Gallium oxide epitaxial quartz device and epitaxial equipment thereof

Abstract

The invention provides a gallium oxide epitaxy quartz device and epitaxy equipment thereof, and relates to the technical field of gallium oxide epitaxy. According to the invention, the first quartz cavity, the second quartz cavity and the gas mixing pipeline are integrated and arranged in the epitaxial cavity, and the introduced gaseous chlorine and the carbon family simple substance in the first quartz cavity directly react in the cavity to generate the carbon family chloride. The interior of the epitaxial cavity is in a high-temperature environment, and carbon-group chloride generated by reaction in the epitaxial cavity is in a gaseous state, so that full-link heat preservation heating and steam pressure control in an external conveying process can be avoided, the process is simplified, and control is convenient. The problem of concentration fluctuation caused by the fact that carbon group chloride steam is easy to condense and low-concentration flow is difficult to regulate and control in the prior art is avoided, it is ensured that components and concentration of reaction gas introduced into the surface of the substrate are stable, and then the growth rate and doping uniformity of a gallium oxide epitaxial layer are ensured.

Description

Technical Field

[0001] This invention relates to the field of gallium oxide epitaxy technology, and more particularly to a quartz device for gallium oxide epitaxy and the epitaxy apparatus thereof. Background Technology

[0002] Gallium oxide, as a novel wide-bandgap semiconductor material, has high voltage resistance, low loss characteristics, and excellent chemical and thermal stability, and has broad application prospects in high-voltage high-power devices, solar-blind ultraviolet detection, and other fields.

[0003] Gallium oxide high-voltage, high-power devices require a lightly doped, thick epitaxial layer as the device layer, with an epitaxial layer thickness of at least 7 μm and a carrier concentration of at least 10. 15 cm -3 -10 18 cm -3 Among epitaxial methods such as MOCVD, MBE, and HVPE, HVPE is the fastest growth method and has significant advantages in fabricating vertical gallium oxide power devices. HVPE is a vapor-phase epitaxy method where, in the source region, metallic gallium reacts with chlorine or hydrogen chloride gas to form gallium chloride. The gallium chloride is then carried by nitrogen gas to the growth temperature region, where it reacts with oxygen to form gallium oxide, which is deposited on the substrate surface. The doping elements for n-type gallium oxide epitaxial layers grown by HVPE are typically chlorides of carbonaceous elements such as silicon, germanium, and tin. The gallium oxide epitaxial layer is lightly doped with a low carrier concentration, generally requiring a doping level of 10⁻⁶. 15 -10 16 cm -3 The order of magnitude requires a low concentration of chloride introduced into the HVPE chamber, for example, at the ppm or ppb level.

[0004] At room temperature, group carbide chlorides are generally in liquid or solid form, requiring a water bath method. The volatilized chloride vapor is transported to the epitaxial cavity via a carrier gas (N2), where it is chemically incorporated into gallium oxide, replacing Ga sites to form donors. These donors provide free electrons, forming charge carriers. The chloride vapor transport process also requires multi-stage dilution to ensure the chloride concentration reaches ppm or ppb levels. Furthermore, the chloride vapor transport process necessitates control of vapor pressure and temperature to prevent condensation and blockage of pipes and valves. This results in complex and difficult-to-control processes when using group carbide chlorides, requiring the adjustment of multiple doping process parameters. Summary of the Invention

[0005] This invention provides a quartz device and epitaxial equipment for gallium oxide epitaxy, to solve the problems of complex and difficult-to-control processes in existing carbon group chloride doping methods during gallium oxide epitaxial growth.

[0006] In a first aspect, embodiments of the present invention provide a quartz apparatus for gallium oxide epitaxy, which is disposed inside an epitaxy cavity; the apparatus includes: a first chlorine gas pipe, a second chlorine gas pipe, a first quartz cavity, a second quartz cavity, and a mixing gas pipe; one end of the first chlorine gas pipe is connected to a chlorine gas source outside the epitaxy furnace, and the other end is connected to the gas inlet of the first quartz cavity; one end of the second chlorine gas pipe is connected to a chlorine gas source outside the epitaxy furnace, and the other end is connected to the gas inlet of the second quartz cavity; the first quartz cavity is used to place carbon group elements; the second quartz cavity is used to place metallic gallium; the gas outlets of both the first and second quartz cavities are connected to the mixing gas pipe; wherein, during gallium oxide epitaxy, the outlet of the mixing gas pipe faces the substrate surface of the gallium oxide to be grown.

[0007] In one possible implementation, the first quartz cavity is located above the second quartz cavity; the gas mixing pipe is located below the second quartz cavity; a first gas outlet pipe is also provided between the gas outlet end of the first quartz cavity and the gas mixing pipe; the first gas outlet pipe passes through the second quartz cavity, and the internal space of the first gas outlet pipe is not connected to the internal space of the second quartz cavity.

[0008] In one possible implementation, the first vent pipe penetrates vertically through the lower wall of the first quartz cavity; the first end of the first vent pipe is located inside the first quartz cavity, and the second end is located outside the first quartz cavity; wherein the height of the first end from the lower wall is higher than the height of the carbon group element to be placed.

[0009] In one possible implementation, a second vent pipe is provided between the vent end of the second quartz cavity and the gas mixing pipe; the second vent pipe penetrates vertically through the lower cavity wall of the second quartz cavity; the first end of the second vent pipe is located inside the second quartz cavity, and the second end is located outside the second quartz cavity; wherein, the height of the first end from the lower cavity wall is higher than the height of the gallium metal to be placed.

[0010] In one possible implementation, the end of the second exhaust pipe is sealed and connected to the end of the mixing pipe; the diameter of the second exhaust pipe is larger than the diameter of the first exhaust pipe; the first exhaust pipe is nested inside the second exhaust pipe and passes through both ends of the second exhaust pipe; the second end of the first exhaust pipe extends into the mixing pipe.

[0011] In one possible implementation, it further includes an oxygen conduit; one end of the oxygen conduit is used to connect to an oxygen source outside the epitaxial furnace, and the outlet of the other end faces the substrate surface of the gallium oxide to be grown.

[0012] In one possible implementation, the outlet end of the oxygen conduit is an annular structure surrounding the gas mixing conduit.

[0013] In one possible implementation, an isolation nitrogen pipeline is also included: one end of the isolation nitrogen pipeline is used to connect to a nitrogen source outside the epitaxial furnace, and the outlet of the other end is located between the outlet of the oxygen pipeline and the outlet of the mixed gas pipeline.

[0014] In one possible implementation, the distance between the oxygen pipe outlet and the substrate is less than the distance between the gas mixing pipe outlet and the substrate.

[0015] Secondly, embodiments of the present invention provide a gallium oxide epitaxial device, including an epitaxial cavity, a substrate, and a quartz device for gallium oxide epitaxy as described in any of the above possible implementations; the quartz device and the substrate are disposed inside the epitaxial cavity; the upper surface of the substrate is used to support a substrate of gallium oxide to be grown; the quartz device is disposed above the substrate, wherein the outlet of the gas mixing pipe faces downward toward the surface of the substrate of gallium oxide to be grown.

[0016] This invention provides a quartz device and epitaxial apparatus for gallium oxide epitaxy. By integrating a first quartz cavity, a second quartz cavity, and a gas mixing pipe within the epitaxial cavity, gaseous chlorine gas is introduced and reacts directly with the carbonaceous elements in the first quartz cavity to generate carbonaceous chlorides. The epitaxial cavity maintains a high-temperature environment, and the generated carbonaceous chlorides are gaseous, avoiding the need for end-to-end heat preservation and steam pressure control during external transport, simplifying the process and facilitating control. Furthermore, using gaseous chlorine gas at room temperature as the gas source, compared to carbonaceous chloride vapor formed by water bath evaporation, the gaseous nature of chlorine makes it easier to achieve accurate metering and transport using conventional high-precision mass flow meters. By adjusting the chlorine flow rate in the first and second chlorine pipelines, the amount of carbon group chlorides generated and the chlorination reaction process of gallium can be precisely controlled. This avoids the concentration fluctuation problems caused by the easy condensation of carbon group chloride vapors and the difficulty in controlling low-concentration flow rates in existing technologies, ensuring the stability of the composition and concentration of the reaction gas introduced into the substrate surface, thereby guaranteeing the growth rate and doping uniformity of the gallium oxide epitaxial layer. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the gallium oxide epitaxial quartz device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the gallium oxide epitaxial device provided in an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0019] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0020] The implementation of the present invention will be described in detail below with reference to the accompanying drawings: Gallium oxide epitaxial growth, such as the HVPE method, primarily utilizes the reaction of metallic gallium (Ga) with chlorine (Cl2) at high temperature to generate a gaseous precursor, gallium chloride (GaCl). Subsequently, GaCl reacts with oxygen (O2) on the substrate surface under the action of a carrier gas (usually nitrogen N2) to form gallium oxide crystals. The reaction formula is as follows:

[0021]

[0022] In the field of gallium oxide epitaxial growth, carbon group chlorides, such as silicon tetrachloride and germanium tetrachloride, are used as source materials for epitaxial doping. Precise concentration control of their vapor phase is a prerequisite for ensuring the uniformity of doping concentration in the epitaxial layer and the stability of device performance. In existing technologies, for carbon group chlorides that are solid or liquid at room temperature, the vapor preparation, transportation, and concentration control typically employ a process route of water bath evaporation, carrier gas transport, and multi-stage dilution to meet the ppm (10⁻⁶) level requirements of the epitaxial reaction. -6 ) or ppb level (10 -9 Low concentration supply and demand.

[0023] Specifically, the existing process is as follows: First, carbon group chloride raw materials, which are solid or liquid at room temperature, are placed in a water bath. The raw materials are heated in the water bath to volatilize, forming carbon group chloride vapor. Then, nitrogen is introduced as a carrier gas to carry away the vapor (which can form saturated vapor, supersaturated vapor, or superheated vapor). Since the concentration of the volatilized carbon group chloride vapor is much higher than the ppm or ppb concentration required for the epitaxial reaction, the carrier gas vapor mixture needs to undergo multi-stage dilution. This dilution process is achieved by continuously replenishing nitrogen and maintaining the temperature throughout the process. Finally, the carbon group chloride vapor and nitrogen mixture, after multi-stage dilution to the required concentration, is introduced into the epitaxial chamber to participate in the epitaxial growth reaction. However, the above-mentioned existing technical solution has the following drawbacks: 1. Controlling ppm / ppb concentrations is challenging, resulting in a complex and unstable process system. The saturated vapor pressure of group carboxyl chloride vapors is extremely sensitive to temperature and pressure changes. During low-concentration control, temperature or pressure fluctuations can easily cause the vapor to condense into a liquid state, leading to drastic fluctuations in the concentration of group carboxyl chlorides in the mixed gas. To avoid these problems, existing processes require strict insulation and heating measures for the volatilization unit, carrier gas delivery pipeline, multi-stage dilution system, and the entire transmission link leading to the epitaxial cavity, along with a high-precision pressure closed-loop control system. This not only significantly increases the complexity of the process equipment, purchase costs, and maintenance costs, but also raises the difficulty of process debugging, making it difficult to maintain a stable concentration output over a long period.

[0024] 2. Insufficient flow rate control precision at ppm-level concentrations. The ppm or ppb-level carboxyl chloride vapor required for epitaxial reactions corresponds to an extremely low actual flow rate of carboxyl chlorides in the mixed gas. Compared to the flow rate control of gaseous precursors, existing conventional flow metering and control equipment, such as mass flow meters, struggles to accurately measure and control such low flow rates. This results in a deviation between the actual supply of carboxyl chloride vapor carried by the carrier gas and the set value, and this deviation tends to accumulate over time, directly affecting the uniformity of the epitaxial layer growth rate and the consistency of doping, ultimately limiting the improvement of semiconductor device performance.

[0025] In summary, existing processes for preparing and controlling the low concentration of carbon group chloride vapors suffer from drawbacks such as high complexity and poor accuracy in concentration and flow control.

[0026] This invention integrates and places a first quartz cavity, a second quartz cavity, and a gas mixing pipe inside the epitaxial cavity. By utilizing the introduced gaseous chlorine gas to directly react with the carbon group elements in the first quartz cavity to generate carbon group chlorides, this invention solves the problem that existing carbon group chloride doping methods are complex and difficult to control during gallium oxide epitaxial growth.

[0027] Figure 1 This is a schematic diagram of a gallium oxide epitaxial quartz device provided in an embodiment of the present invention. (Refer to...) Figure 1 This invention provides a quartz device 1 for gallium oxide epitaxy, which is disposed inside an epitaxy cavity 2. The device includes: a first chlorine gas pipe 11, a second chlorine gas pipe 12, a first quartz cavity 13, a second quartz cavity 14, and a gas mixing pipe 15. One end of the first chlorine gas pipe 11 is connected to a chlorine gas source outside the epitaxy furnace, and the other end is connected to the gas inlet of the first quartz cavity 13. One end of the second chlorine gas pipe 12 is connected to a chlorine gas source outside the epitaxy furnace, and the other end is connected to the gas inlet of the second quartz cavity 14. The first quartz cavity 13 is used to place carbon group elements. The second quartz cavity 14 is used to place metallic gallium. The gas outlets of both the first quartz cavity 13 and the second quartz cavity 14 are connected to the gas mixing pipe 15. During gallium oxide epitaxy, the outlet of the gas mixing pipe 15 faces the substrate surface of the gallium oxide to be grown.

[0028] In some embodiments, the quartz device 1 is disposed inside the epitaxial cavity 2.

[0029] It should be noted that the quartz device 1 can be an independent component used in conjunction with the epitaxial cavity 2, adapted to the internal installation space of the epitaxial cavity 2 and the requirements of the gallium oxide epitaxial process, and can be manufactured separately according to the actual epitaxial specifications.

[0030] Once the quartz device 1 is installed inside the epitaxial cavity 2, it achieves gallium oxide epitaxy through its structural design. On one hand, the first quartz cavity 13 serves as the carrier space for the carbon group elements, and the second quartz cavity 14 serves as the carrier space for metallic gallium, realizing the placement and isolation of the reaction raw materials. On the other hand, the first chlorine gas pipeline 11 and the second chlorine gas pipeline 12 can be connected to an external chlorine gas source, stably delivering gaseous chlorine gas to the corresponding quartz cavities, where it reacts with the carbon group elements and metallic gallium respectively to generate the required chlorides. Finally, the generated reaction gases are mixed through the mixing pipeline 15 and then transported to the reaction area through the outlet facing the substrate surface, ensuring the gallium oxide epitaxial growth reaction. The details are explained below.

[0031] In some embodiments, the device includes: a first chlorine gas pipeline 11, a second chlorine gas pipeline 12, a first quartz cavity 13, a second quartz cavity 14, and a gas mixing pipeline 15.

[0032] For example, the quartz cavity includes a first quartz cavity 13 and a second quartz cavity 14. The quartz cavity, also known as a quartz boat, is made of quartz material and has a closed cavity structure. The closed design ensures that chlorine gas reacts fully with the raw materials within the cavity, preventing premature leakage of the reaction gas. Furthermore, quartz material possesses excellent high-temperature resistance, chemical stability, and light transmittance, making it suitable for the high-temperature reaction environment required for gallium oxide epitaxial growth. It also does not chemically react with chlorine gas, chlorides, or other reaction media, ensuring the purity of the epitaxial layer.

[0033] Exemplarily, the materials of the first chlorine pipeline 11, the second chlorine pipeline 12 and the gas mixing pipeline 15 are all quartz. The high temperature resistance and corrosion resistance of the quartz pipeline can meet the transportation requirements of the reaction medium. The functions of the first chlorine pipeline 11 and the second chlorine pipeline 12 are to transport gases and products related to the reaction, and specifically can be used to transport externally introduced chlorine or hydrogen chloride; the gas mixing pipeline 15 is used to transport the chlorides generated during the reaction.

[0034] In some embodiments, one end of the first chlorine pipeline 11 is used to connect to a chlorine source outside the epitaxial furnace, and the other end is connected to the intake end of the first quartz cavity 13; the first quartz cavity 13 is used to place elemental substances of the carbon group.

[0035] The first chlorine pipeline 11 is a straight-through quartz pipeline structure with openings at both ends. One end is an external connection end, which is used to extend outside the epitaxial cavity 2 and connect to the chlorine source supporting the epitaxial furnace to realize the introduction of external chlorine; the other end is an internal connection end, which is directly connected to the intake end of the first quartz cavity 13 and penetrates into the interior of the first quartz cavity 13 to ensure that chlorine can be directly transported to the reaction area where the elemental substances of the carbon group are located. Based on the above connection structure, the function of the first chlorine pipeline 11 is to directionally input chlorine into the first quartz cavity 13 to provide reaction raw materials for the formation of carbon group chlorides; specifically, after the chlorine transported through this pipeline enters the first quartz cavity 13, it can react with the elemental substances of the carbon group stored in the cavity under a high temperature epitaxial environment to directly generate the carbon group chloride gas required for the epitaxial reaction. This generation process is completed entirely inside the first quartz cavity 13, without the need to prepare it outside the cavity and then transport it as in the prior art.

[0036] Exemplarily, when the elemental substance of the carbon group is high-purity silicon, it reacts with chlorine to form silicon tetrachloride; when the elemental substance of the carbon group is high-purity germanium, it reacts with chlorine to form germanium tetrachloride; when the elemental substance of the carbon group is high-purity tin, it reacts with chlorine to form tin tetrachloride.

[0037] In some embodiments, one end of the second chlorine pipeline 12 is used to connect to a chlorine source outside the epitaxial furnace, and the other end is connected to the intake end of the second quartz cavity 14. The second quartz cavity 14 is used to place gallium metal.

[0038] One end of the second chlorine pipeline 12 is connected to a chlorine source outside the epitaxial furnace, and the other end is connected to the intake end of the second quartz cavity 14 and penetrates into the cavity body, and is used to transport chlorine into the second quartz cavity 14 to react with the gallium metal in the cavity body to form gallium chloride.

[0039] Furthermore, it should be noted that the first chlorine pipeline 11 and the second chlorine pipeline 12 are independent pipeline structures, with their gas delivery and control links completely separated, allowing for independent regulation. Specifically, their control objectives differ clearly: the control objective of the first chlorine pipeline 11 is to regulate the chlorine flow rate entering the first quartz cavity 13 to match the chlorination reaction rate of group carbon elements, thereby controlling the amount of group carbon chlorides generated and ensuring the supply of carbon source required for the epitaxial reaction; the control objective of the second chlorine pipeline 12 is to regulate the chlorine flow rate entering the second quartz cavity 14 to adapt to the chlorination reaction process of metallic gallium, thereby controlling the amount of gallium chloride generated and ensuring the supply of gallium source required for the epitaxial reaction.

[0040] In some embodiments, the gas outlets of the first quartz cavity 13 and the second quartz cavity 14 are both connected to the gas mixing pipe 15; wherein, during gallium oxide epitaxy, the outlet of the gas mixing pipe 15 faces the substrate surface of the gallium oxide to be grown.

[0041] The carbon group chlorides generated in the first quartz cavity 13 and the gallium chlorides generated in the second quartz cavity 14 can be uniformly mixed by entering the mixing pipe 15 through their respective gas outlets, and finally transported to the reaction area through the outlet facing the substrate surface, providing a stable mixed precursor for gallium oxide epitaxial growth.

[0042] In this embodiment of the invention, the first quartz cavity 13, the second quartz cavity 14, and the gas mixing pipe 15 are integrated and disposed inside the epitaxial cavity 2. Gaseous chlorine gas is introduced and reacts directly with the carbonaceous elements in the first quartz cavity 13 to generate carbonaceous chlorides. The epitaxial cavity 2 is a high-temperature environment, and the carbonaceous chlorides generated within it are gaseous, avoiding the need for end-to-end heat preservation and steam pressure control during external transport, simplifying the process and facilitating control. Furthermore, using chlorine gas, which is gaseous at room temperature, as the gas source, compared to the carbonaceous chloride vapor formed by water bath evaporation, the gaseous nature of chlorine makes it easier to achieve accurate metering and transport using conventional high-precision mass flow meters. By adjusting the chlorine flow rate of the first chlorine pipe 11 and the second chlorine pipe 12, the amount of carbon group chloride generated and the chlorination reaction process of metallic gallium can be precisely controlled. This avoids the concentration fluctuation problem caused by the easy condensation of carbon group chloride vapor and the difficulty in controlling the low concentration flow rate in the prior art, ensuring the stability of the composition and concentration of the reaction gas introduced into the substrate surface, thereby ensuring the growth rate and doping uniformity of the gallium oxide epitaxial layer.

[0043] It should be noted that the present invention mixes the carbon group chloride and gallium chloride before delivering them to the substrate surface. By mixing them before delivery, the carbon group elements and gallium elements delivered to the substrate surface are structurally guaranteed to be evenly distributed, thereby ensuring doping uniformity, ensuring the compositional consistency of the gallium oxide epitaxial layer, and thus ensuring the stability of subsequent device performance.

[0044] In one possible implementation, the first quartz cavity 13 and the second quartz cavity 14 can be arranged side by side.

[0045] However, the HVPE epitaxial cavity 2 is typically a cylindrical upper and lower structure, suitable for the fabrication of self-supporting substrates. This design of the HVPE epitaxial cavity 2 is usually a vertical cylinder, internally divided into two main core regions: the upper region is primarily responsible for gas preheating, reaction pretreatment, and deposit removal, and is typically equipped with a cooling system and exhaust ports; the lower region is the reaction zone located at the bottom of the cavity, where the substrate is mounted and directly contacts the reactant gas to undergo the deposition reaction. The gas flow is usually convection or counter-current, with gas entering from the upper part, passing through the bottom reaction zone, and then exiting upwards, forming a stable laminar flow. The cross-sectional area of ​​the upper and lower structure of the epitaxial cavity 2 is limited. The following explains how to correspondingly reduce the volume of the quartz device 1.

[0046] In one possible implementation, the first quartz cavity 13 is located above the second quartz cavity 14; the gas mixing pipe 15 is located below the second quartz cavity 14; a first gas outlet pipe 16 is also provided between the gas outlet end of the first quartz cavity 13 and the gas mixing pipe 15; the first gas outlet pipe 16 passes through the second quartz cavity 14, and the internal space of the first gas outlet pipe 16 is not connected to the internal space of the second quartz cavity 14.

[0047] The components of the quartz device 1 are arranged in an upper and lower structure, specifically: the first quartz cavity 13 is located above the second quartz cavity 14. For example, the vertical projection of the first quartz cavity 13 falls completely within the vertical projection range of the second quartz cavity 14, that is, the size of the second quartz cavity 14 is larger than that of the first quartz cavity 13, forming a layout that is smaller at the top and larger at the bottom.

[0048] The gas mixing pipe 15 is correspondingly located below the second quartz cavity 14. To adapt to this vertical layout, a first gas outlet pipe 16 is also provided between the gas outlet end of the first quartz cavity 13 and the gas mixing pipe 15. The first gas outlet pipe 16 is arranged to penetrate the second quartz cavity 14 in a vertical direction, and the internal space of the first gas outlet pipe 16 is not connected to the internal space of the second quartz cavity 14, so as to ensure that the carbon group chloride generated in the first quartz cavity 13 and the gallium chloride generated in the second quartz cavity 14 do not interfere with each other.

[0049] The core advantage of the above-mentioned top-smaller-bottom-larger top-bottom layout design lies in its significantly improved device integration, achieving a compact arrangement without increasing the overall size of the device. Since the vertical projection of the first quartz cavity 13 falls entirely within the range of the second quartz cavity 14, their vertically superimposed arrangement fully utilizes the vertical space inside the epitaxial cavity 2, avoiding the problem of excessive space occupation caused by horizontal tiling. This adapts to the limited installation space inside the epitaxial cavity 2, improving the compatibility between the device and the epitaxial cavity 2.

[0050] Conversely, if a reverse layout of "larger on top, smaller on bottom" is adopted, the larger and heavier second quartz cavity 14 will be on top, and the smaller and lighter first quartz cavity 13 will be on the bottom, making the center of gravity of the overall structure unstable.

[0051] The design of the first outlet pipe 16, which runs through the second quartz cavity 14 instead of surrounding it, aims to avoid the increased volume caused by a bypass. If it were to bypass the second quartz cavity 14, additional space would be required, increasing the overall size of the device and contradicting the goal of improving integration. Furthermore, a bypass would inevitably result in a curved structure in the first outlet pipe 16, which increases gas transport resistance and could cause carbon group chloride gas to stagnate or fluctuate in flow rate, affecting the uniformity and stability of subsequent mixing with gallium chloride. In addition, curved pipes are more difficult to manufacture, and the brittle nature of quartz makes the curved structure susceptible to damage due to thermal stress under high-temperature epitaxial growth. Therefore, the design of running through the second quartz cavity 14 ensures the straightness of the pipe arrangement, guaranteeing smooth and stable gas transport, while eliminating the need for additional bypass space, maintaining the compact integration characteristics of the device. Simultaneously, the sealed design, where the inside of the pipe and the inside of the quartz cavity are not interconnected, avoids cross-interference between the two reacting gases.

[0052] In some embodiments, the second chlorine gas pipe 12 penetrates the first quartz cavity 13, and the internal space of the second chlorine gas pipe 12 is not connected to the internal space of the first quartz cavity 13. Alternatively, if the first quartz cavity 13 is smaller than the second quartz cavity 14, and there is sufficient space around the first quartz cavity 13 for the second chlorine gas pipe 12 to pass through, it may not need to penetrate the first quartz cavity 13.

[0053] The following describes the exhaust structure of the upper cavity of the quartz device 1, namely the first quartz cavity 13.

[0054] In one possible implementation, the first vent pipe 16 vertically penetrates the lower cavity wall of the first quartz cavity 13; the first end of the first vent pipe 16 is disposed inside the first quartz cavity 13, and the second end is disposed outside the first quartz cavity 13; wherein, the height of the first end from the lower cavity wall is higher than the height of the carbon group element to be placed.

[0055] Exhaust from the upper chamber is achieved through the first exhaust pipe 16. Specifically, the first exhaust pipe 16 vertically penetrates the lower wall of the first quartz chamber 13, with the first end inside the chamber serving as the air inlet and the second end outside the chamber extending to the gas mixing pipe 15. Furthermore, the height of the first end is higher than the height of the carbon group elements inside the chamber. This prevents the raw materials from clogging the pipe and ensures the smooth discharge of the carbon group chloride gas generated in the reaction, preventing gas stagnation within the chamber.

[0056] Compared to sidewall exhaust, top exhaust, or surrounding exhaust, the core advantage of this design is its compact size, which is key to making full use of vertical space and avoiding horizontal redundancy. Sidewall exhaust requires transverse pipes and turning structures, which additionally occupy horizontal space and disrupt the compact layout; top exhaust increases pipe length and occupies vertical redundant space; surrounding exhaust requires reserving space for maneuvering, resulting in a loose device with poor adaptability.

[0057] In this embodiment of the invention, the first gas outlet pipe 16 extends vertically to the gas mixing pipe 15, making full use of the vertical gap between the cavities, eliminating horizontal redundancy and bending structures, significantly reducing the overall volume and improving integration, while simplifying processing and assembly, and ensuring stable gas delivery. Furthermore, after extending, the first gas outlet pipe 16 vertically penetrates the second quartz cavity 14, and the sealed isolation design ensures that the gases in the two cavities are not interconnected, avoiding cross-contamination.

[0058] The following describes the exhaust structure of the lower cavity of the quartz device 1, namely the second quartz cavity 14.

[0059] In one possible implementation, a second air outlet pipe 17 is provided between the air outlet end of the second quartz cavity 14 and the gas mixing pipe 15; the second air outlet pipe 17 vertically penetrates the lower cavity wall of the second quartz cavity 14; the first end of the second air outlet pipe 17 is located inside the second quartz cavity 14, and the second end is located outside the second quartz cavity 14; wherein, the height of the first end from the lower cavity wall is higher than the height of the gallium metal to be placed.

[0060] In this embodiment of the invention, gallium metal is placed at the bottom of the second quartz cavity 14, and the height of the first end is higher than the height of the gallium metal. This can effectively prevent the gallium metal material from clogging the gas inlet of the pipe and ensure smooth exhaust. In addition, the gallium chloride gas generated by the reaction of chlorine gas and gallium metal in the second quartz cavity 14 can be smoothly discharged through this vertical pipe, avoiding gas stagnation in the cavity, which could lead to insufficient reaction or abnormal pressure.

[0061] In addition, the design of the second air outlet pipe 17 vertically penetrating the lower cavity wall and directly connecting to the mixing pipe 15 works in synergy with the vertical layout of the first air outlet pipe 16 in the upper cavity, making full use of the vertical space of the device and avoiding the need for additional horizontal or detour pipes.

[0062] The above describes the exhaust structure of the two quartz chambers. The following describes the connection method between the two exhaust pipes and the mixing pipe 15.

[0063] In one possible implementation, the end of the second air outlet pipe 17 is sealed and connected to the end of the mixing pipe 15; the diameter of the second air outlet pipe 17 is larger than the diameter of the first air outlet pipe 16; the first air outlet pipe 16 is nested inside the second air outlet pipe 17 and passes through both ends of the second air outlet pipe 17; the second end of the first air outlet pipe 16 extends into the mixing pipe 15.

[0064] For example, the first vent pipe 16 is nested within the second vent pipe 17 and passes through both ends of the second vent pipe 17. The first vent pipe 16 and the second vent pipe 17 are arranged concentrically to form a double-layer coaxial structure of inner pipe and outer pipe. The second vent pipe 17 is the outer pipe, and its diameter is larger than that of the first vent pipe 16, which is the inner pipe. The first vent pipe 16 is entirely nested inside the second vent pipe 17 and passes through both ends of the second vent pipe 17 along the axial direction, realizing a through-type nesting of the inner pipe through the outer pipe.

[0065] For example, the end of the second gas outlet pipe 17 is sealed to the end of the gas mixing pipe 15 to ensure no gas leakage. The second end of the first gas outlet pipe 16, i.e. the external end, extends further into the gas mixing pipe 15 after passing through the second gas outlet pipe 17, providing a channel for the transport of carboxylic chlorides.

[0066] It should be clarified that in this concentric nested structure, the internal space of the first gas outlet pipe 16 is the inner cavity, and the internal space of the second gas outlet pipe 17 (i.e., the annular area between the inner and outer pipes) is the outer cavity. The two chambers are independent of each other and do not communicate with each other, so that the two reaction gases can be transported independently, avoiding premature mixing or cross-contamination during the transportation process.

[0067] The concentric nested structure requires no additional horizontal space, significantly improving the integration of pipe connections and avoiding the volume increase problem caused by multiple parallel pipes. In addition, the inner-outer pipe isolation design ensures that the two reactant gases are completely isolated before entering the mixing pipe 15, and mixing only begins within the mixing pipe 15, ensuring the initial stability of the gas components.

[0068] In this embodiment of the invention, based on the independent exhaust of the two quartz cavities, a compact and isolated connection between the two exhaust pipes and the mixing pipe 15 is achieved by concentric nesting and combining them.

[0069] In the gallium oxide epitaxial reaction, the core role of oxygen is to react with the chlorides such as carbon group chlorides and gallium chlorides transported by the gas mixing pipe 15, and finally grow a gallium oxide epitaxial layer on the substrate surface.

[0070] In one possible implementation, an oxygen conduit is also included; one end of the oxygen conduit is used to connect to an oxygen source outside the epitaxial furnace, and the outlet of the other end faces the substrate surface of the gallium oxide to be grown.

[0071] In this embodiment of the invention, an oxygen pipe 18 is added to the quartz device 1. One end of the oxygen pipe 18 extends to the outside of the epitaxial furnace and is connected to an oxygen source to introduce external oxygen; the outlet of the other end faces directly toward the substrate surface of the gallium oxide to be grown, which can ensure that oxygen is delivered to the core reaction area and fully contactes and reacts with the mixed chloride output from the mixing pipe 15.

[0072] Furthermore, the side of the oxygen pipe 18 can be fixed to the second quartz cavity 14, forming an integrated quartz device 1. This integrated design fully utilizes the existing structure of the second quartz cavity 14 as a fixing carrier, eliminating the need for additional independent supports and avoiding the space occupation caused by separate support arrangements. Both the oxygen pipe 18 and the second quartz cavity 14 are made of quartz, ensuring material compatibility. After fixing, they can jointly adapt to the high-temperature environment of the epitaxial reaction, preventing structural loosening caused by differences in the thermal expansion coefficients of different materials and ensuring long-term reliability.

[0073] In one possible implementation, the outlet of the oxygen conduit 18 is annular around the mixing conduit 15.

[0074] The outlet of the oxygen conduit 18 is designed as a ring structure surrounding the gas mixing conduit 15, and the outlet of this ring-shaped outlet still faces the substrate surface where gallium oxide is to be grown. The purpose is to achieve uniform oxygen distribution output: on the one hand, the ring structure surrounding the gas mixing conduit 15 allows oxygen to be sprayed out uniformly in all directions and circumferentially from the annular area around the gas mixing conduit 15, forming an annular gas curtain covering the periphery of the outlet of the gas mixing conduit 15; on the other hand, this circumferentially uniform gas output method allows oxygen and the mixed chloride output from the gas mixing conduit 15 to form a uniform contact environment throughout the substrate reaction area, avoiding the problem of excessively high or low local oxygen concentration caused by traditional single outlets.

[0075] In one possible implementation, an isolation nitrogen pipeline 19 is also included: one end of the isolation nitrogen pipeline 19 is used to connect to a nitrogen source outside the epitaxial furnace, and the outlet of the other end is located between the outlet of the oxygen pipeline 18 and the outlet of the mixing pipeline 15.

[0076] The function of the nitrogen isolation pipe 19 is to isolate the outlet of the oxygen pipe 18 from the outlet of the mixed gas pipe 15. Ideally, the mixed chloride output from the mixed gas pipe 15 and the oxygen output from the oxygen pipe 18 should mix and react only after reaching the substrate surface; contact between the two should be avoided as much as possible before that. If the two gases mix and react prematurely before reaching the substrate, excessive solid particles are easily formed. These particles will adhere to the substrate surface or epitaxial layer, severely damaging the crystal quality of the epitaxial layer and leading to an increase in epitaxial layer defects, failing to meet the fabrication requirements of high-performance gallium oxide devices. Therefore, by continuously outputting nitrogen, the nitrogen isolation pipe 19 forms a nitrogen isolation curtain between the outlet of the oxygen pipe 18 and the outlet of the mixed gas pipe 15, effectively separating the mixed chloride and oxygen and preventing them from reacting prematurely before reaching the substrate, structurally avoiding the risk of premature reaction and particle generation.

[0077] For example, the outlet of the isolation nitrogen pipeline 19 is also a ring structure, and it is arranged around the outlet of the mixing pipeline 15. This ring outlet design is compatible with the ring outlet of the oxygen pipeline 18: the ring structure allows nitrogen to be sprayed evenly around the outlet of the mixing pipeline 15, forming a ring-shaped isolation gas curtain that covers the entire area, ensuring that there are no dead corners in the isolation area and avoiding the problem of premature gas mixing caused by local isolation failure.

[0078] In one possible implementation, the distance between the outlet of the oxygen conduit 18 and the substrate is less than the distance between the outlet of the gas mixing conduit 15 and the substrate.

[0079] The distance between the outlet of oxygen conduit 18 and the substrate surface where gallium oxide is to be grown is less than the distance between the outlet of gas mixing conduit 15 and the substrate surface. The outlet of gas mixing conduit 15 is positioned higher than the outlet of oxygen conduit 18, while the outlet of oxygen conduit 18 is closer to the substrate, creating a vertical height difference. This spatial arrangement aims to further prevent premature contact and reaction between oxygen and the mixed chloride. The mixed chloride and oxygen must react after reaching the substrate surface; premature contact can easily generate solid particles or trigger abnormal deposition.

[0080] The oxygen outlet of the oxygen conduit 18 is close to the substrate. After being ejected, the oxygen mainly concentrates in a localized area near the substrate, making it difficult to diffuse upwards to the height of the outlet of the gas mixing conduit 15. This prevents the oxygen from encountering the freshly discharged mixed chloride near the outlet of the gas mixing conduit 15, thus preventing premature oxidation of gallium oxide in non-target areas. If the outlets of the two conduits were level, the oxygen would easily come into contact with the mixed chloride around the outlet of the gas mixing conduit 15, leading to gallium oxide deposition and growth at the outlet of the gas mixing conduit 15. Long-term deposition would gradually shrink or even block the outlet aperture of the gas mixing conduit 15.

[0081] The height difference layout of this invention, along with the aforementioned isolation nitrogen gas curtain, avoids the risk of abnormal gallium oxide growth at the outlet of the mixing pipe 15, thus ensuring the stability of gas delivery.

[0082] Figure 2 This is a schematic diagram of the gallium oxide epitaxial device provided in an embodiment of the present invention. (Refer to...) Figure 2 This invention provides a gallium oxide epitaxial device, including an epitaxial cavity 2, a base, and a quartz device 1 for gallium oxide epitaxy as described in any of the above possible implementations; the quartz device 1 and the base are disposed inside the epitaxial cavity 2; the upper surface of the base is used to support a substrate to be grown gallium oxide; the quartz device 1 is disposed above the base, wherein the outlet of the gas mixing pipe 15 faces downward toward the surface of the substrate to be grown gallium oxide.

[0083] In some embodiments, inside the epitaxial cavity 2, the quartz device 1, the substrate, and the base are arranged from top to bottom. Specifically, the quartz device 1 is positioned directly above the base, the upper surface of the base is used to support the substrate to be grown gallium oxide, and the substrate is placed with its front side facing upwards, with the growth surface of the substrate aligned with the gas outlet of the quartz device 1 above.

[0084] In the quartz device 1, a group of carbon elements is placed in the first quartz cavity 13, and metallic gallium is placed in the second quartz cavity 14. For example, the amount of group of carbon chlorides generated can be controlled by adjusting the inlet flow rate of the first chlorine gas pipe 11, thereby adjusting the carbon doping concentration. More exemplaryly, the flow rate of chlorine gas entering the upper quartz boat is precisely controlled by a mass flow meter, thereby controlling the amount of tetrachloride (silicon tetrachloride, germanium tetrachloride, or tin tetrachloride) synthesized in the HVPE chamber, thus precisely controlling the doping amount of silicon (or germanium, tin) impurities in the gallium oxide epitaxial layer, ultimately achieving precise control of the carrier concentration in the gallium oxide epitaxial layer.

[0085] In some embodiments, a quartz rotating rod is disposed below the base. The quartz rotating rod is directly connected to the base, providing stable vertical support for the base and the substrate supported above. The quartz rotating rod can drive the base and substrate to rotate synchronously. During epitaxial growth, the rotating substrate allows its surface areas to uniformly and alternately contact the reaction gas transported from top to bottom, effectively avoiding problems such as uneven growth rate and composition fluctuations of the local epitaxial layer caused by slight differences in the gas concentration field.

[0086] For example, the quartz device 1 is located in the source region of the epitaxial cavity 2. The temperature range of the source region is 800 to 900°C.

[0087] For example, the location of the base and substrate is the growth temperature zone of the epitaxial cavity 2. The temperature range of the growth temperature zone is 600 to 1000°C.

[0088] For example, the substrate may be a gallium oxide single crystal substrate, a sapphire substrate, or a silicon substrate, etc.

[0089] For example, the base is a graphite base, a sapphire base, or a silicon carbide base with an external silicon carbide coating.

[0090] For example, chlorine gas at the ppm level is introduced into the first chlorine gas pipeline 11, with nitrogen as the diluent gas. The chlorine gas flows through the upper quartz boat in the first chlorine gas pipeline 11 and reacts with the single-crystal silicon particles therein to generate silicon tetrachloride.

[0091] For example, high-purity chlorine gas is introduced into the first chlorine gas pipeline 11. The high-purity chlorine gas flows through the lower quartz boat without passing through the upper quartz boat, and reacts with the high-purity metallic gallium in the lower quartz boat to produce gallium chloride.

[0092] For example, the silicon tetrachloride and gallium chloride generated by the reaction are mixed at the lower central tube position to form a mixed gas flow.

[0093] For example, nitrogen can be used as a shielding gas to prevent the mixed gas and oxygen from mixing prematurely and depositing gallium oxide on the quartz wall at the outlet of the mixed gas.

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quartz device with gallium oxide epitaxy, characterized in that, For installation inside the epitaxial cavity; the device includes: a first chlorine gas pipe, a second chlorine gas pipe, a first quartz cavity, a second quartz cavity, and a gas mixing pipe; One end of the first chlorine gas pipeline is used to connect to a chlorine gas source outside the epitaxial furnace, and the other end is connected to the gas inlet of the first quartz cavity; One end of the second chlorine gas pipeline is used to connect to a chlorine gas source outside the epitaxial furnace, and the other end is connected to the gas inlet of the second quartz cavity; The first quartz cavity is used to hold carbon group elements; the second quartz cavity is used to hold metallic gallium. The gas outlets of the first and second quartz cavities are both connected to the gas mixing pipe; wherein, during gallium oxide epitaxy, the outlet of the gas mixing pipe faces the substrate surface of the gallium oxide to be grown.

2. The gallium oxide epitaxial quartz device as described in claim 1, characterized in that, The first quartz cavity is located above the second quartz cavity; the gas mixing pipe is located below the second quartz cavity. A first air outlet pipe is also provided between the air outlet end of the first quartz cavity and the gas mixing pipe; the first air outlet pipe passes through the second quartz cavity, and the internal space of the first air outlet pipe is not connected to the internal space of the second quartz cavity.

3. The gallium oxide epitaxial quartz device as described in claim 2, characterized in that, The first air outlet pipe penetrates vertically through the lower cavity wall of the first quartz cavity; The first end of the first vent pipe is located inside the first quartz cavity, and the second end is located outside the first quartz cavity; wherein, the height of the first end from the lower cavity wall is higher than the height of the carbon group element to be placed.

4. The gallium oxide epitaxial quartz device as described in claim 2, characterized in that, A second air outlet pipe is also provided between the air outlet end of the second quartz cavity and the gas mixing pipe; The second air outlet pipe penetrates vertically through the lower cavity wall of the second quartz cavity; The first end of the second vent pipe is located inside the second quartz cavity, and the second end is located outside the second quartz cavity; wherein, the height of the first end from the lower cavity wall is higher than the height of the gallium metal to be placed.

5. The gallium oxide epitaxial quartz device as described in claim 4, characterized in that, The end of the second air outlet pipe is sealed and connected to the end of the mixing pipe; The diameter of the second air outlet pipe is larger than that of the first air outlet pipe; The first air outlet pipe is nested inside the second air outlet pipe and extends through both ends of the second air outlet pipe; The second end of the first gas outlet pipe extends into the gas mixing pipe.

6. The gallium oxide epitaxial quartz device as described in claim 1, characterized in that, Also includes: Oxygen pipeline; One end of the oxygen pipe is used to connect to an oxygen source outside the epitaxial furnace, and the outlet of the other end faces the surface of the substrate to be grown gallium oxide.

7. The gallium oxide epitaxial quartz device as described in claim 6, characterized in that, The outlet of the oxygen pipeline is a ring that surrounds the gas mixing pipeline.

8. The gallium oxide epitaxial quartz device as described in claim 6, characterized in that, It also includes the isolation of nitrogen pipelines: One end of the isolation nitrogen pipeline is used to connect to a nitrogen source outside the epitaxial furnace, and the outlet of the other end is located between the outlet of the oxygen pipeline and the outlet of the mixed gas pipeline.

9. The gallium oxide epitaxial quartz device as described in claim 6, characterized in that, The distance between the oxygen pipe outlet and the substrate is less than the distance between the mixed gas pipe outlet and the substrate.

10. A gallium oxide epitaxial device, characterized in that, Includes an epitaxial cavity, a base, and a quartz device for gallium oxide epitaxy as described in any one of claims 1 to 9; The quartz device and the base are disposed inside the epitaxial cavity; The upper surface of the base is used to support the substrate on which gallium oxide is to be grown; The quartz device is located above the base, wherein the outlet of the gas mixing pipe faces downward toward the substrate surface of the gallium oxide to be grown.

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