A dual tail gas treatment system for a CVD furnace

Abstract

The utility model relates to a double tail gas processing system for CVD furnace belongs to CVD furnace tail gas processing technical field, solves the problem that the flammable and explosive process tail gas produced in SiC coating process of existing CVD furnace mixes with air and causes the risk of combustion and explosion under high temperature, technical scheme is: including a plurality of CVD furnace, every CVD furnace all has the double tail gas control valve through vacuum pipeline connection, and the communication has vacuum pump group between vacuum pipeline and double tail gas control valve, and the double tail gas control valve includes air valve and process valve, and the air valve and process valve three -way tail gas pipeline intercommunication in vacuum pump group, and the air valve far from vacuum pump group one end intercommunication in factory -level air tail gas pipeline, and the process valve far from vacuum pump group one end intercommunication in factory -level process tail gas pipeline, and the factory -level process tail gas pipeline intercommunication has waste gas treatment device, and the air valve and process valve all electric connection in CVD furnace control system, and the air valve and process valve do not open simultaneously, the utility model discloses be applied to CVD furnace tail gas processing.

Description

Technical Field

[0001] This invention provides a dual tail gas treatment system for CVD furnaces, belonging to the field of CVD furnace tail gas treatment technology. Background Technology

[0002] Vacuum silicon carbide (SiC), as a typical representative of third-generation semiconductor materials, has become an ideal choice for manufacturing high-temperature, high-frequency, and high-power electronic devices due to its inherent properties. In the production process of silicon carbide devices, device processing must rely on epitaxial films, making silicon carbide epitaxial equipment crucial in the entire industry chain. It is also the most structurally complex and research-intensive equipment in the industry chain. Chemical vapor deposition (CVD) technology, due to its excellent coverage and controllability, has become the preferred solution for preparing SiC protective coatings on graphite substrates. Currently, CVD furnaces have been successfully commercialized and have become dedicated equipment for SiC coatings.

[0003] Before starting the SiC coating process, a vacuum pump unit is needed to completely remove the air from the CVD furnace chamber, creating a vacuum. The extracted air is then discharged from the exhaust gas end via the vacuum pump unit. During the coating process, the CVD furnace continuously generates process exhaust gases, primarily composed of H2 and HCl. These exhaust gases are also discharged from the exhaust gas end via the vacuum pump unit. In other words, both air exhaust and industrial exhaust gases are discharged through the same exhaust gas end. Because the process exhaust gases contain flammable and explosive gases such as hydrogen, and the coating process requires high-temperature operation, when multiple CVD furnaces operate simultaneously in batches according to production plans and equipment rhythms, the process exhaust gases and air exhaust gases must be processed concurrently. This can easily lead to mixing of the two types of exhaust gases, potentially causing a fire or explosion risk. Utility Model Content

[0004] To address the technical problem that flammable and explosive process exhaust gases generated in the SiC coating process of existing CVD furnaces are prone to mixing with air at high temperatures, posing a risk of combustion and explosion, this invention proposes a dual exhaust gas treatment system for CVD furnaces. The purpose is to ensure that process exhaust gases and air exhaust gases are treated synchronously and safely when multiple CVD furnaces are running simultaneously in batches, thereby eliminating the risk of combustion and explosion.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a dual tail gas treatment system for CVD furnace, including several CVD furnaces, each of which is connected to a dual tail gas control valve through a vacuum pipeline, and a vacuum pump group is connected between the vacuum pipeline and the dual tail gas control valve. The dual tail gas control valve includes an air valve and a process valve, which are respectively connected to the two ends of the three-way tail gas pipeline, and the other end of the three-way tail gas pipeline is connected to the vacuum pump unit. The end of the air valve away from the vacuum pump group is connected to the plant-level air exhaust pipeline, and the end of the process valve away from the vacuum pump group is connected to the plant-level process exhaust pipeline. The plant-level process exhaust pipeline is connected to a waste gas treatment device. Both the air valve and the process valve are electrically connected to the control system of the CVD furnace, and the air valve and the process valve are not opened at the same time.

[0006] Furthermore, both the air valve and the process valve are pneumatic butterfly valves.

[0007] Furthermore, the vacuum line is configured to transmit air or process exhaust gas discharged from the CVD furnace.

[0008] Furthermore, the plant-level air exhaust pipeline is configured to centrally transport the air exhaust gas extracted from each CVD furnace, and the plant-level process exhaust gas pipeline is used to centrally transport the process exhaust gas generated by each CVD furnace.

[0009] Furthermore, the waste gas treatment device is configured to treat process exhaust gas containing H2 and HCl components.

[0010] The advantages of this utility model over the prior art are as follows: 1. This utility model features a dual tail gas control valve, including an air valve and a process valve, which are not opened simultaneously. The CVD furnace control system automatically controls their opening and closing according to the process conditions, enabling separate treatment of process tail gas and air tail gas. This avoids mixing of process tail gas (including flammable and explosive gases) with air tail gas, eliminates the risk of combustion and explosion, and ensures production safety when multiple CVD furnaces are running simultaneously in batches.

[0011] 2. The components of this utility model system are reasonably connected. By utilizing components such as vacuum pump group, vacuum pipeline, and three-way tail gas pipeline, the orderly transmission and control of tail gas is realized. Together with plant-level air tail gas pipeline, plant-level process tail gas pipeline and waste gas treatment device, a complete tail gas treatment process is formed, which meets the tail gas treatment needs of multiple CVD furnaces in SiC coating process and improves the safety and reliability of production. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of the dual tail gas control valve and the vacuum pump unit working together in an embodiment of this utility model.

[0013] In the diagram: 1 is the CVD furnace, 2 is the air valve, 3 is the process valve, 4 is the plant-level process exhaust gas pipeline, 5 is the plant-level air exhaust gas pipeline, 6 is the waste gas treatment device, 7 is the three-way exhaust gas pipeline, 10 is the vacuum pump group, and 11 is the vacuum pipeline. Detailed Implementation

[0014] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0015] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0016] like Figures 1 to 2 As shown, this utility model provides a dual tail gas treatment system for CVD furnaces, including several CVD furnaces 1 for preparing silicon carbide (SiC) coatings. Each CVD furnace 1 is connected to a dual tail gas control valve via a vacuum pipeline 11. The vacuum pipeline 11 is used to transmit air or process tail gas generated in the CVD furnace 1 during the process. A vacuum pump group 10 is also connected between the vacuum pipeline 11 and the dual tail gas control valve. The vacuum pump group 10 provides power for the entire tail gas extraction and transmission process, and can effectively extract the air or process tail gas in the furnace cavity of the CVD furnace 1 and transport it to the subsequent pipelines and treatment devices.

[0017] The dual exhaust gas control valve includes an air valve 2 and a process valve 3. Air valve 2 and process valve 3 are connected to opposite ends of a three-way exhaust gas pipeline 7. The other end of the three-way exhaust gas pipeline 7 is connected to a vacuum pump unit 10, allowing the vacuum pump unit 10 to selectively connect to either air valve 2 or process valve 3 via the three-way exhaust gas pipeline 7. The end of air valve 2 furthest from the vacuum pump unit 10 is connected to a plant-level air exhaust gas pipeline 5, which is used to centrally collect and transport the exhaust gas extracted from each CVD furnace 1. The end of process valve 3 furthest from the vacuum pump unit 10 is connected to a plant-level process exhaust gas pipeline 4, which is used to centrally collect and transport the process exhaust gas generated by each CVD furnace 1 during the coating process stage. The plant-level process tail gas pipeline 4 is also connected to a waste gas treatment device 6. The waste gas treatment device 6 treats the process tail gas discharged from multiple CVD furnaces 1 during the coating process stage, which mainly consists of H2, HCl, etc., to remove harmful components and make it meet the emission requirements.

[0018] Both air valve 2 and process valve 3 are electrically connected to the control system of CVD furnace 1. Air valve 2 and process valve 3 do not open simultaneously. Depending on the process conditions, for example, when CVD furnace 1 is in the vacuum stage, the control system controls air valve 2 to open and process valve 3 to close; when CVD furnace 1 is in the coating process stage and generates process exhaust gas, the control system controls process valve 3 to open and air valve 2 to close. Through this automatic control, the switching between air valve 2 and process valve 3 is achieved, thereby separately handling process exhaust gas and air exhaust gas and preventing them from mixing.

[0019] Both air valve 2 and process valve 3 are pneumatic butterfly valves. Pneumatic butterfly valves have the advantages of rapid opening and closing, good sealing performance, and easy automation control, which can meet the system's requirements for rapid and reliable switching of exhaust gas passages.

[0020] The waste gas treatment device 6 is existing technology and can be purchased. There are no restrictions on the model, as long as it can effectively treat process exhaust gases containing components such as H2 and HCl.

[0021] During operation, when the CVD furnace 1 needs to perform a vacuuming operation before the SiC coating process, the control system of the CVD furnace 1 opens the air valve 2 and closes the process valve 3. At this time, the vacuum pump group 10 starts and extracts the air from the furnace chamber of the CVD furnace 1 through the vacuum pipeline 11. The extracted air passes through the vacuum pipeline 11 and the three-way exhaust gas pipeline 7 in sequence, and finally enters the plant-level air exhaust gas pipeline 5 to complete the emission and collection of air exhaust gas.

[0022] When CVD furnace 1 enters the coating process stage and generates process exhaust gas containing H2, HCl, etc., the control system of CVD furnace 1 opens process valve 3 and closes air valve 2. Vacuum pump unit 10 continues to work, extracting the process exhaust gas from CVD furnace 1. The process exhaust gas passes sequentially through vacuum pipeline 11, three-way exhaust gas pipeline 7, and process valve 3, and enters plant-level process exhaust gas pipeline 4. It is then transported to waste gas treatment device 6 for treatment, removing harmful components before being discharged in compliance with standards.

[0023] When multiple CVD furnaces 1 are operating simultaneously in batches, the control system of each CVD furnace 1 will automatically control the opening of the corresponding air valve 2 or process valve 3 according to its own process stage (vacuuming or coating process), so as to realize the separate treatment of air exhaust gas and process exhaust gas, effectively avoid the mixing of process exhaust gas and air exhaust gas, eliminate the risk of combustion and explosion, and ensure production safety.

[0024] The system in this embodiment forms a complete and safe exhaust gas treatment process through reasonable pipeline connections and automated dual exhaust gas control valves. It meets the exhaust gas treatment needs of multiple CVD furnaces 1 in the SiC coating process, improves the safety and reliability of production, and has significant progress compared with the lack of effective means to separately treat process exhaust gas and air exhaust gas in the prior art.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0026] Regarding the specific structure of this utility model, it should be noted that the connection relationships between the various component modules adopted in this utility model are definite and achievable. Except as specifically described in the embodiments, their specific connection relationships can bring about corresponding technical effects and solve the technical problems proposed by this utility model without relying on the execution of corresponding software programs. The models of the components, modules, and specific components appearing in this utility model, the connection methods between them, and the conventional usage methods and expected technical effects brought about by the above-mentioned technical features, unless specifically described, are all publicly disclosed content in patents, journal articles, technical manuals, technical dictionaries, and textbooks that can be obtained by those skilled in the art before the application date, or belong to conventional technology, common knowledge, and other existing technologies in this field. There is no need to elaborate, which makes the technical solution provided in this case clear, complete, and achievable, and can reproduce or obtain corresponding physical products based on this technical means.

Claims

1. A dual tail gas treatment system for a CVD furnace, characterized in that: It includes several CVD furnaces (1), each of which is connected to a dual tail gas control valve via a vacuum pipeline (11), and a vacuum pump group (10) is connected between the vacuum pipeline (11) and the dual tail gas control valve. The dual tail gas control valve includes an air valve (2) and a process valve (3). The air valve (2) and the process valve (3) are respectively connected to the two ends of the three-way tail gas pipeline (7), and the other end of the three-way tail gas pipeline (7) is connected to the vacuum pump group (10). The air valve (2) is connected to the plant-level air exhaust pipeline (5) at one end away from the vacuum pump group (10), and the process valve (3) is connected to the plant-level process exhaust pipeline (4) at one end away from the vacuum pump group (10). The plant-level process exhaust pipeline (4) is connected to a waste gas treatment device (6). The air valve (2) and the process valve (3) are both electrically connected to the control system of the CVD furnace (1), and the air valve (2) and the process valve (3) are not opened at the same time.

2. The dual tail gas treatment system for a CVD furnace according to claim 1, characterized in that: Both the air valve (2) and the process valve (3) are pneumatic butterfly valves.

3. The dual tail gas treatment system for a CVD furnace according to claim 1, characterized in that: The vacuum line (11) is configured to transfer air or process exhaust gas discharged from the CVD furnace (1).

4. The dual tail gas treatment system for a CVD furnace according to claim 1, characterized in that: The plant-level air exhaust pipeline (5) is configured to centrally transport the air exhaust gas extracted from each CVD furnace (1), and the plant-level process exhaust gas pipeline (4) is used to centrally transport the process exhaust gas generated by each CVD furnace (1).

5. A dual tail gas treatment system for a CVD furnace according to any one of claims 1-4, characterized in that: The waste gas treatment device (6) is configured to treat process tail gas containing H2 and HCl.

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