] Preferably, the patterned substrate is prepared by a method comprising the following steps: transferring a screen pattern structure to a substrate by a patterning method to obtain the patterned substrate.

[0014] Preferably, the patterning method is photolithography, chemical etching, or direct growth.

[0015] This invention also provides a large-size sieve-structure gallium oxide semiconductor thin film prepared by the preparation method described above, wherein the area of ​​the large-size sieve-structure gallium oxide semiconductor thin film is 1~700 cm². 2 .

[0016] This invention provides a method for preparing a large-size screen-structured gallium oxide semiconductor thin film, comprising the following steps: providing a patterned substrate; the patterned substrate comprising a substrate body and periodic patterns, wherein the H / L ratio of the periodic patterns is 3~15:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic patterns; performing gallium oxide epitaxial growth on the surface of the patterned substrate, and then removing the patterned substrate to obtain the large-size screen-structured gallium oxide semiconductor thin film.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: In the process of gallium oxide (GaO) thin film peeling, the high defect density and poor self-supporting ability of GaO films make it difficult to obtain high-quality, large-size, intact GaO films. This invention utilizes a patterned substrate with an H / L ratio of 3 to 15:1 (where H is the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern, i.e., the spacing between two adjacent patterns in the periodic pattern is L) for GaO semiconductor thin film epitaxy. During epitaxial growth, an amorphous layer is first formed on the surface of the patterned substrate to fully release the internal stress caused by the mismatch between the lattice and the coefficient of thermal expansion, thereby greatly reducing the defect density and residual stress within the GaO semiconductor film, improving the film's self-supporting ability, and obtaining a high-quality, intact, large-size GaO film. Simultaneously, during the GaO semiconductor thin film peeling process, the sieve structure formed on the surface of the GaO semiconductor film after removing the patterned substrate can alleviate the mechanical stress caused by the peeling process (including but not limited to the mechanical stress caused by film bending, stretching, and compression during peeling), which also helps to improve the film's self-supporting ability and obtain a high-quality, intact, large-size GaO film. Furthermore, the preparation method of this invention is simple to operate and suitable for industrial application.

[0018] The present invention also provides a large-size sieve structure gallium oxide semiconductor thin film prepared by the preparation method described above. The large-size sieve structure gallium oxide semiconductor thin film of the present invention has a full width at half maximum (FWHM) as low as 0.040°, high crystal quality, low defect density, and low residual stress. Attached Figure Description

[0019] Figure 1 This is a flowchart of the preparation method of the large-size sieve structure gallium oxide semiconductor thin film in Example 1; Figure 2 This is a schematic diagram of the screen layout structure in a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a screen layout arranged in a concentric circle. Figure 4 This is a schematic diagram of the equidistant matrix arrangement of the screen layout structure; Figure 5 This is a schematic diagram of the structure of a hexagonal close-packed screen. Figure 6 A schematic diagram of a screen layout structure combining a concentric circular arrangement with two other arrangement methods; Figure 7 The surface EDS energy spectrum characterization diagram of the gallium oxide semiconductor thin film prepared in Comparative Example 3 is shown. Figure 8 The image shows the surface EDS energy spectrum characterization of the large-size sieve structure gallium oxide semiconductor thin film prepared in Example 11. Figure 9 The results are the full peak half-widths (FWHM) of gallium oxide semiconductor thin films prepared in Example 1, Comparative Example 1, and Comparative Example 2. Sample numbers 1, 2, and 3 correspond to Example 1, Comparative Example 1, and Comparative Example 2, respectively. Figure 10 These are scanning electron microscope (SEM) images of a patterned sapphire substrate taken from different angles, as shown in Example 1. Figure 11 SEM images of a patterned sapphire substrate at different angles, for Comparative Example 1; Figure 12 Comparative Example 2: Scanning electron microscope images of patterned sapphire substrates at different angles; Figure 13 The images show physical images of the gallium oxide semiconductor thin films prepared in Example 1 and Comparative Example 3. In the figure, 1 is the substrate, 2 is the raised pattern, 3 is the concave pattern, 4 is the gallium oxide semiconductor thin film with a large-size screen structure with a concave structure, and 5 is the gallium oxide semiconductor thin film with a large-size screen structure with a raised structure. Detailed Implementation

[0020] This invention provides a method for preparing a large-size sieve-structured gallium oxide semiconductor thin film, comprising the following steps: A patterned substrate is provided; the patterned substrate includes a substrate body and a periodic pattern, wherein the H / L ratio of the periodic pattern is 3~15:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern; Gallium oxide epitaxial growth is performed on the surface of the patterned substrate, and then the patterned substrate is removed to obtain the large-size screen structure gallium oxide semiconductor thin film.

[0021] Unless otherwise specified, all raw materials used in this invention are commercially available products in the field.

[0022] The present invention provides a patterned substrate; the patterned substrate includes a substrate body and a periodic pattern, wherein the H / L ratio of the periodic pattern is 3~15:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern.

[0023] In this invention, the H / L ratio can specifically be 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 9.5:1, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1. This invention addresses the mismatch between the lattice and thermal expansion coefficients of the substrate material and the gallium oxide (GaO) semiconductor thin film by structurally designing a patterned substrate. Simultaneously, a corresponding mesh structure is formed on the surface of the GaO semiconductor thin film after substrate removal, collectively achieving the goal of complete, large-size GaO semiconductor thin film removal. This invention uses a patterned substrate with an H / L ratio of 3-15 for GaO semiconductor thin film epitaxy. During epitaxial growth, an amorphous layer is first formed on the surface of the patterned substrate to fully release the internal stress caused by the lattice and thermal expansion coefficient mismatch, thereby significantly reducing the defect density and residual stress within the GaO semiconductor thin film, improving its self-supporting ability to obtain a complete, large-size GaO thin film. Furthermore, the mesh structure formed on the surface of the GaO semiconductor thin film after removing the patterned substrate during the removal process can alleviate the mechanical stress caused by the removal process (including but not limited to mechanical stress caused by film bending, stretching, and compression during removal), which also helps improve the film's self-supporting ability to obtain a high-quality, complete, large-size GaO thin film.

[0024] In this invention, the distribution of the periodic pattern is not limited; it can be uniformly distributed, non-uniformly distributed, locally present on the substrate, or covering the entire substrate.

[0025] In this invention, the periodic pattern preferably includes one or more of centripetal circular arrangement, equidistant matrix arrangement, and hexagonal close-packed arrangement, more preferably including a combination of centripetal circular arrangement and equidistant matrix arrangement or centripetal circular arrangement and hexagonal close-packed arrangement; when the periodic pattern is preferably centripetal circular arrangement, the gap size between two adjacent centripetal circular arrangement units is preferably 0.05 to 0.5 times the radius of the centripetal circular arrangement unit, specifically it can be 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 times; when the periodic pattern is preferably centripetal circular arrangement, the gap size between two adjacent centripetal circular arrangement units is preferably 0.05 to 0.5 times the radius of the centripetal circular arrangement unit; specifically, it can be 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 times the radius of the centripetal circular arrangement unit. When the periodic pattern is arranged in an equidistant matrix, the gap between two adjacent equidistant matrix units is 0.05 to 0.5 times the length of the equidistant matrix unit, specifically 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 times; when the periodic pattern is arranged in a hexagonal close-packed pattern, the gap between two adjacent hexagonal close-packed units is 0.05 to 0.5 times the length of the hexagonal close-packed unit, specifically 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 times.

[0026] In this invention, the height of the individual graphic is preferably 0.3~3000μm, specifically 0.3, 0.5, 1, 1.9, 2, 2.5, 3, 5, 8, 9, 10, 50, 100, 500, 1000, 1500, 2000, 2500 or 3000μm.

[0027] In this invention, the shape of the individual graphic is preferably a circle, triangle, rectangle, polygon, or irregular shape.

[0028] In this invention, the shape of the single graphic preferably includes one or more of the following: a circular concave hole, a circular protrusion, a square concave hole, a square protrusion, a conical concave hole, a conical protrusion, a square concave hole, a square concave protrusion, a frustum concave hole, a frustum concave protrusion, a square frustum concave hole, a square frustum concave protrusion, a trapezoidal concave hole, a trapezoidal protrusion, a polygonal concave hole, a polygonal protrusion, a polygonal frustum concave hole, a polygonal frustum concave protrusion, an irregularly shaped concave hole, and an irregularly shaped protrusion.

[0029] In this invention, the angle between the hypotenuse of the conical concave hole, conical protrusion, square concave hole, square concave protrusion, truncated cone concave hole, truncated cone protrusion, square concave cone concave hole, square concave cone protrusion, trapezoidal concave hole, trapezoidal protrusion, polygonal concave hole, polygonal protrusion, polygonal truncated cone concave hole and polygonal truncated cone protrusion and the substrate is preferably 90~180°, specifically 90°, 120°, 150° or 180°.

[0030] In this invention, the angle between the hypotenuse of the circular and square concave holes and the substrate is preferably 90-180°, specifically 90°, 120°, 150° or 180°.

[0031] In this invention, the thickness of the substrate is preferably 50~3000μm, specifically 50, 100, 500, 1000, 1500, 2000, 2500 or 3000μm.

[0032] In this invention, the substrate material is preferably a metal, semiconductor, or organic material, specifically copper, aluminum, monocrystalline silicon, polycrystalline silicon, amorphous silicon, silicon dioxide, aluminum oxide, iron oxide, zinc oxide, ITO glass, or PDMS.

[0033] In this invention, the material of the periodic pattern is preferably a metal, semiconductor, or organic material, specifically copper, aluminum, monocrystalline silicon, polycrystalline silicon, amorphous silicon, silicon dioxide, aluminum oxide (sapphire), iron oxide, zinc oxide, ITO glass, or PDMS. The periodic pattern and the substrate can be made of the same material or different materials.

[0034] In this invention, the patterned substrate is preferably prepared by a method comprising the following steps: transferring a screen pattern structure to a substrate by a patterning method to obtain the patterned substrate.

[0035] The present invention preferably designs the screen pattern structure, and the present invention preferably uses EDA software to perform the design.

[0036] Figure 2 This is a schematic diagram of the screen layout structure in a specific embodiment of the present invention. Figure 2 In the diagram, 1 represents the substrate, 2 represents the raised pattern, 3 represents the recessed pattern, 4 represents a large-size gallium oxide semiconductor thin film with a recessed structure and a large-size screen structure, and 5 represents a large-size gallium oxide semiconductor thin film with a raised structure and a large-size screen structure. Figure 2 The left side of the screen has a concave screen pattern structure, while the right side has a convex screen pattern structure.

[0037] In this invention, the screen pattern structure is preferably arranged in a concentric circular pattern. Figure 3 ), Equidistant matrix arrangement ( Figure 4 ), hexagonal close-packed arrangement ( Figure 5 ) or a combination of centripetal circular arrangement and the other two arrangement methods ( Figure 6 ).

[0038] In this invention, the patterning method is preferably photolithography, chemical etching, or direct growth. This invention does not impose specific limitations on the parameters of the patterning method; methods well-known to those skilled in the art can be used.

[0039] In this invention, the chemical etching is preferably reactive ion etching, ion beam etching, or chemical etching.

[0040] After obtaining the patterned substrate, it is preferable to clean it, then fix the cleaned patterned substrate on a corrosion-resistant and high-temperature resistant base, and then transfer it into the reaction chamber for gallium oxide epitaxial growth.

[0041] In this invention, the cleaning is preferably ion cleaning, organic solvent cleaning, deionized water cleaning, acid washing, or alkaline washing. The purpose of the cleaning is to remove organic and inorganic contaminants so as to carry out subsequent steps and improve sample quality. The specific process parameters of the cleaning, such as cleaning time and sequence, are determined according to the selected substrate material and are not particularly limited.

[0042] In this invention, the corrosion-resistant and high-temperature resistant base is preferably made of quartz, ceramic or silicon carbide.

[0043] After obtaining the patterned substrate, the present invention performs gallium oxide epitaxial growth on the surface of the patterned substrate, and then removes the patterned substrate to obtain the large-size screen structure gallium oxide semiconductor thin film.

[0044] In this invention, the reaction source material for gallium oxide epitaxial growth preferably includes gallium-related substances, more preferably including elemental gallium or gallium compounds, wherein the elemental gallium is preferably metallic gallium, which can be liquid, solid, or gallium vapor; the gallium compound is preferably an inorganic salt of gallium, an organic salt of gallium, a gallium oxide, a gallium hydroxide, or a complex of gallium and an organic compound, more preferably gallium chloride, gallium sulfate, gallium acetylacetonate, trimethyl gallium, triethyl gallium, dialkyl gallium halide, gallium oxide, or gallium hydroxide.

[0045] In this invention, the preferred method for gallium oxide epitaxial growth is metal-organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), atomic layer deposition (ALD), sol-gel method, mist-chemical vapor deposition (Mist-CVD), electron beam evaporation (EBM), magnetron sputtering, low-pressure chemical vapor deposition (LPCVD), molecular beam epitaxy (MBE), or halide vapor phase epitaxy (HVPE). This invention does not limit the process conditions for gallium oxide epitaxial growth.

[0046] In this invention, the gallium oxide epitaxial growth preferably includes the following steps: Use nitrogen to purge the residual gas in the reaction chamber; The reaction chamber temperature setting and preheating provide temperature conditions for the oxidation of the patterned substrate (temperature range of 500~1300℃, specifically 500, 550, 600, 800, 1000, 1200 or 1300℃). Turn on the reaction gas (preferably oxygen, with a flow rate of 40 sccm), and the oxidation time of the patterned substrate is preferably 10~100 min, specifically 10, 20, 40, 60, 80 or 100 min; The reaction chamber temperature is set to provide the temperature conditions for gallium oxide thin film growth (temperature range is 400~1000℃, specifically 400, 600, 800 or 1000℃). The reaction chamber is kept at the growth temperature to begin growing gallium oxide thin films. The growth time is preferably 180 min.

[0047] In this invention, the gallium oxide thin film obtained by gallium oxide epitaxial growth is preferably crystalline gallium oxide or amorphous gallium oxide. The crystalline gallium oxide is preferably monocrystalline gallium oxide or polycrystalline gallium oxide. The crystal phase of the monocrystalline gallium oxide is preferably α, β, γ, δ or ε. The crystal phase of the polycrystalline gallium oxide thin film preferably includes any two or more of α, β, γ, δ and ε.

[0048] After the gallium oxide epitaxial growth is completed, the gallium oxide film is preferably taken out after being naturally cooled to room temperature. Preferably, the substrate is thinned first, and then the patterned substrate is removed to obtain the large-size screen structure gallium oxide semiconductor film.

[0049] The present invention does not limit the process of thinning the substrate. Preferably, the gallium oxide film is first cut to remove a portion of the substrate material, and then polished to continue thinning. Alternatively, chemical methods are preferred for thinning.

[0050] The present invention does not limit the thickness of the substrate thinning, but preferably the thinning thickness is 100~1000μm. The amount of thinning is directly related to the film thickness. The purpose is to thin the substrate while retaining the film with the band structure.

[0051] In this invention, the removal of the patterned substrate is preferably a stripping process, which is preferably mechanical stripping, laser stripping, or etch stripping.

[0052] In this invention, the etching and stripping process preferably involves first etching with a corrosive substance and then removing the substrate material.

[0053] This invention does not limit the corrosive substance, but preferably uses a corrosive gas or a corrosive solution. The corrosive gas is preferably an acidic or alkaline gas, specifically an acidic gas composed of hydrogen chloride gas and ozone in a certain proportion (volume ratio of hydrogen chloride gas to ozone 10:1~2:1), or an alkaline gas composed of ammonia gas, water vapor, and ozone in a certain proportion (volume ratio of ammonia gas, water vapor, and ozone 10:1:1~2:1:1). The corrosive solution is preferably an acidic or alkaline solution, more specifically an acidic solution composed of hydrochloric acid solution, sulfuric acid solution, nitric acid solution, and hydrogen peroxide solution in a certain proportion (molar ratio of hydrochloric acid, sulfuric acid, nitric acid, and hydrogen peroxide 5:3:1:0.5~3:2:1:1), or an acidic solution composed of phosphoric acid solution, hydrochloric acid solution, and hydrogen peroxide solution in a certain proportion (molar ratio of phosphoric acid, hydrochloric acid, and hydrogen peroxide 5:3:1~3:1:1). The substrate can be etched using a mixture of acidic solutions (2:1 ratio), or first etched using an acidic solution containing a mixture of chloric acid and hydrogen peroxide in a certain ratio (chloric acid to hydrogen peroxide molar ratio 5:3~3:1), followed by etching with a perchloric acid solution (mass concentration of 50%, perchloric acid reacts with carbon impurities on the surface of the gallium oxide film to remove carbon impurities). Alternatively, it can be an alkaline solution containing a mixture of potassium hydroxide solution, ammonia solution, tetramethylammonium hydroxide solution, and hydrogen peroxide solution in a certain ratio (ammonia solution is calculated as NH3, and the molar ratio of potassium hydroxide, NH3, tetramethylammonium hydroxide, and hydrogen peroxide is 5:3:1:0.5~3:2:1:1), or an alkaline solution containing a mixture of potassium hydroxide solution, tetramethylammonium hydroxide solution, and hydrogen peroxide solution in a certain ratio (potassium hydroxide, tetramethylammonium hydroxide, and hydrogen peroxide molar ratio 5:3:1:0.5~3:2:1:1).

[0054] The present invention does not limit the concentration of the corrosive gas and corrosive solution, but preferably it is 10% to 90% by mass or by volume. In a specific embodiment of the present invention, the corrosive solution is composed of 15wt% phosphoric acid, 10wt% hydrochloric acid, and 20wt% hydrogen peroxide solution in a volume ratio of 0.5:9:0.5, or composed of 25wt% potassium hydroxide, 28wt% ammonia solution, and 5wt% hydrogen peroxide solution in a volume ratio of 8:0.5:1.5, or composed of 10wt% chloric acid and 20wt% hydrogen peroxide solution in a volume ratio of 9.5:0.5.

[0055] In this invention, the waste chemical substances (including waste gas and wastewater) generated in the preparation method are preferably treated according to the specific waste chemical substance category, more preferably by acidic or alkaline waste treatment methods, or the waste can be collected in a centralized manner and transported to a qualified unit for harmless treatment.

[0056] This invention also provides a large-size sieve-structure gallium oxide semiconductor thin film prepared by the preparation method described above, wherein the area of ​​the large-size sieve-structure gallium oxide semiconductor thin film is 1~700 cm². 2 .

[0057] This invention also provides the application of the large-size screen structure gallium oxide semiconductor thin film in the field of optoelectronic devices, which can improve photoelectric response sensitivity and quality factor.

[0058] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0059] Example 1 Figure 1 This is a flowchart of the method for preparing a large-size sieve structure gallium oxide semiconductor thin film in Example 1. The Mist-CVD method is used to epitaxially grow a gallium oxide thin film on a patterned sapphire substrate, including the following steps: S1: Use Tanner EDA software to design the screen pattern structure. The screen pattern is a hexagonal close-packed arrangement, and the shape of each graphic is a conical protrusion.

[0060] S2: The screen pattern structure is transferred to the sapphire substrate by photolithography to obtain a patterned sapphire substrate. The obtained patterned sapphire substrate has an H / L ratio of 9.5:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern. The height of a single pattern is H = 1.9 μm and L = 200 nm.

[0061] S3: Cleaning the patterned sapphire substrate. First, clean the patterned sapphire substrate with acetone for 5 minutes, then with ethanol for 5 minutes, and then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0062] S4: Horizontally fix the cleaned patterned substrate on the quartz base, and then transfer it into the reaction chamber: Select the quartz base according to the substrate size.

[0063] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0064] S5: Preparation of reaction source: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0065] S6: Set growth adjustment and process, atomize the reaction source solution, and atomize the reaction source into uniform droplets in the atomization unit by ultrasonic atomization method. The ultrasonic atomization frequency is 3MHz.

[0066] S7: Large-size sieve structure whole-phase gallium oxide epitaxial sample growth, gallium oxide epitaxial layer growth: Nitrogen gas is used to purge residual gas in the reaction chamber, the reaction chamber temperature is set and preheated, the reaction chamber temperature is set to 550℃; the atomizer is turned on, the reaction source solution is atomized to form uniform droplets; the carrier gas is turned on, nitrogen is used as the carrier gas, the flow rate is 800 sccm; the reaction chamber maintains the growth temperature, and the growth of gallium oxide thin film begins, the growth time is set to 180 min.

[0067] S8: Take out the large-size sieve structure whole-phase gallium oxide epitaxial sample. The gallium oxide thin film growth is over. Turn off the atomizing device and carrier gas and keep it warm for 3 minutes. Then turn on the carrier gas and continuously introduce nitrogen to purge the residual reactants and by-products in the reaction chamber and let it cool naturally to room temperature. Take out the sample.

[0068] S9: Thinning of large-size sieve structure whole-phase gallium oxide epitaxial samples, reducing the substrate portion of patterned sapphire substrate epitaxial samples to 10μm.

[0069] S10: The substrate was removed by sample peeling to obtain a large-size sieve-structured gallium oxide thin film. The thinned sample was placed in a corrosive solution containing 15wt% phosphoric acid, 10wt% hydrochloric acid, and 20wt% hydrogen peroxide in a volume ratio of 0.5:9:0.5 and immersed for 10 minutes to remove the substrate, resulting in a large-size sieve-structured gallium oxide semiconductor thin film with an area of ​​20 cm². 2 The surface carbon content is 5.7%.

[0070] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.040°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0071] Example 2 Same as Example 1, except that the H / L ratio is 3:1 and H is 1.9 μm.

[0072] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm². 2 The FWHM is 0.113° and the surface carbon content is 5.6%.

[0073] Example 3 Same as Example 1, except that the H / L ratio is 6:1 and H is 1.9 μm.

[0074] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm².2 The FWHM is 0.071° and the surface carbon content is 5.7%.

[0075] Example 4 Same as Example 1, except that the H / L ratio is 12:1 and H is 3μm.

[0076] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm². 2 The FWHM is 0.069° and the surface carbon content is 5.6%.

[0077] Example 5 Same as Example 1, except that the H / L ratio is 15:1 and H is 1.9 μm.

[0078] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm². 2 The FWHM is 0.090° and the surface carbon content is 5.6%.

[0079] Example 6 The Mist-CVD method for epitaxial gallium oxide thin films on patterned aluminum substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0080] The screen pattern structure is transferred to an aluminum substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 9.1:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern. The height of a single pattern is 3 μm and L is 330 nm.

[0081] Patterned substrate cleaning: First clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen. Soak the dried substrate in hydrochloric acid for 10 seconds to remove the natural oxide layer on the surface. Then clean it with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0082] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0083] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0084] Preparation of the reaction source solution: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0085] The reaction source solution is atomized. The reaction source is atomized into uniform droplets in the atomization unit by ultrasonic atomization, and the ultrasonic atomization frequency is 3MHz.

[0086] Gallium oxide epitaxial layer growth: Nitrogen gas is used to purge residual gas from the reaction chamber. The reaction chamber temperature is set and preheated to 1250℃. The reaction gas is turned on, using oxygen at a flow rate of 40 sccm. While maintaining the reaction chamber temperature, a 20nm dense aluminum oxide layer is grown on the patterned substrate surface for 10 minutes. The reaction chamber temperature is set to 550℃. The atomization device is turned on, and the reaction source solution is atomized to form uniform droplets. The carrier gas is replaced with nitrogen at a flow rate of 400 sccm. The growth of the gallium oxide thin film begins, with a growth time set to 180 minutes.

[0087] After the gallium oxide thin film growth is completed, the atomizing device and carrier gas are turned off and kept at a constant temperature for 3 minutes. Then, the carrier gas is turned on and nitrogen is continuously introduced to purge the residual reactants and byproducts in the reaction chamber and allowed to cool naturally to room temperature before the sample is removed.

[0088] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0089] The thinned sample was immersed in a corrosive solution containing 15 wt% phosphoric acid, 10 wt% hydrochloric acid, and 20 wt% hydrogen peroxide in a volume ratio of 0.5:9:0.5 for 10 minutes to remove the substrate, yielding a large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​81 cm⁻¹. 2 .

[0090] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.091°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0091] Example 7 The Mist-CVD method for epitaxial gallium oxide thin films on patterned silicon substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0092] The screen pattern structure is transferred to a silicon substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 10:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern. The height of a single pattern is 2 μm and L is 200 nm.

[0093] Patterned substrate cleaning: First clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen. Soak the dried substrate in hydrochloric acid for 10 seconds to remove the natural oxide layer on the surface. Then clean it with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0094] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0095] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0096] Preparation of the reaction source solution: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0097] The reaction source solution is atomized. The reaction source is atomized into uniform droplets in the atomization unit by ultrasonic atomization, and the ultrasonic atomization frequency is 3MHz.

[0098] Gallium oxide epitaxial layer growth: Nitrogen gas is used to purge residual gas in the reaction chamber. The reaction chamber temperature is set and preheated to 950°C. The reaction gas is turned on, using oxygen at a flow rate of 40 sccm. While maintaining the reaction chamber temperature, a 10 nm dense silicon oxide layer is grown on the patterned substrate surface for 10 min. The reaction chamber temperature is set to 550°C. The atomization device is turned on, and the reaction source solution is atomized to form uniform droplets. The carrier gas is replaced with nitrogen at a flow rate of 400 sccm. The growth of the gallium oxide thin film begins, with a growth time set to 180 min.

[0099] After the gallium oxide thin film growth is completed, the atomizing device and carrier gas are turned off and kept at a constant temperature for 3 minutes. Then, the carrier gas is turned on and nitrogen is continuously introduced to purge the residual reactants and byproducts in the reaction chamber and allowed to cool naturally to room temperature before the sample is removed.

[0100] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0101] The thinned sample was immersed in a corrosive solution containing 15 wt% phosphoric acid, 10 wt% hydrochloric acid, and 20 wt% hydrogen peroxide in a volume ratio of 0.5:9:0.5 for 10 minutes to remove the substrate, yielding a large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​81 cm⁻¹. 2 .

[0102] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.089°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0103] Example 8 The Mist-CVD method for epitaxial gallium oxide thin films on patterned polycrystalline silicon substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0104] The screen pattern structure is transferred to a polycrystalline silicon substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 10:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern. The height of a single pattern is 2 μm and L is 200 nm.

[0105] Patterned substrate cleaning: First clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen. Soak the dried substrate in hydrochloric acid for 10 seconds to remove the natural oxide layer on the surface. Then clean it with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0106] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0107] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0108] Preparation of the reaction source solution: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0109] The reaction source solution is atomized. The reaction source is atomized into uniform droplets in the atomization unit by ultrasonic atomization, and the ultrasonic atomization frequency is 3MHz.

[0110] Gallium oxide epitaxial layer growth: Nitrogen gas is used to purge residual gas in the reaction chamber. The reaction chamber temperature is set and preheated to 950°C. The reaction gas is turned on, using oxygen at a flow rate of 40 sccm. While maintaining the reaction chamber temperature, a 10 nm dense silicon oxide layer is grown on the patterned substrate surface for 10 min. The reaction chamber temperature is set to 550°C. The atomization device is turned on, and the reaction source solution is atomized to form uniform droplets. The carrier gas is replaced with nitrogen at a flow rate of 400 sccm. The growth of the gallium oxide thin film begins, with a growth time set to 180 min.

[0111] After the gallium oxide thin film growth is completed, the atomizing device and carrier gas are turned off and kept at a constant temperature for 3 minutes. Then, the carrier gas is turned on and nitrogen is continuously introduced to purge the residual reactants and byproducts in the reaction chamber and allowed to cool naturally to room temperature before the sample is removed.

[0112] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0113] The thinned sample was immersed in a corrosive solution containing 15 wt% phosphoric acid, 10 wt% hydrochloric acid, and 20 wt% hydrogen peroxide in a volume ratio of 0.5:9:0.5 for 10 minutes to remove the substrate, yielding a large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​81 cm⁻¹. 2 .

[0114] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.088°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0115] Example 9 The HVPE method for epitaxial gallium oxide thin films on patterned polycrystalline silicon substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0116] The screen pattern structure is transferred to a polycrystalline silicon substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 10:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern. The height of a single pattern is 2 μm and L is 200 nm.

[0117] Patterned substrate cleaning: Clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0118] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0119] Gallium metal is placed in the gallium reaction region.

[0120] Gallium oxide epitaxial layer growth: Nitrogen gas was used to purge residual gas from the reaction chamber. The reaction chamber temperature was set and preheated to 950°C. The reaction gases were then turned on, using hydrogen chloride and oxygen at flow rates of 30 sccm and 500 sccm, respectively. The reaction chamber was maintained at the growth temperature, and gallium oxide film growth began, with a growth time set to 3 hours.

[0121] After the gallium oxide thin film growth is completed, nitrogen gas is continuously introduced through the carrier gas to purge the residual reactants and byproducts in the reaction chamber and the mixture is allowed to cool naturally to room temperature before the sample is removed.

[0122] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0123] The thinned sample was immersed in a corrosive solution containing 25 wt% potassium hydroxide, 28 wt% ammonia solution, and 5 wt% hydrogen peroxide solution in a volume ratio of 8:0.5:1.5 for 10 minutes to remove the substrate, yielding a large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​81 cm². 2 .

[0124] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.087°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0125] Example 10 The magnetron sputtering method for epitaxially growing gallium oxide thin films on patterned polycrystalline silicon substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0126] The screen pattern structure is transferred to a polycrystalline silicon substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 10:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in a periodic pattern. The height of a single pattern is 2 μm and L is 200 nm.

[0127] Patterned substrate cleaning: Clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0128] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0129] Gallium oxide target material is placed on magnetron sputtering AC target.

[0130] Prepare the vacuum environment by turning on the mechanical pump to evacuate the reaction chamber to 1 Pa, and then turning on the molecular pump to evacuate the reaction chamber to 1 × 10⁻⁶ Pa. -5 Pa.

[0131] Gallium oxide epitaxial layer growth: Turn on the argon gas switch, with an argon gas flow rate of 20 sccm. Set the magnetron sputtering current and voltage to 400V and 0.7A, respectively. After ignition, pre-sputter for 3 minutes, then open the baffle to start sputtering gallium oxide for 90 minutes.

[0132] After the gallium oxide thin film growth is completed, the magnetron sputtering equipment is turned off, the vacuum is released, and the sample is removed.

[0133] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0134] The thinned sample was immersed in a corrosive solution containing 25 wt% potassium hydroxide, 28 wt% ammonia solution, and 5 wt% hydrogen peroxide solution in a volume ratio of 8:0.5:1.5 for 10 minutes to remove the substrate, yielding a large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​81 cm². 2 .

[0135] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.085°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0136] Example 11 The Mist-CVD method for epitaxial gallium oxide thin films on patterned copper substrates includes the following steps: The screen pattern structure was designed using Tanner EDA software. The screen pattern is a hexagonal close-packed arrangement, and the shape of each individual graphic is a conical protrusion.

[0137] The screen pattern structure is transferred to a copper substrate by photolithography to obtain a patterned substrate. The obtained patterned substrate has an H / L ratio of 10:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern. The height of a single pattern is H = 2.5 μm and L = 250 nm.

[0138] Patterned substrate cleaning: First clean the patterned substrate with acetone for 5 minutes, then with ethanol for 5 minutes, then with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen. Soak the dried substrate in hydrochloric acid for 10 seconds to remove the natural oxide layer on the surface. Then clean it with deionized water for 5 minutes. Remove the substrate and dry it with nitrogen.

[0139] Select a quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0140] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0141] Preparation of the reaction source solution: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0142] The reaction source solution is atomized. The reaction source is atomized into uniform droplets in the atomization unit by ultrasonic atomization, and the ultrasonic atomization frequency is 3MHz.

[0143] Gallium oxide epitaxial layer growth: Nitrogen gas is used to purge residual gas from the reaction chamber. The reaction chamber temperature is set and preheated to 650°C. The reaction gas is turned on, using oxygen at a flow rate of 40 sccm. While maintaining the reaction chamber temperature, a 10 nm dense copper oxide layer is grown on the patterned substrate surface for 10 min at a reaction chamber temperature of 550°C. The atomizer is turned on, and the reaction source solution is atomized to form uniform droplets. The carrier gas is replaced with nitrogen at a flow rate of 400 sccm. Gallium oxide thin film growth begins for 180 min.

[0144] After the gallium oxide thin film growth is completed, the atomizing device and carrier gas are turned off and kept at a constant temperature for 3 minutes. Then, the carrier gas is turned on and nitrogen is continuously introduced to purge the residual reactants and byproducts in the reaction chamber and allowed to cool naturally to room temperature before the sample is removed.

[0145] The sample was thinned to 10 μm, reducing the substrate portion of the patterned substrate epitaxial sample.

[0146] The thinned sample was placed in a solution containing 500 mL of 10 wt% chloric acid and 20 wt% hydrogen peroxide in a volume ratio of 9.5:0.5 and immersed for 10 min to remove the patterned copper substrate. During this process, gas will be generated, so pay attention to ventilation. After removing the patterned copper substrate, the sample was immersed in a perchloric acid solution (mass concentration 50%) for 10 min to remove carbon impurities on the film surface.

[0147] A large-size gallium oxide semiconductor thin film with a sieve structure and an area of ​​20 cm² was obtained. 2 .

[0148] XRD analysis showed that the full width at half maximum (FWHM) of the large-size sieve structure gallium oxide semiconductor film was 0.077°, indicating that the sample had high crystal quality, low defect density, and low residual stress.

[0149] Comparative Example 1 Same as Example 1, except that H / L is 1.1379:1, the height H of a single pattern is 330nm, L is 290nm, and the shape of a single pattern is a conical protrusion.

[0150] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm². 2 The FWHM is 0.216° and the surface carbon content is 7%. Compared with the sample in Example 1, the crystal quality is poor, the defect density is high, and the residual stress is large.

[0151] Comparative Example 2 Same as Example 1, except that H / L is 1.458:1, the height H of a single pattern is 350nm, L is 240nm, and the shape of a single pattern is a conical pit.

[0152] The obtained large-size sieve-structured gallium oxide semiconductor thin film has an area of ​​20 cm². 2 The FWHM is 0.247° and the surface carbon content is 6.9%. Compared with the sample in Example 1, the crystal quality is poor, the defect density is high, and the residual stress is large.

[0153] Comparative Example 3 Sapphire substrate cleaning: The sapphire substrate was first cleaned with acetone for 5 minutes, then with ethanol for 5 minutes, and finally with deionized water for 5 minutes. The substrate was then removed and dried with nitrogen gas before use, without patterning.

[0154] Select a suitable quartz base according to the substrate size, fix the substrate horizontally on the quartz base, and then place it in the reaction chamber.

[0155] Fix and adjust the position of the shower head. The shower head is located 2mm directly below the substrate. The upper end of the shower head is parallel to the substrate. The holes in the hole array at the upper end of the shower head form a 45° angle with the normal of the upper end of the shower head, so that the raw material mist is directed towards the substrate surface at a 45° angle.

[0156] Preparation of the reaction source solution: Dissolve 18.5g of gallium acetylacetonate powder in deionized water to prepare a gallium source solution of 0.025mol / L.

[0157] The reaction source solution is atomized. The reaction source is atomized into uniform droplets in the atomization unit by ultrasonic atomization, and the ultrasonic atomization frequency is 3MHz.

[0158] Gallium oxide epitaxial layer growth: Nitrogen gas is used to purge the residual gas in the reaction chamber. The reaction chamber temperature is set and preheated to 550°C. The atomizing device is turned on, and the reaction source solution is atomized to form uniform droplets. The carrier gas is turned on, and nitrogen gas is used as the carrier gas with a flow rate of 400 sccm. The reaction chamber is kept at the growth temperature, and the growth of the gallium oxide thin film begins. The growth time is set to 180 min.

[0159] After the gallium oxide thin film growth is completed, the atomizing device and carrier gas are turned off and kept at a constant temperature for 3 minutes. Then, the carrier gas is turned on and nitrogen is continuously introduced to purge the residual reactants and byproducts in the reaction chamber and allowed to cool naturally to room temperature before the sample is removed.

[0160] The sample was thinned to 10 μm by thinning the substrate portion of the epitaxial sample on the sapphire substrate.

[0161] The thinned sample was placed in a corrosive solution containing 15wt% phosphoric acid, 10wt% hydrochloric acid, and 20wt% hydrogen peroxide in a volume ratio of 0.5:9:0.5, and immersed for 10 minutes to remove the substrate, yielding a fragmented gallium oxide semiconductor film, the largest portion of which had an area of ​​2.5 cm². 2 The surface carbon content is 23.6%.

[0162] XRD analysis showed that the obtained gallium oxide semiconductor thin film had a FWHM of 0.415°. Compared with Example 1, Comparative Examples 2 and 3, the sample had the worst crystal quality, the highest defect density, and the largest residual stress.

[0163] Comparative Example 4 Same as Example 1, except that the H / L ratio is 16:1, the height H of a single graphic is 8μm, the L is 0.5μm, and the shape of a single graphic is a conical protrusion.

[0164] The area of ​​the obtained gallium oxide semiconductor thin film is 20 cm². 2 The FWHM is 0.171° and the surface carbon content is 6.8%. Compared with the sample in Example 1, the crystal quality is poor, the defect density is high, and the residual stress is large.

[0165] Comparative Example 5 Same as Example 1, except that H / L is 20:1, the height H of a single graphic is 8μm, L is 0.4μm, and the shape of a single graphic is a conical protrusion.

[0166] The area of ​​the obtained gallium oxide semiconductor thin film is 20 cm². 2 The FWHM is 0.182° and the surface carbon content is 6.9%. Compared with the sample in Example 1, the crystal quality is poor, the defect density is high, and the residual stress is large.

[0167] Figure 7 The image shows the surface EDS energy spectrum characterization of the gallium oxide semiconductor thin film prepared in Comparative Example 3. Figure 8The image shows the surface EDS energy spectrum characterization of the large-size sieve structure gallium oxide semiconductor film prepared in Example 11. It can be seen that the surface carbon content of the large-size sieve structure gallium oxide semiconductor film prepared in Example 11 is significantly reduced to 3%, while the surface carbon content of the gallium oxide semiconductor film prepared in Comparative Example 3 is 23.6%. This indicates that the etching solution formulation and etching method of Example 11 can effectively remove carbon impurities on the surface of the gallium oxide semiconductor film.

[0168] Figure 9 The results of the full peak half-width at half-maximum (FWHM) of gallium oxide semiconductor thin films prepared in Examples 1, 1, and 2 are shown. Sample numbers 1, 2, and 3 correspond to Examples 1, 1, and 2, respectively. It can be seen that the sample prepared in Example 1 has the best crystal quality, the lowest defect density, and the lowest residual stress.

[0169] Figure 10 The images shown are scanning electron microscope (SEM) images of a patterned sapphire substrate taken from different angles, as shown in Example 1.

[0170] Figure 11 The image shows a patterned sapphire substrate at different angles, as shown in Comparative Example 1.

[0171] Figure 12 Comparative Example 2: Scanning electron microscope images of a patterned sapphire substrate taken from different angles.

[0172] Figure 13 The images shown are actual pictures of the gallium oxide semiconductor films prepared in Example 1 and Comparative Example 3. It can be seen that Comparative Example 3 cannot obtain gallium oxide semiconductor films with large-size sieve structures.

[0173] In summary, this invention: (1) Achieve complete peeling of large-size screen structure gallium oxide semiconductor thin films; (2) A large-size screen structure gallium oxide semiconductor thin film was obtained; (3) The defect density on the surface of the large-size screen structure gallium oxide semiconductor thin film is significantly reduced and the surface stress distribution is uniform, resulting in improved device performance. (4) The carbon impurities on the surface of the obtained large-size sieve structure gallium oxide semiconductor thin film were basically removed, and the surface carbon content was significantly reduced to 3%; (5) The stress concentration phenomenon on the surface of the large-size screen structure gallium oxide semiconductor thin film and the edge of the screen is significantly alleviated, and the integrity of the film is significantly improved.

[0174] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a large-size sieve-structured gallium oxide semiconductor thin film, characterized in that, Includes the following steps: A patterned substrate is provided; the patterned substrate includes a substrate body and a periodic pattern, wherein the H / L ratio of the periodic pattern is 3~15:1, where H refers to the height of a single pattern and L is the distance between two adjacent patterns in the periodic pattern; Gallium oxide epitaxial growth is performed on the surface of the patterned substrate, and then the patterned substrate is removed to obtain the large-size screen structure gallium oxide semiconductor thin film.

2. The preparation method according to claim 1, characterized in that, The periodic pattern includes one or more of the following: centripetal circular arrangement, equidistant matrix arrangement, and hexagonal close-packed arrangement. When the periodic pattern is a centripetal circular arrangement, the gap between two adjacent centripetal circular arrangement units is 0.05 to 0.5 times the radius of the centripetal circular arrangement unit. When the periodic pattern is an equidistant matrix arrangement, the gap between two adjacent equidistant matrix arrangement units is 0.05 to 0.5 times the length of the equidistant matrix arrangement unit. When the periodic pattern is a hexagonal close-packed arrangement, the gap between two adjacent hexagonal close-packed arrangement units is 0.05 to 0.5 times the length of the hexagonal close-packed arrangement unit.

3. The preparation method according to claim 1 or 2, characterized in that, The height of a single graphic is 0.3~3000μm.

4. The preparation method according to claim 1, characterized in that, The shape of the individual graphic can be a circle, triangle, rectangle, polygon, or irregular shape.

5. The preparation method according to claim 1 or 4, characterized in that, The shape of the single graphic includes one or more of the following: circular concave hole, circular protrusion, square concave hole, square protrusion, conical concave hole, conical protrusion, square concave hole, square concave protrusion, truncated cone concave hole, truncated cone protrusion, square concave hole, square concave protrusion, trapezoidal concave hole, trapezoidal protrusion, polygonal concave hole, polygonal protrusion, polygonal truncated cone concave hole, polygonal truncated cone protrusion, irregular graphic concave hole, and irregular graphic protrusion.

6. The preparation method according to claim 5, characterized in that, The angle between the hypotenuse of the conical recess, conical protrusion, square conical recess, square conical protrusion, truncated cone recess, truncated cone protrusion, square conical recess, square conical protrusion, trapezoidal recess, trapezoidal protrusion, polygonal recess, polygonal protrusion, polygonal truncated cone recess, and polygonal truncated cone protrusion and the substrate is independently 90~180°.

7. The preparation method according to claim 5, characterized in that, The angle between the hypotenuse of the circular and square recesses and the substrate is independently 90° to 180°.

8. The preparation method according to claim 1 or 4, characterized in that, The patterned substrate is prepared by a method comprising the following steps: transferring a screen pattern structure to a substrate using a patterning method to obtain the patterned substrate.

9. The preparation method according to claim 8, characterized in that, The patterning method is photolithography, chemical etching, or direct growth.

10. The large-size sieve-structure gallium oxide semiconductor thin film prepared by the preparation method according to any one of claims 1 to 9, characterized in that, The area of ​​the large-size screen structure gallium oxide semiconductor thin film is 1~700cm². 2 .

Images