CVD (Chemical Vapor Deposition) tail gas outlet device

Abstract

The utility model discloses a CVD (Chemical Vapor Deposition) tail gas outlet device which comprises a first chamber and a second chamber, the first chamber is positioned above the second chamber, the first chamber and the second chamber are separated by a thermal insulation layer, the thermal insulation layer is provided with a gas guide channel, and the gas guide channel is communicated with the first chamber and the second chamber; an air inlet is formed in a top plate of the first chamber, and an air outlet guide pipe is arranged on a bottom plate of the second chamber; a plurality of graphite plates are arranged in the first chamber and the second chamber, and a plurality of through holes are formed in the graphite plates; the plurality of graphite plates in the first chamber are arranged at intervals in the vertical direction, and the plurality of graphite plates in the second chamber are arranged at intervals in the vertical direction. The device can slow down the flow velocity of tail gas, improve the stability of deposition pressure in the reaction cavity, improve the deposition efficiency of byproducts in the device, and reduce the deposition of the byproducts in a vacuum pipeline, a filtering device and a vacuum pump.

Description

Technical Field

[0001] The utility model relates to a CVD tail gas outlet device, belonging to the technical field of CVD (chemical vapor deposition). Background Art

[0002] Chemical Vapor Deposition (CVD) is a technology that uses one or more gaseous compounds or single substances containing the target coating elements to generate thin films by chemical reactions on the substrate surface using various energy sources such as heating, plasma excitation or light radiation.

[0003] CVD reaction chamber exhaust is generated when high-purity semiconductor materials are prepared using chemical vapor deposition (CVD). During the CVD process, reactant gases are introduced into the reaction chamber, where they undergo a series of chemical reactions, producing a large amount of exhaust. This exhaust, which contains reaction byproduct silane, precipitated particles, hydrogen chloride gas, residual carrier gas, and diluent gas, is extracted by the vacuum system and then treated in a multi-stage exhaust spray system.

[0004] Due to the large flow rate of reaction gas and fast exhaust gas flow rate in the CVD reaction chamber, the process pressure is unstable, which is greatly different from the set process conditions, affecting the quality of semiconductor material products; the large flow of exhaust gas enters the vacuum system, increasing the workload of the vacuum pump, insufficient suction force, and the exhaust gas cannot be removed in time, and a large amount of it accumulates in the vacuum pipe. Silane by-products adhere to the inner wall of the vacuum pipe or clog the surface of the filter device, and even liquefy into a liquid with high viscosity and remain in the vacuum pipe, creating certain safety hazards. In order to avoid safety hazards caused by the accumulation of by-products, the vacuum pipe needs frequent maintenance, which increases the workload of operators. In addition, the silane by-products retained in the vacuum pipe come into contact with air and are easily hydrolyzed, producing white smoke and a pungent odor, which is harmful to human health.

[0005] In view of the shortcomings of the existing technology, there is an urgent need for a CVD reaction chamber exhaust gas outlet device to slow down the exhaust gas flow rate, disperse the exhaust gas evenly, and slowly dissipate the heat, reduce the exhaust gas liquefaction and retention in the vacuum pipeline and blockage of the filter device surface, improve the exhaust gas emission stability, and reduce the maintenance frequency. Utility Model Content

[0006] In order to overcome the problems existing in the prior art, the present invention provides a CVD tail gas outlet device that helps to slow down the tail gas flow rate. The specific technical solution is as follows.

[0007] A CVD tail gas outlet device, characterized by comprising a first chamber and a second chamber, wherein the first chamber is located above the second chamber, the first chamber and the second chamber are separated by a thermal insulation layer, the thermal insulation layer is provided with an air guide channel, and the air guide channel connects the first chamber and the second chamber;

[0008] An air inlet is provided on the top plate of the first chamber, and an air outlet duct is provided on the bottom plate of the second chamber; multiple graphite plates are provided in both the first chamber and the second chamber, and a plurality of through holes are provided on the graphite plates; the multiple graphite plates in the first chamber are spaced apart in the vertical direction, and the multiple graphite plates in the second chamber are spaced apart in the vertical direction.

[0009] By adopting the above technical solution, the first chamber and the second chamber can effectively alleviate the exhaust gas flow rate. After the high-temperature exhaust gas enters the first chamber, it slowly moves downward after being blocked by the graphite plate. The high-temperature exhaust gas can dissipate heat and cool down through the side wall of the first chamber. The insulation layer can effectively reduce the heat conduction of the high-temperature exhaust gas in the first chamber to the second chamber; the graphite plate in the second chamber also has the effect of slowing down the flow rate; and high-temperature gases have a tendency to flow upward. The exhaust duct in the above solution is arranged on the bottom plate of the second chamber, so the exhaust gas discharged from the exhaust duct is relatively low in temperature, which helps the exhaust duct to recover solid and liquid sediments.

[0010] Furthermore, the first chamber is surrounded by a first outer tube, the top plate and the thermal insulation layer; the second chamber is surrounded by a second outer tube, the bottom plate and the thermal insulation layer.

[0011] Furthermore, in the first chamber, 2-5 graphite plates are provided; in the second chamber, 2-5 graphite plates are provided.

[0012] Furthermore, in the first chamber, the through-holes of two adjacent graphite plates are staggered in the vertical direction. This can increase the exhaust gas's travel path, improving heat dissipation and speed reduction. In the second chamber, the through-holes of two adjacent graphite plates are staggered in the vertical direction.

[0013] Furthermore, in the first chamber, the number and size of through-holes in two adjacent graphite plates are different. This can also increase the exhaust gas's travel path, improving heat dissipation and speed reduction. In the second chamber, the number and size of through-holes in two adjacent graphite plates are different.

[0014] Furthermore, the outlet duct is vertically arranged, with a removable blocking plate at its lower end, and a horizontal outlet pipe connected to its middle. With the outlet duct vertically arranged, larger precipitate particles in the exhaust gas fall onto the removable blocking plate due to gravity, and the exhaust gas is then extracted from the outlet pipe by a downstream vacuum system. The blocking plate can be periodically removed to clean the precipitate.

[0015] Compared with the existing technology, the utility model can slow down the exhaust gas flow rate, improve the deposition pressure stability in the reaction chamber, improve the deposition efficiency of by-products in the device, reduce the deposition of by-products in the vacuum pipe, filter device and vacuum pump, reduce the possibility of blockage, improve the periodic stability of the exhaust gas vacuum system, and reduce the maintenance frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the CVD tail gas outlet device of the utility model;

[0017] Figure 2 is a schematic diagram of a graphite plate;

[0018] Figure 3 is a schematic diagram of another type of graphite plate.

[0019] In the figure: first chamber 100, top plate 101, air inlet 102, first outer tube 103, graphite plate 104, through hole 105, second chamber 200, insulation layer 201, air guide channel 202, second outer tube 203, bottom plate 204, air outlet duct 300, precipitated product particles 300a, sealing plate 301, air outlet pipe 302. DETAILED DESCRIPTION

[0020] The present invention is described in further detail below with reference to the accompanying drawings.

[0021] See also Figure 1-Figure 3 A CVD tail gas outlet device includes a first chamber 100 and a second chamber 200. The first chamber 100 is located above the second chamber 200. The first chamber 100 and the second chamber 200 are separated by a thermal insulation layer 201. The thermal insulation layer 201 is provided with an air guide channel 202, which connects the first chamber 100 and the second chamber 200. The first chamber 100 is surrounded by a first outer tube 103, a top plate 101, and the thermal insulation layer 201; the second chamber 200 is surrounded by a second outer tube 203, a bottom plate 204, and the thermal insulation layer 201.

[0022] An air inlet 102 is provided on the top plate 101 of the first chamber 100, and an air outlet duct 300 is provided on the bottom plate 204 of the second chamber 200; multiple graphite plates 104 are provided in the first chamber 100 and the second chamber 200, and a plurality of through holes 105 are provided on the graphite plates 104; the multiple graphite plates 104 in the first chamber 100 are spaced apart in the vertical direction, and the multiple graphite plates 104 in the second chamber 200 are spaced apart in the vertical direction.

[0023] Preferably, 2-5 graphite plates 104 are provided in the first chamber 100 ; and 2-5 graphite plates 104 are provided in the second chamber 200 .

[0024] In one embodiment, in the first chamber 100, the through-holes 105 of two adjacent graphite plates 104 are vertically staggered. This increases the exhaust gas's path, improving heat dissipation and deceleration. In the second chamber 200, the through-holes 105 of two adjacent graphite plates 104 are vertically staggered.

[0025] In one embodiment, the number and size of through-holes 105 on two adjacent graphite plates 104 in the first chamber 100 are different. This can also increase the exhaust gas's travel path, improving heat dissipation and speed reduction. In the second chamber 200, the number and size of through-holes 105 on two adjacent graphite plates 104 are different.

[0026] Preferably, the outlet duct 300 is vertically arranged, with a removable blocking plate 301 at its lower end. A horizontal outlet pipe 302 is connected to the middle of the outlet duct 300. With the outlet duct 300 vertically arranged, larger precipitate particles 300a in the exhaust gas fall onto the removable blocking plate 301 due to gravity, and the exhaust gas is then drawn away from the outlet pipe 302 by a downstream vacuum system (not shown). The blocking plate 301 can be periodically removed to clean the precipitate.

[0027] The exhaust gas in the CVD reaction chamber enters the first chamber 100 from the air inlet 102. The exhaust gas passes through multiple graphite plates 104 from top to bottom in the first chamber 100, reducing the exhaust gas flow rate while dissipating heat through the first outer cylinder 103. The exhaust gas enters the second chamber 200 from the air guide channel 202 for further buffering and heat dissipation before entering the exhaust duct 300. The larger precipitated product particles 300a in the exhaust gas will fall onto the removable sealing plate 301 under the action of gravity, and the exhaust gas is extracted from the exhaust pipe 302. After multiple layers of filtration, the exhaust gas flow rate is slow, and the flow rate entering the vacuum system is relatively stable, preventing a large amount of exhaust gas from entering the vacuum system at the same time, causing a heavy workload and insufficient suction force on the vacuum pump, which would cause the exhaust gas to be retained and liquefied in the vacuum pipe. This greatly reduces the possibility of the filter device being blocked, improves the stability of exhaust gas emissions, and reduces the frequency of large-scale maintenance of the vacuum system. The precipitation product particles that fall on the removable sealing plate 301 can be cleaned regularly.

[0028] The embodiments of the present invention are described above in conjunction with the accompanying drawings. In the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other. The present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, those skilled in the art can make many forms without departing from the scope of protection of the present invention and the scope of the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A CVD tail gas outlet device, characterized in that: The invention comprises a first chamber (100) and a second chamber (200), wherein the first chamber (100) is located above the second chamber (200), the first chamber (100) and the second chamber (200) are separated by a heat-insulating layer (201), and the heat-insulating layer (201) is provided with an air-guiding channel (202), and the air-guiding channel (202) communicates with the first chamber (100) and the second chamber (200); An air inlet (102) is provided on the top plate (101) of the first chamber (100), and an air outlet duct (300) is provided on the bottom plate (204) of the second chamber (200); a plurality of graphite plates (104) are provided in both the first chamber (100) and the second chamber (200), and a plurality of through holes (105) are provided on the graphite plates (104); the plurality of graphite plates (104) in the first chamber (100) are spaced apart in the vertical direction, and the plurality of graphite plates (104) in the second chamber (200) are spaced apart in the vertical direction.

2. The CVD tail gas outlet device according to claim 1, characterized in that: The first chamber (100) is surrounded by a first outer cylinder (103), the top plate (101) and the thermal insulation layer (201).

3. The CVD tail gas outlet device according to claim 1, characterized in that: The second chamber (200) is surrounded by a second outer cylinder (203), the bottom plate (204) and the thermal insulation layer (201).

4. The CVD tail gas outlet device according to claim 1, characterized in that: In the first chamber (100), 2 to 5 graphite plates (104) are provided; and in the second chamber (200), 2 to 5 graphite plates (104) are provided.

5. The CVD tail gas outlet device according to claim 4, characterized in that: In the first chamber (100), the through holes (105) of two adjacent graphite plates (104) are staggered in the vertical direction.

6. The CVD tail gas outlet device according to claim 4, characterized in that: In the second chamber (200), the through holes (105) of two adjacent graphite plates (104) are staggered in the vertical direction.

7. The CVD tail gas outlet device according to claim 4, characterized in that: In the first chamber (100), the through holes (105) of two adjacent graphite plates (104) are different in number and size.

8. The CVD tail gas outlet device according to claim 4, characterized in that: In the second chamber (200), the through holes (105) of two adjacent graphite plates (104) are different in number and size.

9. The CVD tail gas outlet device according to claim 1, characterized in that: The air outlet duct (300) is vertically arranged, a blocking plate (301) is detachably arranged at the lower end of the air outlet duct (300), and a horizontally arranged air outlet pipe (302) is connected to the middle of the air outlet duct (300).

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