Single crystal drawing system

Abstract

The invention relates to the technical field of single crystal drawing, in particular to a single crystal drawing system. The single crystal drawing system comprises a single crystal furnace, a nitrogen supply unit and an argon supply unit, the single crystal furnace comprises a main chamber and an auxiliary chamber, the main chamber is communicated with the auxiliary chamber through a throat, the upper end of the auxiliary chamber is communicated with a first gas inlet main pipe which is communicated with the nitrogen / argon supply unit, and the throat is communicated with a second gas inlet main pipe which is communicated with the nitrogen / argon supply unit. Therefore, nitrogen can be used for replacing argon to serve as inert gas shielding gas in all stages or part of stages of single crystal drawing, so that the production cost is reduced; meanwhile, the thermal conductivity of nitrogen is higher than that of argon, so that heat can be transferred more effectively, a thermal field in the furnace is more uniform, the crystal growth stability is improved, and the generation probability of crystal defects is reduced. Meanwhile, at the crystal pulling temperature, nitrogen can inhibit volatilization of impurities in silicon to a certain extent, so that the impurities in the crystal are distributed more uniformly, and the electrical property of the crystal can be accurately controlled.

Description

Technical Field

[0001] This application relates to the technical field of single crystal pulling, and in particular to a single crystal pulling system. Background Art

[0002] In the existing single crystal pulling system, argon gas, as an inert gas with stable chemical properties, is usually used to construct an inert atmosphere. However, there are also some disadvantages in using argon gas. First of all, argon gas is a relatively scarce and costly resource, and its production and storage also require specific equipment and processes, which increases the overall production cost. Secondly, during crystal pulling, the convection of argon gas will affect the thermal field stability of single crystal growth, resulting in uneven temperature and concentration distributions at the crystal growth interface, affecting the crystal quality, and it is difficult to control the argon gas convection, and multiple process parameters need to be finely adjusted. Summary of the Invention

[0003] The purpose of the present invention is to provide a single crystal pulling system with a switchable nitrogen supply unit and argon supply unit.

[0004] The present invention provides a single crystal pulling system including a single crystal furnace, a nitrogen supply unit, and an argon supply unit;

[0005] A second intake main pipe is connected to the throat between the main chamber and the auxiliary chamber of the single crystal furnace, and both the nitrogen supply unit and the argon supply unit are connected to the second intake main pipe;

[0006] The upper end of the auxiliary chamber is connected to a first intake main pipe, and both the nitrogen supply unit and the argon supply unit are connected to the first intake main pipe.

[0007] Further, the single crystal pulling system further includes a first pipeline;

[0008] The first end of the first pipeline is connected to the outlet of the nitrogen supply unit, the second end of the first pipeline is connected to the first intake main pipe, and a first flow meter and a first valve are sequentially connected in series on the first pipeline.

[0009] Further, a first cross pipeline is connected between the first end and the second end of the first pipeline, and a first cross valve is provided on the first cross pipeline.

[0010] Further, the single crystal pulling system further includes a second pipeline;

[0011] The first end of the second pipeline is connected to the outlet of the argon supply unit, the second end of the second pipeline is connected to the second intake main pipe;

[0012] A second flowmeter is provided on the second pipeline, and a pressure reducing valve, a third flowmeter and a second valve are connected in series on the second intake main pipeline in sequence.

[0013] Further, the single crystal pulling system further includes a third pipeline;

[0014] The second end of the first pipeline is communicated with the second end of the second pipeline through the third pipeline, and a third valve is provided on the third pipeline.

[0015] Further, a second cross - line pipeline is provided on the second intake main pipeline;

[0016] One end of the second cross - line pipeline is communicated between the second flowmeter and the pressure reducing valve, and the other end of the second cross - line pipeline is communicated with the end of the second valve far from the second flowmeter;

[0017] A second cross - line valve is provided on the second cross - line pipeline.

[0018] Further, the single crystal pulling system further includes a fourth pipeline;

[0019] One end port of the fourth pipeline serves as a reserved port, and the other end of the fourth pipeline is communicated with the first intake main pipeline through a first branch and is communicated with the second intake main pipeline through a second branch.

[0020] Further, a fourth flowmeter is provided on the fourth pipeline, a first branch valve and a first branch check valve are connected in series on the first branch, and a second branch valve is provided on the second branch.

[0021] Further, the single crystal pulling system further includes a gas purification unit;

[0022] Gas extraction pipes are provided in both the main chamber and the auxiliary chamber, and the gas extraction pipes are communicated with the nitrogen supply unit through the gas purification unit.

[0023] Further, the main chamber includes a furnace cover, a main furnace chamber and a lower furnace chamber;

[0024] The upper end of the main furnace chamber is connected to the furnace cover, and the lower end of the main furnace chamber is connected to the lower furnace chamber respectively through a set of flanges;

[0025] The set of connected flanges includes an upper flange and a lower flange. A sealing groove is provided on the upper end surface of the lower flange for loading a sealing ring. A convex portion is provided on the lower end surface of the upper flange, and the convex portion can extend into the sealing groove and press the sealing ring tightly;

[0026] The shells of the furnace lid, the main furnace chamber, and the lower furnace chamber are all double-layer shells, including an inner shell and an outer shell sleeved on the outside of the inner shell. A gap is formed between the outer shell and the inner shell, and a circulating liquid can be introduced into the gap.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The single-crystal pulling system provided by the present invention includes a single-crystal furnace, a nitrogen supply unit, and an argon supply unit. The single-crystal furnace includes a main chamber and a secondary chamber. The secondary chamber is arranged above the main chamber. The upper end of the main chamber is connected to the secondary chamber through a throat. Air inlets are provided at the upper end of the secondary chamber and at the throat. The air inlet at the upper end of the secondary chamber is communicated with a first main air inlet pipe. The nitrogen supply unit and the argon supply unit are respectively connected to the first main air inlet pipe. The air inlet at the throat is communicated with a second main air inlet pipe. The nitrogen supply unit and the argon supply unit are respectively connected to the second main air inlet pipe; thus, nitrogen or argon can be introduced into the single-crystal furnace as an inert gas protective gas through the nitrogen supply unit or the argon supply unit.

[0029] Compared with the traditional single-crystal pulling system that only has an argon supply unit, the present application can use the nitrogen supply unit to replace the argon supply unit in all stages or some stages of single-crystal pulling, and fill nitrogen into the single-crystal furnace to use nitrogen as an inert gas protective gas. Nitrogen is abundant in the air and the production cost is relatively low. Compared with using argon as an inert protective gas, the production cost can be greatly reduced, and the economic benefits of the enterprise can be improved.

[0030] At the same time, the solution of the present application can be modified on the basis of the existing single-crystal pulling system that uses argon as an inert protective gas, so as to introduce a nitrogen supply gas path by adding pipelines, and the modification of the existing structure is small. It has good equipment applicability, is convenient to be popularized and applied in existing single-crystal production enterprises, and reduces the cost and difficulty of technology upgrading;

[0031] At the same time, the thermal conductivity of nitrogen is higher than that of argon, and it can transfer heat more effectively, making the thermal field in the single-crystal furnace more uniform, which helps to improve the stability of crystal growth, reduce the temperature gradient inside the crystal, reduce the generation probability of crystal defects, and improve the quality of single crystals.

[0032] At the same time, at the crystal pulling temperature, nitrogen can inhibit the volatilization of impurities in silicon to a certain extent, make the distribution of impurities in the crystal more uniform, is conducive to precisely controlling the electrical properties of the crystal, and meets the strict requirements of high-end semiconductor device manufacturing for materials. Description of the Drawings

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is a schematic flow chart of the single crystal furnace part in the single crystal pulling system provided by the embodiment of the present invention;

[0035] Figure 2 It is a schematic flow chart of the inert gas supply part in the single crystal pulling system provided by the embodiment of the present invention.

[0036] Reference numerals:

[0037] 1 - First intake main pipe, 2 - Second intake main pipe, 21 - Pressure reducing valve, 22 - Third flow meter, 23 - Second valve, 24 - Second cross - line pipeline, 25 - Second cross - line valve, 3 - First pipeline, 31 - First valve, 32 - First flow meter, 33 - First cross - line pipeline, 34 - First cross - line valve, 35 - Fifth flow meter, 36 - First check valve, 4 - Second pipeline, 41 - Second flow meter, 5 - Third pipeline, 51 - Third valve, 6 - Fourth pipeline, 61 - First branch, 62 - Second branch, 66 - Fourth flow meter, 63 - First branch valve, 64 - First branch check valve, 65 - Second branch valve, 7 - Single crystal furnace, 71 - Main chamber, 72 - Sub - chamber, 73 - Throat. Specific embodiments

[0038] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0039] The components of the embodiments of the present invention usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention.

[0040] 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.

[0041] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. 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 to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The following refers to Figure 1 and Figure 2 Describe the single crystal pulling system according to some embodiments of the present application.

[0044] The present application provides a single crystal pulling system, as Figure 1 and Figure 2 shown, the single crystal pulling system includes a single crystal furnace 7, a nitrogen supply unit, and an argon supply unit.

[0045] The single crystal furnace 7 includes a main chamber 71 and a secondary chamber 72. The secondary chamber 72 is arranged above the main chamber 71. The upper end of the main chamber 71 is connected to the secondary chamber 72 through a throat 73. An isolation valve is provided at the throat 73 to cut off or open the communication between the main chamber 71 and the secondary chamber 72 by using an isolation valve plate. The process of single crystal pulling mainly includes a preparation stage, a heating and melting stage, a crystal pulling stage, and a finishing stage:

[0046] In the preparation stage, each component of the whole system is cleaned and inspected to ensure no impurities and faults, and the raw material is put into the single crystal furnace 7, specifically into the crucible in the main chamber 71. Then, the single crystal furnace 7 is evacuated and filled with an inert gas to displace the air in the furnace.

[0047] In the heating and melting stage, the heating device in the main chamber 71 is turned on to melt the raw material. During this process, the temperature monitoring and regulating module provided on the single crystal furnace 7 is used to ensure that the temperature is uniform and stable. At the same time, an inert gas is filled into the single crystal furnace 7 at a certain flow rate to maintain a positive pressure in the furnace and prevent external air from entering.

[0048] The crystal pulling stage, also known as the seed crystal introduction and growth stage, means that after the raw material is melted, the seed crystal is slowly immersed in the melted raw material solution, and parameters such as temperature and pulling speed are controlled to enable the solution to grow a single crystal on the seed crystal according to a certain crystal orientation. During this period, an inert gas is continuously supplied to maintain an inert atmosphere.

[0049] The finishing stage, also known as the growth end and cooling stage, means that after the single crystal grows to a predetermined size, heating is stopped, and an inert gas is continuously introduced to slowly cool the single crystal to prevent stress generation and crystal defects. After the single crystal cools to a certain temperature, the single crystal is taken out.

[0050] In this embodiment, air inlets are provided at the upper end of the auxiliary chamber 72 and at the throat 73 between the main chamber 71 and the auxiliary chamber 72 for introducing an inert gas. For example, during the preparation stage and the heating and melting stage, after the main chamber 71 is evacuated, an inert gas is introduced into the auxiliary chamber 72 through the air inlet at the throat 73 at a certain pressure and flow rate, so that the pressure in the auxiliary chamber 72 is slightly higher than the pressure in the main chamber 71. Then, the sealing valve plate at the throat 73 is opened, enabling the nitrogen gas in the auxiliary chamber 72 to enter the main chamber 71 under the action of the pressure difference. During the finishing stage, an inert gas is filled into the single crystal furnace 7 through the air inlet at the throat 73, so that the single crystal in the main chamber 71 slowly cools under the protection of the inert gas. During the crystal pulling stage, an inert gas is filled into the single crystal furnace 7 through the air inlet at the top of the auxiliary chamber 72 to form a spraying effect.

[0051] In this embodiment, the single crystal pulling system includes a nitrogen supply unit and an argon supply unit. A first intake main pipe 1 is connected to the air inlet at the upper end of the auxiliary chamber 72, and the nitrogen supply unit and the argon supply unit are respectively connected to the first intake main pipe 1, so that argon gas can be filled into the single crystal furnace 7 from the upper end of the auxiliary chamber 72 through the argon supply unit as an inert gas protection gas, and at the same time, nitrogen gas can also be filled into the single crystal furnace 7 from the upper end of the auxiliary chamber 72 through the nitrogen supply unit as an inert gas protection gas. In actual operation, the nitrogen supply unit or the argon supply unit can be selected to fill an inert gas into the single crystal furnace 7 from the upper end of the auxiliary chamber 72.

[0052] A second intake main pipe 2 is connected to the air inlet at the throat 73, and the nitrogen supply unit and the argon supply unit are respectively connected to the second intake main pipe 2, so that argon gas can be filled into the single crystal furnace 7 from the throat 73 through the argon supply unit as an inert gas protection gas, and at the same time, nitrogen gas can also be filled into the single crystal furnace 7 from the throat 73 through the nitrogen supply unit as an inert gas protection gas. In actual operation, the nitrogen supply unit or the argon supply unit can be selected to fill an inert gas into the single crystal furnace 7 from the throat 73.

[0053] Compared with the traditional single-crystal pulling system that only has an argon gas supply unit, the present application can use the nitrogen gas supply unit to replace the argon gas supply unit in all or some stages of single-crystal pulling, and fill the single-crystal furnace 7 with nitrogen gas, so as to use nitrogen gas as an inert gas protective gas. Nitrogen is abundant in the air and the production cost is relatively low. Compared with using argon as an inert protective gas, it can greatly reduce the production cost and improve the economic benefits of the enterprise.

[0054] At the same time, the solution of the present application can be modified on the basis of the existing single-crystal pulling system that uses argon as an inert protective gas, so as to introduce a nitrogen gas supply gas path by adding pipelines, and the modification of the existing structure is small, with good equipment applicability, which is convenient for popularization and application in existing single-crystal production enterprises, and reduces the cost and difficulty of technology upgrading;

[0055] At the same time, the thermal conductivity of nitrogen is higher than that of argon, which can transfer heat more effectively, make the thermal field in the single-crystal furnace 7 more uniform, help improve the stability of crystal growth, reduce the temperature gradient inside the crystal, reduce the generation probability of crystal defects, and improve the quality of single crystals.

[0056] At the same time, at the crystal pulling temperature, nitrogen can inhibit the volatilization of impurities in silicon to a certain extent, make the impurity distribution in the crystal more uniform, which is beneficial to precisely control the electrical properties of the crystal and meet the strict requirements of high-end semiconductor device manufacturing for materials.

[0057] In this embodiment, preferably, as Figure 2 shown, the single-crystal pulling system further includes a first pipeline 3. The first end of the first pipeline 3 is connected to the outlet of the nitrogen gas supply unit, and the second end of the first pipeline 3 is connected to the first intake main pipe 1, that is, the nitrogen gas supply unit is connected to the first intake main pipe 1 through the first pipeline 3, so as to be able to introduce nitrogen gas into the single-crystal furnace 7 from the upper end of the auxiliary chamber 72. At the same time, a first flow meter 32 and a first valve 31 are sequentially connected in series on the first pipeline 3, so as to be able to measure the nitrogen gas introduced into the single-crystal furnace 7 by using the first flow meter 32 and control the on-off of the first pipeline 3 by using the first valve 31. Preferably, the first flow meter 32 is a float flow meter and the first valve 31 is a solenoid valve.

[0058] In this embodiment, preferably, a first cross-line pipeline 33 is connected between the first end and the second end of the first pipeline 3, and the first cross-line pipeline 33 is provided with a first cross-line valve 34 for controlling the on-off of the first cross-line pipeline 33; therefore, the nitrogen gas supply unit can be connected to the first intake main pipe 1 either through the first pipeline 3 or through the first cross-line pipeline 33. The switching between the two pipelines can be realized through the first valve 31 and the first cross-line valve 34, so that when one of the pipelines fails, the other pipeline can be started to ensure the stability of nitrogen gas transportation. Preferably, the first cross-line valve 34 is a solenoid valve.

[0059] In this embodiment, preferably, a fifth flowmeter 35 and a first one-way valve 36 are sequentially connected to the outlet of the nitrogen supply unit. The first end of the first pipeline 3 is connected to the outlet of the first one-way valve 36, so as to measure the nitrogen output by the nitrogen supply unit through the fifth flowmeter 35, and at the same time, use the first one-way valve 36 to block the reverse flow of the gas.

[0060] In an embodiment of the present application, preferably, as Figure 2 shown, the single crystal pulling system further includes a second pipeline 4. The first end of the second pipeline 4 is connected to the outlet of the argon supply unit, and the second end of the second pipeline 4 is connected to the second intake main pipe 2; that is, the argon supply unit is connected to the second intake main pipe 2 through the second pipeline 4, so as to be able to introduce argon into the single crystal furnace 7 from the throat 73 through the argon supply unit. At the same time, a second flowmeter 41 is provided on the second pipeline 4 to measure the argon output by the argon supply unit through the second flowmeter 41. Preferably, the second flowmeter 41 is a rotameter.

[0061] In this embodiment, preferably, a second one-way valve (not shown in the drawing) is provided on the second pipeline 4. The second one-way valve is located downstream of the second flowmeter 41 to block the reverse flow of the gas by using the second one-way valve.

[0062] In this embodiment, preferably, as Figure 2 shown, a pressure reducing valve 21, a third flowmeter 22 and a second valve 23 are sequentially connected in series on the second intake main pipe 2. The pressure of the gas sent to the throat 73 can be adjusted to the required pressure through the pressure reducing valve 21, the gas flow rate of the gas sent to the throat 73 can be measured through the third flowmeter 22, and the on-off of the second intake main pipe 2 can be controlled through the second valve 23.

[0063] In this embodiment, preferably, as Figure 2 shown, a second cross-line pipeline 24 is provided on the second intake main pipe 2. One end of the first cross-line pipeline 33 is connected to the pipeline between the second flowmeter 41 and the pressure reducing valve, and the other end is connected to the end of the second valve 23 away from the second flowmeter 41. And a second cross-line valve 25 is provided on the second cross-line pipeline 24, so that the gas passing through the pressure reducing valve 21 has two paths to go to the throat 73, and the switching between the two paths can be realized through the second valve 23 and the second cross-line valve 25, so that when one path fails, the other path can be enabled to ensure the stability of gas transmission.

[0064] In an embodiment of the present application, preferably, as Figure 2As shown, the single crystal pulling system further includes a third pipeline 5. The second end of the first pipeline 3 is connected to the second end of the second pipeline 4 through the third pipeline 5; thus, the second end of the first pipeline 3 can be connected to the second intake main pipe 2 through the third pipeline 5, so that the nitrogen supply unit can introduce nitrogen into the single crystal furnace 7 from the throat 73 through the second intake main pipe 2; at the same time, the second end of the second pipeline 4 can also be connected to the first intake main pipe 1 through the third pipeline 5, so that the argon supply unit can fill argon into the single crystal furnace 7 from the upper end of the auxiliary chamber 72 through the first intake main pipe 1. Furthermore, the nitrogen supply unit can introduce nitrogen into the single crystal furnace 7 from both the throat 73 and the upper end of the auxiliary chamber 72, and at the same time, the argon supply unit can also fill argon into the single crystal furnace 7 from both the throat 73 and the upper end of the auxiliary chamber 72.

[0065] In this embodiment, preferably, as Figure 2 shown, a third valve 51 is provided on the third pipeline 5 to control the on / off of the third pipeline 5 through the third valve 51.

[0066] In an embodiment of the present application, preferably, as Figure 2 shown, the single crystal pulling system further includes a fourth pipeline 6. One end port of the fourth pipeline 6 serves as a reserved port, and the other end is connected to the first intake main pipe 1 through a first branch 61 and at the same time is connected to the second intake main pipe 2 through a second branch 62 (or can be directly connected to the intake port at the throat 73). Thus, other inert gas supply units can be connected at the reserved port of the fourth pipeline 6 to be able to replace the nitrogen supply unit and the argon supply unit to introduce inert gas into the single crystal furnace 7, avoiding shutdown caused by failures of the nitrogen supply unit, the argon supply unit or related pipelines.

[0067] In this embodiment, preferably, as Figure 2 shown, a fourth flowmeter 66 is provided on the fourth pipeline 6 to measure the gas transported into the single crystal furnace 7 through the fourth pipeline 6.

[0068] Preferably, a first branch valve 63 and a first branch check valve 64 are connected in series on the first branch 61 to control the on / off of the first branch 61 through the first branch valve 63 and block the reverse flow of gas through the first branch check valve 64.

[0069] Preferably, a second branch valve 65 is provided on the second branch 62 to control the on / off of the second branch 62 through the second branch valve 65.

[0070] In an embodiment of the present application, preferably, the single crystal pulling system further includes a gas purification unit (not shown in the figure). Gas outlet pipes are provided in both the main chamber 71 and the auxiliary chamber 72. The gas outlet pipes are connected to the nitrogen supply unit through the gas purification unit, so that after the nitrogen in the main chamber 71 and the auxiliary chamber 72 flows out, it can be sent to the gas purification unit for purification and then returned to the nitrogen supply unit again. Thus, the recycling of nitrogen is realized, the utilization rate of nitrogen is improved, and the production cost is reduced.

[0071] In an embodiment of the present application, preferably, the main chamber 71 includes a furnace lid, a main furnace chamber, and a lower furnace chamber. The furnace lid is provided at the upper end of the main furnace chamber, and the lower furnace chamber is provided at the lower end of the main furnace chamber. The main furnace chamber is connected to the furnace lid and the lower furnace chamber respectively through a set of flanges. For any set of connected flanges, it includes an upper flange and a lower flange. For example, for the set of flanges between the main furnace chamber and the furnace lid, the flange on the main furnace chamber is the lower flange, and the flange on the furnace lid is the upper flange. For the set of flanges between the main furnace chamber and the lower furnace chamber, the flange on the main furnace chamber is the upper flange, and the flange on the lower furnace chamber is the lower flange. Among them, the lower end surface of the upper flange faces the upper end surface of the lower flange, and a sealing groove is provided on the upper end surface of the lower flange. A sealing ring is filled in the sealing groove, and a protrusion is provided on the lower end surface of the upper flange. When the upper flange is connected to the lower flange, the protrusion can extend into the sealing groove and press the sealing ring, causing the sealing ring to deform, so as to ensure the sealing between the upper flange and the lower flange, and further ensure the sealing of the main chamber 71 and prevent internal gas leakage.

[0072] In this embodiment, preferably, the shells of the furnace lid, the main furnace chamber, and the lower furnace chamber are all double-layer shells, including an inner shell and an outer shell sleeved on the outside of the inner shell. A gap is formed between the outer shell and the inner shell, and a circulating liquid can be introduced into the gap. Thus, the double-layer shell plays a role in heat insulation, reduces heat dissipation, and improves the energy utilization efficiency.

[0073] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A single crystal pulling system, characterized in that: It includes a single crystal furnace, a nitrogen supply unit and an argon supply unit; A second gas intake main pipe is connected at the throat between the main chamber and the auxiliary chamber of the single crystal furnace, and the nitrogen supply unit and the argon supply unit are both connected to the second gas intake main pipe; The upper end of the sub-chamber is connected to a first air intake manifold, and the nitrogen supply unit and the argon supply unit are both connected to the first air intake manifold.

2. The single crystal pulling system according to claim 1, characterized in that: The single crystal pulling system also includes a first pipeline; The first end of the first pipeline is connected to the outlet of the nitrogen supply unit, the second end of the first pipeline is connected to the first intake manifold, and the first flow meter and the first valve are connected in series in sequence on the first pipeline.

3. The single crystal pulling system according to claim 2, characterized in that: A first cross-line pipeline is connected between the first end and the second end of the first pipeline, and a first cross-line valve is provided on the first cross-line pipeline.

4. The single crystal pulling system according to claim 2, characterized in that: The single crystal pulling system further includes a second pipeline; The first end of the second pipeline is connected to the outlet of the argon gas supply unit, and the second end of the second pipeline is connected to the second gas intake manifold; The second pipeline is provided with a second flow meter, and the second intake manifold is serially connected with a pressure reducing valve, a third flow meter and a second valve in sequence.

5. The single crystal pulling system according to claim 4, characterized in that: The single crystal pulling system further includes a third pipeline; The second end of the first pipeline is connected to the second end of the second pipeline through the third pipeline, and a third valve is provided on the third pipeline.

6. The single crystal pulling system according to claim 4, characterized in that: A second cross-line pipeline is provided on the second air intake manifold; One end of the second cross-line pipeline is connected between the second flow meter and the pressure reducing valve, and the other end of the second cross-line pipeline is connected to an end of the second valve away from the second flow meter; A second cross-line valve is provided on the second cross-line pipeline.

7. The single crystal pulling system according to claim 1, characterized in that: The single crystal pulling system further includes a fourth pipeline; The port at one end of the fourth pipeline is used as a reserved port, and the other end of the fourth pipeline is connected to the first intake manifold through the first branch, and is connected to the second intake manifold through the second branch.

8. The single crystal pulling system according to claim 7, characterized in that: The fourth pipeline is provided with a fourth flow meter, the first branch is connected in series with a first branch valve and a first branch check valve in sequence, and the second branch is provided with a second branch valve.

9. The single crystal pulling system according to claim 1, characterized in that: The single crystal pulling system also includes a gas purification unit; The main chamber and the auxiliary chamber are both provided with a gas outlet pipe, and the gas outlet pipe is connected with the nitrogen supply unit through the gas purification unit.

10. The single crystal pulling system according to claim 1, characterized in that: The main chamber comprises a furnace cover, a main furnace chamber and a lower furnace chamber; The upper end of the main furnace chamber is connected to the furnace cover, and the lower end of the main furnace chamber is connected to the lower furnace chamber through a set of flanges respectively; A set of flanges connected to each other includes an upper flange and a lower flange, the upper end surface of the lower flange is provided with a sealing groove for filling a sealing ring, and the lower end surface of the upper flange is provided with a protrusion, which can extend into the sealing groove and press the sealing ring; The shells of the furnace cover, the main furnace chamber and the lower furnace chamber are all double-layer shells, including an inner shell and an outer shell sleeved on the outer side of the inner shell. A gap is formed between the outer shell and the inner shell, and circulating liquid can flow into the gap.

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