An on-line switching device for tank cylinders used in CVD processes

Abstract

An online switching device for a tank gas cylinder of a CVD process, including a gas cylinder, an L-shaped three-way valve, a tail gas treatment pipeline, a T-shaped three-way valve and a mixed gas tank inlet, the gas cylinder is connected with the L-shaped three-way valve through a pipeline, one side of the L-shaped three-way valve is connected with the tail gas treatment pipeline, the other side is connected with a pipeline and connected with the T-shaped three-way valve through a pipeline, the T-shaped three-way valve is connected with the mixed gas tank inlet, the L-shaped three-way valve can switch the flow direction of the gas in the gas cylinder, and the gas is selected to be introduced into the tail gas treatment pipeline or flow to the T-shaped three-way valve, including, the utility model adopts a pipeline self-cleaning type double-channel gas supply system, solves the problem of gas supply interruption caused by insufficient pressure (or volume) of process gas in the process of chemical vapor deposition furnace process, wherein the pipeline self-cleaning system also ensures the purity of the gas supply gas.

Description

Technical Field

[0001] This utility model relates to the field of chemical vapor deposition (CVD) processes, and in particular to an online switching device for gas cylinders used in CVD processes. Background Technology

[0002] Chemical vapor deposition (CVD) technology is widely used in aerospace and semiconductor fields. For example, it is used for anti-oxidation coatings (such as PyC / SiC ceramic coatings) on the surface of hot-end components of aero engines and surface coatings (such as SiC / TaC coatings) on wafer carriers in the epitaxial process of third-generation semiconductor SiC substrates. In addition, diamond deposition of diamond films in microwave plasma chemical vapor deposition (MPCVD) all require the use of flammable, explosive, and corrosive gas cylinders.

[0003] Chemical vapor deposition (CVD) processes inevitably involve the use of flammable, explosive, and toxic gases. These gases are mostly contained in gas cylinders or tanks, which have limited capacity. Therefore, when the gas pressure in a cylinder becomes insufficient, it needs to be replaced. Furthermore, CVD processes not only require high temperature uniformity and pressure in the working area, but also maintain high gas purity. Microwave plasma chemical vapor deposition (MPCVD) even demands a high degree of continuity in the process gas supply; otherwise, deposition uniformity issues will arise. Moreover, traditional cylinder supply systems typically employ single-cylinder or multi-cylinder groups.

[0004] In summary, traditional gas cylinder supply methods are essentially single-channel supply methods, only changing the supply time by altering the container capacity. In actual use, gas cylinder replacement is inevitable, which interrupts the gas supply and affects the quality of chemical vapor deposition. Furthermore, during online gas cylinder replacement, some connecting pipes will inevitably be exposed to the external environment, affecting the gas purity during the chemical vapor deposition process and causing unpredictable impacts on high-purity equipment. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defect of the existing technology that the gas supply will be interrupted during the gas cylinder replacement process, which will affect the quality of chemical vapor deposition or the purity of the gas, and to provide an online switching device for canned gas cylinders used in CVD process.

[0006] The technical solution adopted by this utility model to solve its technical problem is an online switching device for a gas cylinder used in CVD process, including a gas cylinder, an L-shaped three-way valve, a tail gas treatment pipeline, a T-shaped three-way valve, and a mixing tank inlet. The gas cylinder is connected to the L-shaped three-way valve through a pipeline. One side of the L-shaped three-way valve is connected to the tail gas treatment pipeline, and the other side is connected to a pipeline and then to the T-shaped three-way valve. The T-shaped three-way valve is connected to the mixing tank inlet. The L-shaped three-way valve can switch the flow direction of the gas in the gas cylinder, selecting to let the gas flow into the tail gas treatment pipeline or into the T-shaped three-way valve.

[0007] Furthermore, the gas cylinder, L-type three-way valve, exhaust gas treatment pipeline, T-type three-way valve, and mixing tank inlet are connected to form an online switching device via a sealed cabinet.

[0008] Furthermore, there are two gas cylinders and two L-shaped three-way valves.

[0009] Furthermore, the T-type three-way valve connects two gas cylinders and an L-type three-way valve, and the T-type three-way valve can control whether it is a single connection or a double connection.

[0010] Furthermore, the gas cylinder, L-shaped three-way valve, and exhaust gas treatment pipeline form a pipeline self-cleaning system, and the gas in the gas cylinder is flushed into the exhaust gas treatment pipeline through the L-shaped three-way valve.

[0011] Furthermore, the T-type three-way valve can control the intake volume or mixing ratio of the two gas cylinders.

[0012] This utility model has the following beneficial technical effects:

[0013] This invention employs a self-cleaning dual-channel gas supply system, which solves the problem of gas supply interruption caused by insufficient pressure (or volume) during the chemical vapor deposition furnace process. The self-cleaning system also ensures the purity of the supplied gas. The self-cleaning system is designed to flush the exposed pipe sections with the gas itself inside the tank, ensuring that the gas entering the process gas system is of high purity. The dual-channel proportional distribution structure, through a T-type three-way valve, allows for adjustment of the opening degree according to the pressure and volume of the gas tank, making the inlet pressure more stable. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an embodiment of an online switching device for a gas cylinder used in CVD process according to this utility model.

[0015] Explanation of reference numerals in the attached figures:

[0016] 1. Gas cylinder; 2. L-type three-way valve; 3. Exhaust gas treatment pipeline; 4. T-type three-way valve; 5. Mixing tank inlet. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] Reference Figure 1 This embodiment employs a separate sealed enclosure, ensuring the device remains within a sealed system, preventing serious gas leakage. The enclosure includes a gas cylinder 1, an L-shaped three-way valve 2, a tail gas treatment pipeline 3, a T-shaped three-way valve 4, and a mixing tank inlet 5. The gas cylinder 1 is connected to one port of the L-shaped three-way valve 2 via a pipeline. One port of the L-shaped three-way valve 2 is connected to the tail gas treatment pipeline 3, and the other port is connected to the T-shaped three-way valve 4. The ports of the L-shaped three-way valve 2 and the T-shaped three-way valve 4 are connected by a pipeline. One port of the T-shaped three-way valve 4 is connected to the mixing tank inlet 5. The L-shaped three-way valve 2 and the T-shaped three-way valve 4 can be controlled manually or via a PLC program to control the gas flow direction and flow rate within the gas cylinder 1. The L-shaped three-way valve 2 can switch the gas flow direction in the gas cylinder 1, selecting whether to direct the gas into the tail gas treatment pipeline 3 or to the T-shaped three-way valve 4. The T-shaped three-way valve 4 can control the intake volume or mixing ratio of the two gas cylinders 1. Meanwhile, the exhaust gas treatment pipe 3 and the mixing tank inlet 5 are both connected to different outlets. For example, the exhaust gas treatment pipe 3 is connected to the exhaust gas treatment system, and the mixing tank inlet 5 is connected to the gas reaction chamber for corresponding production.

[0019] There are two gas cylinders 1, L-type three-way valves 2, and exhaust gas treatment pipelines 3. These components form a self-cleaning system and are symmetrically positioned on both sides of a T-type three-way valve 4. Gas from the cylinders is flushed through the L-type three-way valves 2 into the exhaust gas treatment pipeline 3. Each gas cylinder 1 has a dual-station, dual-channel configuration. After the pipeline is assembled into each cylinder 1, the gas first passes through the L-type three-way valves 2 to flush out impurities and other gases from the pipeline before entering the exhaust gas treatment pipeline 3. This ensures the pipeline is filled with the required gas. After flushing, the L-type three-way valves 2 switch the gas flow direction, directing the process gas into the T-type three-way valve 4.

[0020] The T-type three-way valve 4 can be set to a single-channel mode or a dual-channel proportional mixing mode. In the single-channel mode, it can supply gas to a single gas cylinder 1. In the dual-channel mode, it can adjust the mixing ratio according to the pressure and gas volume of different gas cylinders 1 to ensure that the pressure is stable and the flow rate is controllable when the gas enters the mixing tank inlet 5.

[0021] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. An online switching device for gas cylinders used in CVD processes, characterized in that, The system includes a gas cylinder (1), an L-shaped three-way valve (2), a tail gas treatment pipeline (3), a T-shaped three-way valve (4), and a mixing tank inlet (5). The gas cylinder (1) is connected to the L-shaped three-way valve (2) through a pipeline. One side of the L-shaped three-way valve (2) is connected to the tail gas treatment pipeline (3), and the other side is connected to a pipeline and then connected to the T-shaped three-way valve (4). The T-shaped three-way valve (4) is connected to the mixing tank inlet (5). The L-shaped three-way valve (2) can switch the flow direction of the gas in the gas cylinder (1) and select to let the gas flow into the tail gas treatment pipeline (3) or flow into the T-shaped three-way valve (4).

2. The online switching device for CVD gas cylinders according to claim 1, characterized in that, The gas cylinder (1), L-type three-way valve (2), tail gas treatment pipeline (3), T-type three-way valve (4), and mixing tank inlet (5) form an online switching device through a sealed atmosphere cabinet.

3. The online switching device for CVD gas cylinders according to claim 1, characterized in that, There are two gas cylinders (1) and L-shaped three-way valves (2).

4. The online switching device for CVD gas cylinders according to claim 1, characterized in that, The T-type three-way valve (4) connects two gas cylinders (1) and an L-type three-way valve (2), and the T-type three-way valve (4) can control whether it is a single connection or a double connection.

5. The online switching device for CVD gas cylinders according to claim 1, characterized in that, The gas cylinder (1), L-shaped three-way valve (2), and exhaust gas treatment pipeline (3) form a pipeline self-cleaning system. The gas in the gas cylinder (1) is flushed through the L-shaped three-way valve (2) to the exhaust gas treatment pipeline (3).

6. The online switching device for CVD gas cylinders according to claim 1, characterized in that, The T-type three-way valve (4) can control the air intake or mixing ratio of the two gas cylinders (1).

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