Exhaust system and tail gas treatment system for silicon carbide deposition apparatus

Abstract

The utility model relates to a silicon carbide deposition device exhaust system and tail gas treatment system belongs to the field of chemical vapor deposition, solve the problem that the gas in the deposition chamber cannot be uniformly deposited and the service life is short when the silicon carbide deposition device exhaust system and tail gas treatment system recycle tail gas, technical scheme: the exhaust system includes vacuum pipeline, and the vacuum pipeline includes first branch pipe, second branch pipe and third branch pipe, and the first branch pipe is connected to the deposition chamber, and the second branch pipe is connected on the vacuum pump group, and the third branch pipe is connected on the main pipe of exhaust gas distribution vacuum pipeline, two fourth branch pipes of exhaust gas distribution vacuum pipeline are connected with first manual butterfly valve and second manual butterfly valve respectively, and first manual butterfly valve is connected with first pneumatic butterfly valve, first differential pressure gauge, electric regulating valve, second differential pressure gauge and the input end of exhaust gas collection pipeline in proper order, and the input end of exhaust gas collection pipeline is connected through second pneumatic butterfly valve with second manual butterfly valve, the utility model discloses be applied to chemical vapor deposition.

Description

Technical Field

[0001] This invention provides an exhaust system and tail gas treatment system for a silicon carbide deposition apparatus, belonging to the field of chemical vapor deposition technology. Background Technology

[0002] Traditional silicon carbide deposition equipment delivers MTS (trichloromethylsilane) as bubbles into the deposition chamber, where it is treated at high temperatures to form a silicon carbide film. This process requires a continuous supply of MTS. During deposition, a large amount of acidic gases and small solid particles are generated, which are then discharged into a tail gas treatment system via a vacuum pump for exhaust gas treatment. This process has the following problems:

[0003] First, the utilization rate of MTS gas is less than 50%, and the content of carbon tetrachloride, trichloromethylsilane, etc. in the tail gas is relatively high, resulting in a lot of waste and high cost.

[0004] Second, the large amount of strong acid gas (HCl gas) contained in the exhaust gas is highly corrosive to the vacuum pump.

[0005] Third, the process cannot meet the requirement of using a vacuum pump for a long time (more than 100 hours), and the gas in the deposition chamber cannot be deposited evenly. Utility Model Content

[0006] This invention addresses the technical problem of uneven gas deposition and short service life in exhaust systems and exhaust gas treatment systems for silicon carbide deposition devices during exhaust gas recovery. It proposes an exhaust system and exhaust gas treatment system for silicon carbide deposition devices.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: an exhaust system and tail gas treatment system for a silicon carbide deposition device. The exhaust system for a silicon carbide deposition device is characterized in that it includes a vacuum pipeline, which includes a first branch pipe, a second branch pipe and a third branch pipe. The first branch pipe is connected to the deposition chamber, the second branch pipe is connected to the vacuum pump group, and the third branch pipe is connected to the main pipe of the exhaust gas distribution vacuum pipeline.

[0008] The two fourth branches of the exhaust gas distribution vacuum pipeline are respectively connected to the first manual butterfly valve and the second manual butterfly valve. The first manual butterfly valve is sequentially connected to the first pneumatic butterfly valve, the first differential pressure gauge, the electric regulating valve, the second differential pressure gauge, and the input end of the exhaust gas collection pipeline. The second manual butterfly valve is connected to the input end of the exhaust gas collection pipeline through the second pneumatic butterfly valve. The output end of the exhaust gas collection pipeline is connected to multiple solid impurity collection devices and the first exhaust gas treatment pipeline.

[0009] The first pneumatic butterfly valve, the second pneumatic butterfly valve, and the electric regulating valve are all communicatively connected to the output end of the control system, and the first differential pressure gauge and the second differential pressure gauge are all communicatively connected to the input end of the control system.

[0010] Furthermore, a first vacuum gauge, a second vacuum gauge, and a pneumatic valve are sequentially connected to the second branch pipe, with the pneumatic valve located near the vacuum pump assembly end.

[0011] Furthermore, both the first and second pneumatic butterfly valves are connected to solenoid valves.

[0012] Furthermore, the diameters of the two fourth branch pipes are smaller than the diameter of the main pipe.

[0013] Furthermore, a pneumatic ball valve is connected between the second branch pipe and the first vacuum gauge.

[0014] Furthermore, the first manual butterfly valve, the second manual butterfly valve, the first pneumatic butterfly valve, and the second pneumatic butterfly valve are all made of corrosion-resistant materials.

[0015] Furthermore, the surfaces of the first manual butterfly valve, the second manual butterfly valve, the first pneumatic butterfly valve, and the second pneumatic butterfly valve are coated with an anti-corrosion layer.

[0016] Furthermore, the vacuum pump unit adopts a pneumatic dry vacuum pump unit.

[0017] A tail gas treatment system based on the exhaust system of the silicon carbide deposition apparatus described above includes a tail gas treatment device. The tail gas treatment device includes a first alkaline spray tower, which is connected to a first tail gas treatment pipeline of the exhaust system of the silicon carbide deposition apparatus. The first alkaline spray tower is also sequentially connected to a second alkaline spray tower, a first fan, a third alkaline spray tower, a fourth alkaline spray tower, and a second fan. The second fan is also connected to a high-altitude discharge pipeline.

[0018] Furthermore, both the first and second fans use explosion-proof variable frequency motors for their drive motors.

[0019] The advantages of this utility model over the prior art are as follows:

[0020] 1. This utility model separates the vacuum pump unit and the exhaust gas treatment device through a vacuum pipeline. The exhaust gas treatment device is connected to the vacuum pipeline through an exhaust system, so that the gas passes through different paths when vacuuming before deposition and when exhausting during deposition. This effectively avoids the exhaust gas from corroding the vacuum pump unit when passing through it during deposition, and increases the service life of the vacuum pump unit.

[0021] 2. The electric regulating valve, the first differential pressure gauge and the second differential pressure gauge of this utility model work together to dynamically adjust the flow rate and flow of exhaust gas in the exhaust system, so that the exhaust gas is discharged from the sedimentation chamber into the exhaust system at a uniform and stable speed.

[0022] 3. This utility model can prevent solid impurity particles from clogging the various pipelines in the exhaust system through the solid impurity collection device, and at the same time reduce the content of solid impurity particles entering the exhaust gas treatment device, effectively reducing the maintenance cost of the exhaust gas treatment device.

[0023] 4. The two fans of this utility model work together to keep the sedimentation chamber and exhaust system under a slight negative pressure. Compared with the traditional vacuum pump structure that extracts exhaust gas, it can prolong the residence time of MTS gas in the sedimentation chamber, allowing the MTS gas to react fully and resulting in better economic benefits.

[0024] 5. A pneumatic ball valve is connected between the second branch pipe and the first vacuum gauge in this utility model. During the deposition operation, closing the pneumatic ball valve can effectively prevent the exhaust gas from corroding the first vacuum gauge and extend the service life of the first vacuum gauge. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the exhaust system for the silicon carbide deposition apparatus of this utility model;

[0027] Figure 2 This is a schematic diagram of the exhaust gas treatment system based on the exhaust system of a silicon carbide deposition device according to the present invention.

[0028] In the diagram: 1 is the sedimentation chamber, 2 is the vacuum pipeline, 3 is the first vacuum gauge, 4 is the pneumatic ball valve, 5 is the second vacuum gauge, 6 is the pneumatic valve, 7 is the vacuum pump group, 8 is the exhaust gas distribution vacuum pipeline, 9 is the first manual butterfly valve, 10 is the first pneumatic butterfly valve, 11 is the first differential pressure gauge, 12 is the second differential pressure gauge, 13 is the exhaust gas collection pipeline, 14 is the solid impurity collection device, 15 is the first tail gas treatment pipeline, 16 is the second tail gas treatment pipeline, 17 is the first alkali spray tower, 18 is the second alkali spray tower, 19 is the first fan, 20 is the third alkali spray tower, 21 is the fourth alkali spray tower, 22 is the second fan, 23 is the high-altitude discharge pipeline, 24 is the second manual butterfly valve, and 25 is the second pneumatic butterfly valve. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] like Figures 1 to 2 As shown, this utility model provides an exhaust system for a silicon carbide deposition apparatus, including a vacuum pipeline 2. The vacuum pipeline 2 includes a first branch pipe, a second branch pipe, and a third branch pipe. The first branch pipe is connected to the deposition chamber 1, the second branch pipe is connected to a vacuum pump assembly 7 (in this embodiment, the vacuum pump assembly 7 is a pneumatic dry vacuum pump assembly 7), and the third branch pipe is connected to the main pipe of the exhaust gas distribution vacuum pipeline 8. Two fourth branch pipes of the exhaust gas distribution vacuum pipeline 8 are respectively connected to a first manual butterfly valve 9 and a second manual butterfly valve 24. The diameters of the two fourth branch pipes are smaller than the diameter of the main pipe, and the diameters of the two fourth branch pipes are the same.

[0032] The first manual butterfly valve 9 is sequentially connected to the first pneumatic butterfly valve 10, the first differential pressure gauge 11, the electric regulating valve, the second differential pressure gauge 12, and the input end of the exhaust manifold 13. The second manual butterfly valve 24 is connected to the input end of the exhaust manifold 13 via the second pneumatic butterfly valve 25. The output end of the exhaust manifold 13 is connected to multiple solid impurity collection devices 14 and multiple first exhaust gas treatment pipelines 15. In this embodiment, the output end of the exhaust manifold 13 is connected to two solid impurity collection devices 14 and one first exhaust gas treatment pipeline 15. Those skilled in the art can make adaptive adjustments according to actual needs.

[0033] Specifically, the first manual butterfly valve 9, the second manual butterfly valve 24, the first pneumatic butterfly valve 10, and the second pneumatic butterfly valve 25 are all made of corrosion-resistant materials or have an anti-corrosion coating on their surfaces. By closing the first manual butterfly valve 9 and the second manual butterfly valve 24, the connection between the sedimentation chamber 1 and the first exhaust gas treatment pipeline 15 can be blocked, preventing air from entering the sedimentation chamber 1. By opening the first manual butterfly valve 9 and / or the second manual butterfly valve 24, the exhaust gas generated in the sedimentation chamber 1 can be discharged into the exhaust gas treatment device through the first exhaust gas treatment pipeline 15.

[0034] The first pneumatic butterfly valve 10 and the second pneumatic butterfly valve 25 are connected to a solenoid valve. The solenoid valve controls the opening or closing of the first pneumatic butterfly valve 10 and / or the second pneumatic butterfly valve 25, thereby controlling the operation of the exhaust system.

[0035] The first pneumatic butterfly valve 10, the second pneumatic butterfly valve 25, and the electric regulating valve are all communicatively connected to the output end of the control system, and the first differential pressure gauge 11 and the second differential pressure gauge 12 are all communicatively connected to the input end of the control system.

[0036] The first differential pressure gauge 11 measures the first differential pressure value between the input end of the electric regulating valve and atmospheric pressure, and transmits the measured first differential pressure value to the control system. The second differential pressure gauge 12 measures the second differential pressure value between the output end of the electric regulating valve and atmospheric pressure, and transmits the measured second differential pressure value to the control system. After data processing, the control system feeds back the difference between the first and second differential pressure values ​​as a control signal to the electric regulating valve to adjust the opening angle of the electric regulating valve, control the gas pressure at the input and output ends of the electric regulating valve, and dynamically adjust the flow rate of the exhaust gas through the two fourth branch pipes. The two fourth branch pipes work together to achieve full reaction of MTS gas and stable discharge of exhaust gas generated during deposition, thereby achieving uniform deposition and greatly improving the deposition quality. Specifically, by adjusting the opening angle of the electric regulating valve, most of the exhaust gas is discharged from the fourth branch pipe without the electric regulating valve, and a small portion of the exhaust gas is discharged from the fourth branch pipe connected to the electric regulating valve. The fourth branch pipe, which is not connected to the electric regulating valve, serves as the main exhaust end for discharging exhaust gas. This allows for fine-tuning of the opening and closing angle of the electric regulating valve to effectively control the flow rate and volume of exhaust gas entering the exhaust system, thus achieving stable exhaust gas delivery.

[0037] In this embodiment, the solid impurity collection device 14 adopts a solid impurity collection tank to collect solid impurity particles carried in the exhaust gas. As the exhaust gas temperature gradually decreases, the solid impurities carried in the exhaust gas gradually deposit in the solid impurity collection tank, which can effectively reduce the blockage of various pipelines in the exhaust system by solid impurities.

[0038] The second branch pipe is sequentially connected to a first vacuum gauge 3, a second vacuum gauge 5, and a pneumatic valve 6, with the pneumatic valve 6 located near the vacuum pump assembly 7. A pneumatic ball valve 4 connects the second branch pipe to the first vacuum gauge 3. Before deposition, when the vacuum pump assembly 7 is used to evacuate the deposition chamber 1, the first vacuum gauge 3 can be used to measure the high vacuum pressure of the deposition chamber 1 and the exhaust system. During deposition, closing the pneumatic ball valve 4 can effectively reduce the corrosion of the first vacuum gauge 3 by the exhaust gas containing corrosive gases generated during deposition. The first vacuum gauge 3 is a 1 Torr vacuum gauge. The second vacuum gauge 5 is used to measure the low vacuum pressure of the deposition chamber 1 when the vacuum pump assembly 7 is used to evacuate the deposition chamber 1 before deposition, as well as to measure the pressure within the system consisting of the deposition chamber 1, the exhaust system, and the exhaust gas treatment device. The second vacuum gauge 5 is a 1000 Torr vacuum gauge. The first vacuum gauge 3 and the second vacuum gauge 5 work together to monitor the vacuum status of the system throughout the evacuation process. The pneumatic valve 6 is used to control the connection between the vacuum pump group 7 and the deposition chamber 1. During deposition, the pneumatic valve 6 and the vacuum pump group 7 are closed to prevent the vacuum pump group 7 from contacting corrosive gases at the source, thereby increasing the service life of the vacuum pump group 7.

[0039] The exhaust gas treatment system for the silicon carbide deposition apparatus described above, provided by this utility model, includes an exhaust gas treatment device. The exhaust gas treatment device includes a first alkaline spray tower 17, which is connected to a first exhaust gas treatment pipeline 15 of the exhaust system for the silicon carbide deposition apparatus. The first alkaline spray tower 17 is also connected in sequence to a second alkaline spray tower 18, a first fan 19, a third alkaline spray tower 20, a fourth alkaline spray tower 21, and a second fan 22. The second fan 22 is also connected to a high-altitude emission pipeline 23. The high-altitude emission pipeline 23 is used to discharge exhaust gas that meets emission standards. The first alkaline spray tower 17, the second alkaline spray tower 18, the first fan 19, the third alkaline spray tower 20, the fourth alkaline spray tower 21, and the second fan 22 are connected by a second exhaust gas treatment pipeline 16.

[0040] After passing through the first alkaline spray tower 17, the second alkaline spray tower 18, the third alkaline spray tower 20 and the fourth alkaline spray tower 21 in sequence, the exhaust gas containing strong acid discharged from the exhaust manifold 13 can be fully neutralized, reducing the corrosion of the acidic gas on the fan.

[0041] The first fan 19 and the second fan 22 both provide suction power for the exhaust system. In this embodiment, the drive motors of both the first fan 19 and the second fan 22 are explosion-proof variable frequency motors, which can provide a wind pressure of 4000Pa. The operating frequency of the first fan 19 and the second fan 22 can be adjusted by monitoring the pressure difference between the input and output terminals of the electric regulating valve by the first differential pressure gauge 11 and the second differential pressure gauge 12. This adjusts the pressure required in the deposition chamber 1 and the exhaust system during deposition operations, thereby achieving stable exhaust and ensuring that the deposition operation lasts for no less than 100 hours.

[0042] In addition, the separate installation of the first fan 19 and the second fan 22 can ensure that the pressure in the deposition chamber 1 and the exhaust system remains constant during deposition operations, thereby further ensuring the deposition quality.

[0043] The working principle of this utility model is as follows:

[0044] Before the deposition operation, open the pneumatic ball valve 4 and pneumatic valve 6, and use the vacuum pump set 7 to draw a vacuum into the deposition chamber 1, the exhaust system and the pipelines connecting them. The first vacuum gauge 3 and the second vacuum gauge 5 work together to detect the vacuum status of the deposition chamber 1, the exhaust system and the pipelines connecting them throughout the process of vacuuming.

[0045] During sedimentation, pneumatic ball valve 4 and pneumatic valve 6 are closed, while the first manual butterfly valve 9, the second manual butterfly valve 24, the first pneumatic butterfly valve 10, and the second pneumatic butterfly valve 25 are opened. By adjusting the opening angle of the electric regulating valve, the flow rate and velocity of the tail gas entering the two fourth branch pipes are dynamically adjusted, ensuring that the tail gas is discharged from the sedimentation chamber 1 into the exhaust system at a uniform and stable speed. The temperature of the tail gas decreases when it enters the exhaust manifold, at which point the solid impurity particles contained in the tail gas fall into the solid impurity collection device 14. Under the action of the first fan 19 and the second fan 22, the gas in the tail gas is sequentially fed into the first alkaline spray tower 17, the second alkaline spray tower 18, the third alkaline spray tower 20, and the fourth alkaline spray tower 21 through the first tail gas treatment pipeline 15 for neutralization reaction, reducing the corrosion of the fans by the acidic gas. The treated tail gas is discharged through the high-altitude exhaust pipeline 23.

[0046] 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.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An exhaust system for a silicon carbide deposition apparatus, characterized in that: The vacuum pipeline (2) includes a first branch pipe, a second branch pipe and a third branch pipe. The first branch pipe is connected to the deposition chamber (1), the second branch pipe is connected to the vacuum pump group (7), and the third branch pipe is connected to the main pipe of the exhaust gas distribution vacuum pipeline (8). The two fourth branches of the exhaust gas distribution vacuum pipeline (8) are respectively connected to the first manual butterfly valve (9) and the second manual butterfly valve (24). The first manual butterfly valve (9) is connected in sequence to the first pneumatic butterfly valve (10), the first differential pressure gauge (11), the electric regulating valve, the second differential pressure gauge (12), and the input end of the exhaust gas collection pipeline (13). The second manual butterfly valve (24) is connected to the input end of the exhaust gas collection pipeline (13) through the second pneumatic butterfly valve (25). The output end of the exhaust gas collection pipeline (13) is connected to multiple solid impurity collection devices (14) and the first exhaust gas treatment pipeline (15). The first pneumatic butterfly valve (10), the second pneumatic butterfly valve (25), and the electric regulating valve are all communicatively connected to the output end of the control system, and the first differential pressure gauge (11) and the second differential pressure gauge (12) are all communicatively connected to the input end of the control system.

2. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: The second branch pipe is connected in sequence to a first vacuum gauge (3), a second vacuum gauge (5) and a pneumatic valve (6), with the pneumatic valve (6) located near the vacuum pump assembly (7).

3. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: Both the first pneumatic butterfly valve (10) and the second pneumatic butterfly valve (25) are connected to solenoid valves.

4. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: The diameters of the two fourth branch pipes are smaller than the diameter of the main pipe.

5. The exhaust system for a silicon carbide deposition apparatus according to claim 2, characterized in that: A pneumatic ball valve (4) is connected between the second branch pipe and the first vacuum gauge (3).

6. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: The first manual butterfly valve (9), the second manual butterfly valve (24), the first pneumatic butterfly valve (10), and the second pneumatic butterfly valve (25) are all made of corrosion-resistant materials.

7. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: The surfaces of the first manual butterfly valve (9), the second manual butterfly valve (24), the first pneumatic butterfly valve (10), and the second pneumatic butterfly valve (25) are coated with an anti-corrosion layer.

8. The exhaust system for a silicon carbide deposition apparatus according to claim 1, characterized in that: The vacuum pump unit (7) adopts a pneumatic dry vacuum pump unit (7).

9. A tail gas treatment system based on the exhaust system of a silicon carbide deposition apparatus as described in any one of claims 1 to 8, characterized in that: The device includes an exhaust gas treatment unit, which includes a first alkaline spray tower (17). The first alkaline spray tower (17) is connected to the first exhaust gas treatment pipeline (15) of the exhaust system for the silicon carbide deposition device. The first alkaline spray tower (17) is also connected in sequence to a second alkaline spray tower (18), a first fan (19), a third alkaline spray tower (20), a fourth alkaline spray tower (21), and a second fan (22). The second fan (22) is also connected to a high-altitude discharge pipeline (23).

10. The exhaust gas treatment system for a silicon carbide deposition apparatus according to claim 9, characterized in that: The drive motors of the first fan (19) and the second fan (22) are both explosion-proof variable frequency motors.

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