Gallium oxide epitaxial device compatible with HVPE and MOCVD processes and gallium oxide film preparation process

Abstract

The invention discloses a gallium oxide epitaxial device compatible with HVPE and MOCVD processes and a gallium oxide film preparation process. The gallium oxide epitaxial device comprises a source region, an epitaxial growth region, a tail exhaust system and a cooling system, the source region adopts a furnace tube structure, a gallium boat for containing Ga metal is arranged in the source region, the source region is used for heating the Ga metal and providing Ga-containing gas, the epitaxial growth region is placed in a glove box, a substrate enters and exits from the epitaxial growth region in a manual mode, and a gallium oxide film is formed in the epitaxial growth region by the substrate; the gas inlet end of the epitaxial growth region is connected with the source region through a pipeline with a gas flow shut-off valve, a plurality of gas conveying pipes are arranged at the gas inlet end, the exhaust end of the epitaxial growth region is connected with a tail exhaust system, and the tail exhaust system is used for exhausting waste gas in the epitaxial growth region; and the cooling system is connected with the source region, the epitaxial growth region and the tail exhaust system respectively. The device has the advantages of being compact in structure, convenient to operate, high in reliability and the like, and gallium oxide epitaxial layers with different growth rates and different epitaxial thicknesses can be prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of gallium oxide thin film preparation, and in particular to a gallium oxide epitaxial device and a gallium oxide thin film preparation process compatible with HVPE and MOCVD processes. Background Art

[0002] Gallium oxide (Ga2O3) material has excellent properties such as large bandgap, high breakdown field strength, low on-resistance, and low growth cost. It can be used to make semiconductor devices such as solar-blind ultraviolet optoelectronic devices and high-power power electronic devices. It has strategic significance in the fields of new energy vehicles and next-generation communications. There are five crystal structures of gallium oxide, of which β-Ga2O3 is grown by the melt method. β-Ga2O3 is also the fourth-generation semiconductor material that has been most studied in academia and is closest to application.

[0003] As a strategic advanced semiconductor material, gallium oxide materials have received great attention in recent years. The domestic gallium oxide single crystal substrate preparation technology has developed rapidly, and the development of 6-inch substrates and small-scale commercialization of 4-inch substrates have been achieved. However, the gallium oxide epitaxial growth process is still in the scientific research stage. For gallium oxide power devices, epitaxy is an indispensable link, and the quality of epitaxial film plays a vital role in device performance. The choice of epitaxial equipment and process route determines the quality of epitaxial film and future industrialization costs, so it is necessary to conduct in-depth research on epitaxial equipment and process routes.

[0004] At present, the technical routes used to prepare gallium oxide epitaxial materials in the prior art include MBE, HVPE, OVPE, LPCVD, MOCVD, Mist-CVD, etc. The MBE method has an extremely low deposition rate, is expensive, and has high vacuum requirements. It is only suitable for manufacturing lateral devices and is not suitable for future industrialization needs. Therefore, it is mainly used for laboratory research. The fogging of the Mist-CVD method is extremely difficult to control. It is mainly used for the epitaxial growth of α-Ga2O3. The application field is also relatively limited and difficult to promote on a large scale. The HVPE method is a method that is currently studied more for gallium oxide epitaxy. It has a fast growth rate, low equipment and process costs, and a low fatal defect density of the epitaxial layer achieved by the HVPE method. The above advantages are suitable for future industrial growth, but the surface roughness of the thick film epitaxial film is relatively large, and CMP polishing is required after epitaxy. It is easy to have uncontrollable doping of Si elements, which affects the stability and reliability of the device. At present, Japan's NCT company has achieved SBD device tape-out through the HVPE method, proving the feasibility of the HVPE route. In addition, the MOCVD method is also one of the mainstream choices for many research institutes and universities to carry out gallium oxide epitaxy, because the MOCVD method has a fast film deposition speed, good film quality, good doping controllability, and can be mass-produced. However, MOCVD equipment is relatively complex and expensive. Commonly used gallium sources such as trimethylgallium (TMGa) or triethylgallium (TEGa) are 5 to 10 times more expensive than metallic gallium. The raw material utilization efficiency in the epitaxial process is low, so the process cost is high, which limits the current exploration of the MOCVD method for gallium oxide epitaxial growth technology.

[0005] Since the current domestic exploration of gallium oxide epitaxial equipment and process routes is in the early stages of research and development, there is no HVPE equipment and MOCVD equipment dedicated to gallium oxide epitaxial process, which limits the further development of the gallium oxide industry. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a gallium oxide epitaxial device and a gallium oxide thin film preparation process which are compatible with HVPE and MOCVD processes and have compact structure, convenient operation and high stability, in view of the current application prospects of gallium oxide devices and the research needs of the current mainstream HVPE and MOCVD epitaxial process routes.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A gallium oxide epitaxial device compatible with HVPE and MOCVD processes comprises: a source region, an epitaxial growth region, a tail exhaust system and a cooling system; the source region adopts a furnace tube structure, and a gallium boat for containing Ga metal is arranged in the furnace tube, the source region is used to heat Ga metal and provide Ga-containing gas, the epitaxial growth region is placed in a glove box, a substrate enters and exits the epitaxial growth region manually, and a gallium oxide thin film is formed on the substrate in the epitaxial growth region; the air inlet end of the epitaxial growth region is connected to the source region through a pipeline with an air flow shut-off valve, and the air inlet end of the epitaxial growth region is provided with a plurality of gas delivery pipes, the exhaust end of the epitaxial growth region is connected to the tail exhaust system, and the tail exhaust system is used to exhaust the waste gas in the epitaxial growth region; the cooling system is respectively connected to the source region, the epitaxial growth region and the tail exhaust system to realize cooling of the source region, the epitaxial growth region and the tail exhaust system.

[0009] As a further improvement of the present invention, it also includes a support transmission system, which is sealed from the bottom of the epitaxial growth area and penetrates the epitaxial growth area to support and drive the substrate to rotate and rise and fall in the epitaxial growth area.

[0010] As a further improvement of the present invention, an upper cover plate that automatically opens and closes is provided on the top of the epitaxial growth zone, the upper cover plate is located at the air inlet end of the epitaxial growth zone, and a uniform flow component is provided on the inner side of the top of the epitaxial growth zone, and the uniform flow component is connected to the source zone and the gas delivery pipe to achieve uniform distribution of process gases in the epitaxial growth zone; the exhaust end of the epitaxial growth zone is located at the bottom of the epitaxial growth zone.

[0011] As a further improvement of the present invention, the supporting transmission system includes a motor and a substrate base for supporting a substrate, the motor is arranged on the outer side of the bottom of the epitaxial growth zone, the transmission shaft of the motor passes through the bottom of the epitaxial growth zone in a magnetic fluid sealed manner and extends into the epitaxial growth zone, the substrate base is arranged in the epitaxial growth zone and connected to the transmission shaft, and the substrate base is connected to the heating element to realize the rotation, lifting and heating of the substrate in the epitaxial growth zone.

[0012] As a further improvement of the present invention, the epitaxial growth zone includes an outer wall chamber and an inner wall chamber which are nested, and the outer wall chamber adopts a double-layer water-cooling structure, and the double-layer water-cooling structure is connected to a cooling system.

[0013] As a further improvement of the present invention, a heating component is provided outside the outer wall chamber, or a heating component is provided between the outer wall chamber and the inner wall chamber to achieve uniform heating of the epitaxial growth zone.

[0014] As a further improvement of the present invention, the inner wall chamber is made of high-purity SiC material or high-purity SiC / TaC coated graphite material.

[0015] As a further improvement of the present invention, the source region includes an outer tube and an inner tube, and the outer tube and the inner tube are nested to form a furnace tube structure. The gas inlet end of the furnace tube structure is provided with a plurality of gas delivery pipes, which are respectively connected to a Cl2 source, an H2O vapor source, an Ar source or an N2 source, for delivering process gas to the source region; a resistance heating component is provided between the outer tube and the inner tube to achieve heating of the source region to a preset Ga-containing gas preparation temperature.

[0016] As a general technical concept, the present invention also provides a gallium oxide thin film preparation process based on the gallium oxide epitaxial device compatible with HVPE and MOCVD processes, wherein the preparation process is an HVPE process, comprising the following steps:

[0017] The first step is to place metal Ga in the gallium boat; purge the glove box to make the glove box a N2 environment, open the upper cover of the epitaxial growth area, manually place the wafer on the substrate base, close the upper cover, and pass N2 to purge the inner wall chamber;

[0018] Step 2: Heat the source area and maintain it at 850°C ± 10°C by means of a resistance heating assembly;

[0019] Step 3: Heat the epitaxial growth area and maintain it at 1050°C ± 10°C through a heating assembly on the epitaxial growth area, and maintain the pressure of the epitaxial growth area at 800mbar ± 10mbar through a tail exhaust system;

[0020] Step 4: Using N2 as carrier gas, Cl2 is introduced into the gas inlet of the source region to react with the metal Ga in the gallium boat to generate GaCl gas, which then enters the epitaxial growth region through a pipeline with a gas flow shutoff valve.

[0021] Step 5: O2 and doping gas are introduced into the epitaxial growth area. O2 reacts with GaCl gas to generate Ga2O3, which is then deposited on the surface of the substrate to form a thin film.

[0022] As a general technical concept, the present invention also provides a gallium oxide thin film preparation process based on the gallium oxide epitaxial device compatible with HVPE and MOCVD processes, wherein the preparation process is a MOCVD process, comprising the following steps:

[0023] The first step is to purge the glove box to make the glove box a N2 environment, open the upper cover of the epitaxial growth area, manually place the wafer on the substrate base, close the upper cover, and pass N2 to purge the inner wall chamber;

[0024] Step 2: N2 is introduced to purge the source area and the epitaxial growth area. After the purge is completed, the gas flow shut-off valve is closed;

[0025] Step 3: heat the epitaxial growth area through the heating assembly on the epitaxial growth area and maintain it at 900°C±10°C; maintain the pressure of the epitaxial growth area at 600mbar±10mbar through the tail exhaust system;

[0026] Step 4: TMGa precursor, O2 and doping gas are introduced into the epitaxial growth area. O2 reacts with the TMGa precursor to generate Ga2O3, and Ga2O3 is deposited on the surface of the substrate to form a thin film.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] 1. The gallium oxide epitaxial growth device compatible with HVPE and MOCVD processes of the present invention sets the source region and the epitaxial growth region independently, connects the source region and the epitaxial growth region through a pipeline with a gas flow shut-off valve, places the epitaxial growth region in a glove box, and manually enables the substrate to enter and exit the epitaxial growth region. The operation is simple and convenient. The source region is used to heat Ga metal, so that the Ga-containing gas is stably delivered to the epitaxial growth region. At the same time, a plurality of gas delivery pipes are provided at the end of the epitaxial growth region, and corresponding process gases can be delivered according to actual process requirements. The MOCVD and HVPE process capabilities are integrated, and a gallium oxide epitaxial layer preparation scheme with different growth rates and different epitaxial thicknesses is provided, which provides a new solution for the preparation of gallium oxide epitaxial layers, greatly reduces the research cost of gallium oxide epitaxy, and meets the scientific research and exploration needs for the preparation of gallium oxide epitaxial layers.

[0029] 2. The gallium oxide thin film preparation process of the present invention is implemented based on the above-mentioned gallium oxide epitaxial device, which significantly improves the film quality of the epitaxial layer, realizes precise control of the doping concentration, and effectively improves the stability and reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structural principle of a gallium oxide epitaxial device in a specific embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the HVPE process flow in a specific embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of the MOCVD process flow in a specific embodiment of the present invention;

[0033] Legend: 1. Substrate; 100. Source region; 101. Gallium boat; 102. Outer tube; 103. Inner tube; 104. Resistance heating component; 105. Thyristor; 106. Air flow shut-off valve; 107. Temperature controller; 108. Temperature measuring element; 200. Epitaxial growth region; 201. Outer wall chamber; 202. Induction heating coil; 203. Inner wall chamber; 204. Upper cover; 205. Flow uniforming component; 206. Monitoring component; 300. Support transmission system; 301. Substrate base; 302. Motor; 400. Exhaust system; 500. Exhaust gas processor; 600. Cooling system. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0035] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0037] Example 1

[0038] like Figure 1As shown, the gallium oxide epitaxial device compatible with HVPE and MOCVD processes of the present invention comprises: a source region 100, an epitaxial growth region 200, a tail exhaust system 400 and a cooling system 600. The source region 100 adopts a furnace tube structure, and a gallium boat 101 for holding Ga metal is arranged in the furnace tube. The source region 100 is used to heat Ga metal and provide Ga-containing gas. The epitaxial growth region 200 is placed in a glove box, and the substrate 1 is manually moved in and out of the epitaxial growth region 200, and the substrate 1 completes the gallium oxide film in the epitaxial growth region 200. The source region 100 and the epitaxial growth region 200 are arranged side by side, and the air inlet end of the epitaxial growth region 200 is connected to the source region 100 through a pipeline with an airflow shut-off valve 106, and the air inlet end of the epitaxial growth region 200 is provided with a plurality of gas delivery pipes, and the exhaust end of the epitaxial growth region 200 is connected to the tail exhaust system 400, and the tail exhaust system 400 is used to discharge the exhaust gas in the epitaxial growth region 200, and transport it to the tail gas processor 500 for treatment before being discharged. The cooling system 600 is respectively connected to the source region 100, the epitaxial growth region 200 and the tail exhaust system 400, so as to realize the cooling of the source region 100, the epitaxial growth region 200 and the tail exhaust system 400, so as to ensure the cooling of the high-heat components and improve the safety and reliability of the equipment. The cooling system 600 is provided with a water flow and water temperature detection component to realize the precise control of the cooling effect of each high-heat component.

[0039] like Figure 1 As shown, multiple gas delivery pipes at the gas inlet end of the epitaxial growth zone 200 are respectively connected to the doping source, oxygen source (configurable oxygen or ozone, etc.), Mo source (configurable TMGa or TEGa, etc.) and N2 / Ar source, and at least one extended gas delivery pipe is reserved at the gas inlet end of the epitaxial growth zone 200 to facilitate the expansion of the process. Through the setting of the epitaxial growth zone 200, various epitaxial processes can share the functional systems such as substrate 1 transmission, heating, and pressure control, which improves the process window range of the device, realizes the integration of existing multi-machine functions, and greatly reduces the cost of gallium oxide epitaxy research.

[0040] In this embodiment, the source region 100 and the epitaxial growth region 200 are independently arranged, and the source region 100 and the epitaxial growth region 200 are connected through a pipeline with a gas flow shut-off valve 106. The epitaxial growth region 200 is placed in a glove box, the glove box cavity is purged by N2 or compressed air, and the side of the glove box is connected to a manual conveying system. Before and after the epitaxial process is started, the top cover of the epitaxial growth region 200 is opened, and the substrate substrate or epitaxial wafer is placed and taken out by manually taking and placing the wafer. By setting up a glove box, the safety and process quality of the epitaxial process are improved. By using the source region 100 to heat the Ga metal, the Ga-containing gas is stably transported to the epitaxial growth region 200. At the same time, a plurality of gas delivery pipes are arranged at the end of the epitaxial growth zone 200, which can deliver corresponding process gases according to actual process requirements. The MOCVD and HVPE process capabilities are integrated to provide gallium oxide epitaxial layer preparation solutions with different growth rates and different epitaxial thicknesses, providing a new solution for the preparation of gallium oxide epitaxial layers, greatly reducing the research cost of gallium oxide epitaxy, and meeting the scientific research and exploration needs for the preparation of gallium oxide epitaxial layers.

[0041] like Figure 1 As shown, the gallium oxide epitaxial device of this embodiment further includes a support transmission system 300. The support transmission system 300 is sealed from the bottom of the epitaxial growth region 200 and penetrates the epitaxial growth region 200 to carry and drive the substrate 1 to rotate and rise and fall in the epitaxial growth region 200 to improve the uniformity of the coating on the surface of the substrate 1.

[0042] In this embodiment, an upper cover plate 204 that opens and closes automatically is provided at the top of the epitaxial growth region 200. The upper cover plate 204 is located at the air inlet end of the epitaxial growth region 200. The upper cover plate 204 realizes automatic opening and closing operations through components such as a cylinder and a guide rail. A uniform flow component 205 is provided on the inner side of the top of the epitaxial growth region 200. The uniform flow component 205 is connected to the source region 100 and the gas delivery pipe to achieve uniform distribution of process gas in the epitaxial growth region 200. The uniform flow component 205 can specifically adopt the form of a combination of a uniform flow plate and a spray plate to improve the uniformity of gas distribution. The exhaust end of the epitaxial growth region 200 is located at the bottom of the epitaxial growth region 200, that is, the exhaust end is arranged opposite to the air inlet end.

[0043] like Figure 1As shown, the support transmission system 300 includes a motor 302 and a substrate base 301 for carrying the substrate 1, and the substrate base 301 is a monolithic design. The motor 302 is arranged outside the bottom of the epitaxial growth region 200, and the transmission shaft of the motor 302 penetrates the bottom of the epitaxial growth region 200 in a magnetic fluid sealing manner and extends into the epitaxial growth region 200. The substrate base 301 is arranged in the epitaxial growth region 200 and is connected to the transmission shaft, and the substrate base 301 is connected to the heating element to realize the rotation, lifting and heating of the substrate 1 in the epitaxial growth region 200. In this embodiment, the substrate base 301 can be a graphite base, and the surface is coated with a high-purity SiC or TaC coating. The graphite base is connected to the heating element, which can both support the substrate 1 and heat the substrate 1.

[0044] Since the motor 302 can realize the lifting function, the distance between the substrate base 301 and the gas inlet end of the epitaxial growth zone 200 can be adjusted, which helps to compensate for the concentration control problem caused by the short or long distance of the reaction gas moving from the inlet to the outlet, and further optimizes the process uniformity and doping concentration uniformity.

[0045] like Figure 1 As shown, the epitaxial growth region 200 is a cylindrical structure, including an outer wall chamber 201 and an inner wall chamber 203 which are nested. The outer wall chamber 201 needs to have sufficient strength to support the weight of the materials in the inner wall chamber 203. The outer wall chamber 201 adopts a double-layer water cooling structure, and the double-layer water cooling structure is connected to the cooling system 600.

[0046] In this embodiment, a heating component is provided outside the outer wall chamber 201. In other embodiments, a heating component is provided between the outer wall chamber 201 and the inner wall chamber 203 to achieve uniform heating of the epitaxial growth region 200. When induction heating is adopted, an induction heating coil 202 is concentrically arranged on the surface of the outer wall chamber 201, and the outer wall chamber 201 is made of quartz. When resistance heating is adopted, multiple resistance wires are arranged between the outer wall chamber 201 and the inner wall chamber 203 for heating, and the outer wall chamber 201 is made of metal.

[0047] In this embodiment, the inner wall chamber 203 is made of a material that does not react with O2, H2O, Cl2 and HCl, for example, it is made of high-purity SiC material or high-purity SiC / TaC coated graphite material. Other materials that have heating and heat preservation functions and do not react with process gases can also be selected.

[0048] In this embodiment, a transparent observation window made of quartz material is provided at the exhaust end of the outer wall chamber 201. Combined with the infrared temperature measuring probe provided in the inner wall chamber 203, the reaction temperature of the substrate base can be measured in real time. The remote host computer reads the temperature value in real time and adjusts the power and frequency of the induction power input or the power of the thyristor input in the resistance heating according to the temperature deviation, so that the epitaxial growth zone 200 is uniformly controllable in a wide temperature range of 550°C to 1400°C, and the temperature uniformity is ≤±0.5°C, thereby realizing precise control of the reaction temperature of the growth chamber and improving the process stability.

[0049] like Figure 1 As shown, the source region 100 includes an outer tube 102 and an inner tube 103. The outer tube 102 and the inner tube 103 are nested to form a furnace tube structure, and a plurality of gas delivery pipes are provided at the gas inlet end of the furnace tube structure to be respectively connected to a Cl2 source, a H2O vapor source, an Ar source or a N2 source, for delivering process gas to the source region 100, and reacting with the metal gallium placed in the gallium boat 101 to generate GaCl gas or Ga2O gas, and the GaCl gas or Ga2O gas is delivered to the epitaxial growth region 200 under the carrier gas N2 or Ar.

[0050] In this embodiment, a resistance heating assembly 104 is provided between the outer tube 102 and the inner tube 103 to heat the source region 100 to a preset Ga-containing gas preparation temperature. Figure 1 As shown, a temperature measurement and control circuit is formed by a thyristor 105, a temperature control meter 107 and a temperature measuring element 108 to control the resistance heating component 104, so that the heating temperature can be uniformly controlled within a range of 500°C to 1400°C.

[0051] In this embodiment, the outer tube 102 adopts a double-layer water-cooling structure and is connected to the cooling system 600 to achieve cooling of the source area 100 .

[0052] In this embodiment, the source region 100 and the epitaxial growth region 200 use inner walls made of high-purity SiC / TaC material, which effectively avoids the influence of unintentional doping of the epitaxial film by Si or C, metal and non-metal impurities contained in the quartz inner tube of the existing HVPE device or the graphite heating body of the MOCVD device, thereby greatly improving the film quality of the epitaxial layer, achieving precise control of the doping concentration, and effectively improving the stability and reliability of the device.

[0053] In this embodiment, the tail exhaust system 400 includes a dry pump and a connecting pipe with a butterfly valve, the connecting pipe is connected to the cooling system 600, one end of the connecting pipe is connected to the dry pump, and the other end of the connecting pipe is connected to the epitaxial growth zone 200 to extract the exhaust gas in the epitaxial growth zone 200 and realize the exhaust gas cooling. Specifically, an exhaust gas collector is arranged inside the inner wall chamber 203 and around the substrate base 301, and is tightly fitted with the top plate and the bottom plate of the inner wall chamber 203 respectively, and then penetrates the bottom plate of the inner wall chamber 203, and communicates with the tail exhaust port of the outer wall chamber 201, so as to realize the discharge of reaction byproducts and residual reactants during the epitaxial process in the inner wall chamber 203. Through the cooperation of the corrosion-resistant dry pump and the butterfly valve, and the thin film gauge is arranged in the connecting pipe, the atmosphere and pressure control of the epitaxial growth zone 200 is realized, so as to realize the pressure controllable range from atmospheric pressure to 5Pa. Since the HVPE and MOCVD processes contain dust and the reaction gases are highly toxic, filters are installed in the connecting pipes to filter dust particles in the reaction by-products and absorb toxic reaction gases, thereby improving the safety of the equipment and facilitating maintenance.

[0054] Example 2

[0055] like Figure 2 As shown, the gallium oxide thin film preparation process of the present invention is a HVPE process, which is implemented based on the gallium oxide epitaxial device in Example 1 and includes the following steps:

[0056] The first step is to place metal Ga in the gallium boat 101; purge the glove box to make it a N2 environment, open the upper cover 204 of the epitaxial growth area 200, manually place the wafer on the substrate base 301, close the upper cover 204, and pass N2 to purge the inner wall chamber 203.

[0057] In the second step, the source region 100 is heated by the resistance heating assembly 104 and maintained at 850°C.

[0058] The third step is to heat the epitaxial growth region 200 and maintain the temperature at 1050° C. through the heating assembly on the epitaxial growth region 200 , and maintain the pressure of the epitaxial growth region 200 at 800 mbar through the tail exhaust system 400 .

[0059] In the fourth step, N2 is used as a carrier gas, and Cl2 is introduced into the gas inlet end of the source region 100 to react with the metal Ga in the gallium boat 101 to generate GaCl gas, and the GaCl gas enters the epitaxial growth region 200 through a pipeline with a gas flow shut-off valve 106.

[0060] Step 5: O2 and doping gas are introduced into the epitaxial growth region 200. The doping gas may be SiCl4 or GeCl4. O2 reacts with GaCl gas to generate Ga2O3, which is deposited on the surface of the substrate 1 to form a thin film. It can be understood that the amount of GaCl gas and O2 introduced can be flexibly adjusted according to the actual epitaxial growth requirements.

[0061] During the epitaxial growth process, the distance between the substrate base 301 and the current equalizer 205 is kept fixed, and the motor 302 always keeps rotating at a constant speed to improve the thickness uniformity of the gallium oxide film on the surface of the substrate 1.

[0062] Example 3

[0063] like Figure 3 As shown, the gallium oxide thin film preparation process of the present invention is a MOCVD process, which is implemented based on the gallium oxide epitaxial device in Example 1 and includes the following steps:

[0064] The first step is to purge the glove box to make the glove box a N2 environment, open the upper cover 204 of the epitaxial growth area 200, manually place the wafer onto the substrate base 301, close the upper cover 204, and pass N2 to purge the inner wall chamber 203.

[0065] The second step is to introduce N2 to purge the source region 100 and the epitaxial growth region 200. After the purge is completed, the gas flow shut-off valve 106 is closed to prevent the source region 100 and the epitaxial growth region 200 from communicating with each other, and to keep the cavity pressure of the source region 100 slightly higher than the atmospheric pressure.

[0066] The third step is to heat the epitaxial growth region 200 and maintain the temperature at 900° C. by means of the heating assembly on the epitaxial growth region 200 ; and to maintain the pressure of the epitaxial growth region 200 at 600 mbar by means of the tail exhaust system 400 .

[0067] Step 4: TMGa precursor, O2 and doping gas are introduced into the epitaxial growth region 200. The doping gas may be SiCl4 or GeCl4. O2 reacts with the TMGa precursor to generate Ga2O3, which is deposited on the surface of the substrate 1 to form a thin film. It can be understood that the amount of TMGa precursor and O2 introduced can be flexibly adjusted according to the actual epitaxial growth requirements.

[0068] During the epitaxial growth process, the distance between the substrate base 301 and the current equalizer 205 is kept fixed, and the motor 302 always keeps rotating at a constant speed to improve the thickness uniformity of the gallium oxide film on the surface of the substrate 1.

[0069] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A gallium oxide epitaxial device compatible with HVPE and MOCVD processes, characterized in that: include: A source region (100), an epitaxial growth region (200), a tail exhaust system (400) and a cooling system (600); the source region (100) adopts a furnace tube structure, and a gallium boat (101) for containing Ga metal is arranged in the furnace tube; the source region (100) is used to heat Ga metal and provide Ga-containing gas; the epitaxial growth region (200) is placed in a glove box, and a substrate (1) is manually moved in and out of the epitaxial growth region (200), and a gallium oxide thin film is formed on the substrate (1) in the epitaxial growth region (200); the gas inlet of the epitaxial growth region (200) The end of the epitaxial growth zone (200) is connected to the source zone (100) through a pipeline with an air flow shut-off valve (106), and the air inlet end of the epitaxial growth zone (200) is provided with a plurality of gas delivery pipes, the exhaust end of the epitaxial growth zone (200) is connected to a tail exhaust system (400), and the tail exhaust system (400) is used to exhaust the waste gas in the epitaxial growth zone (200); the cooling system (600) is respectively connected to the source zone (100), the epitaxial growth zone (200) and the tail exhaust system (400), so as to realize cooling of the source zone (100), the epitaxial growth zone (200) and the tail exhaust system (400).

2. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to claim 1, characterized in that: It also includes a support transmission system (300), which is sealed from the bottom of the epitaxial growth region (200) and penetrates the epitaxial growth region (200) to support and drive the substrate (1) to rotate and rise and fall in the epitaxial growth region (200).

3. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to claim 2, characterized in that: An automatically opened and closed upper cover plate (204) is provided on the top of the epitaxial growth region (200), the upper cover plate (204) is located at the gas inlet end of the epitaxial growth region (200), and a uniform flow component (205) is provided on the inner side of the top of the epitaxial growth region (200), the uniform flow component (205) is connected to the source region (100) and the gas delivery pipe, so as to achieve uniform distribution of process gas in the epitaxial growth region (200); the exhaust end of the epitaxial growth region (200) is located at the bottom of the epitaxial growth region (200).

4. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to claim 2, characterized in that: The support transmission system (300) comprises a motor (302) and a substrate base (301) for carrying a substrate (1); the motor (302) is arranged outside the bottom of the epitaxial growth region (200); a transmission shaft of the motor (302) penetrates the bottom of the epitaxial growth region (200) in a magnetic fluid sealing manner and extends into the epitaxial growth region (200); the substrate base (301) is arranged in the epitaxial growth region (200) and connected to the transmission shaft; and the substrate base (301) is connected to a heating element, so as to realize rotation, lifting and heating of the substrate (1) in the epitaxial growth region (200).

5. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to any one of claims 1 to 4, characterized in that: The epitaxial growth zone (200) comprises an outer wall chamber (201) and an inner wall chamber (203) which are nested, and the outer wall chamber (201) adopts a double-layer water cooling structure, and the double-layer water cooling structure is connected to a cooling system (600).

6. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to claim 5, characterized in that: A heating component is provided outside the outer wall chamber (201), or a heating component is provided between the outer wall chamber (201) and the inner wall chamber (203), so as to achieve uniform heating of the epitaxial growth zone (200).

7. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to claim 5, characterized in that: The inner wall chamber (203) is made of high-purity SiC material or high-purity SiC / TaC coated graphite material.

8. The gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to any one of claims 1 to 4, characterized in that: The source region (100) comprises an outer tube (102) and an inner tube (103), wherein the outer tube (102) and the inner tube (103) are nested to form a furnace tube structure, wherein a plurality of gas delivery tubes are provided at the gas inlet end of the furnace tube structure, respectively connected to a Cl2 source, an H2O vapor source, an Ar source or an N2 source, for delivering process gas to the source region (100); a resistance heating component (104) is provided between the outer tube (102) and the inner tube (103), so as to heat the source region (100) to a preset Ga-containing gas preparation temperature.

9. A process for preparing a gallium oxide thin film based on a gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to any one of claims 1 to 8, characterized in that: The preparation process is a HVPE process, comprising the following steps: The first step is to place metal Ga in a gallium boat (101); purge a glove box to make the glove box an N2 environment, open the upper cover plate (204) of the epitaxial growth area (200), manually place the wafer on the substrate base (301), close the upper cover plate (204), and pass N2 to purge the inner wall chamber (203); Step 2: heating the source region (100) by means of a resistance heating assembly (104) and maintaining the temperature at 850°C ±10°C; Step 3: heating the epitaxial growth region (200) by means of a heating assembly on the epitaxial growth region (200) and maintaining the temperature at 1050°C±10°C, and maintaining the pressure of the epitaxial growth region (200) at 800mbar±10mbar by means of a tail exhaust system (400); Step 4: Using N2 as carrier gas, Cl2 is introduced into the gas inlet of the source region (100) to react with the metal Ga in the gallium boat (101) to generate GaCl gas, and the GaCl gas enters the epitaxial growth region (200) through a pipeline with a gas flow shut-off valve (106); Step 5: O2 and doping gas are introduced into the epitaxial growth region (200), and O2 reacts with GaCl gas to generate Ga2O3, which is then deposited on the surface of the substrate (1) to form a thin film.

10. A process for preparing a gallium oxide thin film based on a gallium oxide epitaxial device compatible with HVPE and MOCVD processes according to any one of claims 1 to 8, characterized in that: The preparation process is a MOCVD process, comprising the following steps: The first step is to purge the glove box so that the glove box is in a N2 environment, open the upper cover plate (204) of the epitaxial growth area (200), manually place the wafer on the substrate base (301), close the upper cover plate (204), and pass N2 to purge the inner wall chamber (203); Step 2: introducing N2 to purge the source region (100) and the epitaxial growth region (200). After the purge is completed, the gas flow shutoff valve (106) is closed; Step 3: heating the epitaxial growth region (200) by means of a heating component on the epitaxial growth region (200) and maintaining the temperature at 900°C±10°C; maintaining the pressure of the epitaxial growth region (200) at 600mbar±10mbar by means of a tail exhaust system (400); In the fourth step, a TMGa precursor, O2 and a doping gas are introduced into the epitaxial growth region (200), and O2 reacts with the TMGa precursor to generate Ga2O3, which is then deposited on the surface of the substrate (1) to form a thin film.

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