Silicon carbide epitaxial growth equipment and method

Abstract

The invention discloses silicon carbide epitaxial growth equipment and a silicon carbide epitaxial growth method. The method comprises an etching stage and an epitaxial growth stage, and the etching stage comprises the steps that hydrogen is introduced into a reaction cavity based on a top spraying assembly, and in-situ etching is conducted on the surface of a substrate located in the reaction cavity through the hydrogen; the epitaxial growth stage comprises the steps that growth source gas is introduced into the reaction cavity based on a top spraying assembly, side wall purging gas is introduced into the reaction cavity based on a side wall purging assembly, and the side wall purging gas flows towards the substrate side along the surface of a graphite cylinder in the reaction cavity and restrains the growth source gas on the inner side of the graphite cylinder. The carbon-silicon ratio and the source gas distribution on the surface side of the substrate are adjusted to grow an epitaxial layer. According to the method, the uniformity of the N doping concentration and the thickness of the epitaxial layer on the silicon carbide substrate is flexibly regulated and controlled by regulating and controlling the side wall purging gas flow, so that the quality of the epitaxial wafer is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor deposition technology, and in particular to a silicon carbide epitaxial growth device and method. Background Art

[0002] Compared with the first generation of semiconductor Si materials, the third generation of semiconductor SiC materials has shown a huge application market in the fields of high temperature resistance, high voltage resistance and high power devices. With the iteration of CVD equipment, the optimization of epitaxial process and the advancement of device manufacturing technology, SiC electronic power devices have been widely used in new energy vehicles, aerospace and other fields.

[0003] However, unlike Si devices, SiC electronic power devices are usually prepared on SiC homoepitaxial layers, so the quality of the homoepitaxial layers directly affects the performance and yield of downstream chips. Good SiC thickness and concentration uniformity can not only reduce the discreteness of chip performance, but also improve chip reliability. Studies have found that the different depletion modes of growth sources and doping sources along the radial direction of the wafer are the root cause of the unevenness of SiC materials. In order to improve the quality of SiC homoepitaxial layers as much as possible, domestic and foreign scholars have done a lot of research on the uniformity of SiC materials, but there is still a lack of a method to flexibly control the uniformity of silicon carbide epitaxial wafer materials. Summary of the invention

[0004] In order to overcome the above shortcomings, the purpose of the present application is to provide a silicon carbide epitaxial growth device and method.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for epitaxial growth of silicon carbide.

[0007] A method for epitaxial growth of silicon carbide, the method comprising an etching stage and an epitaxial growth stage, wherein:

[0008] The etching stage comprises:

[0009] Introducing hydrogen into the reaction chamber based on a top spray assembly, and utilizing the hydrogen to in-situ etch the surface of the substrate located in the reaction chamber;

[0010] The epitaxial growth stage comprises:

[0011] Based on the top spray assembly, the growth source gas is introduced into the reaction chamber, and based on the side wall purge assembly, the side wall purge gas is introduced into the reaction chamber. The side wall purge gas flows along the surface of the graphite tube in the reaction chamber toward the substrate side while constraining the growth source gas inside it, and adjusting the carbon-silicon ratio and source gas distribution (i.e., growth source gas distribution) on the substrate surface side to grow the epitaxial layer. Through such a design, during the epitaxial reaction, the side wall purge gas that does not participate in the reaction is introduced into the reaction chamber, and the side wall purge gas is used to interfere / disturb the growth source gas (also called process gas) inside the graphite tube when flowing, so as to adjust the carbon-silicon ratio and (growth) source gas distribution on the substrate side, optimize the concentration uniformity and thickness uniformity of the epitaxial film, and the generated epitaxial wafers have good consistency between batches.

[0012] In one embodiment, in the silicon carbide epitaxial growth method, the growth source gas introduced into the reaction chamber based on the top spray assembly includes a carbon source gas, a silicon source gas, a hydrogen chloride gas and a nitrogen gas, wherein the carbon source gas includes ethylene or propane, and the silicon source gas includes trichlorosilane or silane.

[0013] In one embodiment, the total flow rate of the silicon source introduced into the reaction chamber by the top spray assembly is 500-1000 sccm.

[0014] Based on the total flow rate of the carbon source introduced into the reaction chamber by the top spray assembly being 100-200 sccm,

[0015] Based on the total flow rate of hydrogen chloride gas introduced into the reaction chamber by the top spray assembly being 100-5000 sccm,

[0016] The C / S i ratio at the air inlet end of the reaction chamber is 0.6-1.2, and the flow rate of the side wall purge gas introduced into the reaction chamber by the side wall purge assembly is 4-10 L / min.

[0017] In one embodiment, the method further comprises a preparation stage, wherein the preparation stage comprises:

[0018] The substrate is placed on the susceptor of the reaction chamber, the reaction chamber is evacuated based on the gas inlet and the gas outlet, and the pressure and temperature of the reaction chamber and the rotation speed of the susceptor are adjusted.

[0019] Furthermore, in the preparation stage,

[0020] The pressure of the reaction chamber is adjusted to 100-300 mbar,

[0021] The temperature of the reaction chamber is adjusted to 1580-1650°C based on the heating assembly.

[0022] The rotation speed of the susceptor in the reaction chamber is adjusted to 500-1000 rpm.

[0023] Furthermore, in the etching stage,

[0024] Based on the flow rate of hydrogen introduced into the reaction chamber by the top spray assembly being 90-130 L / min,

[0025] The duration of the etching stage is 5-15 minutes.

[0026] Furthermore, the side wall purge gas is argon, which flows along the surface of the graphite tube in the reaction chamber toward the substrate side while constraining the growth source gas inside thereof to adjust the carbon-silicon ratio and source gas distribution (i.e., growth source gas distribution) from the center to the edge of the substrate.

[0027] Furthermore, the epitaxial layer grown on the surface of the substrate includes a central portion and an edge portion, the C / Si ratio and thickness of the central portion of the epitaxial layer are inversely proportional to the flow rate of the purge gas introduced into the inner wall of the reaction chamber, and the C / Si ratio and thickness of the edge portion of the epitaxial layer are directly proportional to the flow rate of the purge gas introduced into the inner wall of the reaction chamber.

[0028] In one embodiment, in the silicon carbide epitaxial growth method,

[0029] After the epitaxial growth stage, the method further comprises:

[0030] The top spray assembly introduces gas into the reaction chamber to cool the substrate to below 800° C.

[0031] The epitaxial wafer is transferred from the reaction chamber to the unloading chamber based on a robot.

[0032] The embodiment of the present application provides a silicon carbide epitaxial growth device, which includes a housing,

[0033] The graphite cylinder in the shell is coaxially arranged with the shell, and the shell has a reaction chamber.

[0034] A spray device is arranged on the top side of the shell, and the spray device includes a top spray component and a side wall purge component.

[0035] The base is rotatably arranged at the bottom of the reaction chamber. A carrying plate is arranged on the base, and the carrying plate is used to place the substrate. A heating component is arranged in the base.

[0036] Beneficial Effects

[0037] This solution flexibly controls the uniformity of the doping concentration and thickness of the epitaxial layer on the silicon carbide substrate by regulating the flow rate of the sidewall purge gas, thereby improving the quality of the epitaxial wafer. Specifically, the flow rate of the sidewall purge gas is increased during epitaxial growth, and the flow rate of the sidewall purge gas is increased. After the flow rate increases, a negative pressure is formed in the edge area of ​​the reaction chamber (the area close to the side wall), so that the growth source gas located in the middle area of ​​the reaction chamber diffuses to the edge area of ​​the reaction chamber, thereby causing the thickness of the center part of the epitaxial layer grown on the substrate to become thinner and thinner relative to the edge part, thereby achieving the purpose of adjusting the uniformity of the thickness of the epitaxial layer. In addition, after adding the sidewall purge gas, the overall thickness becomes thinner because the growth source gas diffuses outward, resulting in a decrease in the overall growth source utilization rate.

[0038] Secondly, the diffusion amounts of carbon source gas and silicon source gas in the radial direction of the epitaxial layer are different. With the increase of sidewall purge gas flow rate, the C / Si ratio (carbon-silicon ratio) at the edge of the epitaxial layer gradually increases relative to the C / Si at the center. As a result, as the sidewall purge gas continues to increase, the doping concentration at the edge of the epitaxial layer gradually decreases relative to the doping concentration at the center, thereby achieving the purpose of adjusting the uniformity of the doping concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure. The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions and are only intended to illustrate the content of the present application.

[0040] Figure 1 FIG. 4 is a flow chart of a method for epitaxial growth of silicon carbide in one embodiment of the present invention.

[0041] Figure 2 This is a trend diagram of N doping concentration distribution of an epitaxial wafer when sidewall purge gas is introduced in one embodiment of the present invention.

[0042] Figure 3 This is a graph showing the distribution trend of epitaxial wafer thickness when sidewall purge gas is introduced in one embodiment of the present invention.

[0043] Figure 4 FIG. 4 is a structural diagram of a silicon carbide epitaxial growth device in another embodiment of the present invention.

[0044] Figure 5 FIG. 1 is a schematic diagram of gas flow during operation of a silicon carbide epitaxial growth device in another embodiment of the present invention.

[0045] The components in the figure are shown as follows:

[0046] 1. Reaction chamber; 2. Carrier plate; 3. Top spray device; 4. Graphite cylinder; 5. Bottom heater; 6. Side wall heater; 7. Substrate; 8. Insulation layer; 9. Air guide cylinder; 10. Side wall purge device. DETAILED DESCRIPTION

[0047] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the present application and are not limited to the scope of the present application. The implementation conditions adopted in the examples can be further adjusted as the conditions of the specific manufacturer, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0048] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In this article, "electrical connection" includes the situation where the constituent elements are connected together through an element with some electrical function. "Elements with some electrical function" are not particularly limited as long as they can transfer electrical signals between the connected constituent elements. "Elements with some electrical function" can be, for example, electrodes or wiring, or switching elements such as transistors, or other functional elements such as resistors, inductors or capacitors. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0049] In this application, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0050] Example

[0051] As described in the background art, good SiC thickness and concentration uniformity can not only reduce the discreteness of chip performance, but also improve chip reliability. However, the existing technology is currently unable to control the uniformity of silicon carbide epitaxial wafer materials.

[0052] The study found that the different depletion modes of the growth source and the doping source along the radial direction of the wafer are the fundamental reasons for the unevenness of SiC materials.

[0053] In view of the above content, the inventors have improved the method of epitaxial growth of silicon carbide, specifically:

[0054] During the epitaxial growth stage, a side wall purge gas (argon) is introduced into the reaction chamber through a side wall purge assembly, and the uniformity of the epitaxial wafer material is flexibly controlled by adjusting the flow rate of the side wall purge gas.

[0055] Increasing the side wall purge gas flow rate will increase the side wall purge gas flow velocity. After the flow velocity increases, negative pressure is formed in the edge area of ​​the reaction chamber (the area close to the side wall of the reaction chamber), causing the growth source gas located in the middle area of ​​the reaction chamber to diffuse to the edge area of ​​the reaction chamber, causing the thickness of the center part of the epitaxial layer grown on the substrate to become thinner and thinner relative to the edge part, thereby achieving the purpose of adjusting the thickness uniformity.

[0056] Secondly, the diffusion amount of carbon source gas and silicon source gas in the radial direction of epitaxial layer is different. With the increase of sidewall purge gas flow rate, the C / Si ratio of epitaxial layer edge part gradually increases relative to the C / Si ratio of central part. As a result, with the continuous increase of sidewall purge gas, the doping concentration of epitaxial layer edge part gradually decreases relative to the doping concentration of central part, thereby achieving the purpose of adjusting the uniformity of doping concentration. The substrate after epitaxial growth is also called epitaxial wafer.

[0057] Based on the above concept, the silicon carbide epitaxial growth device and method proposed in the present application will be described below in conjunction with the accompanying drawings.

[0058] In one embodiment, the method comprises an etching phase and an epitaxial growth phase, wherein:

[0059] The etching phase includes:

[0060] Hydrogen is introduced into the reaction chamber based on the top spray assembly, and the surface of the substrate in the reaction chamber is etched in situ by the hydrogen; after the etching stage, the epitaxial growth stage is entered.

[0061] The epitaxial growth stage includes:

[0062] The growth source gas is introduced into the reaction chamber based on the top spray assembly, and the side wall purge gas is introduced into the reaction chamber based on the side wall purge assembly. The side wall purge gas flows along the surface of the graphite tube in the reaction chamber toward the substrate side while constraining the growth source gas inside, adjusting the carbon-silicon ratio and the distribution of the growth source gas on the surface side of the substrate to grow an epitaxial layer. Preferably, a buffer layer is first grown on the substrate, and then an epitaxial layer is grown on the buffer layer. (Sometimes the buffer layer and the epitaxial layer thereon are collectively referred to as the epitaxial layer). The side wall purge gas does not participate in the reaction. The flow rate of the introduced side wall purge gas is between 4L / min-10L / min.

[0063] like Figure 1 As shown, a method for epitaxial growth of silicon carbide is provided for this embodiment, which comprises the following steps:

[0064] S1, placing the substrate into a reaction chamber of a silicon carbide epitaxial device, and evacuating the reaction chamber;

[0065] S2, adjusting the pressure, temperature and rotation speed of the reaction chamber;

[0066] S3, introducing hydrogen into the reaction chamber of the silicon carbide epitaxial device (vertical airflow) based on the spray assembly, and in-situ etching the surface of the substrate located in the reaction chamber by the hydrogen;

[0067] S4, introducing growth source gas into the reaction chamber based on the top spray assembly, and introducing side wall purge gas into the reaction chamber based on the side wall purge assembly, wherein the side wall purge gas can form a negative pressure in the edge area of ​​the reaction chamber to adsorb the growth source gas, so that the growth source gas located in the middle area of ​​the reaction chamber diffuses to the edge area of ​​the reaction chamber, and the buffer layer and the epitaxial layer are sequentially grown on the surface of the substrate using the growth source gas;

[0068] S5. After the epitaxial growth is completed, a gas (such as hydrogen) is introduced into the reaction chamber based on the spray assembly to cool the epitaxial wafer formed by the epitaxial growth of the substrate. Then, the epitaxial wafer is transferred from the reaction chamber to the transfer chamber (TM chamber) and then to the unloading chamber based on the robot, and then cooled to room temperature again in the unloading chamber.

[0069] In the above embodiment, the substrate (4H—Si C) placed in the reaction chamber in step S1 has a 4° off-angle.

[0070] In the above embodiment, step S2 adjusts the pressure of the reaction chamber to 100-300 mbar (such as 200 mbar).

[0071] The temperature of the reaction chamber is adjusted to 1580-1650° C. (eg, 1620° C.) based on the heating assembly, and the rotation speed of the susceptor in the reaction chamber is adjusted to 500-1000 rpm (eg, 600 rpm).

[0072] In the above embodiment, in step S3, the flow rate of hydrogen introduced into the reaction chamber by the spray assembly is 90-130 L / min (such as 100 L / min), and the duration of the etching stage is 5-15 min (such as 10 min).

[0073] In the above embodiment, in step S4, the carbon source gas introduced into the reaction chamber by the spray assembly includes ethylene or propane, and the silicon source gas introduced into the reaction chamber by the spray assembly includes trichlorosilane or silane, and the total flow rate of the silicon source introduced is 500-1000 sccm (standard cubic centimeter per minute);

[0074] The total flow rate of the carbon source introduced is 100-200 sccm, the total flow rate of the hydrogen chloride introduced is 100-5000 sccm, and the C / Si ratio at the air inlet end of the reaction chamber needs to be maintained at 0.6-1.2.

[0075] In the above embodiment, in step S5, the epitaxial wafer formed by epitaxial growth of the substrate is cooled by hydrogen, and the temperature needs to be cooled to below 800°C.

[0076] In the above embodiment, during the epitaxial growth stage:

[0077] The silicon source is trichlorosilane (TCS), the carbon source is ethylene (C2H4), the total flow rate of trichlorosilane (TCS) is 800sccm, the total flow rate of ethylene (C2H4) is 155sccm, the total flow rate of HCL is 600sccm, the C / Si ratio at the inlet end is maintained at 0.77, and during the epitaxial growth process, the inventors respectively introduced different flow rates of side wall purge gas (4L / min, 6L / min, 10L / min) into the reaction chamber

[0078] like Figure 2 As mentioned above, the 0 on the horizontal axis of the figure is the center of the epitaxial wafer, and then the center extends outward, and the edge is 70mm. It can be seen from the figure that with the increase of the side wall purge flow rate, the N doping concentration distribution trend of the epitaxial wafer gradually changes from a "U" shape to an "inverted U" shape, such as Figure 3 As shown in the figure, with the increase of the sidewall purge gas flow rate, the thickness distribution trend of the epitaxial wafer gradually changes from "W" type to "M" type.

[0079] When the sidewall purge gas flow rate is 6L / min, the thickness / concentration uniformity of the epitaxial wafer reaches the optimal level, with a thickness uniformity of 0.81% and a concentration uniformity of 1.8%.

[0080] It can be seen that by introducing sidewall purge gas (argon) into the reaction chamber during the epitaxial growth stage and adjusting the flow rate of the sidewall purge gas, the doping concentration and thickness uniformity of the epitaxial layer on the substrate can be flexibly adjusted, thereby improving the quality of the epitaxial wafer.

[0081] This embodiment provides a silicon carbide epitaxial growth device, such as Figure 4 As shown, including:

[0082] The shell comprises a cylindrical shell having a reaction chamber 1 therein.

[0083] A carrier plate 2 is provided at the bottom of the reaction chamber 1. The carrier plate 2 is used to place the substrate 7 to be epitaxially grown. The carrier plate 2 is placed on a support portion (support cylinder, not shown), and the support portion is connected to a driving device. During the epitaxial growth reaction process, the carrier plate 2 needs to rotate with the substrate 7. The carrier plate 2 is connected to a driving device that provides rotation, such as a driving motor, etc. A heater (also called a bottom heater 5) is provided in the support portion. The support portion is also called a base.

[0084] A graphite cylinder 4 is provided in the housing. Preferably, the graphite cylinder 4 is coaxially provided with the housing. The graphite cylinder 4 may be an integral structure or may be formed by connecting two graphite cylinders 4 in series. An air guide cylinder 9 is provided in the housing, and its axial cross section is in an eight-shaped or trumpet-shaped shape. The material of the air guide cylinder 9 is selected from graphite. In one embodiment, the purge gas 11 introduced through the air vent of the side wall purge device 10 is guided through the air guide cylinder 9 to blow toward the surface of the graphite cylinder 4, and flows along the surface of the graphite cylinder 4 toward the substrate 7 side, and the flow rate of the purge gas is adjusted to form an airflow on the surface of the graphite cylinder 4 (the airflow is as shown in FIG. 1 ). Figure 5 As shown in FIG. 1 , the growth source gas 31 introduced by the top spray device 3 diffuses toward the edge of the reaction chamber 1 (the side wall of the reaction chamber 1, i.e., the surface side of the graphite cylinder 4) while flowing toward the substrate 7, thereby adjusting the carbon-silicon ratio of the growth source gas from the center to the edge of the substrate 7, thereby adjusting the doping concentration and thickness of the epitaxial layer on the substrate 7, improving the uniformity of the doping concentration and thickness, and thus improving the epitaxial quality. The growth source gas includes a carbon source gas, a silicon source gas, and a doping gas (including hydrogen chloride gas in some cases).

[0085] A side wall heater 6 is also provided in the shell, and the side wall heater 6 is located outside the graphite cylinder 4 and inside the insulation layer 8. The side wall heater 6 and the bottom heater 5 are both electrically connected to an external power source, and the materials both include graphite material. The reaction chamber is heated by the cooperation of the side wall heater 6 and the bottom heater 5 to reach the preset process temperature of epitaxial growth. The side wall heater 6 and the bottom heater 5 are collectively referred to as a heating assembly.

[0086] A top spray device 3 is provided at the top of the reaction chamber 1. The spray area of ​​the top spray device 3 is circular. The air hole opened in the middle of the spray area is used to introduce the growth source gas and hydrogen. In this embodiment, the gas flow direction introduced by the spray device is roughly perpendicular to the surface of the substrate 7. In some cases, the epitaxial growth device is also called a vertical epitaxial growth device. Preferably, the top spray device (top spray assembly) 3 is designed integrally with the side wall purge device 10. The side wall purge device 10 is located at the periphery of the top spray assembly. The side wall purge device 10 is guided to the surface of the graphite cylinder 4 through the gas guide cylinder 9 (sometimes also called the upper graphite cylinder), and flows along the surface of the graphite cylinder 4 toward the substrate side. While flowing, it forms interference / turbance to the process gas introduced by the top spray device 3, adjusts the carbon-silicon ratio of the process gas (process gas) from the center to the edge of the substrate 7, and thereby adjusts the doping concentration and thickness of the thin film grown on the substrate, and improves the uniformity of the doping concentration and thickness.

[0087] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with the technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A method for epitaxial growth of silicon carbide, It is characterized in that The method comprises an etching stage and an epitaxial growth stage, wherein: The etching stage comprises: Introducing hydrogen into the reaction chamber based on a top spray assembly to perform in-situ etching on the surface of the substrate located in the reaction chamber; The epitaxial growth stage comprises: Growth source gas is introduced into the reaction chamber based on a top spray assembly, and side wall purge gas is introduced into the reaction chamber based on a side wall purge assembly. The side wall purge gas flows along the surface of the graphite tube in the reaction chamber toward the substrate side while constraining the growth source gas inside thereof, thereby adjusting the carbon-silicon ratio and source gas distribution on the substrate surface side to grow an epitaxial layer.

2. The method for epitaxial growth of silicon carbide according to claim 1, It is characterized in that The growth source gas introduced into the reaction chamber based on the top spray assembly includes carbon source gas, silicon source gas, hydrogen chloride gas and nitrogen. The carbon source gas includes ethylene or propane, and the silicon source gas includes trichlorosilane or silane.

3. The method for epitaxial growth of silicon carbide according to claim 1 or 2, It is characterized in that Based on the total flow rate of the silicon source introduced into the reaction chamber by the top spray assembly being 500-1000 sccm, Based on the total flow rate of the carbon source introduced into the reaction chamber by the top spray assembly being 100-200 sccm, Based on the total flow rate of hydrogen chloride introduced into the reaction chamber by the top spray assembly being 100-5000 sccm, The carbon-silicon ratio of the gas introduced into the reaction chamber is between 0.6 and 1.2, and the flow rate of the side wall purge gas introduced into the reaction chamber is between 4 and 10 L / min.

4. The method for epitaxial growth of silicon carbide according to claim 1, It is characterized in that The method further comprises a preparation phase, which comprises: The substrate is placed on a carrier plate in the reaction chamber, the reaction chamber is evacuated, the pressure in the reaction chamber is adjusted based on a top spray assembly, the temperature in the reaction chamber is adjusted based on a heating assembly, and the support portion is driven by a driving device to rotate the carrier plate together with the substrate.

5. The method for epitaxial growth of silicon carbide according to claim 4, It is characterized in that During the preparation phase, The pressure of the reaction chamber is adjusted to 100-300 mbar, The temperature of the reaction chamber is adjusted to 1580-1650°C based on the heating assembly. The rotation speed of the susceptor in the reaction chamber is adjusted to 500-1000 rpm.

6. The method for epitaxial growth of silicon carbide according to claim 1, It is characterized in that In the etching stage, Based on the flow rate of hydrogen introduced into the reaction chamber by the top spray assembly being between 90-130 L / min, The duration of the etching stage is between 5 and 15 minutes.

7. The method for epitaxial growth of silicon carbide according to claim 1, It is characterized in that The side wall purge gas is argon gas, which flows along the surface of the graphite cylinder in the reaction chamber toward the substrate while restricting the growth source gas inside thereof to adjust the carbon-silicon ratio and source gas distribution from the center to the edge of the substrate.

8. The method for epitaxial growth of silicon carbide according to claim 7, It is characterized in that The epitaxial layer grown on the surface of the substrate includes a central portion and an edge portion. The carbon-to-silicon ratio and thickness of the central portion of the epitaxial layer are inversely proportional to the flow rate of the purge gas introduced into the inner side wall of the reaction chamber, and the carbon-to-silicon ratio and thickness of the edge portion of the epitaxial layer are proportional to the flow rate of the purge gas introduced into the inner side wall of the reaction chamber.

9. The method for epitaxial growth of silicon carbide according to claim 8, It is characterized in that After the epitaxial growth stage, the method further comprises: Gas is introduced into the reaction chamber based on the top spray assembly to cool the temperature of the substrate to below 800° C., and the epitaxial wafer is transferred from the reaction chamber to the unloading chamber based on a robot.

10. A silicon carbide epitaxial growth device, It is characterized in that include: case, The graphite cylinder in the shell is coaxially arranged with the shell, and the shell has a reaction chamber. A spray device is arranged on the top side of the shell, and the spray device includes a top spray component and a side wall purge component. The base is rotatably arranged at the bottom of the reaction chamber. A carrying plate is arranged on the base, and the carrying plate is used to place the substrate. A heating component is arranged in the base.

Images