Comprehensive control system for gas used in single crystal furnace

Abstract

The utility model discloses a comprehensive control system for gas used in a single crystal furnace, which comprises a single crystal furnace, an argon supply subsystem, a tail gas recovery subsystem and a gas replacement subsystem, and the single crystal furnace is divided into a main chamber and an auxiliary chamber through an isolating valve. And the argon supply subsystem comprises an argon recovery pure argon rectification device, a high-purity argon buffer tank, a first filter and a pressure reducing valve, and is connected with the main chamber and the auxiliary chamber through a gas supply main pipeline. The tail gas recovery subsystem comprises a main pump, an auxiliary pump, a first dust remover, a second dust remover, a gas holder and an argon recovery catalytic purification device. And the gas replacement subsystem comprises an argon recovery high-nitrogen rectification device, a high-purity nitrogen buffer tank, a second filter and a high-purity nitrogen supply pipeline. Compared with the prior art, the device has the advantages that the device has excellent performance in the aspects of gas replacement and gas supply, and a more reliable and economical gas control solution is provided for production of the single crystal furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of single crystal silicon preparation, in particular to a comprehensive control system for gases used in a single crystal furnace. Background Art

[0002] Single crystal silicon is a high-purity semiconductor material with excellent electrical and thermal properties. Due to the high order of its crystal structure, single crystal silicon is widely used in the semiconductor industry to manufacture high-tech products such as integrated circuits (ICs), solar cells, photovoltaic cells, lasers, etc. Its high purity and integrity of crystal structure make single crystal silicon an indispensable key material in modern electronics and energy fields.

[0003] The single crystal furnace is a key equipment for preparing single crystal silicon. It includes two chambers: the main chamber and the auxiliary chamber. During the pulling process of single crystal silicon, a high degree of purity and inert atmosphere must be maintained to ensure the quality of single crystal silicon. In the operations of separation of the main chamber and the auxiliary chamber, feeding, and lifting rods, it is usually necessary to use high-purity argon gas to build an inert atmosphere under vacuum to protect the pulling of single crystal silicon. After the main chamber and the auxiliary chamber are separated, the auxiliary chamber needs to be gas-displaced, and high-purity argon gas is used to fill the auxiliary chamber to restore the inert atmosphere under vacuum.

[0004] However, the efficiency of argon gas utilization in traditional technologies is low, the recovery rate is low, and the use of high-purity argon gas during the sub-chamber replacement process results in high recovery costs, which not only increases production costs but also wastes precious gas resources. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the above technical defects. To solve the above technical problems, the utility model provides a technical solution as follows: a comprehensive gas control system used in a single crystal furnace, comprising a single crystal furnace, an argon gas supply subsystem, an exhaust gas recovery subsystem and a gas replacement subsystem;

[0006] The single crystal furnace is divided into a main chamber and a sub-chamber by a single crystal furnace isolation valve;

[0007] The argon gas supply subsystem comprises an argon recovery pure argon distillation device, a high-purity argon buffer tank, a first filter, a pressure reducing valve and an argon gas supply main pipeline. The gas outlet end of the argon recovery pure argon distillation device is connected to the high-purity argon buffer tank, the first filter and the pressure reducing valve in sequence through the argon gas supply main pipeline. The gas outlet end of the first filter is connected to the main chamber gas supply pipeline and the auxiliary chamber gas supply pipeline which are respectively connected to the main chamber and the auxiliary chamber;

[0008] The tail gas recovery subsystem includes a main pump, a secondary pump, a first dust collector, a second dust collector, a gas cabinet, an argon recovery catalytic purification device, a main chamber tail gas recovery pipeline and a secondary chamber tail gas recovery pipeline, the two ends of the main chamber tail gas recovery pipeline are respectively connected to the main chamber and the argon recovery pure argon distillation device, and the main chamber tail gas recovery pipeline sequentially connects the main pump, the first dust collector, the second dust collector, the gas cabinet and the argon recovery catalytic purification device, the secondary chamber tail gas recovery pipeline is connected to the secondary chamber and the secondary pump is arranged on the secondary chamber tail gas recovery pipeline, and the gas outlet end of the secondary chamber tail gas recovery pipeline is connected to the main chamber tail gas recovery pipeline;

[0009] The gas replacement subsystem includes an argon recovery high nitrogen distillation device, a high purity nitrogen buffer tank, a second filter and a high purity nitrogen gas supply pipeline. The high purity nitrogen gas supply pipeline sequentially connects the argon recovery high nitrogen distillation device, the high purity nitrogen buffer tank and the second filter, and the gas outlet end of the high purity nitrogen gas supply pipeline is connected to the auxiliary chamber gas supply pipeline. The auxiliary chamber tail gas recovery pipeline is connected to the auxiliary chamber tail gas discharge pipe through a first three-way valve, and the main chamber tail gas recovery pipeline is connected to the main chamber tail gas discharge pipe through a second three-way valve.

[0010] Preferably, the argon supply subsystem also includes a liquid argon backup storage tank, a liquid argon gasification device and an argon replenishing pipeline, the argon replenishing pipeline connects the liquid argon backup storage tank and the liquid argon gasification device in sequence, a valve is provided on the argon replenishing pipeline, and the outlet end of the argon replenishing pipeline is connected to the main argon supply pipeline at the inlet end of the high-purity argon buffer tank.

[0011] Preferably, the tail gas recovery subsystem also includes a liquid nitrogen backup storage tank, a liquid nitrogen gasification device and a nitrogen replenishment pipeline. The nitrogen replenishment pipeline connects the liquid nitrogen backup storage tank and the liquid nitrogen gasification device in sequence. A valve is provided on the nitrogen replenishment pipeline, and the gas outlet end of the nitrogen replenishment pipeline is connected to the high-purity nitrogen supply pipeline.

[0012] Preferably, a pressure gauge is provided on the main chamber exhaust gas discharge pipe, a vent pipe is connected between the main chamber exhaust gas discharge pipe and the main chamber exhaust gas recovery pipeline, and a safety valve is provided on the vent pipe.

[0013] Preferably, a mass flow controller is provided on the main argon gas supply pipeline, and a first stop valve and a second stop valve are provided on the main chamber gas supply pipeline and the auxiliary chamber gas supply pipeline, respectively.

[0014] Preferably, a third stop valve is provided on the argon gas supply main pipeline located at the gas outlet end of the argon recovery pure argon distillation device.

[0015] Preferably, a compressor is also provided on the main chamber tail gas recovery pipeline.

[0016] Preferably, a fourth stop valve is provided at the gas outlet end of the high-purity nitrogen gas supply pipeline.

[0017] Preferably, a manual valve pipeline is also provided on the main argon gas supply pipeline.

[0018] The advantages of the utility model compared with the prior art are:

[0019] The whole set of argon recovery equipment adopts the design of hydrogen-free argon production device, in which nitrogen replacement is selected for the replacement of the auxiliary chamber, which can not only effectively save gas costs, but also avoid cross contamination of nitrogen supply pipeline and argon supply pipeline, and improve the reliability and stability of the system. The manual valve and mass flow meter control the two pipelines to achieve precise control of the nitrogen supply of the auxiliary chamber replacement, which not only effectively reduces the replacement time, but also ensures the pressure in the single crystal furnace, and avoids cross contamination of nitrogen supply and argon supply pipeline.

[0020] In addition, in the auxiliary chamber replacement nitrogen supply pipeline, a design of a manual valve pipeline and a mass flow controller to control two pipelines is adopted, which not only improves the efficiency of replacement, but also ensures that the pressure in the single crystal furnace meets the standard. At the same time, a second stop valve is installed on the auxiliary chamber gas supply pipeline for argon supply, which can not only maintain pressure balance, but also serve as a follow-up guarantee after failure, increasing the safety of the system.

[0021] Another highlight of this device design is that it can simultaneously replace the main and auxiliary chambers after the main chamber is charged, which further improves the operational flexibility and efficiency of the system. Through these design solutions, the entire set of argon recovery equipment has shown superior performance in gas replacement and supply, providing a more reliable and economical gas control solution for the production of single crystal furnaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the integrated gas control system of a single single crystal furnace according to an embodiment of the present application.

[0023] Figure 2 It is a schematic diagram of a comprehensive gas control system for multiple single crystal furnaces according to an embodiment of the present application.

[0024] As shown in the figure: 1. Single crystal furnace, 2. Main chamber, 3. Sub-chamber, 4. Argon recovery pure argon distillation device, 5. High-purity argon buffer tank, 6. First filter, 7. Pressure reducing valve, 8. Argon gas supply main pipeline, 9. Main chamber gas supply pipeline, 10. Sub-chamber gas supply pipeline, 11. Main pump, 12. Sub-pump, 13. First dust collector, 14. Second dust collector, 15. Gas cabinet, 16. Argon recovery catalytic purification device, 17. Main chamber tail gas recovery pipeline, 18. Sub-chamber tail gas recovery pipeline, 19. Argon recovery high nitrogen distillation device, 20. High-purity nitrogen buffer tank, 21. Second filter, 22 , high-purity nitrogen gas supply pipeline, 23, the first three-way valve, 24, the auxiliary chamber exhaust pipe, 25, the second three-way valve, 26, the main chamber exhaust pipe, 27, the liquid argon backup storage tank, 28, the liquid argon gasification equipment, 29, the argon gas replenishment pipeline, 30, the liquid nitrogen backup storage tank, 31, the liquid nitrogen gasification equipment, 32, the nitrogen gas replenishment pipeline, 33, the pressure gauge, 34, the vent pipe, 35, the safety valve, 36, the mass flow controller, 37, the first stop valve, 38, the second stop valve, 39, the third stop valve, 40, the compressor, 41, the fourth stop valve, 42, the manual valve pipeline. DETAILED DESCRIPTION

[0025] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0026] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings, wherein the same parts are represented by the same reference numerals.

[0027] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0028] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0029] Combined with Figure 1 -Attached Figure 2 In order to solve the above technical problems, the technical solution provided by the utility model is: a comprehensive gas control system used in a single crystal furnace, including a single crystal furnace 1, an argon gas supply subsystem, an exhaust gas recovery subsystem and a gas replacement subsystem, wherein the single crystal furnace 1 uses CVR to replace the imported products with conventional threaded connection methods for the single crystal furnace front pipe joints, which can greatly reduce the gas leakage rate and improve the recovery rate.

[0030] The single crystal furnace 1 is divided into a main chamber 2 and a sub-chamber 3 by a single crystal furnace isolation valve;

[0031] The argon gas supply subsystem includes an argon recovery pure argon distillation device 4, a high-purity argon buffer tank 5, a first filter 6, a pressure reducing valve 7 and an argon gas supply main pipeline 8. The gas outlet end of the argon recovery pure argon distillation device 4 is connected to the high-purity argon buffer tank 5, the first filter 6 and the pressure reducing valve 7 in sequence through the argon gas supply main pipeline 8. The gas outlet end of the first filter 6 is connected to a main chamber gas supply pipeline 9 and a sub-chamber gas supply pipeline 10 which are respectively connected to the main chamber 2 and the sub-chamber 3;

[0032] The tail gas recovery subsystem includes a main pump 11, a secondary pump 12, a first dust collector 13, a second dust collector 14, a gas cabinet 15, an argon recovery catalytic purification device 16, a main chamber tail gas recovery pipeline 17 and a secondary chamber tail gas recovery pipeline 18, the two ends of the main chamber tail gas recovery pipeline 17 are respectively connected to the main chamber 2 and the argon recovery pure argon distillation device 4, and the main chamber tail gas recovery pipeline 17 sequentially connects the main pump 11, the first dust collector 13, the second dust collector 14, the gas cabinet 15 and the argon recovery catalytic purification device 16, the secondary chamber tail gas recovery pipeline 18 is connected to the secondary chamber 3 and the secondary pump 12 is arranged on the secondary chamber tail gas recovery pipeline 18, and the gas outlet end of the secondary chamber tail gas recovery pipeline 18 is connected to the main chamber tail gas recovery pipeline 17;

[0033] The gas replacement subsystem includes an argon recovery high nitrogen distillation device 19, a high purity nitrogen buffer tank 20, a second filter 21 and a high purity nitrogen gas supply pipeline 22. The high purity nitrogen gas supply pipeline 22 connects the argon recovery high nitrogen distillation device 19, the high purity nitrogen buffer tank 20 and the second filter 21 in sequence, and the gas outlet end of the high purity nitrogen gas supply pipeline 22 is connected to the auxiliary chamber gas supply pipeline 10. The auxiliary chamber exhaust gas recovery pipeline 18 is connected to the auxiliary chamber exhaust gas exhaust pipe 24 through the first three-way valve 23, and the main chamber exhaust gas recovery pipeline 17 is connected to the main chamber exhaust gas exhaust pipe 26 through the second three-way valve 25.

[0034] In one embodiment, the argon supply subsystem further includes a liquid argon backup storage tank 27, a liquid argon gasification device 28, and an argon supplementary pipeline 29. The argon supplementary pipeline 29 sequentially connects the liquid argon backup storage tank 27 and the liquid argon gasification device 28. A valve is provided on the argon supplementary pipeline 29, and the gas outlet of the argon supplementary pipeline 29 is connected to the argon gas supply main pipeline 8 at the gas inlet end of the high-purity argon buffer tank 5. When the argon recovery pure argon distillation device 4 cannot meet the pressure requirement of the high-purity argon buffer tank 5, the hydraulic pressure in the liquid argon backup storage tank 27 is gasified by the liquid argon gasification device 28 and supplemented into the high-purity argon buffer tank 5.

[0035] In one embodiment, the tail gas recovery subsystem further includes a liquid nitrogen backup storage tank 30, a liquid nitrogen gasification device 31 and a nitrogen supplement pipeline 32. The nitrogen supplement pipeline 32 sequentially connects the liquid nitrogen backup storage tank 30 and the liquid nitrogen gasification device 31. A valve is provided on the nitrogen supplement pipeline 32, and the gas outlet of the nitrogen supplement pipeline 32 is connected to the high-purity nitrogen gas supply pipeline 22. When the argon recovery high nitrogen distillation device 19 cannot meet the pressure requirement of the high-purity nitrogen gas supply pipeline 22, the hydraulic pressure in the liquid nitrogen backup storage tank 30 is gasified by the liquid nitrogen gasification device 31 and supplemented into the high-purity nitrogen gas supply pipeline 22.

[0036] In one embodiment, a pressure gauge 33 is provided on the main chamber exhaust gas discharge pipe 26 , a vent pipe 34 is connected between the main chamber exhaust gas discharge pipe 26 and the main chamber exhaust gas recovery pipeline 17 , and a safety valve 35 is provided on the vent pipe 34 .

[0037] In one embodiment, a mass flow controller 36 is provided on the argon gas supply main pipeline 8, and a first stop valve 37 and a second stop valve 38 are respectively provided on the main chamber gas supply pipeline 9 and the auxiliary chamber gas supply pipeline 10. The first stop valve 37 and the second stop valve 38 can be used to control the amount of argon gas entering the main chamber 2 and the auxiliary chamber 3, respectively.

[0038] In one embodiment, a third stop valve 39 is provided on the argon gas supply main pipeline 8 located at the gas outlet of the argon recovery pure argon distillation device 4. The third stop valve 39 is the main valve on the argon gas supply main pipeline 8 and is used to control the opening and closing of the entire argon gas supply main pipeline 8.

[0039] In one embodiment, a booster pump 40 is further provided on the main chamber exhaust gas recovery pipeline 17 , and the booster pump 40 can further increase the flow rate of the exhaust gas in the main chamber 2 and the sub-chamber 3 .

[0040] In one embodiment, a fourth stop valve 41 is provided at the gas outlet end of the high-purity nitrogen gas supply pipeline 22 .

[0041] Working principle: When the single crystal furnace 1 is working normally, the argon is recovered from the pure argon distillation device 4 and supplied to the high-purity argon buffer tank 5 through the argon gas supply main pipeline 8. At the same time, when the argon recovery pure argon distillation device 4 cannot meet the pressure requirement of the high-purity argon buffer tank 5, the hydraulic pressure in the liquid argon backup storage tank 27 is gasified by the liquid argon gasification equipment 28 and replenished into the high-purity argon buffer tank 5. After the high-purity argon buffer tank 5 buffers and filters, it is reduced in pressure through the pressure reducing valve 7 to meet the use requirements of the mass flow controller 36, and then the main chamber 2 and the sub-chamber 3 are respectively supplied through the main chamber supply pipeline 9 and the sub-chamber supply pipeline 10. The mass flow controller 36 maintains the pressure of the argon gas supply main pipeline 8. In the specific implementation process, the argon gas supply main pipeline 8 is also provided with a manual valve pipeline 42 for rapid argon filling;

[0042] The main chamber 2 and the auxiliary chamber 3 extract the argon in the single crystal furnace 1 through the main pump 11 and the auxiliary pump 12 respectively. The extracted gas passes through the main chamber tail gas recovery pipeline 17 and the auxiliary chamber tail gas recovery pipeline 18 and then merges into the first dust collector 13 and enters the second dust collector 14. After dust removal, it is buffered and pressurized by the gas cabinet 15 and then catalytically oxidized, adsorbed and dried by the argon recovery catalytic purification device 16; the argon in the argon recovery catalytic purification device 16 enters the argon recovery pure argon distillation device 4 for distillation and purification.

[0043] During the crystal taking process, a certain amount of air will enter the sub-chamber 3 of the single crystal furnace 1, resulting in a large amount of argon impurities being subsequently filled in, which brings certain difficulties to the subsequent processing process. The optimized process is as follows: the original argon source is provided by the argon recovery high nitrogen distillation device 19, which enters the high-purity nitrogen buffer tank 20 through valve adjustment, and then passes through the second filter 21 to enter the sub-chamber 3 for replacement. Adjust the opening of the first three-way valve 23 and the second three-way valve 25, and the replaced gas is pumped out by the auxiliary pump 12 and discharged to the exhaust gas dust removal device. The replacement steps are as follows: first, the auxiliary pump 12 extracts the gas in the sub-chamber 3, and the sub-chamber 3 is filled with 5.5Kg / cm 2 When the oxygen content in the gas extracted by the auxiliary pump 12 is below 1000PPM, stop filling with nitrogen, continue to evacuate until the vacuum degree reaches 20 Torr and then stop evacuating.

[0044] The above description of the utility model and its implementation methods is not restrictive. The drawings show only one implementation method of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention of the utility model, they should all fall within the protection scope of the utility model.

Claims

1. A comprehensive gas control system for a single crystal furnace, characterized in that: It comprises a single crystal furnace (1), an argon gas supply subsystem, an exhaust gas recovery subsystem and a gas replacement subsystem; The single crystal furnace (1) is divided into a main chamber (2) and a sub-chamber (3) by a single crystal furnace isolation valve; The argon gas supply subsystem comprises an argon recovery pure argon distillation device (4), a high-purity argon buffer tank (5), a first filter (6), a pressure reducing valve (7) and an argon gas supply main pipeline (8); the gas outlet end of the argon recovery pure argon distillation device (4) is connected to the high-purity argon buffer tank (5), the first filter (6) and the pressure reducing valve (7) in sequence through the argon gas supply main pipeline (8); the gas outlet end of the first filter (6) is connected to a main chamber gas supply pipeline (9) and a secondary chamber gas supply pipeline (10) which are respectively connected to the main chamber (2) and the secondary chamber (3); The tail gas recovery subsystem comprises a main pump (11), an auxiliary pump (12), a first dust collector (13), a second dust collector (14), a gas cabinet (15), an argon recovery catalytic purification device (16), a main chamber tail gas recovery pipeline (17) and a secondary chamber tail gas recovery pipeline (18); the two ends of the main chamber tail gas recovery pipeline (17) are respectively connected to the main chamber (2) and the argon recovery pure argon distillation device (4); and the main chamber tail gas recovery pipeline (17) sequentially connects the main pump (11), the first dust collector (13), the second dust collector (14), the gas cabinet (15) and the argon recovery catalytic purification device (16); the secondary chamber tail gas recovery pipeline (18) is connected to the secondary chamber (3); the auxiliary pump (12) is arranged on the secondary chamber tail gas recovery pipeline (18); and the gas outlet end of the secondary chamber tail gas recovery pipeline (18) is connected to the main chamber tail gas recovery pipeline (17); The gas replacement subsystem comprises an argon recovery high nitrogen distillation device (19), a high purity nitrogen buffer tank (20), a second filter (21) and a high purity nitrogen gas supply pipeline (22); the high purity nitrogen gas supply pipeline (22) sequentially connects the argon recovery high nitrogen distillation device (19), the high purity nitrogen buffer tank (20) and the second filter (21); and the gas outlet end of the high purity nitrogen gas supply pipeline (22) is connected to the auxiliary chamber gas supply pipeline (10); the auxiliary chamber tail gas recovery pipeline (18) is connected to the auxiliary chamber tail gas discharge pipe (24) via a first three-way valve (23); and the main chamber tail gas recovery pipeline (17) is connected to the main chamber tail gas discharge pipe (26) via a second three-way valve (25).

2. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: The argon supply subsystem further comprises a liquid argon backup storage tank (27), a liquid argon gasification device (28) and an argon supply pipeline (29). The argon supply pipeline (29) sequentially connects the liquid argon backup storage tank (27) and the liquid argon gasification device (28). A valve is provided on the argon supply pipeline (29), and the gas outlet end of the argon supply pipeline (29) is connected to the argon supply main pipeline (8) at the gas inlet end of the high-purity argon buffer tank (5).

3. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: The tail gas recovery subsystem further comprises a liquid nitrogen backup storage tank (30), a liquid nitrogen gasification device (31) and a nitrogen supplement pipeline (32); the nitrogen supplement pipeline (32) sequentially connects the liquid nitrogen backup storage tank (30) and the liquid nitrogen gasification device (31); a valve is provided on the nitrogen supplement pipeline (32); and a gas outlet end of the nitrogen supplement pipeline (32) is connected to a high-purity nitrogen gas supply pipeline (22).

4. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: The main chamber exhaust gas discharge pipe (26) is provided with a pressure gauge (33), a vent pipe (34) is connected between the main chamber exhaust gas discharge pipe (26) and the main chamber exhaust gas recovery pipeline (17), and a safety valve (35) is provided on the vent pipe (34).

5. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: The argon gas supply main pipeline (8) is provided with a mass flow controller (36), and the main chamber gas supply pipeline (9) and the auxiliary chamber gas supply pipeline (10) are respectively provided with a first stop valve (37) and a second stop valve (38).

6. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: A third stop valve (39) is provided on the argon gas supply main pipeline (8) located at the gas outlet end of the argon recovery pure argon distillation device (4).

7. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: A compressor (40) is also provided on the main chamber tail gas recovery pipeline (17).

8. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: A fourth stop valve (41) is provided at the gas outlet end of the high-purity nitrogen gas supply pipeline (22).

9. The integrated gas control system for a single crystal furnace according to claim 1, characterized in that: The argon gas supply main pipeline (8) is also provided with a manual valve pipeline (42).

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