Air inlet device of silicon carbide vapor deposition equipment
By adding protective gas pipelines and automatic purge systems to the intake device of silicon carbide vapor deposition equipment, the problems of cleaning pipeline corrosion, monitoring window temperature failure and pipeline failure are solved, and the safety and maintenance of the equipment are achieved Increased costs.
Patent Information
- Application Number
- CN202411653719.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-02-18
AI Technical Summary
The air intake devices of existing silicon carbide vapor deposition equipment have problems such as the cleaning pipes being easily corroded, the monitoring windows being affected by deposition, and the infrared temperature measurement failure, and the inability to clean the pipes themselves, resulting in high safety risks and maintenance costs.
Design an intake device including doped gas pipeline, reaction gas pipeline, purge gas pipeline and protective gas pipeline, add a separate protective gas pipeline to prevent corrosion, use an inert gas to protect the monitoring window, and introduce a fully automatic pipe Road purge system for self-cleaning function.
It effectively prevents corrosion of cleaning pipes, reduces the need for replacement of transparent layer of monitoring windows, reduces labor and maintenance costs, and improves equipment safety through automatic purge system.
Smart Images
Figure CN119465093A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of silicon carbide vapor deposition equipment, and in particular to an air intake device of silicon carbide vapor deposition equipment. Background Art
[0002] The production of high-purity silicon carbide materials mostly adopts chemical vapor deposition, which uses one or more gases to decompose through heating to produce reaction products, and then deposits high-purity silicon carbide crystals on the surface of the substrate. During the reaction process, the flow stability, concentration uniformity and purity of the reaction gas will affect the quality of the final product. Therefore, an air intake device is required to fully mix the reaction gas, adjust the flow and pressure, and control the ratio of gas components before transporting it to the reactor.
[0003] Since silane gas has active chemical properties and is extremely sensitive to water vapor and air, before the reaction gas is introduced into the pipeline, it must be ensured that there is no impurity such as moisture and air in the pipeline. In addition, this type of gas is highly toxic, and it is very dangerous when the staff opens the reactor or pipeline. Therefore, protective gas must be introduced to blow the pipeline clean before and after production to ensure the safety and reliability of the pipeline.
[0004] During the production process of the reactor chamber, temperature fluctuations can cause inconsistent lattice arrangement when silicon carbide crystallizes. It is necessary to constantly monitor the temperature changes inside the furnace. Usually, an infrared thermometer is used to monitor the temperature inside the furnace through a transparent monitoring window installed on the reactor wall. However, when silicon carbide is deposited, it will cover the inside of the furnace chamber. When the transparent monitoring window is covered with silicon carbide deposits, the light transmittance is seriously affected and the temperature measurement fails.
[0005] In the prior art, since the cleaning pipe is connected to the exhaust gas treatment device, the corrosive gas in the box can easily diffuse into the cleaning pipe, causing pipeline corrosion; at the same time, the monitoring window of the reactor adopts a built-in transparent layer to facilitate infrared temperature measurement, but in order to prevent the transmittance of the monitoring window from being affected by deposition, the transparent layer needs to be replaced frequently; the existing air intake device cannot clean the pipeline, and the reaction gas still remains in the pipeline after shutdown, which poses a great safety risk to the staff when performing maintenance or opening the furnace.
[0006] Therefore, in order to solve the problems that the cleaning pipe in the above-mentioned air intake device is prone to corrosion, the infrared temperature measurement of the monitoring window is affected by deposition, and the pipe cannot be self-cleaned, an air intake device for silicon carbide vapor deposition equipment can be designed. Summary of the invention
[0007] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an air intake device for silicon carbide vapor deposition equipment, so as to solve the problem in the prior art that the cleaning pipe is connected to the exhaust gas treatment box, and the corrosive gas in the box is easily diffused into the cleaning pipe, causing pipeline corrosion; at the same time, the monitoring window of the reactor adopts a built-in transparent layer to facilitate infrared temperature measurement, but in order to prevent the transmittance of the monitoring window from being affected by deposition, the transparent layer needs to be replaced frequently; the existing air intake device cannot clean the pipeline, and the reaction gas still remains in the pipeline after shutdown, which poses a great safety risk to the staff when performing maintenance or opening the furnace.
[0008] To solve the above technical problems, the technical solution of the present invention is: an air intake device of a silicon carbide vapor deposition device, comprising a doping gas pipeline, a reaction gas pipeline, a purge gas pipeline and a protective gas pipeline, the air intake end of the monitoring window is connected to the protective gas pipeline, the air intake end of the reactor is connected to the reaction gas pipeline, the air intake end of the tail gas treatment device is connected to the doping gas pipeline, and the doping gas pipeline, the reaction gas pipeline, the purge gas pipeline and the protective gas pipeline are arranged in parallel and connected to each other;
[0009] The reaction gas pipeline includes a reaction gas pipeline pressure gauge 1, a connection 2, a reaction gas main line filter 1, a reaction gas pipeline pressure gauge 2, a connection 3, a gas mixer, a mass flow meter 3, a pneumatic three-way ball valve, a connection 4, a reaction gas pipeline pressure gauge 3, a reaction gas main line filter 2, a reaction gas pipeline pressure gauge 4, a reaction gas pipeline pressure gauge 5, a reaction gas branch line and a reaction gas main line. The reaction gas pipeline is provided with a reaction gas branch line and a reaction gas main line. The reaction gas main line is sequentially installed with a reaction gas pipeline pressure gauge 1, a reaction gas main line filter 1, a reaction gas pipeline pressure gauge 2, a gas mixer, a mass flow meter 3, a pneumatic three-way ball valve, a reaction gas pipeline pressure gauge 3, a reaction gas main line filter 2 and a reaction gas pipeline pressure gauge 4 from the inlet.
[0010] Preferably, a separate protective gas pipeline is added to the air intake device to prevent the cleaning pipeline from being corroded; and an inert gas is introduced into the monitoring window to protect the monitoring window to prevent deposition on the monitoring window. Compared with the existing technical solutions, the step of replacing the transparent layer of the monitoring window can be omitted, saving labor costs; at the same time, a fully automatic pipeline purge system is added to the air intake device, which can automatically clean the pipeline as needed, thereby improving the safety of the equipment.
[0011] Preferably, the doping gas pipeline includes a doping gas pipeline filter, a first pressure regulating valve, a doping gas pipeline pressure gauge, a mass flowmeter 1, a mass flowmeter 2, a one-way valve 1, a doping gas main pipeline, a doping gas branch and a connection point 1. The doping gas pipeline is provided with a doping gas main pipeline and a doping gas branch. The doping gas main pipeline is installed with a doping gas pipeline filter, a first pressure regulating valve, a doping gas pipeline pressure gauge, a mass flowmeter 1, a mass flowmeter 2 and a one-way valve 1 in sequence from the inlet.
[0012] Preferably, the purge gas pipeline includes a purge gas pipeline filter, a second pressure regulating valve, a purge gas pipeline pressure gauge, a mass flow meter four, a purge gas pipeline control valve one, a one-way valve two, a purge gas pipeline control valve two and a connection five. The purge gas pipeline is sequentially installed with a purge gas pipeline filter, a second pressure regulating valve, a purge gas pipeline pressure gauge, a mass flow meter four, and a one-way valve two from the inlet, and the inlet and outlet ends of the one-way valve two are both installed with a purge gas pipeline control valve one and a purge gas pipeline control valve two.
[0013] Preferably, the protective gas pipeline includes a protective gas pipeline filter, a third pressure regulating valve, a protective gas pipeline pressure gauge, a mass flow meter 5, a pneumatic ball valve 1, a check valve 3, a pneumatic ball valve 2, a first protective gas branch, a protective gas main line and a second protective gas branch, and the protective gas pipeline is provided with a first protective gas branch, a protective gas main line and a second protective gas branch. The protective gas main line is sequentially installed with a protective gas pipeline filter, a third pressure regulating valve, a protective gas pipeline pressure gauge, a mass flow meter 5, a pneumatic ball valve 1, a check valve 3, and a pneumatic ball valve 2 from the inlet.
[0014] Preferably, mass flowmeter 1 and mass flowmeter 2 are connected in parallel, the doping gas main line and the doping gas branch line are connected, the connection between the doping gas branch line and the reaction gas branch line forms connection point 1, and the connection between the doping gas main line and the reaction gas line forms connection point 3.
[0015] Preferably, the reaction gas branch line and the reaction gas main line are connected via a pneumatic three-way ball valve, and the connection between the reaction gas pipeline and the purge gas pipeline forms a connection point four.
[0016] Preferably, the first shielding gas branch is connected to the shielding gas main line, the shielding gas main line is connected to the second shielding gas branch, the reaction gas line is connected to the shielding gas main line to form connection two, and the purge gas line is connected to the second shielding gas branch to form connection five.
[0017] Preferably, the outlet end of the main reaction gas line is connected to the reaction furnace, the outlet end of the reaction gas branch line is connected to the tail gas treatment device, and the outlet end of the first protective gas branch line is connected to the monitoring window.
[0018] Beneficial effects of the present invention:
[0019] The present invention improves the air intake device and adds a separate protective gas pipeline. The protective gas pipeline can prevent the exhaust gas in the exhaust gas treatment device from entering the pipeline system of the air intake device, thereby preventing the pipeline system of the air intake device from being corroded. At the same time, the protective gas pipeline can also protect the monitoring window, prevent substances from depositing on the surface of the monitoring window and thus affecting the light transmittance, and can also save the step of replacing the transparent layer material of the monitoring window, saving manpower and maintenance costs. A new purge pipeline system is also added, which can perform targeted cleaning of other pipelines as needed, thereby improving the safety of the equipment during operation or maintenance. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Shown is a schematic diagram of the pipeline distribution structure of the air intake device of the silicon carbide vapor deposition equipment of the present invention.
[0021] Explanation of the reference numerals: 1. doping gas pipeline; 11. doping gas pipeline filter; 12. first pressure regulating valve; 13. doping gas pipeline pressure gauge; 14. mass flow meter 1; 15. mass flow meter 2; 16. one-way valve 1; 17. doping gas main pipeline; 18. doping gas branch; 19. connection 1; 2. reaction gas pipeline; 21. reaction gas pipeline pressure gauge 1; 22. connection 2; 23. reaction gas main pipeline filter 1; 24. reaction gas pipeline pressure gauge 2; 25. connection 3; 26. gas mixer; 27. mass flow meter 3; 28. pneumatic three-way ball valve; 29. connection 4; 210. reaction gas pipeline pressure gauge 1; 212. reaction gas main pipeline filter 2; 213. reaction gas pipeline Pressure gauge two; 214, reaction gas pipeline pressure gauge three; 215, reaction gas branch; 216, reaction gas main line; 3, purge gas pipeline; 31, purge gas pipeline filter; 32, second pressure regulating valve; 33, purge gas pipeline pressure gauge; 34, mass flow meter four; 35, purge gas pipeline control valve one; 36, one-way valve two; 37, purge gas pipeline control valve two; 38, connection five; 4, protective gas pipeline; 41, protective gas pipeline filter; 42, third pressure regulating valve; 43, protective gas pipeline pressure gauge; 44, mass flow meter five; 45, pneumatic ball valve one; 46, one-way valve three; 47, pneumatic ball valve two; 48, first protective gas branch; 49, protective gas main line; 410, second protective gas branch. DETAILED DESCRIPTION
[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0023] See also Figure 1The present invention provides an embodiment: an air intake device of a silicon carbide vapor deposition device, comprising a doping gas pipeline 1, a reaction gas pipeline 2, a purge gas pipeline 3 and a protective gas pipeline 4, the air intake end of the monitoring window is connected to the protective gas pipeline 4, the air intake end of the reactor is connected to the reaction gas pipeline 2, the air intake end of the tail gas treatment device is connected to the doping gas pipeline 1, and the doping gas pipeline 1, the reaction gas pipeline 2, the purge gas pipeline 3 and the protective gas pipeline 4 are arranged in parallel and connected to each other; the reaction gas pipeline 2 comprises a reaction gas pipeline pressure gauge 1 21, a connection 22, a reaction gas main pipeline filter 1 23, a reaction gas pipeline pressure gauge 2 24, a connection 3 25, a gas mixer 26, a mass flow meter 3 27, and a pneumatic 3 A ball valve 28, a connection point four 29, a reaction gas pipeline pressure gauge three 210, a reaction gas main pipeline filter two 212, a reaction gas pipeline pressure gauge four 213, a reaction gas pipeline pressure gauge five 214, a reaction gas branch 215 and a reaction gas main pipeline 216. The reaction gas pipeline 2 is provided with a reaction gas branch 215 and a reaction gas main pipeline 216. The reaction gas main pipeline 216 is installed with a reaction gas pipeline pressure gauge one 21, a reaction gas main pipeline filter one 23, a reaction gas pipeline pressure gauge two 24, a gas mixer 26, a mass flow meter three 27, a pneumatic three-way ball valve 28, a reaction gas pipeline pressure gauge three 210, a reaction gas main pipeline filter two 212 and a reaction gas pipeline pressure gauge four 213 in sequence from the entrance.
[0024] See also Figure 1In this embodiment, the doping gas pipeline 1 includes a doping gas pipeline filter 11, a first pressure regulating valve 12, a doping gas pipeline pressure gauge 13, a mass flow meter 14, a mass flow meter 2 15, a one-way valve 16, a doping gas main pipeline 17, a doping gas branch 18 and a connection 19. The doping gas main pipeline 17 and the doping gas branch 18 are provided on the doping gas pipeline 1. The doping gas main pipeline 17 is equipped with the doping gas pipeline filter 11 in sequence from the inlet , a first pressure regulating valve 12, a doping gas pipeline pressure gauge 13, a mass flow meter 1 14, a mass flow meter 2 15 and a one-way valve 16; the purge gas pipeline 3 includes a purge gas pipeline filter 31, a second pressure regulating valve 32, a purge gas pipeline pressure gauge 33, a mass flow meter 4 34, a purge gas pipeline control valve 1 35, a one-way valve 2 36, a purge gas pipeline control valve 2 37 and a connection 5 38. The purge gas pipeline 3 is equipped with purge gas pipes in sequence from the inlet to the outlet. The protective gas pipeline 4 includes a protective gas pipeline filter 41, a third pressure regulating valve 42, a protective gas pipeline pressure gauge 43, a mass flow meter 5 44, a pneumatic ball valve 1 45, a check valve 3 46, and a pneumatic ball valve 2 47. , a first shielding gas branch 48, a shielding gas main line 49 and a second shielding gas branch 410. The shielding gas pipeline 4 is provided with a first shielding gas branch 48, a shielding gas main line 49 and a second shielding gas branch 410. The shielding gas main line 49 is installed with a shielding gas pipeline filter 41, a third pressure regulating valve 42, a shielding gas pipeline pressure gauge 43, a mass flow meter five 44, a pneumatic ball valve one 45, a check valve three 46, and a pneumatic ball valve two 47 in sequence from the entrance.
[0025] See also Figure 1 In this embodiment, mass flow meter 14 and mass flow meter 2 15 are connected in parallel, doping gas main line 17 and doping gas branch line 18 are connected, the connection between doping gas branch line 18 and reaction gas branch line 215 forms connection 19, and the connection between doping gas main line 17 and reaction gas pipeline 2 forms connection 3 25; reaction gas branch line 215 and reaction gas main line 216 are connected through pneumatic three-way ball valve 28, and the connection between reaction gas pipeline 2 and purge gas pipeline 3 forms connection 4 29; first protective gas branch line 48 and protective gas main line 49 are connected, protective gas main line 49 and second protective gas branch line 410 are connected, reaction gas pipeline 2 and protective gas main line 49 are connected to form connection 2 22, and purge gas pipeline 3 and second protective gas branch 410 are connected to form connection 5 38; the outlet end of reaction gas main line 216 is connected to reaction furnace, the outlet end of reaction gas branch line 215 is connected to exhaust gas treatment device, and the outlet end of first protective gas branch 48 is connected to monitoring window.
[0026] In the actual production process, the gases in the reaction gas pipeline, doping gas pipeline, purge gas pipeline and protective gas pipeline can select corresponding gas types as reaction gas, doping gas, purge gas and protective gas according to actual production needs. The present invention does not limit the types of gases in the reaction gas pipeline, doping gas pipeline, purge gas pipeline and protective gas pipeline. The following is only an example to describe the working process of the air intake device. At the same time, according to production needs, filters, pressure regulating valves, pressure gauges, and mass flow meters can be respectively set on each gas pipeline, which are respectively used to filter gas, adjust gas pressure, monitor gas pressure, monitor and adjust gas flow, and ensure the stability of gas flow and pressure in each pipeline. No specific location is limited here.
[0027] Methyltrichlorosilane is used as the reaction gas, hydrogen is used as the purge gas, argon can be used as both the protective gas and the purge gas, and nitrogen can be used as both the doping gas and the purge gas.
[0028] Embodiment 1
[0029] The tail gas treatment device adds a separate protective gas pipeline, and the doping gas nitrogen is transported to the reaction gas branch 215 through the doping gas branch 18. At this time, the reaction gas branch 215 is under positive pressure, which can prevent the tail gas from blowing back to the reaction gas branch 215 and causing corrosion to the pipeline. The reaction gas silane is introduced into the inlet of the reaction gas pipeline 2, and the pneumatic three-way ball valve 28 controls the connection of the reaction gas main pipeline 216. The reaction gas branch 215 is closed, and the reaction gas is now introduced into the reactor; at the same time, nitrogen is introduced into the inlet of the doping gas pipeline 1 through the connection point three 25 to enter the reaction gas pipeline 2 for doping. After being fully mixed by the gas mixer 26, it enters the reactor together with the reaction gas to participate in the reaction.
[0030] Embodiment 2
[0031] The first protective gas branch 48 is connected to the monitoring window, and argon gas is introduced into the inlet of the protective gas pipeline 4 and then into the monitoring window through the first protective gas branch 48 to protect the monitoring window from being covered by the deposits inside the reactor. At this time, the pneumatic ball valve 47 is closed, and argon gas does not enter the reaction gas pipeline 2, which can prevent the monitoring window from being deposited. Compared with the existing technical solutions, the step of replacing the transparent layer of the monitoring window can be omitted, saving labor costs.
[0032] Embodiment 3
[0033] After the deposition is completed, when the protective gas argon is used to purge the pipeline, the pneumatic ball valve 47 is opened, and the argon gas is introduced into the reaction gas pipeline 2 through the connection 22, and enters the reaction furnace to replace the residual reaction gas. The entire reaction gas pipeline is purged through the protective gas main line 49, and the protective gas branch line 410 can also enter the purge gas pipeline 3 to purge only the rear section of the reaction gas pipeline 2. The pipeline area to be purged can be selected according to actual needs, and the pipeline can be automatically cleaned as needed to improve the safety of the equipment.
[0034] Before introducing the reaction gas, hydrogen is introduced in advance to clean the inside of the reactor; after the inside of the reactor is cleaned, the reaction gas silane is introduced into the inlet of the reaction gas pipeline 2, the pneumatic three-way ball valve 28 controls the connection of the reaction gas main pipeline 216, and the reaction gas branch 215 is closed, and the reaction gas is introduced into the reactor at this time; at the same time, nitrogen is introduced into the inlet of the doping gas pipeline 1 for doping, and after being fully mixed by the gas mixer 26, it enters the reactor together with the reaction gas to participate in the reaction; at the same time, argon is introduced into the inlet of the protective gas pipeline 4, and the first The protective gas branch 48 leads to the monitoring window to protect the monitoring window from being covered by the deposits inside the reactor. At this time, the pneumatic ball valve 47 is closed and argon gas does not enter the reaction gas pipeline 2. After the deposition is completed, since there are still gases such as silane and hydrogen inside the reactor and the reaction gas pipeline 2, and silane and hydrogen are both flammable and explosive, and silane is highly toxic, the gas inside the pipeline and the reactor needs to be replaced before the furnace is opened. At this time, the pneumatic three-way ball valve 28 is opened, and argon gas enters the reaction gas pipeline 2 and enters the reactor to replace the residual reaction gas.
[0035] Through the above steps, a separate protective gas pipeline is added to the air intake device, and the protective gas pipeline can prevent the exhaust gas in the exhaust treatment device from entering the pipeline system of the air intake device, thereby preventing the pipeline system of the air intake device from being corroded; at the same time, the protective gas pipeline can also protect the monitoring window, prevent the deposition of substances on the surface of the monitoring window and thus affect the light transmittance, and can also save the step of replacing the transparent layer material of the monitoring window, saving manpower and maintenance costs; a new purge pipeline system is also added, which can perform targeted cleaning of other pipelines as needed, thereby improving the safety of the equipment during operation or maintenance.
[0036] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention.
Claims
1. An air intake device for silicon carbide vapor deposition equipment, comprising a reaction furnace, a monitoring window and an exhaust gas treatment device; characterized in that: It also comprises a doping gas pipeline (1), a reaction gas pipeline (2), a purge gas pipeline (3) and a protective gas pipeline (4); the air inlet end of the monitoring window is connected to the protective gas pipeline (4); the air inlet end of the reaction furnace is connected to the reaction gas pipeline (2); the air inlet end of the tail gas treatment device is connected to the doping gas pipeline (1); and the doping gas pipeline (1), the reaction gas pipeline (2), the purge gas pipeline (3) and the protective gas pipeline (4) are arranged in parallel and are interconnected; The reaction gas pipeline (2) comprises a reaction gas pipeline pressure gauge 1 (21), a connection 2 (22), a reaction gas main pipeline filter 1 (23), a reaction gas pipeline pressure gauge 2 (24), a connection 3 (25), a gas mixer (26), a mass flow meter 3 (27), a pneumatic three-way ball valve (28), a connection 4 (29), a reaction gas pipeline pressure gauge 3 (210), a reaction gas main pipeline filter 2 (212), a reaction gas pipeline pressure gauge 4 (213), a reaction gas pipeline pressure gauge 5 (214), a reaction gas branch (215) and a reaction gas branch (216). The reaction gas main line (216) is provided with a reaction gas branch line (215) and a reaction gas main line (216). The reaction gas main line (216) is provided with a reaction gas line pressure gauge 1 (21), a reaction gas line filter 1 (23), a reaction gas line pressure gauge 2 (24), a gas mixer (26), a mass flow meter 3 (27), a pneumatic three-way ball valve (28), a reaction gas line pressure gauge 3 (210), a reaction gas line filter 2 (212) and a reaction gas line pressure gauge 4 (213) in sequence from the inlet.
2. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 1, characterized in that: The doping gas pipeline (1) comprises a doping gas pipeline filter (11), a first pressure regulating valve (12), a doping gas pipeline pressure gauge (13), a mass flow meter (14), a mass flow meter (15), a one-way valve (16), a doping gas main pipeline (17), a doping gas branch pipeline (18) and a first connection point (19). The doping gas pipeline (1) is provided with a doping gas main pipeline (17) and a doping gas branch pipeline (18). The doping gas main pipeline (17) is provided with a doping gas pipeline filter (11), a first pressure regulating valve (12), a doping gas pipeline pressure gauge (13), a mass flow meter (14), a mass flow meter (15) and a one-way valve (16) in sequence from the inlet.
3. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 1, characterized in that: The purge gas pipeline (3) comprises a purge gas pipeline filter (31), a second pressure regulating valve (32), a purge gas pipeline pressure gauge (33), a mass flow meter (4) (34), a purge gas pipeline control valve (35), a check valve (36), a purge gas pipeline control valve (37) and a fifth connection point (38). The purge gas pipeline (3) is provided with a purge gas pipeline filter (31), a second pressure regulating valve (32), a purge gas pipeline pressure gauge (33), a mass flow meter (4) (34), a check valve (36) and a fifth connection point (38) in sequence from the inlet. The inlet and outlet ends of the check valve (36) are both provided with a purge gas pipeline control valve (35) and a purge gas pipeline control valve (37).
4. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 1, characterized in that: The protective gas pipeline (4) comprises a protective gas pipeline filter (41), a third pressure regulating valve (42), a protective gas pipeline pressure gauge (43), a mass flow meter five (44), a pneumatic ball valve one (45), a check valve three (46), a pneumatic ball valve two (47), a first protective gas branch (48), a protective gas main pipeline (49) and a second protective gas branch (410). The protective gas pipeline (4) is provided with the first protective gas branch (48), the protective gas main pipeline (49) and the second protective gas branch (410). The protective gas main pipeline (49) is provided with the protective gas pipeline filter (41), the third pressure regulating valve (42), the protective gas pipeline pressure gauge (43), the mass flow meter five (44), the pneumatic ball valve one (45), the check valve three (46) and the pneumatic ball valve two (47) in sequence from the inlet.
5. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 2, characterized in that: The mass flow meter 1 (14) and the mass flow meter 2 (15) are connected in parallel, the doping gas main line (17) and the doping gas branch line (18) are connected, the connection point between the doping gas branch line (18) and the reaction gas branch line (215) forms a connection point 1 (19), and the connection point between the doping gas main line (17) and the reaction gas line (2) forms a connection point 3 (25).
6. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 1, characterized in that: The reaction gas branch line (215) and the reaction gas main line (216) are connected via a pneumatic three-way ball valve (28), and the connection point between the reaction gas pipeline (2) and the purge gas pipeline (3) forms a connection point four (29).
7. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 4, characterized in that: The first shielding gas branch (48) is connected to the shielding gas main line (49), the shielding gas main line (49) is connected to the second shielding gas branch (410), the reaction gas line (2) and the shielding gas main line (49) are connected to form a second connection (22), and the purge gas line (3) and the second shielding gas branch (410) are connected to form a fifth connection (38).
8. The gas inlet device of the silicon carbide vapor deposition equipment according to claim 1, characterized in that: The outlet end of the reaction gas main line (216) is connected to the reaction furnace, the outlet end of the reaction gas branch line (215) is connected to the tail gas treatment device, and the outlet end of the first protective gas branch line (48) is connected to the monitoring window.