Method for reducing line breaking frequency of first drop of single crystal furnace

Abstract

The invention provides a method for reducing the first-drop line breaking frequency of a single crystal furnace, and relates to the field of monocrystalline silicon production. The method comprises the following steps: S10, starting an auxiliary pump, and communicating the auxiliary pump with an auxiliary chamber of the single crystal furnace for vacuumizing operation; s20, after the pressure in the furnace body reaches the first set furnace pressure P1, communication between the auxiliary pump and the auxiliary chamber is cut off, and the auxiliary pump is closed; s30, starting a main pump, communicating the main pump with a main chamber of the single crystal furnace, and introducing protective gas; s40, the communication between the main pump and the main chamber is cut off, and the main pump is closed; according to the invention, impurity diffusion and residue can be reduced, so that the first-casting line breaking frequency of the single crystal furnace is reduced.

Description

Technical Field

[0001] The invention relates to the field of single crystal silicon production, and in particular to a method for reducing the frequency of first-time disconnection of a single crystal furnace. Background Art

[0002] The direct pulling method is one of the main methods for pulling single crystal silicon rods. This method is to put polycrystalline silicon into the quartz crucible of the single crystal furnace, heat and melt the polycrystalline silicon with a graphite heater, and then complete the pulling of the single crystal silicon rod through processes such as temperature adjustment, crystal seeding, shoulder release, shoulder rotation, equal diameter, finishing, and furnace shutdown.

[0003] Most of the wire breaks in the existing single crystal furnace pulling production are first-time wire breaks. First-time wire breaks are caused by the failure of silicon materials to melt successfully or the breakage during crystal growth due to various reasons during the first melting process. The high frequency of first-time wire breaks is related to many factors, including furnace cleanliness, raw material quality, thermal field stability, operating technology, etc. In the production of single crystal furnaces, the first-time wire break phenomenon will increase costs, reduce daily output and work efficiency, so reducing the first-time wire break is an important issue in the existing single crystal furnace production. Summary of the invention

[0004] In order to solve the problems in the prior art of increased costs and reduced daily output and working efficiency caused by first-time disconnection in single crystal furnace production, the present invention provides a method for reducing the frequency of first-time disconnection in a single crystal furnace, which can change the original evacuation mode, reduce impurity diffusion and residue, and thus reduce the frequency of first-time disconnection.

[0005] The technical solution adopted by the present invention is:

[0006] A method for reducing the frequency of disconnection during the first operation of a single crystal furnace comprises the following steps:

[0007] S10. Turn on the auxiliary pump and connect the auxiliary pump and the auxiliary chamber of the single crystal furnace to perform a vacuum operation;

[0008] S20. After the internal pressure of the furnace reaches the first set furnace pressure P1, the connection between the auxiliary pump and the auxiliary chamber is cut off, and the auxiliary pump is turned off;

[0009] S30. Turn on the main pump, connect the main pump and the main chamber of the single crystal furnace, and introduce protective gas;

[0010] S40. Cut off the communication between the main pump and the main chamber, and turn off the main pump.

[0011] Furthermore, after the auxiliary pump is opened in S10, the auxiliary pump ball valve is opened at an interval t1 to communicate with the auxiliary pump and the auxiliary chamber; after the auxiliary pump ball valve is closed in S20 to cut off the connection between the auxiliary pump and the auxiliary chamber, the auxiliary pump is closed at an interval t2; after the main pump is opened in S30, the main pump ball valve is opened at an interval t3 to communicate with the main pump and the main chamber; after the main pump ball valve is closed in S40 to cut off the connection between the main pump and the main chamber, the main pump is closed at an interval t4.

[0012] Furthermore, the interval time t1 is longer than 25 s; the interval time t2 is longer than 25 s; the interval time t3 is longer than 50 s; and the interval time t4 is longer than 50 s.

[0013] Furthermore, in the S30, the protective gas is introduced after the internal pressure of the furnace body is lower than the second set furnace pressure P2, and the protective gas is turned off after a certain period of time.

[0014] Furthermore, the S30 further includes:

[0015] After the first introduction of protective gas is completed, the protective gas is introduced again and the protective gas is turned off after a certain period of time.

[0016] Further, the S40 includes:

[0017] After the argon gas is turned off and the furnace is evacuated until the internal pressure of the furnace body is less than the third set furnace pressure P3, the connection between the main pump and the main chamber is cut off, and the main pump is turned off.

[0018] Furthermore, the main chamber is composed of a furnace cover at the top, a furnace tube in the middle and a furnace bottom plate at the bottom; and an insulation tube is arranged in the main chamber, and a crucible is arranged in the insulation tube; a guide tube is arranged above the crucible, a main heater is arranged on the circumferential outer side of the crucible, and a bottom heater is arranged below the crucible; graphite electrodes are connected below the main heater and the bottom heater.

[0019] Furthermore, an exhaust pipe is provided on the furnace bottom plate near the edge, and the exhaust pipe can be connected to the main pump and the main chamber.

[0020] Furthermore, the auxiliary chamber is arranged in the middle part above the furnace cover, and the auxiliary pump and the auxiliary chamber are connected through an exhaust pipe.

[0021] Furthermore, the first set furnace pressure P1 is 200~350Torr; the auxiliary pump pumping speed is 18000~25000L / min; and the main pump pumping speed is 33000~40000L / min.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention performs vacuuming operation in sections by using the auxiliary pump on the exhaust pipe of the auxiliary chamber and the main pump on the exhaust pipe of the main chamber, so that the vacuuming speed is low when there are more impurities inside the furnace body, thereby avoiding impurity turbulence; and the vacuuming speed is high when there are fewer impurities inside the furnace body, thereby improving the efficiency of vacuuming, achieving rapid vacuuming while reducing the residual impurities attached to the silicon material and the thermal field components, thereby avoiding the breakage of the crystal pulling caused by the residual impurities, thereby solving the problems of increased costs caused by the disconnection of the first investment in the single crystal furnace production in the prior art, as well as reduced daily output and working time efficiency;

[0024] 2. The present invention can ensure the purity of the protective gas inside the furnace during the crystal pulling process by performing two times of protective gas flow, and can prevent the silicon melt from reacting with oxygen or other gases in the air inside the furnace at high temperature, thereby avoiding oxidation or contamination of the silicon single crystal, thereby achieving reduction of impurities and improvement of quality of single crystal silicon products produced by the single crystal furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 is a flow chart of a frequency reduction method according to an embodiment of the present invention;

[0027] Figure 2 is a three-dimensional schematic diagram of a single crystal furnace according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the external structure of a single crystal furnace according to an embodiment of the present invention;

[0029] Figure 4 It is a schematic diagram of the heat preservation tube layer of the single crystal furnace according to an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the internal structure of a single crystal furnace according to an embodiment of the present invention;

[0031] Figure 6 This is a cross-sectional view of the internal structure of a single crystal furnace according to an embodiment of the present invention.

[0032] Reference numerals: 100 - main chamber, 110 - furnace cover, 120 - furnace barrel, 130 - furnace bottom plate, 132 - exhaust pipe, 134 - main pump, 136 - main pump ball valve, 138 - support rod, 140 - insulation barrel, 150 - main heater, 160 - bottom heater, 170 - crucible, 180 - guide barrel, 190 - graphite electrode;

[0033] 200- auxiliary chamber, 210- exhaust pipe, 220- auxiliary pump, 230- auxiliary pump ball valve. DETAILED DESCRIPTION

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0035] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0036] The embodiments of the invention are described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] Research on existing technologies shows that the phenomenon of first-time wire breakage is mainly related to the cleanliness of the furnace body, the quality of raw materials and the stability of the thermal field. Further research has found that the cleanliness of the furnace body of the single crystal furnace, especially the impurity content inside the furnace body before use, is the dominant factor in the first-time wire breakage. During the furnace assembly process before the single crystal furnace is used, the thermal field of the single crystal furnace is exposed to the atmosphere, and impurities will enter the furnace body, resulting in an increase in first-time wire breakage during the single crystal pulling process.

[0039] Before the single crystal furnace is produced, the air and impurities inside the furnace body can be removed by vacuuming to create an oxygen-free and clean environment for silicon melting and crystal growth. The vacuuming operation helps prevent oxidation and protect some small parts inside the furnace body. At the same time, the sealing of the furnace body needs to be checked during use to ensure that there will be no gas leakage during high-temperature operation that affects the quality of crystal growth. In the prior art, the vacuuming method is usually to directly vacuum the furnace by turning on the main pump 134 after closing the furnace. However, due to the excessive pumping speed of the pump, the impurities inside the furnace body will form turbulence and float around at the moment of opening. Although some impurities can be discharged from the exhaust pipe 132, some impurities will also adhere to the silicon material and thermal field components.

[0040] See also Figure 1-Figure 6 The present embodiment provides a method for reducing the frequency of disconnection during the first operation of a single crystal furnace, which is used for the vacuuming step before the single crystal furnace is used. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace can change the original vacuuming mode, reduce the diffusion and residue of impurities, and thus reduce the frequency of disconnection during the first operation of a single crystal furnace. The structure of the single crystal furnace used in the present embodiment mainly includes: a furnace cover 110, a furnace drum 120, a furnace bottom plate 130, an insulation drum 140, a heater, a crucible 170, a guide drum 180, and a sub-chamber 200.

[0041] like Figure 2-Figure 6As shown in the figure, the furnace cover 110 at the top, the furnace barrel 120 in the middle and the furnace bottom plate 130 at the bottom together constitute the main chamber 100 of the single crystal furnace; the auxiliary chamber 200 is located above the furnace cover 110, has a cylindrical outer wall, and is connected to the main chamber 100. Inside the main chamber 100, a heat preservation barrel 140, a heater and a crucible 170 are arranged from the outside to the inside. Among them, the heat preservation barrel 140 is wrapped with soft felt to provide a heat insulation space for the heater and crucible 170 inside it. The heater includes a main heater 150 and a bottom heater 160, which are respectively arranged on the circumferential outer side and below the crucible 170 to uniformly heat the crucible 170; a foot plate is arranged below the main heater 150, and connecting plates are arranged on both sides of the bottom heater 160. The foot plate and the connecting plate are both used to connect the graphite electrode 190 below, and the graphite electrode 190 is arranged below through the furnace bottom plate 130. The crucible 170 is used to melt silicon materials, and a guide tube 180 is arranged above to guide the crystal pulling production. The single crystal furnace has high requirements for the internal thermal field distribution. In the single crystal furnace of this embodiment, the insulation tube 140, the main heater 150, the bottom heater 160, the graphite electrode 190, the crucible 170 and the guide tube 180 are all thermal field components that constitute the thermal field. At the same time, the main chamber 100 is provided with an exhaust pipe 132 for replacing gas, and the exhaust pipe 132 is connected to the main pump 134 and the inside of the main chamber 100. The main pump 134 is used to provide the pumping speed and control the pressure in the main chamber 100. The auxiliary chamber 200 is provided with an exhaust pipe 210 for replacing gas, and the exhaust pipe 210 is connected to the auxiliary pump 220 and the inside of the auxiliary chamber 200. The auxiliary pump 220 is used to provide the pumping speed and control the pressure in the auxiliary chamber 200, so that the pressure of the main chamber 100 and the auxiliary chamber 200 is balanced. Among them, the exhaust pipe 132 of the main chamber 100 is vertically arranged on the furnace bottom plate 130, but because a support rod 138 needs to be arranged in the middle of the furnace bottom plate 130, and a bottom heater 160 is also arranged around the support rod 138, there are usually two exhaust pipes 132, and they are arranged near the edge of the furnace bottom plate 130. Therefore, when the main pump 134 is used for vacuuming, the pumping speed distribution in the circumferential direction of the furnace is uneven, the airflow path is not smooth, and it is easy to generate eddy currents and turbulence in the local area of ​​the furnace body. The exhaust pipe 210 of the auxiliary chamber 200 is horizontally arranged on the side of the auxiliary chamber 200, and the auxiliary chamber 200 is arranged in the middle of the upper part of the main chamber 100. Therefore, when the auxiliary pump 220 is used for vacuuming, the pumping speed distribution in the circumferential direction of the furnace is balanced, the airflow path will be relatively smooth, and it is not easy to generate eddy currents and turbulence in the local area of ​​the furnace body.

[0042] The method of reducing the frequency of disconnection during the first operation of a single crystal furnace in this embodiment mainly includes performing the following steps before crystal pulling:

[0043] S10. Turn on the auxiliary pump 220, and then open the auxiliary pump ball valve 230 at an interval of t1 to connect the auxiliary pump 220 and the auxiliary chamber 200, and perform a vacuum operation on the inside of the furnace body formed by the main chamber 100 and the auxiliary chamber 200. In this embodiment, since the auxiliary pump 220 is originally used to vacuum the auxiliary chamber 200 with a smaller volume, the pumping speed of the auxiliary pump 220 is usually relatively small (in this embodiment, the pumping speed of the auxiliary pump 220 is 22000L / min; the pumping speed of the main pump 134 is 36000L / min). Turning on the auxiliary pump 220 to vacuumize can reduce the flow rate of impurity molecules inside the furnace body, and at the same time, the airflow path during the vacuuming is relatively smooth, which weakens the turbulent motion and prevents impurities from floating in a closed environment and causing impurities to adhere to the closed space. In addition, the interval time t1 of the delayed opening of the auxiliary pump ball valve 230 is 30S. The interval time t1 is set mainly to reduce the pressure in the exhaust pipe 210 first, avoid backflow when opening the auxiliary pump ball valve 230, and prevent impurities in the exhaust pipe 210 from being introduced into the auxiliary chamber 200.

[0044] S20. After the internal pressure of the furnace body reaches the first set furnace pressure P1, the auxiliary pump ball valve 230 is closed to cut off the connection between the auxiliary pump 220 and the auxiliary chamber 200, and then the auxiliary pump 220 is closed at an interval t2. In this embodiment, the interval t2 of the delayed closing of the auxiliary pump 220 is 30S, and the interval t2 is also set to prevent the backflow from introducing impurities into the auxiliary chamber 200.

[0045] S30. Turn on the main pump 134, and then turn on the main pump ball valve 136 at an interval t3 to connect the main pump 134 and the main chamber 100. In this embodiment, the first set furnace pressure P1 is 300Torr. When the internal pressure of the furnace body reaches the first set furnace pressure P1, the internal pressure of the furnace body is relatively low, and most of the impurities have been discharged from the exhaust pipe 210 of the auxiliary chamber 200. At this time, after stopping the auxiliary pump 220 and switching to the main pump 134 for vacuuming, no large amount of impurity turbulence will be generated. Therefore, switching back to the main pump 134 for vacuuming is not easy to produce impurity residues, and at the same time, the pumping speed can be increased to improve the efficiency of the vacuuming operation. In addition, the interval t3 of the delayed opening of the main pump ball valve 136 is 1min. The interval t3 is set mainly to reduce the pressure in the exhaust pipe 132 first, avoid backflow when opening the main pump ball valve 136, and prevent the introduction of impurities in the exhaust pipe 132 into the main chamber 100. In addition, S30 also includes: after the internal pressure of the furnace body is less than the second set furnace pressure P2, the argon valve at the top of the auxiliary chamber 200 is opened to introduce argon to flow argon, and the argon is automatically turned off after a certain time is set. In this embodiment, the second set furnace pressure P2 is 1 Torr, and the set argon flow time is 5 minutes. When the internal pressure of the furnace body reaches P2, argon is introduced during the vacuuming process to supplement and maintain the pressure inside the furnace body, so that a positive pressure is generated inside the furnace body to prevent external air from entering the furnace body. Since argon is an inert gas with extremely inactive chemical properties, it can prevent the silicon melt from reacting with oxygen or other gases in the air inside the furnace body at high temperature during the crystal pulling process, thereby avoiding oxidation or contamination of the silicon single crystal. It should also be pointed out that in one or more other embodiments, other chemically inactive gases such as nitrogen can also be used instead of argon as a protective gas. The characteristics of argon are that its cost is lower than other gases, and argon also has the advantage of poor thermal conductivity, which helps to isolate the hot zone around the melt from the water-cooled vacuum chamber wall. In addition, S30 also includes: after the first argon flow is completed, the argon valve at the top of the auxiliary chamber 200 is opened again to flow argon, and the argon is automatically turned off after a certain time is set. The second argon flow time is set to 5 minutes. Through the second argon flow, the gas inside the furnace body can be further replaced, the original air components inside the furnace body can be fully removed, and the purity of the argon gas in the atmosphere inside the furnace body can be improved.

[0046] S40. After the argon gas is turned off and the furnace pressure is evacuated until it is less than the third set furnace pressure P3, the main pump ball valve 136 is closed to cut off the connection between the main pump 134 and the main chamber 100. After that, the main pump 134 is turned off at an interval of t4 and a leak test is performed to detect the gas tightness of the main chamber 100 to prevent gas leakage due to poor sealing under high temperature and high vacuum environment, which affects the quality of crystal growth and causes safety accidents. In this embodiment, the third set furnace pressure P3 is 30mTorr. When the pressure inside the furnace is less than P3, the furnace becomes a negative pressure with a lower pressure, so that a negative pressure environment is maintained inside the furnace during the production of silicon single crystals by the Czochralski method. On the one hand, the negative pressure environment can promptly take away the silicon oxides and volatile impurities generated by the high temperature, keep the vacuum degree in the single crystal furnace stable, reduce the influence of external factors on the vacuum degree in the single crystal furnace, and ensure the quality of the silicon single crystal; on the other hand, the negative pressure environment can also shorten the crystal growth cycle and improve production efficiency.

[0047] In summary, in the present embodiment, the vacuum pumping operation is performed in sections by the auxiliary pump 220 on the exhaust pipe 210 of the auxiliary chamber 200 and the main pump 134 on the exhaust pipe 210 of the main chamber 100, so that when there are more impurities inside the furnace body, the vacuum pumping speed is lower, thereby avoiding impurity turbulence; and when there are fewer impurities inside the furnace body, the vacuum pumping speed is higher, and the vacuum pumping efficiency is improved, thereby achieving rapid vacuum pumping while reducing the residual impurities attached to the silicon material and the thermal field components, avoiding crystal pulling breakage caused by residual impurities, thereby solving the problems of increased costs caused by the initial disconnection of the single crystal furnace production in the prior art, as well as reduced daily output and working hour efficiency.

[0048] At the same time, in this embodiment, by performing multiple argon flows, the purity of the argon gas inside the furnace during the crystal pulling process can be ensured, and the silicon melt can be prevented from reacting with oxygen or other gases in the air inside the furnace at high temperatures, thereby avoiding oxidation or contamination of the silicon single crystal, thereby achieving reduction of impurities and improvement of quality of single crystal silicon products produced by the single crystal furnace.

[0049] It should also be pointed out that in one or more other embodiments, when the first set furnace pressure P1 is in the range of 200~350Torr, the turbulence in the furnace is controllable, and there are fewer residual impurities, which can significantly reduce the frequency of first disconnection. At the same time, when the second set furnace pressure P2 is in the range of 0.5~1.2Torr, the impurities in the furnace have basically been pumped out of the furnace body, and it is suitable to introduce argon gas for subsequent protection. And, when the third set furnace pressure P3 is in the range of 25~40mTorr, the impurities in the furnace have basically been pumped out of the furnace body, and it is suitable to introduce argon gas for subsequent protection. In addition, in one or more other embodiments, the pumping speed of the auxiliary pump 220 can be selected as 18000~25000L / min, which can prevent turbulence caused by excessive pumping speed; the pumping speed of the main pump 134 can be selected as 33000~40000L / min to ensure the efficiency of vacuum pumping. In one or more other embodiments, the interval time t1 needs to be maintained at more than 25 seconds; the interval time t2 needs to be maintained at more than 25 seconds; the interval time t3 needs to be maintained at more than 50 seconds; and the interval time t4 needs to be maintained at more than 50 seconds, in order to prevent reflux.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for reducing the frequency of disconnection during the first operation of a single crystal furnace, characterized in that: The following steps are involved: S10. Turning on the auxiliary pump (220), and connecting the auxiliary pump (220) and the auxiliary chamber (200) of the single crystal furnace to perform a vacuum operation; S20. After the internal pressure of the furnace body reaches the first set furnace pressure P1, the connection between the auxiliary pump (220) and the auxiliary chamber (200) is cut off, and the auxiliary pump (220) is turned off; S30. Turn on the main pump (134), connect the main pump (134) and the main chamber (100) of the single crystal furnace, and introduce protective gas; S40. Cut off the communication between the main pump (134) and the main chamber (100), and shut down the main pump (134).

2. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 1, characterized in that: After the auxiliary pump (220) is opened in S10, the auxiliary pump ball valve (230) is opened at an interval t1 to connect the auxiliary pump (220) and the auxiliary chamber (200); after the auxiliary pump ball valve (230) is closed in S20 to cut off the connection between the auxiliary pump (220) and the auxiliary chamber (200), the auxiliary pump (220) is closed at an interval t2; after the main pump (134) is opened in S30, the main pump ball valve (136) is opened at an interval t3 to connect the main pump (134) and the main chamber (100); after the main pump ball valve (136) is closed in S40 to cut off the connection between the main pump (134) and the main chamber (100), the main pump (134) is closed at an interval t4.

3. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 2, characterized in that: The interval time t1 is longer than 25 s; the interval time t2 is longer than 25 s; the interval time t3 is longer than 50 s; and the interval time t4 is longer than 50 s.

4. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 1, characterized in that: In the step S30 , the protective gas is introduced after the internal pressure of the furnace body is lower than the second set furnace pressure P2 , and the protective gas is turned off after a certain period of time.

5. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 4, characterized in that: The S30 further includes: After the first introduction of protective gas is completed, the protective gas is introduced again and the protective gas is turned off after a certain period of time.

6. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 1, characterized in that: The S40 includes: After the argon gas is turned off and the furnace is evacuated until the pressure inside the furnace is less than a third set furnace pressure P3, the connection between the main pump (134) and the main chamber (100) is cut off, and the main pump (134) is turned off.

7. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 1, characterized in that: The main chamber (100) is composed of a furnace cover (110) at the top, a furnace tube (120) in the middle, and a furnace bottom plate (130) at the bottom; a heat preservation tube (140) is arranged in the main chamber (100), and a crucible (170) is arranged in the heat preservation tube (140); a guide tube (180) is arranged above the crucible (170), a main heater (150) is arranged on the circumferential outer side of the crucible (170), and a bottom heater (160) is arranged below the crucible (170); graphite electrodes (190) are connected below the main heater (150) and the bottom heater (160).

8. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 7, characterized in that: An exhaust pipe (132) is provided on the furnace bottom plate (130) near the edge, and the exhaust pipe (132) can be connected to the main pump (134) and the main chamber (100).

9. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to claim 7, characterized in that: The auxiliary chamber (200) is arranged in the middle portion above the furnace cover (110), and the auxiliary pump (220) and the auxiliary chamber (200) are connected via an exhaust pipe (210).

10. The method for reducing the frequency of disconnection during the first operation of a single crystal furnace according to any one of claims 1 to 9, characterized in that: The first set furnace pressure P1 is 200-350 Torr; the pumping speed of the auxiliary pump (220) is 18000-25000 L / min; and the pumping speed of the main pump (134) is 33000-40000 L / min.

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