Single crystal furnace
By passing inert gas into the sub-room of the single crystal furnace to carry and discharge metal dust generated by mechanical wear, the problem of metal dust affecting crystal quality is solved, and the crystal quality and the life of the crystal rod head is improved.
Patent Information
- Application Number
- CN202420923653.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-04-29
AI Technical Summary
During the growth of crystal rods in a single crystal furnace, metal dust generated by wear of mechanical components will fall to the growth liquid level, affecting the crystal quality.
By passing the first inert gas into the secondary chamber, metal dust generated by wear of mechanical components is carried and discharged through the exhaust device to reduce the growth liquid level of the metal dust entering the main chamber.
It effectively reduces the amount of metal dust entering the growth liquid level, improves the quality of the crystal, and extends the life of the crystal rod head.
Smart Images
Figure CN222455302U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of single crystal furnaces, in particular to a single crystal furnace. Background Art
[0002] At present, the Czochralski method is mostly used for the ingot pulling. The main production equipment of the Czochralski method is a single crystal furnace, which mainly includes a main chamber, a sub-chamber, a crucible, a thermal field component, a crucible lifting mechanism, a crystal ingot pulling mechanism, etc. Among them, the crystal ingot pulling mechanism adopts a winding wheel lifting mechanism, and the high-purity environment of the single crystal furnace directly affects the crystal quality.
[0003] The high-purity environment of a single crystal furnace mainly depends on the high-purity maintenance of various positions on the furnace table by the staff before the furnace is opened. However, after the furnace is closed and crystal pulling production begins, the metal dust generated by the mechanical movement and wear of various mechanical parts located above the growth liquid surface of the crucible will fall directly onto the growth liquid surface, affecting the quality of the crystal. In particular, the contact wear between the winding wheel of the crystal rod pulling mechanism and the winding of the tungsten wire rope is the main source of metal dust.
[0004] like Figure 1 As shown, the dust formed by silicon materials in the production process is currently mainly removed by introducing argon gas from the top of the sub-chamber into the main chamber to bring impurities out from the bottom of the main chamber. In this process, the metal dust produced by mechanical wear and carried by the argon gas will inevitably pass through the growth liquid surface, resulting in a large amount of metal dust remaining on the growth liquid surface, affecting the crystal quality. Utility Model Content
[0005] The utility model aims to provide a single crystal furnace to reduce the introduction of metal dust during the growth of a crystal rod and improve the quality of the crystal.
[0006] The utility model provides a single crystal furnace, comprising:
[0007] Main room;
[0008] A secondary chamber is arranged above the main chamber, and the secondary chamber is communicated with the main chamber;
[0009] A gas supply device, the gas outlet of the gas supply device is connected to the auxiliary chamber, and is used to introduce a first path of inert gas into the auxiliary chamber, and the gas outlet direction of the gas supply device in the auxiliary chamber intersects with the axis of the auxiliary chamber;
[0010] An exhaust device, wherein the air inlet of the exhaust device is connected to the auxiliary chamber and is used for exhausting the gas in the auxiliary chamber.
[0011] When the above technical solution is adopted, during the crystal rod pulling process, a first inert gas is introduced into the sub-chamber through the gas supply device, and the gas outlet of the gas supply device intersects with the axis of the sub-chamber in the gas outlet direction in the sub-chamber. The first inert gas carries metal dust generated by the wear of the crystal rod pulling mechanism during operation during circulation in the sub-chamber, and finally the gas carrying the metal dust is discharged into the exhaust device. Compared with the existing operation of only introducing argon gas from the top of the sub-chamber into the main chamber to bring the dust impurities generated by the silicon material out from the bottom of the main chamber, the utility model can discharge the metal dust generated by the wear of mechanical parts out of the sub-chamber in advance through the first inert gas in the sub-chamber, reducing the circulation of metal dust toward the main chamber, thereby reducing the metal dust generated by mechanical wear entering the growth liquid surface in the crucible below, thereby improving the quality of crystal pulling.
[0012] In some possible implementations, the crystal rod pulling mechanism of the single crystal furnace is disposed at the top of the sub-chamber, and the pulling rope of the crystal rod pulling mechanism extends into the sub-chamber along the axial direction of the sub-chamber.
[0013] In some possible implementations, the distance between the gas outlet of the gas supply device and the upper edge of the auxiliary chamber is less than or equal to 50 mm. In this arrangement, considering that the crystal rod pulling mechanism has crystal growth and crystal rotation actions, the structure moves frequently, and is the main source of metal dust. Therefore, the first inert gas is introduced into the auxiliary chamber as close to the crystal rod pulling mechanism as possible, so the gas outlet of the gas supply device is set within 50 mm from the upper edge of the auxiliary chamber.
[0014] In some possible implementations, the air outlet of the air supply device and the air inlet of the exhaust device are located at the same height; or the air inlet of the exhaust device is located below the air outlet of the air supply device. Such an arrangement is conducive to the discharge of gas carrying metal dust.
[0015] In some possible implementations, the second chamber has a first gas path inlet and a first gas path outlet respectively formed on the opposite outer walls of the second chamber; the gas outlet of the gas supply device is connected to the first gas path inlet, and the gas inlet of the gas exhaust device is connected to the first gas path outlet, so as to facilitate the connection between the gas supply device, the gas exhaust device and the second chamber.
[0016] In some possible implementations, there are multiple first gas path inlets and multiple first gas path outlets, and both are arranged along the circumference of the secondary chamber. In this way, multiple first gas path inlets and multiple first gas path outlets are arranged along the circumference, which can increase the distribution density of the first path inert gas in the secondary chamber and carry more metal dust for discharge.
[0017] In some possible implementations, the projections of the first gas path inlet and the first gas path outlet in a plane perpendicular to the axial direction of the secondary chamber are symmetrical relative to the axis of the secondary chamber. In this arrangement, the first inert gas introduced through the first gas path inlet and discharged through the first gas path outlet passes through the axis of the secondary chamber, that is, through the pulling rope of the crystal rod pulling mechanism, which can improve the cleaning efficiency of the metal dust attached to the pulling rope, reduce the left and right shaking of the pulling rope caused by the airflow that does not pass through the axis, and improve the pulling stability.
[0018] In some possible implementations, the number of first gas path inlets and first gas path outlets is equal, and both are 4 to 8. In this way, this number can not only increase the distribution density of the first path inert gas, but also reduce the difficulty of setting the first gas path inlets and first gas path outlets.
[0019] In some possible implementations, the single crystal furnace further includes an inlet shunt pipe and an outlet shunt pipe, the inlet shunt pipe and the outlet shunt pipe are arranged opposite to each other and surround the outer periphery of the auxiliary chamber;
[0020] The air inlet manifold has a first main through hole and a first manifold hole, the first main through hole is connected to the air outlet of the air supply device, and the first manifold hole is connected to the first air path inlet in a one-to-one correspondence;
[0021] The air outlet shunt pipe has a second main through hole and a second shunt hole, the second main through hole is connected to the air inlet of the exhaust device, and the second shunt hole is connected to the first air path outlet in a one-to-one correspondence.
[0022] When the above technical solution is adopted, the air supply device passes the first path of inert gas into the air inlet manifold, and passes into the auxiliary chamber through the first manifold hole of the air inlet manifold. The gas carrying metal dust in the auxiliary chamber enters the air outlet manifold through the second manifold hole, and finally enters the exhaust device and is discharged. The air inlet manifold and the air outlet manifold are provided to facilitate the connection between the auxiliary chamber and the air supply device and the exhaust device.
[0023] In some possible implementations, the air inlet manifold and the air outlet manifold are detachably connected to the auxiliary chamber or are an integral structure.
[0024] In some possible implementations, the inlet and outlet shunt pipes are embedded in a structure integrally formed on the furnace wall of the auxiliary chamber, thereby making the structure more compact.
[0025] In some possible implementations, the exhaust device includes a first exhaust pipe and a control valve located on the first exhaust pipe, and the air inlet of the first exhaust pipe is connected to the auxiliary chamber. In this way, the first exhaust pipe is controlled to be on and off by the control valve, thereby controlling the on and off of the first path of inert gas.
[0026] In some possible implementations, the single crystal furnace further includes a dust filter connected to the gas outlet of the exhaust device. In this configuration, the dust filter is used to filter out metal dust in the exhausted gas to recover and reuse the gas.
[0027] In some possible implementations, the single crystal furnace further includes an axial ventilation device for introducing a second inert gas into the sub-chamber from the top of the sub-chamber along the axial direction of the sub-chamber. The second inert gas circulates from top to bottom along the axial direction of the sub-chamber, mainly to remove dust generated by silicon materials during the production process, thereby reducing the adverse effects of silicon material dust on the growth liquid surface. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:
[0029] Figure 1 It is a structural schematic diagram of a single crystal furnace in the prior art;
[0030] Figure 2 A schematic diagram of the structure of a single crystal furnace provided in an embodiment of the utility model;
[0031] Figure 3 A schematic diagram of the arrangement of a first gas path inlet and a first gas path outlet of a single crystal furnace provided in an embodiment of the utility model;
[0032] Figure 4 A schematic diagram of the arrangement of a first gas path inlet and a first gas path outlet of another single crystal furnace provided in an embodiment of the utility model;
[0033] Figure 5 A schematic diagram of the arrangement of the first gas path inlet and the first gas path outlet of the third single crystal furnace provided in an embodiment of the utility model;
[0034] Figure 6 A schematic diagram of the arrangement of the first gas path inlet and the first gas path outlet of a fourth single crystal furnace provided in an embodiment of the utility model.
[0035] Figure numerals: 1 is the sub-chamber, 11 is the first gas path inlet, 12 is the first gas path outlet, 2 is the main chamber, 21 is the exhaust port, 3 is the crucible, 4 is the thermal field component, 5 is the first exhaust pipe, 6 is the crystal rod pulling mechanism, 61 is the pulling rope, 7 is the air supply device, 71 is the first air inlet pipe, 72 is the flow control valve, 8 is the dust filter, and 9 is the control valve. DETAILED DESCRIPTION
[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.
[0039] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0040] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0041] like Figure 2As shown, the embodiment of the utility model provides a single crystal furnace, which includes a main chamber 2, a sub-chamber 1, a crystal rod pulling mechanism 6, a gas supply device 7 and an exhaust device; wherein the sub-chamber 1 is arranged above the main chamber 2, and the sub-chamber 1 is connected to the main chamber 2; the gas outlet of the gas supply device 7 is connected to the sub-chamber, and is used to introduce a first path of inert gas into the sub-chamber 1, and the gas outlet direction of the gas supply device 7 in the sub-chamber intersects with the axis of the sub-chamber; the gas inlet of the exhaust device is connected to the sub-chamber, and is used to exhaust the gas in the sub-chamber 1. In addition, the single crystal furnace generally also includes a crucible 3 and a thermal field component 4, the crucible 3 and the thermal field component 4 are arranged in the main chamber 2, the crucible 3 is used to contain silicon materials, and the thermal field component 4 is used for heating and heat preservation.
[0042] The specific operation process of the single crystal furnace is as follows:
[0043] During the process of pulling the crystal rod, when it is necessary to introduce the first inert gas, the first inert gas is introduced into the auxiliary chamber 1 through the gas supply device 7, and the outlet direction of the gas supply device 7 in the auxiliary chamber 1 intersects with the axis of the auxiliary chamber 1. The first inert gas carries metal dust generated by the wear of the mechanical parts of the single crystal furnace during operation during the circulation in the auxiliary chamber 1, and finally the gas carrying the metal dust is discharged from the auxiliary chamber 1 into the exhaust device. Compared with the existing operation of only introducing the inert gas from the top of the auxiliary chamber 1 into the main chamber 2 to bring the dust impurities generated by the silicon material out from the bottom of the main chamber 2, the utility model introduces the first inert gas into the auxiliary chamber 1, and discharges the metal dust generated by the wear of the mechanical parts in the auxiliary chamber 1 out of the auxiliary chamber 1 in advance through the first inert gas, thereby reducing the circulation of metal dust in the direction of the main chamber 2, and further reducing the metal dust generated by mechanical wear from entering the growth liquid surface in the crucible 3 below, thereby improving the quality of crystal pulling.
[0044] According to estimation, the use of the single crystal furnace in this embodiment can reduce the metal introduction by about 0.1-0.2 g / furnace, and the metal concentration in the crystal rod can be reduced by 1-2 ppm: the head life of the crystal rod can be increased by about 5%-10%. In the prior art, the head life is about 5000-8000 us. After using this single crystal furnace, the head life can reach 6000-9500 us.
[0045] Furthermore, in the present embodiment, the single crystal furnace includes a crystal rod pulling mechanism 6 for pulling and rotating the crystal rod, the crystal rod pulling mechanism 6 is arranged at the upper part of the sub-chamber 1, and the pulling rope 61 of the crystal rod pulling mechanism 6 extends into the sub-chamber 1 along the axial direction of the sub-chamber 1. The crystal rod pulling mechanism 6 generates metal dust due to wear during operation and partially adheres to the pulling rope 61, which is the main source of metal dust generated during the operation of the mechanical parts. The dust impurities attached to the pulling rope 61 will fall into the melt in the main chamber 2 under the blowing of the gas in the sub-chamber 1 or during the movement of the pulling rope 61. Therefore, the gas supply device 7 and the exhaust device are connected to the sub-chamber 1, and the first inert gas introduced mainly cleans the metal dust generated by the wear of the crystal rod pulling mechanism 6 entering the sub-chamber 1, thereby reducing the circulation of metal dust to the main chamber 2, and further reducing the metal dust generated by mechanical wear entering the growth liquid surface in the crucible 3 below, thereby improving the quality of crystal pulling.
[0046] like Figure 2-Figure 6 As shown, in some embodiments, the outer walls on opposite sides of the secondary chamber 1 are respectively provided with a first gas path inlet 11 and a first gas path outlet 12; the gas outlet of the gas supply device 7 is communicated with the first gas path inlet 11, and the gas inlet of the exhaust device is communicated with the first gas path outlet 12. The gas outlet of the gas supply device 7 is directly connected to the first gas path inlet 11 provided on the outer wall of the secondary chamber 1, and the gas inlet of the exhaust device is directly connected to the first gas path outlet 12 provided on the outer wall of the secondary chamber 1, so as to facilitate the communication between the gas supply device 7, the exhaust device and the secondary chamber 1.
[0047] Of course, in addition to opening the first gas path inlet 11 and the first gas path outlet 12 on the outer walls of both sides of the secondary chamber 1 to connect the gas supply device 7 and the exhaust device, other methods can also be used to connect the secondary chamber 1 with the gas supply device 7 and the exhaust device, for example, the gas supply pipeline is extended from the top of the secondary chamber 1 into the secondary chamber 1 for a distance, and the end of the gas supply pipeline extending outside the secondary chamber 1 is connected with the gas supply device 7, and the end of the gas supply pipeline extending into the secondary chamber 1 is used as the gas outlet of the gas supply device 7, and the gas outlet direction of the gas outlet intersects with the axis of the secondary chamber 1, which can also realize the ventilation of the gas supply device 7 into the secondary chamber 1. Similarly, the exhaust pipeline is extended from the top of the secondary chamber 1 into the secondary chamber 1 for a distance, and the end of the exhaust pipeline extending outside the secondary chamber 1 is connected with the exhaust device, and the end of the exhaust pipeline extending into the secondary chamber 1 is used as the air inlet of the exhaust device, which can also realize the exhaust of the exhaust device. It is not necessary to open the first gas path inlet 11 and the first gas path outlet 12 on the outer walls of both sides of the secondary chamber 1.
[0048] In some embodiments, the distance between the gas outlet of the gas supply device 7 and the upper edge of the auxiliary chamber 1 is less than or equal to 50 mm. For example, when the outer wall of the auxiliary chamber 1 is provided with a first gas path inlet 11, the distance between the first gas path inlet 11 and the upper edge of the auxiliary chamber 1 is less than or equal to 50 mm. Specifically, it can be 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, etc. Since the crystal rod pulling mechanism 6 is frequently operated and is the main source of metal dust, the position of the first inert gas is as close as possible to the position of the crystal rod pulling mechanism 6, so the first gas path inlet 11 is set at a position within 50 mm from the upper edge of the auxiliary chamber 1 to clean more metal dust generated by the crystal rod pulling mechanism 6. Of course, the first gas path inlet 11 can also be set in other shaft sections of the auxiliary chamber 1, but the cleaning and discharge effect of the metal dust is not as good as the cleaning effect of the metal dust from the upper area of the auxiliary chamber 1. While the first inert gas can be introduced into the upper area, it can also be introduced into other shaft sections for cleaning together.
[0049] Further, in the present embodiment, the air outlet of the air supply device 7 and the air inlet of the exhaust device are located at the same height; or, the air inlet of the exhaust device is located below the air outlet of the air supply device 7. For example, when the outer wall of the secondary chamber 1 is provided with a first air path inlet 11 and a first air path outlet 12, the first air path inlet 11 and the first air path outlet 12 are arranged at the same height position on the secondary chamber 1; or, the first air path inlet 11 is arranged at a position higher than the first air path outlet 12 on the secondary chamber 1. With such arrangement, after the first inert gas enters the secondary chamber 1 from the first air path inlet 11, the gas and metal dust will tend to flow downward under the action of gravity, and the setting position of the first air path outlet 12 will be flush with or slightly lower than the setting position of the first air path inlet 11, which is conducive to the gas carrying metal dust to be discharged from the first air path outlet 12.
[0050] Furthermore, the height difference between the first gas path inlet 11 and the first gas path outlet 12 is less than or equal to 20 mm. If the height difference is too large, more metal dust will flow toward the main chamber, which is not conducive to being carried by the gas and discharged from the side wall of the secondary chamber 1.
[0051] In some embodiments, the number of the first gas path inlet 11 and the first gas path outlet 12 are both multiple, and the first gas path inlet 11 and the first gas path outlet 12 are arranged along the circumference of the secondary chamber 1. That is, the multiple first gas path inlets 11 are arranged along the circumference on one side of the secondary chamber 1, and the multiple first gas path outlets 12 are arranged along the circumference on the other side of the secondary chamber 1. The number of the first gas path inlets 11 and the number of the first gas path outlets 12 can be the same or different. In this way, the multiple first gas path inlets 11 and the first gas path outlets 12 are arranged along the circumference, which can increase the distribution density of the first path inert gas in the secondary chamber 1, can form more airflow in the cross section of the secondary chamber 1, can carry more metal dust to be discharged, and block the metal dust from flowing toward the main chamber 2.
[0052] like Figure 3-Figure 6 As shown, further, in some embodiments, the projections of the first gas path inlet 11 and the first gas path outlet 12 in the plane perpendicular to the axial direction of the auxiliary chamber 1 are symmetrical relative to the axis of the auxiliary chamber 1. That is, the number of the first gas path inlet 11 and the first gas path outlet 12 is equal, and the projections on the cross section of the auxiliary chamber 1 are symmetrical relative to the axis of the auxiliary chamber 1, and the projections of the axes of the first gas path inlet 11 and the first gas path outlet 12 on the cross section of the auxiliary chamber 1 are along the radial direction of the auxiliary chamber 1. In this way, the gas introduced through the first gas path inlet 11 and discharged through the first gas path outlet 12 passes through the axis of the auxiliary chamber 1, that is, through the pulling rope 61 of the crystal rod pulling mechanism 6, which can improve the cleaning efficiency of the metal dust attached to the pulling rope 61, can reduce the left and right shaking of the pulling rope 61 caused by the airflow that does not pass through the axis, and improve the pulling stability.
[0053] For example, the first gas path inlet 11 and the first gas path outlet 12 can be one or more, and the first gas path inlet 11 and the first gas path outlet 12 correspond to each other one by one and are centrally symmetrical. For example, the first gas path inlet 11 and the first gas path outlet 12 can form one pair, two pairs, three pairs, four pairs, five pairs, six pairs, seven pairs, eight pairs or more pairs. The more pairs there are, the denser the flow of the first inert gas in the sub-chamber 1 is, and the better the cleaning effect is. Considering the difficulty of setting the first gas path inlet 11 and the first gas path outlet 12, 4 to 8 pairs are preferred.
[0054] Of course, the first gas path inlet 11 and the first gas path outlet 12 may not be symmetrical with respect to the axis of the secondary chamber 1. For example, the number of the first gas path inlet 11 is one, and the number of the first gas path outlet 12 is multiple; or the number of the first gas path inlet 11 is multiple, and the number of the first gas path outlet 12 is one; or the axis of the first gas path inlet 11 and the axis of the first gas path outlet 12 do not pass through the axis of the secondary chamber 1, etc. As long as the first path inert gas can be introduced and the exhaust gas can be exhausted, it will be fine.
[0055] In some possible implementations, the single crystal furnace further includes an inlet manifold and an outlet manifold, which are arranged opposite to each other and surround the outer periphery of the auxiliary chamber 1, that is, the inlet manifold and the outlet manifold are both arc segments of annular tubes, which are respectively arranged on the opposite outer walls of the auxiliary chamber 1. The inlet manifold has a first main through hole and a first manifold hole, the number of the first main through holes can be one or more, preferably one, the number of the first manifold holes can be one or more, the first main through hole is connected to the air outlet of the air supply device 7, and the first manifold hole is connected to the first gas path inlet 11 in a one-to-one correspondence; the outlet manifold has a second main through hole and a second manifold hole, the number of the second main through holes can be one or more, preferably one, the number of the second manifold holes can be one or more, the second main through hole is connected to the air inlet of the exhaust device, and the second manifold hole is connected to the first gas path outlet 12 in a one-to-one correspondence.
[0056] When the above technical solution is adopted, the air supply device 7 passes the first path of inert gas from the first main through hole into the air inlet diverter pipe, and diverts it into the auxiliary chamber 1 through the first diverter hole of the air inlet diverter pipe. The gas carrying metal dust in the auxiliary chamber 1 is diverted into the air outlet diverter pipe through the second diverter hole, and finally enters the exhaust device from the second main through hole and is discharged. The connection between the auxiliary chamber 1 and the air supply device 7 and the exhaust device is facilitated by setting the air inlet diverter pipe and the air outlet diverter pipe. The air supply device 7 only needs to be connected to a first main through hole of the air inlet diverter pipe, and the exhaust device only needs to be connected to a second main through hole of the air outlet diverter pipe, and the disassembly and assembly operation is simple.
[0057] Of course, the air inlet splitter pipe and the air outlet separation furnace pipe may not be provided, and the air supply device 7 is directly connected to the first air path inlet 11 , and the exhaust device is directly connected to the first air path outlet 12 .
[0058] In some embodiments, the air inlet and outlet shunt pipes are detachably connected or integrally connected to the auxiliary chamber 1. The detachable connection structure facilitates disassembly, maintenance and replacement of the air inlet and outlet shunt pipes. The air inlet and outlet shunt pipes are located outside the furnace wall of the auxiliary chamber 1.
[0059] In other embodiments, the inlet and outlet manifolds are embedded and integrally formed on the furnace wall of the auxiliary chamber 1. That is, the inlet and outlet manifolds are integrally formed with the furnace wall of the auxiliary chamber 1, and the flow channels and the corresponding main through holes and manifold holes are directly formed on the furnace wall, so that the structure is more compact. As long as it can be connected with the gas supply device 7 and the exhaust device to realize the introduction and exhaust of the first inert gas, it is not limited to the structural forms listed in this embodiment.
[0060] like Figure 2As shown, in some embodiments, the exhaust device includes a first exhaust pipe 5 and a control valve 9 located on the first exhaust pipe 5, and the first exhaust pipe 5 is connected to the first gas path outlet 12. In this way, the first exhaust pipe 5 is controlled to be on and off by the control valve 9, thereby controlling the on and off of the first path of inert gas.
[0061] For example, the control valve 9 may be a ball valve, a butterfly valve, a solenoid valve, etc., as long as it can realize the opening and closing of the first exhaust pipe 5 .
[0062] In some possible implementations, the single crystal furnace further includes a dust filter 8 connected to the exhaust end of the exhaust device. Specifically, the dust filter 8 is disposed on the first exhaust pipe 5. The dust filter 8 can filter and purify the exhausted gas and filter out the metal dust therein so as to be reused as the first inert gas later. In order to ensure smooth exhaust of the gas from the dust filter 8, the dust filter 8 is cleaned regularly. The dust filter 8 can be cleaned after 5 to 10 furnaces are completed to prevent blockage.
[0063] In some embodiments, the gas supply device 7 includes a first gas inlet pipe 71 and a flow control valve 72 disposed on the first gas inlet pipe 71 for controlling the flow of the first inert gas.
[0064] In some possible implementations, the flow rate of the first inert gas is 5L / min to 20L / min. Specifically, it can be 5L / min, 10L / min, 13L / min, 15L / min, 20L / min, etc. If the flow rate is too small, the cleaning effect on the metal dust is weak, and if the flow rate is too large, it will have a greater impact on the pulling stability of the pulling rope 61. The first inert gas within the flow range of this embodiment can carry away as much metal dust generated by mechanical wear as possible, and will not affect the stability of the crystal rod pulling.
[0065] Furthermore, since silicon dust is generated in the process of being put into the single crystal furnace and other volatile impurities are generated in the process of melting the silicon material, which will also have an adverse effect on the growth liquid level, in some embodiments, the single crystal furnace also includes an axial ventilation device, which is used to introduce a second inert gas into the sub-chamber 1 from the top of the sub-chamber 1 along the axial direction of the sub-chamber 1, and the second inert gas can take away the dust of the silicon material from the bottom and / or side wall of the main chamber 2. The gas inlet of the axial ventilation device is arranged at the top of the sub-chamber 1, and the exhaust port 21 is arranged at the bottom of the main chamber 2. The axial ventilation device and the gas supply device 7 can share a gas source or use different gas sources respectively. The first inert gas and the second inert gas can be the same or different, and can be argon, helium, etc. The first inert gas and the second inert gas are turned on and off and the flow rate is adjusted by controlling the valve on the axial ventilation device and the flow control valve 72 of the gas supply device 7. The second inert gas introduced through the axial ventilation device brings out most of the impurities such as silicon material dust generated when the silicon material is put into the single crystal furnace and silicon material steam generated when the silicon material is melted, from the bottom exhaust port 21 of the main chamber 2, thereby reducing the adverse effects of silicon material dust impurities on the growth liquid surface.
[0066] During the furnace sealing stage, melting stage, seeding stage, shoulder releasing stage, equal diameter stage and finishing stage in the process of crystal rod pulling, the second inert gas is introduced into the sub-chamber 1 from the top along the axial direction of the sub-chamber 1. In order to reduce the lateral disturbance of the first inert gas flow on the pulling rope 61 during the seeding and shoulder releasing processes, improve the stability of the seeding and shoulder releasing processes, and ensure the overall quality of subsequent crystal pulling, the first inert gas is not introduced into the sub-chamber 1 during the seeding and shoulder releasing stages. The first inert gas can be introduced in the equal diameter stage and the finishing stage to clean up the metal dust generated by mechanical wear when the crystal rod pulling mechanism 6 is mainly in action. The second inert gas The total flow rate of the second inert gas and the first inert gas is 40L / min to 80L / min. Specifically, the total flow rate can be 40L / min, 50L / min, 60L / min, 70L / min, 80L / min, etc., that is, the second inert gas is axially introduced in the whole process, and the flow rate of the second inert gas is adjusted according to whether the first inert gas is radially introduced. When the first inert gas is not introduced, the flow rate of the second inert gas maintains the total flow rate. When the first inert gas is introduced, the flow rate of the second inert gas is reduced accordingly, so that the total flow rate of the first inert gas and the second inert gas remains unchanged.
[0067] For example, the conditions of the first inert gas and the second inert gas are shown in Table 1 below:
[0068] Table 1. The flow of the first inert gas and the second inert gas
[0069]
[0070] Since the dust generated by silicon materials during the production process will continue throughout the entire process, the second inert gas is axially introduced from the furnace sealing stage to the final finishing stage, and the first inert gas is radially introduced in the equal diameter stage and the finishing stage to clean up the metal dust generated by mechanical wear when the crystal rod pulling mechanism 6 is in main motion. The total flow rate of the first inert gas and the second inert gas remains unchanged to ensure the stable pressure in the single crystal furnace.
[0071] It should be noted that when the first inert gas and the second inert gas are introduced at the same time, the first inert gas and the second inert gas are mixed in the auxiliary chamber 1, and the first inert gas is mainly discharged from the side wall of the auxiliary chamber 1, and it is not excluded that a part of it is discharged from the bottom of the main chamber 2 with the second inert gas. At the same time, the second inert gas is mainly discharged from the bottom of the main chamber 2, and it is not excluded that a part of it is discharged from the side wall of the auxiliary chamber 1 with the first inert gas. Overall, it does not affect the gas carrying metal dust out of the auxiliary chamber 1.
[0072] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.
[0073] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.
Claims
1. A single crystal furnace, characterized in that: include: Main room; A secondary chamber, disposed above the main chamber, the secondary chamber being communicated with the main chamber; A gas supply device, wherein the gas outlet of the gas supply device is connected to the auxiliary chamber, and is used to introduce a first path of inert gas into the auxiliary chamber, and the gas outlet direction of the gas outlet of the gas supply device in the auxiliary chamber intersects with the axis of the auxiliary chamber; An exhaust device, wherein an air inlet of the exhaust device is communicated with the auxiliary chamber and is used for exhausting the gas in the auxiliary chamber.
2. The single crystal furnace according to claim 1, characterized in that: The distance between the air outlet of the air supply device and the upper edge of the auxiliary chamber is less than or equal to 50 mm.
3. The single crystal furnace according to claim 1, characterized in that: The air outlet of the air supply device and the air inlet of the exhaust device are located at the same height; Or the air inlet of the exhaust device is located below the air outlet of the air supply device.
4. The single crystal furnace according to any one of claims 1 to 3, characterized in that: The opposite outer walls of the secondary chamber are respectively provided with a first gas path inlet and a first gas path outlet; the gas outlet of the gas supply device is communicated with the first gas path inlet, and the gas inlet of the exhaust device is communicated with the first gas path outlet.
5. The single crystal furnace according to claim 4, characterized in that: There are plural numbers of the first gas path inlet and the first gas path outlet, and the first gas path inlet and the first gas path outlet are arranged along the circumferential direction of the secondary chamber.
6. The single crystal furnace according to claim 4, characterized in that: Projections of the first gas path inlet and the first gas path outlet in a plane perpendicular to the axial direction of the secondary chamber are symmetrical relative to the axis center of the secondary chamber.
7. The single crystal furnace according to claim 4, characterized in that: The single crystal furnace further comprises an inlet shunt pipe and an outlet shunt pipe, wherein the inlet shunt pipe and the outlet shunt pipe are arranged opposite to each other and surround the outer periphery of the auxiliary chamber; The air inlet manifold has a first main through hole and a first diverter hole, the first main through hole is connected to the air outlet of the air supply device, and the first diverter hole is connected to the first air path inlet in a one-to-one correspondence; The air outlet shunt pipe has a second main through hole and a second shunt hole, the second main through hole is connected to the air inlet of the exhaust device, and the second shunt hole is connected to the first air path outlet in a one-to-one correspondence.
8. The single crystal furnace according to claim 7, characterized in that: The air inlet shunt pipe and the air outlet shunt pipe are detachably connected to the auxiliary chamber or are an integral structure.
9. The single crystal furnace according to claim 8, characterized in that: The air inlet shunt pipe and the air outlet shunt pipe are structures that are embedded and integrally formed on the furnace wall of the auxiliary chamber.
10. The single crystal furnace according to claim 1, characterized in that: The exhaust device includes a first exhaust pipe and a control valve located on the first exhaust pipe, and an air inlet of the first exhaust pipe is communicated with the sub-chamber.
11. The single crystal furnace according to claim 1, characterized in that: It also includes a dust filter connected to the air outlet end of the exhaust device.
12. The single crystal furnace according to claim 1, characterized in that: It also includes an axial ventilation device for introducing a second path of inert gas into the auxiliary chamber from the top of the auxiliary chamber along the axial direction of the auxiliary chamber.