Gallium oxide epitaxial wafer preparation method, epitaxial growth system and gallium oxide epitaxial wafer

Abstract

The present invention provides a method for preparing a gallium oxide epitaxial wafer, an epitaxial growth system and a gallium oxide epitaxial wafer. The method comprises: placing a (100)-surface gallium oxide substrate in a reaction chamber, introducing a carrier gas of a first preset flow rate, setting the pressure in the reaction chamber to the first preset pressure, and heating the reaction chamber to a first preset temperature; introducing a second preset flow rate of hydrogen to pretreat the (100)-surface gallium oxide substrate; setting the pressure in the reaction chamber to the second preset pressure, heating the source region to the second preset temperature, and heating the growth region to a third preset temperature; introducing a third preset flow rate of hydrogen chloride, a fourth preset flow rate of oxygen and a fifth preset flow rate of hydrogen in the reaction chamber to perform gas phase epitaxy, so as to prepare a (100)-surface gallium oxide epitaxial film on the surface of the (100)-surface gallium oxide substrate. The present invention can promote step flow growth, reduce polycrystalline particle aggregation, reduce three-dimensional island growth, and improve the surface continuity and quality of the epitaxial film.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a gallium oxide epitaxial wafer preparation method, an epitaxial growth system and a gallium oxide epitaxial wafer. Background Art

[0002] As a new generation of ultra-wide bandgap semiconductor materials, gallium oxide has important application prospects in the field of high-power, low-loss power electronic devices due to its excellent properties. Gallium oxide materials for power devices are composed of two parts: substrate and epitaxial film. As the epitaxial film of the device functional layer, high-thickness, high-quality homoepitaxial growth is required to meet the use requirements of high-voltage and high-power devices.

[0003] At present, among the gallium oxide substrates used in power devices, the (001) and (100) planes are easier to achieve large-size single crystal preparation, especially the (001) plane has achieved commercialization of substrates and epitaxial wafers. However, there are still many difficulties in the homoepitaxial growth of gallium oxide on the (100) plane. The existing metal-organic chemical vapor deposition (MOCVD) epitaxial technology cannot achieve the preparation of high-thickness and high-quality epitaxial films, and the growth rate is slow and the epitaxial size is small. The hydride vapor phase epitaxy (HVPE) technology has a fast growth rate and high crystal purity, but the HVPE method for growing (100)-plane gallium oxide epitaxial films has problems such as poor continuity and aggregation of polycrystalline particles. Summary of the invention

[0004] The embodiments of the present invention provide a gallium oxide epitaxial wafer preparation method, an epitaxial growth system and a gallium oxide epitaxial wafer to solve the problems of poor continuity and polycrystalline grain aggregation in growing a (100) face gallium oxide epitaxial film by HVPE method.

[0005] In a first aspect, an embodiment of the present invention provides a method for preparing a gallium oxide epitaxial wafer, comprising:

[0006] Placing a (100)-plane gallium oxide substrate in a reaction chamber, introducing a carrier gas at a first preset flow rate, setting the pressure in the reaction chamber to a first preset pressure, and heating the reaction chamber to a first preset temperature;

[0007] Passing hydrogen gas at a second preset flow rate to pretreat the (100)-plane gallium oxide substrate;

[0008] Setting the pressure in the reaction chamber to a second preset pressure, raising the temperature of the source region to a second preset temperature, and raising the temperature of the growth region to a third preset temperature;

[0009] A third preset flow rate of hydrogen chloride, a fourth preset flow rate of oxygen, and a fifth preset flow rate of hydrogen are introduced into the reaction chamber to perform vapor phase epitaxy to prepare a (100)-plane gallium oxide epitaxial film on the surface of the (100)-plane gallium oxide substrate.

[0010] In a possible implementation, the fifth preset flow rate ranges from 0.5 to 1.5 sccm.

[0011] In a possible implementation, the fifth preset flow rate decreases as the off-angle of the (100)-plane gallium oxide substrate increases.

[0012] In a possible implementation, the off-angle range of the (100)-plane gallium oxide substrate is 0° to 6°.

[0013] In one possible implementation, the third preset flow rate ranges from 10 to 30 sccm, the fourth preset flow rate ranges from 20 to 200 sccm, the second preset pressure ranges from 100 to 400 mbar, the second preset temperature ranges from 850 to 900°C, and the third preset temperature ranges from 950 to 1000°C.

[0014] In a possible implementation manner, the flow rate ratio of the third preset flow rate to the fourth preset flow rate is determined based on the off angle of the (100)-plane gallium oxide substrate.

[0015] In a possible implementation, the second preset flow rate ranges from 20 to 50 sccm, and the duration of pre-treating the (100)-plane gallium oxide substrate ranges from 10 to 15 minutes.

[0016] In a possible implementation, the first preset flow rate is 5200 sccm, the carrier gas is nitrogen or argon, the first preset pressure ranges from 100 to 400 mbar, and the first preset temperature ranges from 500 to 600°C.

[0017] In a possible implementation manner, before setting the pressure in the reaction chamber to the second preset pressure, the method further includes:

[0018] The introduction of hydrogen was stopped, and the pressure in the reaction chamber was set to 0 mbar until the hydrogen in the reaction chamber was completely removed.

[0019] In a second aspect, an embodiment of the present invention provides an epitaxial growth system, comprising a reaction chamber, an air intake device, a pressure regulating device, a temperature regulating device, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the reaction chamber, the air intake device, the pressure regulating device, and the temperature regulating device are controlled to perform the steps of the method for preparing a gallium oxide epitaxial wafer as described in the first aspect or any possible implementation of the first aspect.

[0020] In a third aspect, an embodiment of the present invention provides a gallium oxide epitaxial wafer, which is prepared based on the gallium oxide epitaxial wafer preparation method described in the first aspect or any possible implementation of the first aspect.

[0021] The embodiment of the present invention provides a gallium oxide epitaxial wafer preparation method, an epitaxial growth system and a gallium oxide epitaxial wafer. Before homoepitaxial growth, the gallium oxide substrate is pretreated by hydrogen to remove the sub-damaged layer on the surface of the gallium oxide substrate, expose the atomic steps, and promote step flow growth. In the process of homoepitaxial growth, hydrogen is added to the reaction source gas to promote surface migration, which is beneficial to obtain step flow growth. At the same time, the characteristic of hydrogen decomposing gallium oxide is utilized to reduce the aggregation of polycrystalline particles and reduce three-dimensional island growth, so as to improve the surface consistency and quality of the epitaxial film. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a flow chart of a method for preparing a gallium oxide epitaxial wafer provided in one embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of an epitaxial growth system provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0025] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0027] See also Figure 1 , which shows a flow chart of the method for preparing a gallium oxide epitaxial wafer provided by an embodiment of the present invention, and is described in detail as follows:

[0028] Step 101, placing a (100)-plane gallium oxide substrate in a reaction chamber, introducing a carrier gas at a first preset flow rate, setting the pressure in the reaction chamber to a first preset pressure, and heating the reaction chamber to a first preset temperature.

[0029] In this embodiment, a (100)-surface gallium oxide substrate is placed in a reaction chamber, a carrier gas is introduced, and the ambient pressure and temperature are set to create good initial conditions for the subsequent step of performing homoepitaxial growth of (100)-surface gallium oxide. The flow rate of the carrier gas, the pressure and temperature of the reaction chamber can be set according to actual conditions. (100)-surface gallium oxide homoepitaxial growth refers to homoepitaxially growing a micron-sized gallium oxide single crystal film on a (100)-surface gallium oxide single crystal substrate.

[0030] Step 102 , introducing hydrogen gas at a second preset flow rate to pre-treat the (100)-plane gallium oxide substrate.

[0031] In this embodiment, since gallium oxide is a monoclinic crystal, the properties of different crystal planes vary greatly. At the same time, due to the existence of pre-reaction, polycrystalline aggregation is more likely to occur during the epitaxial growth process, which ultimately makes the epitaxial film surface poorly coherent and easily generates polycrystalline particles.

[0032] In this embodiment, a small amount of hydrogen is introduced. By utilizing the property of hydrogen to decompose gallium oxide, the sub-damaged layer on the surface of the gallium oxide substrate can be removed, exposing the atomic steps and promoting step flow growth. Step flow growth refers to the process in which adsorbed atoms are adsorbed to the surface of the crystal plane, diffuse and migrate on the table until they reach the step, where they form a compound and are incorporated into the crystal lattice. As the growth proceeds, the steps flow from left to right. After a layer is grown, the surface still maintains a step state. Step flow growth is the best epitaxial layer growth mode for obtaining a complete lattice structure and a smooth surface.

[0033] Step 103, setting the pressure in the reaction chamber to a second preset pressure, heating the source region to a second preset temperature, and heating the growth region to a third preset temperature.

[0034] In this embodiment, after the pretreatment in step 101 and step 102 is completed, the environment of the epitaxial growth system is adjusted to perform subsequent epitaxial growth. The second preset pressure, the second preset temperature and the third preset temperature can all be selected according to actual conditions.

[0035] Step 104 , introducing hydrogen chloride at a third preset flow rate, oxygen at a fourth preset flow rate, and hydrogen at a fifth preset flow rate into the reaction chamber to perform vapor phase epitaxy to prepare a (100)-plane gallium oxide epitaxial film on the surface of the (100)-plane gallium oxide substrate.

[0036] In this embodiment, the conventional HVPE method grows the (100)-plane gallium oxide epitaxial film, and the reaction sources used are hydrogen chloride and oxygen. However, due to the unique monoclinic crystal characteristics of β-Ga2O3, the properties of different crystal planes are quite different, especially the (100) plane has a low surface energy and a low atomic surface migration rate. Using only hydrogen chloride and oxygen as reaction sources, it is easy to form three-dimensional island growth and produce composite defects of screw dislocations and polycrystalline particle aggregation, resulting in poor surface continuity of the epitaxial layer, making it difficult to obtain a single crystal epitaxial layer with a smooth surface.

[0037] In this embodiment, a small amount of hydrogen is introduced during epitaxial growth, which can act as a promoter, promote surface migration during the growth process, and is conducive to obtaining step flow growth; at the same time, hydrogen can decompose gallium oxide, and the introduction of hydrogen can reduce the aggregation of polycrystalline particles during the growth process and improve the surface continuity and quality of the epitaxial film.

[0038] In the embodiment of the present invention, before homoepitaxial growth is performed, the gallium oxide substrate is pretreated with hydrogen to remove the sub-damaged layer on the surface of the gallium oxide substrate, expose the atomic steps, and promote step flow growth. In the process of homoepitaxial growth, hydrogen is added to the reaction source gas to promote surface migration, which is beneficial to obtaining step flow growth. At the same time, the characteristic of hydrogen decomposing gallium oxide is utilized to reduce the aggregation of polycrystalline particles and reduce three-dimensional island growth, thereby improving the surface continuity and quality of the epitaxial film.

[0039] In a possible implementation, the fifth preset flow rate ranges from 0.5 to 1.5 sccm.

[0040] In this embodiment, the hydrogen introduced during the epitaxial growth process is used to promote surface migration and decompose the aggregated gallium oxide, reduce the aggregation of polycrystalline particles, and reduce the three-dimensional island growth. An appropriate hydrogen flow rate should be selected to improve the quality of the epitaxial film without decomposing the gallium oxide epitaxial film in large quantities. The flow rate range provided in this embodiment can achieve a good epitaxial growth effect.

[0041] In a possible implementation, the fifth preset flow rate decreases as the off-angle of the (100)-plane gallium oxide substrate increases.

[0042] In this embodiment, as the off-angle of the gallium oxide substrate increases, the atomic step width on the surface of the gallium oxide substrate decreases, and the flow rate of the introduced hydrogen is reduced accordingly, which is more conducive to obtaining step flow growth.

[0043] In a possible implementation, the off-angle range of the (100)-plane gallium oxide substrate is 0° to 6°.

[0044] In this embodiment, the off-angle of the gallium oxide substrate refers to the angular deviation of the wafer surface relative to the ideal crystal plane. The off-angle range of commonly used gallium oxide substrates is usually between ±0.5° and ±3°. This embodiment is applicable to gallium oxide substrates with an off-angle range of 0-6°.

[0045] In one possible implementation, the third preset flow rate ranges from 10 to 30 sccm, the fourth preset flow rate ranges from 20 to 200 sccm, the second preset pressure ranges from 100 to 400 mbar, the second preset temperature ranges from 850 to 900°C, and the third preset temperature ranges from 950 to 1000°C.

[0046] In this embodiment, the growth temperature, reaction chamber pressure and reaction gas flow rate will affect the effect of HVPE epitaxial growth. Too high a temperature may cause material decomposition, while too low a temperature may affect the quality of the film. The ratio of different gases directly affects the composition and crystal quality of the film. Generally, high pressure is conducive to increasing the growth rate, but may increase the defect density in the film; low pressure can improve the quality of the film, but the growth rate will be slower.

[0047] The third preset flow rate range, the fourth preset flow rate range, the second preset pressure range of 100-400 mbar, 850-900° C. and the third preset temperature range provided in this embodiment can achieve better epitaxial growth effect.

[0048] In a possible implementation manner, the flow rate ratio of the third preset flow rate to the fourth preset flow rate is determined based on the off angle of the (100)-plane gallium oxide substrate.

[0049] In this embodiment, in the thin film deposition process, the substrate deflection angle has an important influence on the quality and uniformity of the thin film. The change of the substrate deflection angle will directly affect the way the reaction source gas reaches the substrate surface, thereby affecting the growth characteristics of the thin film. Therefore, it is necessary to adjust the reaction source gas flow ratio according to the difference in substrate deflection angle.

[0050] In a possible implementation, the second preset flow rate ranges from 20 to 50 sccm, and the duration of pre-treating the (100)-plane gallium oxide substrate ranges from 10 to 15 minutes.

[0051] In this embodiment, the purpose of pre-treating the gallium oxide substrate is to remove the sub-damaged layer on the surface of the gallium oxide substrate. The flow rate range and treatment time provided in this embodiment can achieve a good pre-treatment effect. As the flow rate of hydrogen gas increases, the reaction rate of hydrogen gas with the surface of the gallium oxide substrate increases, and the time for pre-treating the gallium oxide substrate can be appropriately shortened.

[0052] In a possible implementation, the first preset flow rate is 5200 sccm, the carrier gas is nitrogen or argon, the first preset pressure ranges from 100 to 400 mbar, and the first preset temperature ranges from 500 to 600°C.

[0053] In this embodiment, during the epitaxial growth process, the carrier gas is an auxiliary gas, which is mainly used to transport the reaction gas to the substrate in the reaction chamber and help maintain the stability of the reaction environment. The flow rate of the carrier gas, the reaction temperature, and the reaction pressure should be determined by comprehensively considering the required reaction rate and the chemical properties of the reactants.

[0054] The carrier gas flow rate, the range of the first preset pressure and the reaction of the first preset temperature in this embodiment are determined based on the reaction characteristics of the gallium oxide pretreatment, and the specific reaction pressure and temperature can be selected within the range according to actual needs.

[0055] In a possible implementation manner, before setting the pressure in the reaction chamber to the second preset pressure, the method further includes:

[0056] The introduction of hydrogen was stopped, and the pressure in the reaction chamber was set to 0 mbar until the hydrogen in the reaction chamber was completely removed.

[0057] In this embodiment, since the hydrogen flow rate used in the pretreatment process is much larger than the hydrogen flow rate introduced during the epitaxial growth process, if there is residual hydrogen from the pretreatment process in the reaction chamber during epitaxial growth, the hydrogen flow rate actually participating in the reaction during the epitaxial growth process may have a large error, resulting in poor results in the actual epitaxial growth process.

[0058] In order to prevent the epitaxial growth process from being affected by the residual hydrogen in the reaction chamber, the hydrogen in the reaction chamber should be completely removed after the pretreatment is completed before the epitaxial growth is performed.

[0059] In a specific embodiment, the method for preparing a gallium oxide epitaxial wafer provided by the present invention may include the following steps:

[0060] Step (1): placing a gallium oxide substrate in a reaction chamber, using 5200 sccm of nitrogen or argon as a carrier gas, and setting the pressure in the reaction chamber to 100-400 mbar;

[0061] Step (2): heating up the epitaxial growth system to ensure that the chamber temperature rises to 500-600°C;

[0062] Step (3): After the temperature is stabilized, hydrogen gas is introduced into the chamber to pre-treat the substrate, wherein the flow rate of hydrogen gas is in the range of 20-50 sccm and the treatment time is in the range of 10-15 min;

[0063] Step (4): After the preset time is reached, stop introducing hydrogen and set the pressure in the chamber to 0 mbar until the hydrogen is completely removed;

[0064] Step (5): resetting the pressure in the reaction chamber to 100-400 mbar, raising the source zone temperature of the epitaxial growth system to 850-900°C, and raising the growth zone temperature to 950-1000°C;

[0065] Step (6): after the temperature stabilizes, hydrogen chloride and oxygen are introduced into the chamber as reaction source gases, wherein the flow rate of hydrogen chloride is in the range of 10-30 sccm, and the flow rate of oxygen is in the range of 20-200 sccm;

[0066] Step (7): introducing a small amount of hydrogen gas, wherein the flow rate of hydrogen gas is in the range of 0.5 to 1.5 sccm;

[0067] Step (8): After the epitaxial growth is completed, the chamber temperature is set to 23°C and wait for the temperature to naturally cool to room temperature;

[0068] Step (9): Repeat steps (1) to (7), which is applicable to the preparation of homoepitaxial films on gallium oxide substrates with an inclination angle of 0 to 6° (100). According to the difference in the substrate inclination angle, the flow ratio of the reaction source gas and the flow rate of hydrogen are adjusted.

[0069] According to the actual demand for epitaxial film thickness, the above steps (1) to (7) can be repeated multiple times to perform multiple epitaxial growths to prepare gallium oxide epitaxial wafers with different epitaxial film thicknesses.

[0070] As can be seen from the above, the embodiment of the present invention uses a trace amount of hydrogen to assist the reaction source gas to prepare the (100)-face gallium oxide epitaxial film, which promotes the step flow growth method, overcomes the problems of poor continuity and polycrystalline aggregation in the preparation of the (100)-face gallium oxide epitaxial film by conventional HVPE technology, and achieves high-quality single crystal epitaxial growth, with a smooth epitaxial film surface and good continuity. The present invention effectively promotes the epitaxial growth research of gallium oxide materials and provides new ideas for the subsequent production of gallium oxide devices and their performance improvement.

[0071] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0072] An embodiment of the present invention also provides an epitaxial growth system, comprising a reaction chamber, an air intake device, a pressure regulating device, a temperature regulating device, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the processor controls the reaction chamber, the air intake device, the pressure regulating device, and the temperature regulating device to perform the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0073] Figure 2 Schematic diagram of an epitaxial growth system provided by an embodiment of the present invention. Figure 2 As shown, the epitaxial growth system 2 of this embodiment includes: a processor 20, a memory 21, and a computer program 22 stored in the memory 21 and executable on the processor 20. When the processor 20 executes the computer program 22, the steps in the above-mentioned embodiments of the method for preparing a gallium oxide epitaxial wafer are implemented. Alternatively, when the processor 20 executes the computer program 22, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0074] Exemplarily, the computer program 22 may be divided into one or more modules / units, which are stored in the memory 21 and executed by the processor 20 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 22 in the epitaxial growth system 2.

[0075] The epitaxial growth system 2 may include, but is not limited to, a processor 20 and a memory 21. Those skilled in the art will appreciate that Figure 2 It is only an example of the epitaxial growth system 2 and does not constitute a limitation of the epitaxial growth system 2. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the epitaxial growth system may also include input and output devices, network access devices, buses, etc.

[0076] The processor 20 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0077] The memory 21 may be an internal storage unit of the epitaxial growth system 2, such as a hard disk or memory of the epitaxial growth system 2. The memory 21 may also be an external storage device of the epitaxial growth system 2, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the epitaxial growth system 2. Furthermore, the memory 21 may also include both an internal storage unit and an external storage device of the epitaxial growth system 2. The memory 21 is used to store the computer program and other programs and data required by the epitaxial growth system. The memory 21 may also be used to temporarily store data that has been output or is to be output.

[0078] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0079] An embodiment of the present invention further provides a gallium oxide epitaxial wafer, which is prepared based on the gallium oxide epitaxial wafer preparation method described in the first aspect or any possible implementation of the first aspect.

[0080] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0081] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for preparing a gallium oxide epitaxial wafer, characterized in that: include: Placing a (100)-plane gallium oxide substrate in a reaction chamber, introducing a carrier gas at a first preset flow rate, setting the pressure in the reaction chamber to a first preset pressure, and heating the reaction chamber to a first preset temperature; Passing hydrogen gas at a second preset flow rate to pretreat the (100)-plane gallium oxide substrate; Setting the pressure in the reaction chamber to a second preset pressure, raising the temperature of the source region to a second preset temperature, and raising the temperature of the growth region to a third preset temperature; A third preset flow rate of hydrogen chloride, a fourth preset flow rate of oxygen, and a fifth preset flow rate of hydrogen are introduced into the reaction chamber to perform HVPE vapor phase epitaxy to prepare a (100)-face gallium oxide epitaxial film on the surface of the (100)-face gallium oxide substrate.

2. The method for preparing a gallium oxide epitaxial wafer according to claim 1, characterized in that: The fifth preset flow rate ranges from 0.5 to 1.5 sccm.

3. The method for preparing a gallium oxide epitaxial wafer according to claim 2, characterized in that: The fifth preset flow rate decreases as the off-angle of the (100)-plane gallium oxide substrate increases; the off-angle range of the (100)-plane gallium oxide substrate is 0° to 6°.

4. The method for preparing a gallium oxide epitaxial wafer according to claim 1, characterized in that: The third preset flow rate ranges from 10 to 30 sccm, the fourth preset flow rate ranges from 20 to 200 sccm, the second preset pressure ranges from 100 to 400 mbar, the second preset temperature ranges from 850 to 900°C, and the third preset temperature ranges from 950 to 1000°C.

5. The method for preparing a gallium oxide epitaxial wafer according to claim 4, characterized in that: The flow rate ratio of the third preset flow rate to the fourth preset flow rate is determined based on the off angle of the (100)-plane gallium oxide substrate.

6. The method for preparing a gallium oxide epitaxial wafer according to claim 1, characterized in that: The second preset flow rate ranges from 20 to 50 sccm, and the duration of pre-treating the (100)-plane gallium oxide substrate ranges from 10 to 15 minutes.

7. The method for preparing a gallium oxide epitaxial wafer according to claim 1, characterized in that: The first preset flow rate is 5200 sccm, the carrier gas is nitrogen or argon, the first preset pressure ranges from 100 to 400 mbar, and the first preset temperature ranges from 500 to 600°C.

8. The method for preparing a gallium oxide epitaxial wafer according to claim 1, characterized in that: Before setting the pressure in the reaction chamber to the second preset pressure, the method further comprises: The introduction of hydrogen was stopped, and the pressure in the reaction chamber was set to 0 mbar until the hydrogen in the reaction chamber was completely removed.

9. An epitaxial growth system, characterized in that: The method comprises a reaction chamber, an air inlet device, a pressure regulating device, a temperature regulating device, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the reaction chamber, the air inlet device, the pressure regulating device, and the temperature regulating device are controlled to execute the steps of the method according to any one of claims 1 to 8.

10. A gallium oxide epitaxial wafer, characterized in that: The gallium oxide epitaxial wafer is prepared based on the method for preparing the gallium oxide epitaxial wafer according to any one of claims 1 to 8.

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