Nitrogen recovery device with filtering function

Abstract

The invention discloses a nitrogen recovery device with a filtering function, and relates to the technical field of gas filtering systems. The device comprises a first filtering system and a second filtering system, and the first filtering system is used for filtering mixed gas generated by a subsequent cleaning reactor in the dichlorosilane thermal decomposition reaction and recycling nitrogen; and the second filtering system is used for filtering mixed gas generated by the subsequent cleaning reactor in the silicon nitride deposition reaction and recycling nitrogen. By arranging the first filtering system and the second filtering system, nitrogen waste gas generated in different working procedures is treated respectively, two kinds of nitrogen containing different gas impurities are separated before filtering, meanwhile, different filtering devices are adopted for independently filtering the two kinds of nitrogen waste gas respectively, and the filtering efficiency is improved. And finally, hydrogen in the nitrogen gas is removed until the content of the gas reaction source in the nitrogen gas is greatly reduced, so that the nitrogen gas is purified for multiple times, and more by-products cannot be generated in the filtering process of the nitrogen gas.

Description

Technical Field

[0001] The present invention relates to the technical field of gas filtration systems, and particularly to a nitrogen recovery device with a filtration function. Background Art

[0002] Principle of atomic layer thin film deposition technology: When the temperature and pressure in the reaction chamber are within a certain specific range, gas reaction sources A and B (such as commonly used SiCl 2 H 2 / dichlorosilane, NH 3 / ammonia) are alternately introduced into the reaction chamber and reach the surface of the silicon wafer. By circulating in turn, a thin film is deposited on the surface of the silicon wafer in a single atomic layer growth manner. Both gas reaction sources require an intake device for isolation and gas homogenization. If the two gas reaction sources meet at the intake end, a chemical reaction will occur immediately. They need to enter the cavity alternately in the form of pulses to prevent the reaction before reaching the substrate.

[0003] During atomic layer deposition, nitrogen gas needs to be frequently introduced into the reactor to clean the intake pipeline and the chamber of the reactor to prevent the influence on the intake pipeline caused by the residue of the gas reaction source. The nitrogen gas used for cleaning needs to be recovered afterwards. When SiCl 2 H 2 / dichlorosilane and NH 3 / ammonia are used as reaction sources, a large amount of by-products such as chlorine gas and hydrogen gas, as well as residual dichlorosilane and ammonia, will be mixed in the nitrogen gas. At present, when the nitrogen recovery device for the deposition reaction of dichlorosilane and ammonia filters and recovers the nitrogen gas mixed with impurities, the nitrogen gas containing different gas impurities will be mixed together for filtration and purification treatment. The dichlorosilane and ammonia in the mixed gas will continue to react, affecting the actual nitrogen gas filtration and recovery process. Therefore, a nitrogen recovery device with a filtration function is proposed. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that when the current nitrogen recovery device for the deposition reaction of dichlorosilane and ammonia filters and recovers the nitrogen gas mixed with impurities, the nitrogen gas containing different gas impurities will be mixed together for filtration and purification treatment, and the dichlorosilane and ammonia in the mixed gas will continue to react, affecting the actual nitrogen gas filtration and recovery process. The present invention provides a nitrogen recovery device with a filtration function.

[0005] The present invention specifically adopts the following technical solutions to achieve the above purpose:

[0006] A nitrogen recovery device with a filtering function, comprising a first filtering system and a second filtering system. The first filtering system is used to filter the mixed gas generated by cleaning the reactor after the thermal decomposition reaction of dichlorosilane and recover nitrogen. The second filtering system is used to filter the mixed gas generated by cleaning the reactor after the silicon nitride deposition reaction and recover nitrogen;

[0007] The first filtering system includes a first water bath tower. One side of the first water bath tower is fixedly installed with a first intake air three-way valve. One end of the first intake air three-way valve is fixedly installed with a first intake pipe. One side of the first water bath tower is fixedly installed with a first gas transmission pipe. A molecular sieve filtering device is arranged on one side of the first water bath tower. One end of the first gas transmission pipe is connected to the intake end of the molecular sieve filtering device. The outlet end of the molecular sieve filtering device is fixedly installed with a decomposition pipe. A thermal decomposition furnace is arranged on one side of the molecular sieve filtering device. One end of the decomposition pipe is connected to the intake end of the thermal decomposition furnace. The outlet end of the thermal decomposition furnace is fixedly installed with a first circulation three-way valve. One end of the first circulation three-way valve is fixedly installed with a first circulation pipe. One end of the first circulation pipe is fixedly installed on the other end of the first intake air three-way valve. The other end of the first circulation three-way valve is fixedly installed with a first exhaust pipe;

[0008] The second filtering system includes a second water bath tower. One side of the second water bath tower is fixedly installed with a second intake air three-way valve. One end of the second intake air three-way valve is fixedly installed with a second intake pipe. One side of the second water bath tower is fixedly installed with a second gas transmission pipe. An activated carbon filtering box is arranged on one side of the first water bath tower. One end of the second gas transmission pipe is connected to the intake end of the activated carbon filtering box. The outlet end of the activated carbon filtering box is fixedly installed with a second circulation three-way valve. One end of the second circulation three-way valve is fixedly installed with a second circulation pipe. One end of the second circulation pipe is fixedly installed on the other end of the second intake air three-way valve. The other end of the second circulation three-way valve is fixedly installed with a second exhaust pipe. One end of the second exhaust pipe is communicated with the first circulation pipe.

[0009] Further, a hydrogen energy high-temperature activation furnace is arranged on one side of the molecular sieve filtering device. One side of the hydrogen energy high-temperature activation furnace is fixedly installed with an infusion three-way pipe and a liquid return three-way pipe. A high-temperature gas cavity is arranged inside the molecular sieve filtering device. The other two ends of the infusion three-way pipe and the liquid return three-way pipe are both connected to the high-temperature gas cavity.

[0010] Further, a hydrogen three-way pipe is fixedly installed at the exhaust end of the molecular sieve filtering device. The other end of the hydrogen three-way pipe is connected to the inside of the hydrogen energy high-temperature activation furnace.

[0011] Further, a drying and filtering box is fixedly installed at the top of the high-temperature hydrogen activation furnace. One end of the hydrogen three-way pipe is communicated with the inside of the drying and filtering box, and the drying and filtering box is communicated with the inside of the high-temperature hydrogen activation furnace.

[0012] Further, water supply pipes are fixedly installed at the tops of the first water bath tower and the second water bath tower. One ends of the two water supply pipes respectively extend into the first water bath tower and the second water bath tower and are both fixedly installed with spray trays. Drain pipes are fixedly installed at one sides of the bottoms of the first water bath tower and the second water bath tower.

[0013] Further, a placement rack is fixedly installed inside the activated carbon filtering box. A plurality of evenly distributed end face plates are arranged inside the activated carbon filtering box. Double-layer mesh cylinders are arranged on one sides of the end face plates. One ends of the double-layer mesh cylinders close to the end face plates are both fixedly installed with screw connecting pipes. The end face plates are screwed to the double-layer mesh cylinders through the end face plates, and the double-layer mesh cylinders are all slidably inserted on the placement rack.

[0014] Further, one end of the second gas pipeline extends into the activated carbon filtering box and is fixedly installed with a plurality of shunt pipes evenly distributed from top to bottom. The shunt pipes are all horizontally arranged. A plurality of evenly distributed shunt nozzles are fixedly installed on the side walls of the shunt pipes. One ends of the plurality of shunt nozzles are respectively inserted into the interiors of the plurality of double-layer mesh cylinders.

[0015] Further, a maintenance and sealing door is arranged on one side of the thermal decomposition furnace.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. By setting the first filtering system and the second filtering system, the nitrogen waste gas generated in different processes of the atomic layer deposition process is separately treated. Before filtering, the two kinds of nitrogen containing different gas impurities are separated, and different filtering devices are used to separately filter the two kinds of nitrogen waste gas until the content of the gas reaction source in the nitrogen is greatly reduced, and finally the hydrogen in the nitrogen is removed, completing the multiple purification of the nitrogen and ensuring that no more by-products will appear during the filtering process of the nitrogen;

[0018] 2. By setting the high-temperature hydrogen activation furnace, after the molecular sieve filtering device is used for a long time, the filtering performance of the molecular sieve particles inside it will be greatly reduced and then gradually inactivated. At this time, the high-temperature hydrogen activation furnace will input high-temperature gas into the high-temperature gas cavity of the molecular sieve filtering device through the infusion three-way pipe to heat the molecular sieve particles in the molecular sieve filtering device, so that the molecular sieve particles are activated at high temperature and the adsorbed hydrogen inside is precipitated, completing the activation of the molecular sieve filtering device and the extraction of hydrogen;

[0019] 3. By providing a hydrogen three-way pipe in the present invention, the hydrogen gas precipitated inside the molecular sieve filtration device due to the activation of molecular sieve particles will be input into the high-temperature hydrogen energy activation furnace through the hydrogen three-way pipe and reused as supplementary energy by the high-temperature hydrogen energy activation furnace, realizing the recycling of the by-product hydrogen gas from atomic layer deposition. The adsorbent particles in the drying and filtration box will dry and adsorb the hydrogen gas input through the hydrogen three-way pipe, removing the small amount of water molecules and floating dust impurities contained in the hydrogen gas, and then the purified hydrogen gas will be input into the high-temperature hydrogen energy activation furnace for reuse;

[0020] 4. By providing a spray tray in the present invention, the purified water dissolved with gas impurities such as chlorine gas and ammonia gas in the first water bath tower and the second water bath tower is discharged through the drain pipe, and the new purified water is re-input into the first water bath tower and the second water bath tower through the water supply pipe. The gas floating upward after the water bath treatment will be secondarily filtered by the purified water sprayed out from the spray tray, thereby increasing the dissolution amount of gas impurities such as chlorine gas and ammonia gas in the purified water and improving the filtration effect;

[0021] 5. By providing a double-layer mesh cylinder in the present invention, the ammonia impurities in the gas input into the activated carbon filtration box by the second gas pipeline will be absorbed by the activated carbon particles in the double-layer mesh cylinder. When the activated carbon filtration box is used for a long time, the activated carbon filtration box can be opened, the double-layer mesh cylinder can be sequentially taken out and the end face plate can be unscrewed to replace the internal activated carbon particles, and then the double-layer mesh cylinder can be refilled into the activated carbon filtration box to ensure that the activated carbon filtration box always has sufficient adsorption performance;

[0022] 6. By providing a shunt nozzle in the present invention, the mixed gas input into the activated carbon filtration box by the second gas pipeline will be shunted through multiple shunt pipes and sequentially input into the interiors of the double-layer mesh cylinders through multiple shunt nozzles, enabling the gas to sequentially pass through the inner cylinder, the activated carbon particle layer, and the outer cylinder of the double-layer mesh cylinder, so that the gas can fully contact with the activated carbon particles, ensuring that the activated carbon particles can fully absorb the ammonia impurities and improving the filtration effect of the activated carbon filtration box on ammonia;

[0023] 7. By providing a maintenance sealing door in the present invention, after the residual dichlorosilane is thermally decomposed in the thermal decomposition furnace, the gas by-products will be mixed with other gases through the first circulation pipe and gradually filtered, while the fixed impurities such as elemental silicon will remain inside the thermal decomposition furnace. The staff can regularly open the maintenance sealing door on one side of the thermal decomposition furnace to clean and recycle the solid impurities inside the thermal decomposition furnace, preventing excessive impurities from accumulating inside the thermal decomposition furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the first perspective three-dimensional structure schematic diagram of the present invention;

[0025] Figure 2 is the second perspective three-dimensional structure schematic diagram of the present invention;

[0026] Figure 3 is a schematic top view structure of the present invention;

[0027] Figure 4 is a schematic three-dimensional internal structure diagram of the first water bath tower and the second water bath tower of the present invention;

[0028] Figure 5 is a schematic three-dimensional structure diagram of the hydrogen energy high-temperature activation furnace of the present invention;

[0029] Figure 6 is a schematic three-dimensional internal structure diagram of the activated carbon filter box of the present invention;

[0030] Figure 7 is a schematic three-dimensional internal structure diagram of the second gas transmission pipe and the double-layer mesh cylinder of the present invention;

[0031] Figure 8 is the present invention Figure 7 schematic diagram of the structure at position A in;

[0032] Reference numerals: 1, first water bath tower; 2, first intake three-way valve; 3, first intake pipe; 4, first gas transmission pipe; 5, molecular sieve filtration equipment; 6, decomposition tube; 7, thermal decomposition furnace; 8, first circulation three-way valve; 9, first circulation pipe; 10, first exhaust pipe; 11, second water bath tower; 12, second intake three-way valve; 13, second intake pipe; 14, second gas transmission pipe; 15, activated carbon filter box; 16, second circulation three-way valve; 17, second circulation pipe; 18, second exhaust pipe; 19, hydrogen energy high-temperature activation furnace; 20, infusion three-way pipe; 21, liquid return three-way pipe; 22, hydrogen three-way pipe; 23, drying and filtering box; 24, water supply pipe; 25, spray tray; 26, drain pipe; 27, end face plate; 28, double-layer mesh cylinder; 29, screw connection pipe; 30, shunt pipe; 31, shunt nozzle; 32, maintenance and sealing door. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0035] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0036] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0037] As Figures 1 to 8 shown, a nitrogen recovery device with a filtering function includes a first filtering system and a second filtering system. The first filtering system is used to filter the mixed gas generated by cleaning the reactor after the thermal decomposition reaction of dichlorosilane and recover nitrogen. The second filtering system is used to filter the mixed gas generated by cleaning the reactor after the silicon nitride deposition reaction and recover nitrogen.

[0038] As Figure 4 shown, the first filtering system includes a first water bath tower 1. One side of the first water bath tower 1 is fixedly installed with a first intake air three-way valve 2. One end of the first intake air three-way valve 2 is fixedly installed with a first intake pipe 3. One side of the first water bath tower 1 is fixedly installed with a first gas transmission pipe 4. As Figure 1 、 Figure 3As shown in the figure, a molecular sieve filtration device 5 is provided on one side of the first water bath tower 1. One end of the first gas transmission pipe 4 is connected to the intake end of the molecular sieve filtration device 5. A decomposition pipe 6 is fixedly installed at the outlet end of the molecular sieve filtration device 5. A thermal decomposition furnace 7 is provided on one side of the molecular sieve filtration device 5. One end of the decomposition pipe 6 is connected to the intake end of the thermal decomposition furnace 7. A first circulation three-way valve 8 is fixedly installed at the outlet end of the thermal decomposition furnace 7. One end of the first circulation three-way valve 8 is fixedly installed with a first circulation pipe 9. One end of the first circulation pipe 9 is fixedly installed on the other end of the first intake three-way valve 2. The other end of the first circulation three-way valve 8 is fixedly installed with a first exhaust pipe 10; specifically, at the beginning of the atomic layer deposition process, dichlorosilane is first introduced into the reactor for thermal decomposition to generate elemental silicon on the silicon wafer. Then, nitrogen is introduced into the reactor to clean the remaining mixed gas (dichlorosilane, chlorine, hydrogen). At this time, the mixed gas mixed with nitrogen is discharged from the reactor through the first intake pipe 3. Then, ammonia is introduced into the reactor to react with silicon to generate silicon nitride for film coating. Then, nitrogen is introduced again to clean the remaining gas, and the mixed gas is discharged through the second intake pipe 13 to complete a single cycle. After that, the above steps are repeated until a silicon nitride film with a specified thickness is obtained;

[0039] The above reaction process includes the following steps:

[0040] (1) Dichlorosilane is introduced into the reactor and undergoes thermal decomposition: SiCl 2 H 2 = Si(s) + Cl 2 (g) + H 2 (g);

[0041] (2) Nitrogen is introduced, and the mixed gas is discharged through the first intake pipe 3;

[0042] (3) Ammonia is introduced to react with the elemental silicon generated on the silicon wafer to generate a silicon nitride film: 2NH 3 + 2Si(s) = 2SiN(s) + 3H 2 (g);

[0043] (4) Nitrogen is introduced again, and the mixed gas is discharged through the second intake pipe 13;

[0044] (5) The above steps are repeated multiple times until a silicon nitride film with a specified thickness is obtained;

[0045] In the first filtration system, a mixed gas containing nitrogen, a small amount of unreacted dichlorosilane, and by-products chlorine and hydrogen is input into the first water bath tower 1 through the first inlet pipe 3. After being treated by water bath, most of the chlorine is dissolved in water, and the remaining gas is input into the molecular sieve filtration device 5 through the first gas transmission pipe 4. Most of the hydrogen in the mixed gas is filtered out by the molecular sieve. Finally, the mixed gas is input into the thermal decomposition furnace 7 through the decomposition pipe 6 for heating, so that the remaining dichlorosilane undergoes thermal decomposition to achieve the primary purification of nitrogen. Then, the nitrogen containing impurities is re-input into the first water bath tower 1 through the first circulation three-way valve 8, the first circulation pipe 9, and the first intake three-way valve 2 for multiple cycle filtrations to increase the nitrogen content until the filtered nitrogen reaches the specified concentration;

[0046] As Figure 4 shown, the second filtration system includes a second water bath tower 11. One side of the second water bath tower 11 is fixedly installed with a second intake three-way valve 12. One end of the second intake three-way valve 12 is fixedly installed with a second inlet pipe 13. One side of the second water bath tower 11 is fixedly installed with a second gas transmission pipe 14. As Figure 2 , Figure 3As shown in the figure, an activated carbon filter box 15 is provided on one side of the first water bath tower 1. One end of the second gas transmission pipe 14 is connected to the intake end of the activated carbon filter box 15. The outlet end of the activated carbon filter box 15 is fixedly installed with a second circulating three-way valve 16. One end of the second circulating three-way valve 16 is fixedly installed with a second circulating pipe 17. One end of the second circulating pipe 17 is fixedly installed on the other end of the second intake three-way valve 12. The other end of the second circulating three-way valve 16 is fixedly installed with a second exhaust pipe 18. One end of the second exhaust pipe 18 is communicated with the first circulating pipe 9. Specifically, in the second filtration system, a mixed gas containing nitrogen, a small amount of unreacted ammonia, and by-product hydrogen will be input into the second water bath tower 11 through the second intake pipe 13. Part of the ammonia will be removed through the water bath treatment. Then the mixed gas will be input into the activated carbon filter box 15 through the second gas transmission pipe 14, so that most of the remaining ammonia will continue to be adsorbed and removed by the activated carbon. The ammonia containing part of the impurities will continue to be input into the second water bath tower 11 through the second circulating three-way valve 16, the second circulating pipe 17, and the second intake three-way valve 12 for multiple rounds of cyclic filtration until the ammonia concentration is reduced to below the specified value. Then the nitrogen in the second filtration system will be input into the first circulating pipe 9 through the second exhaust pipe 18 and mixed with the gas in the first filtration system to jointly filter the hydrogen. Finally, the nitrogen after multiple purifications will be transmitted to the storage system for standby through the first exhaust pipe 10. This nitrogen recovery device separately treats the nitrogen waste gas generated in different processes of the atomic layer deposition process by setting the first filtration system and the second filtration system, separates the two kinds of nitrogen containing different gas impurities before filtration, and simultaneously uses different filtration equipment to separately filter the two kinds of nitrogen waste gas until the content of the gas reaction source in the nitrogen drops significantly, and finally removes the hydrogen in the nitrogen to complete the multiple purifications of the nitrogen, ensuring that no more by-products will appear during the filtration process of the nitrogen.

[0047] As Figure 1 shown, a hydrogen energy high-temperature activation furnace 19 is provided on one side of the molecular sieve filtration device 5. As Figure 5 shown, an infusion three-way pipe 20 and a liquid return three-way pipe 21 are fixedly installed on one side of the hydrogen energy high-temperature activation furnace 19. A high-temperature gas chamber is provided inside the molecular sieve filtration device 5. The other two ends of the infusion three-way pipe 20 and the liquid return three-way pipe 21 are both communicated with the high-temperature gas chamber. Specifically, by setting the hydrogen energy high-temperature activation furnace 19, after the molecular sieve filtration device 5 has been used for a long time, the filtration performance of the molecular sieve particles inside it will drop significantly and then gradually become inactivated. At this time, the hydrogen energy high-temperature activation furnace 19 will input high-temperature gas into the high-temperature gas chamber of the molecular sieve filtration device 5 through the infusion three-way pipe 20 to heat the molecular sieve particles in the molecular sieve filtration device 5, so that the molecular sieve particles are activated at high temperature and the adsorbed hydrogen inside is precipitated, completing the activation of the molecular sieve filtration device 5 and the extraction of hydrogen.

[0048] As Figure 3, Figure 5 As shown in Figure 5 , a hydrogen tee 22 is fixedly installed at the exhaust end of the molecular sieve filtration device 5, and the other end of the hydrogen tee 22 is connected to the inside of the hydrogen energy high-temperature activation furnace 19; specifically, by setting the hydrogen tee 22, the hydrogen gas precipitated due to the activation of the molecular sieve particles inside the molecular sieve filtration device 5 will be input into the hydrogen energy high-temperature activation furnace 19 through the hydrogen tee 22 and reused as a supplementary energy source by the hydrogen energy high-temperature activation furnace 19, realizing the recycling of the by-product hydrogen gas of atomic layer deposition.

[0049] As Figure 5 shown, a drying and filtering box 23 is fixedly installed at the top of the hydrogen energy high-temperature activation furnace 19. One end of the hydrogen tee 22 is connected to the inside of the drying and filtering box 23, and the drying and filtering box 23 is connected to the inside of the hydrogen energy high-temperature activation furnace 19; specifically, by setting the drying and filtering box 23, the adsorbent particles in the drying and filtering box 23 will dry and adsorb the hydrogen gas input by the hydrogen tee 22, removing the small amount of water molecules and floating dust impurities contained in the hydrogen gas, and then inputting the purified hydrogen gas into the hydrogen energy high-temperature activation furnace 19 for reuse.

[0050] As Figure 4 shown, water supply pipes 24 are fixedly installed at the tops of the first water bath tower 1 and the second water bath tower 11. One ends of the two water supply pipes 24 respectively extend into the first water bath tower 1 and the second water bath tower 11 and are both fixedly installed with spray trays 25. Drain pipes 26 are fixedly installed at one sides of the bottoms of the first water bath tower 1 and the second water bath tower 11; specifically, by setting the spray trays 25, the purified water dissolved with gas impurities such as chlorine gas and ammonia gas in the first water bath tower 1 and the second water bath tower 11 are respectively discharged through the two drain pipes 26. At the same time, new purified water is re-input into the first water bath tower 1 and the second water bath tower 11 through the water supply pipes 24. The gas floating upward through the water bath treatment will be secondarily filtered by the purified water sprayed out from the spray trays 25, thereby increasing the dissolution amount of gas impurities such as chlorine gas and ammonia gas in the purified water and improving the filtering effect.

[0051] As Figure 6 shown, a placement rack is fixedly installed inside the activated carbon filtration box 15. A plurality of evenly distributed end face plates 27 are arranged inside the activated carbon filtration box 15. As Figure 7 , Figure 8As shown, double-layer mesh cylinders 28 are provided on one side of the end face plate 27. At one end of each double-layer mesh cylinder 28 close to the end face plate 27, a screw pipe 29 is fixedly installed. The end face plate 27 is screwed to the double-layer mesh cylinder 28 through the end face plate 27. The double-layer mesh cylinders 28 are all slidably inserted on the placement rack. In this embodiment, the double-layer mesh cylinder 28 is a structure of an inner cylinder and an outer cylinder. The ends of the inner cylinder and the outer cylinder away from the screw pipe 29 are closed, and activated carbon particles are loaded in the interlayer between the inner cylinder and the outer cylinder. Specifically, by providing the double-layer mesh cylinder 28, ammonia impurities in the gas input into the activated carbon filter box 15 by the second air delivery pipe 14 will be absorbed by the activated carbon particles in the double-layer mesh cylinder 28. When the activated carbon filter box 15 is used for a long time, the activated carbon filter box 15 can be opened, the double-layer mesh cylinders 28 are sequentially pulled out and the end face plate 27 is unscrewed to replace the internal activated carbon particles, and then the double-layer mesh cylinders 28 are refilled into the activated carbon filter box 15 to ensure that the activated carbon filter box 15 always has sufficient adsorption performance.

[0052] As Figure 7 shown, one end of the second air delivery pipe 14 extends into the activated carbon filter box 15 and fixedly installs a plurality of shunt pipes 30 evenly distributed from top to bottom. The shunt pipes 30 are all horizontally arranged, and a plurality of evenly distributed shunt nozzles 31 are fixedly installed on the side walls of the shunt pipes 30. One ends of the plurality of shunt nozzles 31 are respectively inserted into the interiors of the plurality of double-layer mesh cylinders 28. Specifically, by providing the shunt nozzles 31, the mixed gas input into the activated carbon filter box 15 by the second air delivery pipe 14 will be shunted by the plurality of shunt pipes 30 and sequentially input into the interiors of the respective double-layer mesh cylinders 28 through the plurality of shunt nozzles 31, so that the gas sequentially passes through the inner cylinder, the activated carbon particle layer and the outer cylinder of the double-layer mesh cylinder 28, thereby enabling the gas to be in full contact with the activated carbon particles, ensuring that the activated carbon particles can fully absorb ammonia impurities, and improving the filtering effect of the activated carbon filter box 15 on ammonia.

[0053] As Figure 1 shown, a maintenance sealing door 32 is provided on one side of the thermal decomposition furnace 7. Specifically, by providing the maintenance sealing door 32, after the residual dichlorosilane is thermally decomposed in the thermal decomposition furnace 7, the gas by-products will be mixed with other gases through the first circulation pipe 9 and gradually filtered, while the fixed impurities such as elemental silicon will stay inside the thermal decomposition furnace 7. The staff can regularly open the maintenance sealing door 32 on one side of the thermal decomposition furnace 7 to clean and recycle the solid impurities inside the thermal decomposition furnace 7 to prevent excessive accumulation of impurities inside the thermal decomposition furnace 7.

[0054] In summary: When the nitrogen recovery device is in use, in the first filtration system, a mixed gas containing nitrogen, a small amount of unreacted dichlorosilane, and by-products chlorine and hydrogen is input into the first water bath tower 1 through the first intake pipe 3. After water bath treatment, most of the chlorine is dissolved in water, and the remaining gas is input into the molecular sieve filtration device 5 through the first gas transmission pipe 4. Most of the hydrogen in the mixed gas is filtered out by the molecular sieve, and finally the mixed gas is input into the thermal decomposition furnace 7 through the decomposition pipe 6 for heating, causing the remaining dichlorosilane to undergo thermal decomposition to achieve the primary purification of nitrogen. Then, the nitrogen containing impurities is re-input into the first water bath tower 1 through the first circulation three-way valve 8, the first circulation pipe 9, and the first intake three-way valve 2 for multiple cycles of filtration to increase the nitrogen content until the filtered nitrogen reaches the specified concentration. In the second filtration system, a mixed gas containing nitrogen, a small amount of unreacted ammonia, and by-product hydrogen is input into the second water bath tower 11 through the second intake pipe 13. After water bath treatment, part of the ammonia is removed, and then the mixed gas is input into the activated carbon filtration box 15 through the second gas transmission pipe 14, enabling most of the remaining ammonia to be continuously adsorbed and removed by the activated carbon. The ammonia containing some impurities will continue to be re-input into the second water bath tower 11 through the second circulation three-way valve 16, the second circulation pipe 17, and the second intake three-way valve 12 for multiple rounds of circulation filtration until the ammonia concentration is reduced to below the specified value. Then, the nitrogen in the second filtration system is input into the first circulation pipe 9 through the second exhaust pipe 18 to be mixed with the gas in the first filtration system to jointly filter the hydrogen. Finally, the nitrogen purified multiple times is transmitted to the storage system through the first exhaust pipe 10 for standby. The nitrogen recovery device separately processes the nitrogen waste gas generated in different processes of the atomic layer deposition process by setting the first filtration system and the second filtration system, separates the two kinds of nitrogen containing different gas impurities before filtration, and simultaneously uses different filtration devices to separately filter the two kinds of nitrogen waste gas until the content of the gas reaction source in the nitrogen drops significantly, and finally removes the hydrogen in the nitrogen to complete the multiple purification of nitrogen, ensuring that no more by-products will appear during the filtration of nitrogen. By setting the hydrogen energy high-temperature activation furnace 19, after the long-term use of the molecular sieve filtration device 5, the filtration performance of the molecular sieve particles inside it will drop significantly and gradually become inactivated. At this time, the hydrogen energy high-temperature activation furnace 19 will input high-temperature gas into the high-temperature gas chamber of the molecular sieve filtration device 5 through the infusion three-way pipe 20 to heat the molecular sieve particles in the molecular sieve filtration device 5, causing the molecular sieve particles to be activated at high temperature and release the hydrogen adsorbed inside, completing the activation of the molecular sieve filtration device 5 and the extraction of hydrogen. By setting the hydrogen three-way pipe 22, the hydrogen released due to the activation of the molecular sieve particles inside the molecular sieve filtration device 5 will be input into the hydrogen energy high-temperature activation furnace 19 through the hydrogen three-way pipe 22 and reused as supplementary energy by the hydrogen energy high-temperature activation furnace 19 to achieve the recovery and utilization of the by-product hydrogen in the atomic layer deposition. By setting the drying filtration box 23,The adsorbent particles in the drying and filtering box 23 will dry and adsorb the hydrogen input by the hydrogen tee 22, removing a small amount of water molecules and floating dust impurities contained in the hydrogen. After the hydrogen is purified, it is input into the hydrogen energy high-temperature activation furnace 19 for reuse. By setting the spray tray 25, the purified water dissolved with gas impurities such as chlorine and ammonia in the first water bath tower 1 and the second water bath tower 11 is discharged through the two drain pipes 26 respectively. At the same time, new purified water is re-input into the first water bath tower 1 and the second water bath tower 11 through the water supply pipe 24. The gas floating upward after the water bath treatment will be secondarily filtered by the purified water sprayed out from the spray tray 25, thereby increasing the dissolution amount of gas impurities such as chlorine and ammonia in the purified water and improving the filtering effect. By setting the double-layer mesh cylinder 28, the ammonia impurities in the gas input by the second gas pipe 14 into the activated carbon filtering box 15 will be absorbed by the activated carbon particles in the double-layer mesh cylinder 28. When the activated carbon filtering box 15 is used for a long time, the activated carbon filtering box 15 can be opened, the double-layer mesh cylinder 28 is sequentially pulled out and the end face plate 27 is unscrewed to replace the internal activated carbon particles, and then the double-layer mesh cylinder 28 is refilled into the internal part of the activated carbon filtering box 15, so as to ensure that the activated carbon filtering box 15 always has sufficient adsorption performance. By setting the shunt nozzles 31, the mixed gas input by the second gas pipe 14 into the activated carbon filtering box 15 will be shunted through a plurality of shunt pipes 30 and sequentially input into the interiors of the respective double-layer mesh cylinders 28 through a plurality of shunt nozzles 31, so that the gas sequentially passes through the inner cylinder, the activated carbon particle layer and the outer cylinder of the double-layer mesh cylinder 28, thereby enabling the gas to be in full contact with the activated carbon particles, ensuring that the activated carbon particles can fully absorb the ammonia impurities and improving the filtering effect of the activated carbon filtering box 15 on ammonia. By setting the maintenance sealing door 32, after the residual dichlorosilane is thermally decomposed in the thermal decomposition furnace 7, the gas by-products will be mixed with other gases through the first circulation pipe 9 and gradually filtered, while the fixed impurities such as elemental silicon will stay inside the thermal decomposition furnace 7. The staff can regularly open the maintenance sealing door 32 on one side of the thermal decomposition furnace 7 to clean and recycle the solid impurities inside the thermal decomposition furnace 7, preventing excessive accumulation of impurities inside the thermal decomposition furnace 7.,

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A nitrogen recovery device with filtering function, characterized in that: It comprises a first filtering system and a second filtering system, wherein the first filtering system is used to filter the mixed gas generated by the subsequent cleaning reactor of the dichlorosilane thermal decomposition reaction and recover the nitrogen, and the second filtering system is used to filter the mixed gas generated by the subsequent cleaning reactor of the silicon nitride deposition reaction and recover the nitrogen; The first filtering system comprises a first water bath tower (1), a first air inlet three-way valve (2) is fixedly mounted on one side of the first water bath tower (1), a first air inlet pipe (3) is fixedly mounted on one end of the first air inlet three-way valve (2), a first air supply pipe (4) is fixedly mounted on one side of the first water bath tower (1), a molecular sieve filtering device (5) is arranged on one side of the first water bath tower (1), one end of the first air supply pipe (4) is connected to the air inlet end of the molecular sieve filtering device (5), and a first air supply pipe (4) is fixedly mounted on the air outlet end of the molecular sieve filtering device (5). A decomposition tube (6), a thermal decomposition furnace (7) is arranged on one side of the molecular sieve filtration device (5), one end of the decomposition tube (6) is connected to the air inlet end of the thermal decomposition furnace (7), a first circulation three-way valve (8) is fixedly installed at the air outlet end of the thermal decomposition furnace (7), a first circulation tube (9) is fixedly installed at one end of the first circulation three-way valve (8), one end of the first circulation tube (9) is fixedly installed on the other end of the first air inlet three-way valve (2), and a first exhaust pipe (10) is fixedly installed at the other end of the first circulation three-way valve (8); The second filtering system comprises a second water bath tower (11), a second air inlet three-way valve (12) is fixedly mounted on one side of the second water bath tower (11), a second air inlet pipe (13) is fixedly mounted on one end of the second air inlet three-way valve (12), a second air supply pipe (14) is fixedly mounted on one side of the second water bath tower (11), an activated carbon filter box (15) is arranged on one side of the first water bath tower (1), and one end of the second air supply pipe (14) is connected to the air inlet of the activated carbon filter box (15). The activated carbon filter box (15) is connected to the second end, a second circulation three-way valve (16) is fixedly installed at the outlet end of the activated carbon filter box (15), a second circulation pipe (17) is fixedly installed at one end of the second circulation three-way valve (16), one end of the second circulation pipe (17) is fixedly installed on the other end of the second air intake three-way valve (12), a second exhaust pipe (18) is fixedly installed at the other end of the second circulation three-way valve (16), and one end of the second exhaust pipe (18) is connected to the first circulation pipe (9).

2. A nitrogen recovery device with filtering function according to claim 1, characterized in that: A hydrogen energy high temperature activation furnace (19) is arranged on one side of the molecular sieve filtration device (5), a liquid infusion tee (20) and a liquid return tee (21) are fixedly installed on one side of the hydrogen energy high temperature activation furnace (19), a high temperature air cavity is arranged inside the molecular sieve filtration device (5), and the other two ends of the liquid infusion tee (20) and the liquid return tee (21) are both connected to the high temperature air cavity.

3. A nitrogen recovery device with filtering function according to claim 2, characterized in that: A hydrogen three-way pipe (22) is fixedly installed at the exhaust end of the molecular sieve filtering device (5), and the other end of the hydrogen three-way pipe (22) is connected to the interior of the hydrogen energy high-temperature activation furnace (19).

4. The nitrogen recovery device with filtering function according to claim 3, characterized in that: A drying filter box (23) is fixedly installed on the top of the hydrogen energy high temperature activation furnace (19), one end of the hydrogen three-way pipe (22) is connected to the interior of the drying filter box (23), and the drying filter box (23) is connected to the interior of the hydrogen energy high temperature activation furnace (19).

5. The nitrogen recovery device with filtering function according to claim 1, characterized in that: A water supply pipe (24) is fixedly installed on the top of the first water bath tower (1) and the second water bath tower (11), one end of the two water supply pipes (24) respectively extends into the interior of the first water bath tower (1) and the second water bath tower (11) and is fixedly installed with a spray plate (25), and a drainage pipe (26) is fixedly installed on one side of the bottom of the first water bath tower (1) and the second water bath tower (11).

6. The nitrogen recovery device with filtering function according to claim 1, characterized in that: A placement rack is fixedly installed inside the activated carbon filter box (15), and a plurality of evenly distributed end disks (27) are arranged inside the activated carbon filter box (15). A double-layer mesh cylinder (28) is arranged on one side of each end disk (27), and a screw tube (29) is fixedly installed on one end of each double-layer mesh cylinder (28) close to the end disk (27). The end disk (27) is screwed to the double-layer mesh cylinder (28) through the end disk (27), and the double-layer mesh cylinder (28) is slidably plugged into the placement rack.

7. The nitrogen recovery device with filtering function according to claim 6, characterized in that: One end of the second air supply pipe (14) extends to the interior of the activated carbon filter box (15) and is fixedly installed with a plurality of diversion pipes (30) evenly distributed from top to bottom, the diversion pipes (30) are all horizontally arranged, and a plurality of evenly distributed diversion nozzles (31) are fixedly installed on the side walls of the diversion pipes (30), and one end of the plurality of diversion nozzles (31) is respectively inserted into the interior of the plurality of double-layer mesh cylinders (28).

8. The nitrogen recovery device with filtering function according to claim 1, characterized in that: A maintenance sealing door (32) is provided on one side of the thermal decomposition furnace (7).

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