Silicon carbide single crystal furnace with replaceable growth chamber

Abstract

The utility model discloses a silicon carbide single crystal furnace with a replaceable growth chamber. The silicon carbide single crystal furnace comprises a furnace body, a first lifting and rotating system, a second lifting and rotating system and a replaceable growth chamber assembly, a furnace cover is arranged at the top of the furnace body, and a closable opening is formed in the center of the furnace cover; the replaceable growth chamber assembly at least comprises a growth chamber for TSSG and a growth chamber for PVT, the growth chamber for TSSG is used for growing silicon carbide single crystals through a liquid phase method, when the growth chamber for TSSG is used, the closable opening of the furnace cover is opened, the growth chamber for TSSG is further provided with a seed crystal lifting rod, and the seed crystal lifting rod is used for lifting the seed crystal. A seed crystal tray for bonding seed crystals is arranged at the lower end of the seed crystal lifting rod, and the upper end of the seed crystal lifting rod is connected with the first lifting rotating system and is used for driving the seed crystal tray to rotate up and down. According to the utility model, functional diversification of compatibility of a liquid phase method and a gas phase method of the silicon carbide single crystal furnace can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of silicon carbide single crystal furnaces, and in particular to a novel silicon carbide liquid phase single crystal furnace. Background Art

[0002] Silicon carbide single crystal furnace is a key equipment for producing silicon carbide (SiC) single crystal material, which is very important in semiconductor and high temperature applications due to its high melting point, high hardness, high corrosion resistance and excellent electronic properties, such as in power electronics, optoelectronics and microwave components.

[0003] The first step in the silicon carbide industry chain is to grow silicon carbide ingots. Among the material types of silicon carbide, there are two main types: p-type and n-type. They differ in their conductive properties and are suitable for different applications: in p-type ingots, electron vacancies (i.e. holes) are the main carriers; in n-type ingots, electrons are the main carriers.

[0004] At present, the mainstream method for growing silicon carbide single crystals on the market is physical vapor transport (PVT), which can achieve the growth of eight-inch silicon carbide single crystals in China. The PVT method uses materials such as silicon (Si) to sublimate into Si vapor at high temperature, and the Si vapor is transferred to the seed crystal bonded to the crucible cover, and then crystallized to form silicon carbide crystals. SiC crystals grown by the PVT method have defects such as microtubes, which have an adverse effect on the performance of later processed devices. If you want to grow doped SiC single crystals by the PVT method, you need to add doping elements to the raw materials. At present, the technology of growing N-type SiC crystals by the PVT method is relatively mature, and when preparing p-type SiC substrates by the PVT method, Al4C3 needs to be added to provide Al source. However, since the Al source has a high saturated vapor pressure in a high temperature environment, it is difficult to obtain continuous and stable p-type doping, that is, the main disadvantage of using the PVT method is that it is difficult to obtain p-type ingots.

[0005] In the process of growing SiC crystals, the liquid phase method (also known as the top seed solution method, TSSG) is a method for growing SiC single crystals that has developed rapidly in recent years. TSSG melts the Si raw material contained in the crucible, melts it into a solution at high temperature, and uses the solubility of carbon (C) in the solution to corrode the graphite crucible, and then pulls the silicon carbide single crystal on the seed crystal in contact with the solution surface. Compared with the PVT method, the SiC crystals grown by the TSSG method have no micropipe defects and are relatively easy to expand, but there are also high technical barriers. Inappropriate process parameters will destroy the dynamic balance during the crystal growth process and produce adverse effects such as polycrystalline growth. Due to the low solubility of C in Si solution, it is usually necessary to add a metal co-solvent to increase the solubility of C in the solution. Adding a co-solvent such as Al can achieve the growth of p-type SiC crystals, but the technology for growing n-type SiC single crystals by the liquid phase method is still immature. That is: the main disadvantage of using the TSSG method is that it is difficult to obtain n-type ingots.

[0006] Therefore, the single crystal furnace of the prior art is only used for one growth method. If you want to be compatible with the production of high-quality p-type and n-type SiC single crystals at the same time, you need to equip multiple single crystal furnaces at the same time. The maintenance cost of single crystal furnace equipment is high, and equipping multiple single crystal furnaces will undoubtedly increase the burden of labor and equipment costs for manufacturers. How to provide a device that is compatible with the production of high-quality p-type and n-type SiC single crystals has become a technical problem that needs to be solved urgently in this field. Utility Model Content

[0007] In order to solve the above technical problems, the utility model provides a silicon carbide single crystal furnace which can replace the growth chamber components according to production needs, thereby being suitable for growing silicon carbide single crystals by both liquid phase method and gas phase method.

[0008] The specific plan is as follows:

[0009] A silicon carbide single crystal furnace with a replaceable growth chamber, comprising a furnace body, a first lifting and rotating system, a second lifting and rotating system, and a replaceable growth chamber component;

[0010] A furnace cover is provided on the top of the furnace body, and a closable opening is provided at the center of the furnace cover;

[0011] The first lifting and rotating system is arranged above the furnace body;

[0012] The second lifting and rotating system is arranged below the furnace body, and is provided with a turntable, a rotating rod, and a crucible lifting and rotating device, the upper part of the rotating rod is connected to the turntable, and the lower part of the rotating rod is connected to the crucible lifting and rotating device, which is used to drive the turntable to perform lifting and rotating motion;

[0013] The replaceable growth chamber components are respectively installed in the furnace body, and the replaceable growth chamber components are respectively provided with a graphite crucible, an insulation layer, and an induction coil. A crucible cover is provided on the top of the graphite crucible. The insulation layer includes a first insulation layer, a second insulation layer, and a third insulation layer. The first insulation layer is stacked on the top of the crucible cover, the second insulation layer is wrapped on the outside of the graphite crucible, and the third insulation layer is padded under the graphite crucible. The third insulation layer is installed on the turntable to realize that the turntable drives the graphite crucible to rotate up and down; the induction coil is sleeved on the periphery of the insulation layer and fixed to the bottom of the furnace body;

[0014] The replaceable growth chamber assembly includes at least one growth chamber for TSSG and one growth chamber for PVT:

[0015] The TSSG growth chamber is used for growing silicon carbide single crystals by a liquid phase method. When the TSSG growth chamber is used, the closable opening of the furnace cover is opened, and the TSSG growth chamber is further provided with a seed crystal lifting rod, the lower end of which is provided with a seed crystal tray for bonding seed crystals, and the upper end of the seed crystal lifting rod is connected to the first lifting and rotating system, so as to drive the seed crystal tray to rotate up and down;

[0016] The PVT growth chamber is used for growing silicon carbide single crystals by a vapor phase method. When the PVT growth chamber is used, the closable opening of the furnace cover is closed.

[0017] Furthermore, the first insulation layer of the TSSG growth chamber and the center of the crucible cover are both provided with through holes, and the seed crystal lifting rod passes through the closable opening of the furnace cover and extends into the interior of the graphite crucible through the through holes.

[0018] Furthermore, the first lifting and rotating system is provided with a lifting frame, a first positioning screw, a first lifting motor, a first rotating motor, and a furnace top; the first positioning screw is provided with a first slider capable of longitudinal movement; the first lifting motor is connected to the first slider for controlling the longitudinal movement of the first slider; the first rotating motor is connected to the seed crystal lifting rod for controlling the rotational movement of the seed crystal lifting rod; a first flexible bellows and an infrared thermometer are provided on the furnace top; the upper part of the seed crystal lifting rod passes through the furnace top and extends into the first flexible bellows to ensure the airtightness of the single crystal furnace; a first magnetic fluid is provided above the first flexible bellows for improving the airtightness of the single crystal furnace; the infrared thermometer is used to detect the internal temperature of the graphite crucible.

[0019] Furthermore, the furnace top is provided with a first through hole and a second through hole, the second through hole is provided with a glass window, the infrared thermometer is fixed above the glass window, the upper part of the seed crystal pulling rod passes through the first through hole and extends into the first flexible bellows, and the infrared thermometer irradiates the interior of the graphite crucible of the TSSG growth chamber through the second through hole, the closable opening of the furnace cover, the first insulation layer and the through hole of the crucible cover to detect the internal temperature of the graphite crucible.

[0020] Furthermore, the crucible lifting and rotating device is provided with a second rotating motor, a second flexible bellows, a second magnetic fluid, a second lifting motor, a second slider, and a second positioning screw. The second rotating motor is connected to the rotating rod for controlling the rotating rod to rotate; the lower end of the rotating rod is connected to the second magnetic fluid through the second flexible bellows, and the second lifting motor is connected to the second magnetic fluid for controlling the rotating rod to move longitudinally. A lifting nut is provided on the second positioning screw. The second lifting motor drives the lifting nut to perform longitudinal lifting movement on the second positioning screw by controlling the longitudinal movement of the second slider, thereby controlling the lifting movement of the rotating rod and the turntable.

[0021] Furthermore, the furnace body is provided with a gas circuit system for vacuum extraction and maintaining air pressure, the replaceable growth chamber assembly is respectively provided with an air inlet and an air extraction port, and the air inlet and the air outlet are connected to the gas circuit system; the gas circuit system is provided with a gate valve and a vacuum pump, the gate valve extends into the replaceable growth chamber assembly to introduce inert gas, and the vacuum pump includes an exhaust pump and a pressure regulating pump, so as to perform vacuum extraction and air pressure regulation on the replaceable growth chamber assembly.

[0022] Furthermore, the furnace body is also provided with a cooling water system, and a water pipe is passed through the interior of the induction coil, and the water pipe is connected to the cooling water system to cool and protect the induction coil.

[0023] Furthermore, the induction coil is fixed to the bottom of the furnace body through a support rod.

[0024] Furthermore, the material of the second thermal insulation layer and the third thermal insulation layer is soft graphite felt and / or hard graphite felt, and the material of the first thermal insulation layer is soft graphite felt.

[0025] Furthermore, a steel pad for lifting the furnace cover is provided on the outer side of the furnace body.

[0026] Beneficial effects:

[0027] The utility model creatively adopts a replaceable growth chamber component. By using a crucible cover with a through hole in the center and a first insulation layer, a seed crystal pulling rod is extended into the crucible to pull and grow a silicon carbide single crystal, thereby meeting the production conditions of a liquid phase single crystal furnace. By using a crucible cover and a first insulation layer without a through hole in the center, the reaction temperature is further increased, so that the single crystal furnace can also have the function of growing silicon carbide single crystals by a vapor phase method. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the planar structure of a growth chamber for TSSG;

[0029] Figure 2 It is a schematic diagram of the planar structure of a growth chamber for PVT;

[0030] Figure 3 yes Figure 1 A magnified view of the structure of the growth chamber for TSSG;

[0031] Figure 4 yes Figure 2 A magnified view of the structure of the growth chamber for PVT;

[0032] Figure 5 is a schematic diagram of the three-dimensional structure of the first lifting and rotating system;

[0033] Figure 6 It is a schematic diagram of the three-dimensional structure of the second lifting and rotating system.

[0034] Wherein: 1-furnace body, 2-first lifting and rotating system, 21-lifting frame, 22-first positioning screw, 221-first slider, 23-first lifting motor, 24-first rotating motor, 25-furnace top, 251-first flexible bellows, 252-infrared thermometer, 253-first magnetic fluid, 3-second lifting and rotating system, 31-second rotating motor, 32-second flexible bellows, 33-second magnetic fluid, 34-second lifting motor, 35-second slider, 36-second positioning screw, 4-turntable, 5-turn rod, 6-furnace cover, 7-graphite crucible, 71-crucible cover, 8-induction coil, 9-first insulation layer, 10-second insulation layer, 11-third insulation layer, 12-TSSG growth chamber, 13-PVT growth chamber, 14-seed crystal lifting rod, 15-seed crystal tray. DETAILED DESCRIPTION

[0035] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0036] The utility model is now further described in conjunction with the accompanying drawings and specific implementation methods.

[0037] Embodiment 1:

[0038] This embodiment 1 provides a silicon carbide single crystal furnace with a replaceable growth chamber, comprising a furnace body 1, a first lifting and rotating system 2, a second lifting and rotating system 3, and a replaceable growth chamber assembly. Specifically:

[0039] The first lifting and rotating system 2 is disposed above the furnace body 1 .

[0040] The second lifting and rotating system 3 is arranged below the furnace body 1, and the second lifting and rotating system 3 is provided with a turntable 4, a rotating rod 5, and a crucible lifting and rotating device. The upper part of the rotating rod 5 passes through the bottom of the furnace body 1 to connect to the turntable 4, and the lower part of the rotating rod 5 passes through the bottom of the furnace body 1 to connect to the crucible lifting and rotating device, which is used to drive the turntable 4 to perform lifting and rotating movements.

[0041] A furnace cover 6 is disposed on the top of the furnace body 1 , and a closable opening is disposed at the center of the furnace cover 6 .

[0042] The replaceable growth chamber components are respectively installed in the furnace body 1, and the replaceable growth chamber components are respectively provided with a graphite crucible 7, an insulating layer, and an induction coil 8. The top of the graphite crucible 7 is provided with a crucible cover 71. The insulating layer includes a first insulating layer 9, a second insulating layer 10, and a third insulating layer 11. The first insulating layer 9 is stacked on the top of the crucible cover 71, and the second insulating layer 10 is wrapped on the outside of the graphite crucible 7. The third insulating layer 11 is padded under the graphite crucible 7, and the third insulating layer 11 is installed on the turntable 4 to realize that the turntable 4 drives the graphite crucible 7 to rotate up and down.

[0043] As a preferred solution of the utility model, the materials of the second insulation layer 10 and the third insulation layer 11 can be one or more of soft graphite felt and hard graphite felt, respectively, and the material of the first insulation layer 9 is soft graphite felt, which replaces the traditional quartz tube. As a result, the single crystal furnace has a larger operating space and can withstand and be heated to a higher temperature.

[0044] The heat insulating layer of the utility model can increase the temperature in the graphite crucible 7 and keep the temperature field stable.

[0045] The induction coil 8 of the present invention is mounted on the outer periphery of the insulation layer and fixed to the bottom of the furnace body 1 by a support rod or other common fixing method. A medium frequency power supply is provided outside the furnace body 1 to control the heating of the induction coil. The present invention heats the graphite crucible 7 through the induction coil 8 to dissolve the silicon-containing raw material.

[0046] The replaceable growth chamber assembly of the utility model comprises at least one growth chamber 12 for TSSG and one growth chamber 13 for PVT. In the actual production process, the number of the growth chamber 12 for TSSG and the growth chamber 13 for PVT can be set according to demand.

[0047] When using the TSSG growth chamber 12, the closable opening of the furnace cover 6 is opened, and the TSSG growth chamber 12 is also provided with a seed crystal lifting rod 14, and the lower end of the seed crystal lifting rod 14 is provided with a seed crystal tray 15 for bonding the seed crystal, and the upper end of the seed crystal lifting rod 14 is connected to the first lifting and rotating system 2 by means of screw holes or the like, so as to drive the seed crystal tray 15 to rotate up and down. The connection method can be a spiral structure, or other connection methods in the prior art can be used.

[0048] As a preferred solution of the utility model, the first insulation layer 9 of the TSSG growth chamber 12 and the center of the crucible cover 71 are both provided with through holes, and the seed crystal pulling rod 14 passes through the closable opening of the furnace cover 6 and extends into the interior of the graphite crucible 7 through the through holes.

[0049] As a further preferred embodiment of the present invention, the first lifting and rotating system 2 is provided with a lifting frame 21, a first positioning screw 22, a first lifting motor 23, a first rotating motor 24, and a furnace top 25. The first positioning screw 22 is provided with a first slider 221 that can perform longitudinal movement. The first lifting motor 23 is connected to the first slider 221 to control the first slider 221 to perform longitudinal movement. The first rotating motor 24 is connected to the seed crystal lifting rod 14 to control the seed crystal lifting rod 14 to perform rotational movement. The furnace top 25 is provided with a first flexible bellows 251 and an infrared thermometer 252. The upper part of the seed crystal lifting rod 14 passes through the furnace top 25 and extends into the first flexible bellows 251 to ensure the airtightness of the single crystal furnace. A first magnetic fluid 253 is provided above the first flexible bellows 251 to improve the airtightness of the single crystal furnace. The infrared thermometer 252 is used to detect the internal temperature of the graphite crucible 7.

[0050] As a further preferred embodiment of the present invention, the furnace top 25 is provided with a first through hole and a second through hole, the second through hole is provided with a glass window, the infrared thermometer 252 is fixed above the glass window, the upper part of the seed crystal lifting rod 14 passes through the first through hole and extends into the first flexible bellows 251, and the infrared thermometer 252 is irradiated to the inside of the graphite crucible 7 of the TSSG growth chamber 12 through the second through hole, the closable opening of the furnace cover 6, the first insulation layer 9 and the through hole of the crucible cover 71 to detect the internal temperature of the graphite crucible 7.

[0051] When the PVT growth chamber 13 is used, the TSSG growth chamber 12 is taken out and replaced with the PVT growth chamber 13, the reaction temperature is increased, and the closable opening of the furnace cover 6 is closed to provide a closed environment so that the crucible cover 71 can be bonded to the seed crystal for growing silicon carbide. In addition, a through hole or other opening can be provided on the closable opening of the furnace cover 6 for the infrared thermometer 252 to pass through and irradiate the inside of the graphite crucible 7 of the PVT growth chamber 13 to detect the internal temperature of the graphite crucible 7.

[0052] As a preferred embodiment of the present invention, the crucible lifting and rotating device is provided with a second rotating motor 31, a second flexible bellows 32, a second magnetic fluid 33, a second lifting motor 34, a second slider 35, and a second positioning screw 36. The second rotating motor 31 is connected to the rotating rod 5 for controlling the rotating rod 5 to rotate; the lower end of the rotating rod 5 is connected to the second magnetic fluid 33 through the second flexible bellows 32, and the second lifting motor 34 is connected to the second magnetic fluid 32 for controlling the rotating rod 5 to move longitudinally; a lifting nut is provided on the second positioning screw 36, and the second lifting motor 34 drives the lifting nut to perform longitudinal lifting movement on the second positioning screw 36 by controlling the longitudinal movement of the second slider 35, thereby controlling the lifting movement of the rotating rod 5 and the turntable 4.

[0053] As another preferred embodiment of the present invention, the present invention is provided with a gas circuit system for vacuum extraction and maintaining air pressure in the furnace body 1, and the replaceable growth chamber assembly is respectively provided with an air inlet and an air extraction port, and the air inlet and the air outlet are connected to the gas circuit system; the gas circuit system is provided with a gate valve and a vacuum pump, and the gate valve extends into the replaceable growth chamber assembly to introduce inert gas, and the vacuum pump includes an exhaust pump and a pressure regulating pump, so as to perform vacuum extraction and air pressure regulation on the replaceable growth chamber assembly.

[0054] As a further preferred solution of the utility model, the furnace body 1 is further provided with a cooling water system, and a water pipe is passed through the interior of the induction coil 8 , and the water pipe is connected to the cooling water system to cool and protect the induction coil 8 .

[0055] The utility model is also provided with structures such as an external power supply, which can be assembled according to common accessories, components, devices, etc. in the art.

[0056] The use of the utility model:

[0057] Turn on the power and assemble the single crystal furnace:

[0058] When growing silicon carbide single crystals by liquid phase method, the replaceable growth chamber assembly is replaced with a TSSG growth chamber, and when using the TSSG growth chamber, the closable opening of the furnace cover is opened. The crucible cover and the center of the first insulation layer of the TSSG growth chamber are both provided with through holes to enable the seed crystal lifting rod to carry the seed crystal tray into the graphite crucible to bond the seed crystal.

[0059] When growing silicon carbide single crystals by a vapor phase method, the replaceable growth chamber assembly is replaced with a PVT growth chamber. When using the PVT growth chamber, the reaction temperature is increased and the closable opening of the furnace cover is closed. The graphite crucible of the PVT growth chamber is sealed, and no through hole is opened in the center of the crucible cover. The first insulation layer is sealed and no through hole is opened in the center to achieve the best insulation effect, and the seed crystal is bonded to the crucible cover.

[0060] Therefore, the utility model can realize the functional diversification of the silicon carbide single crystal furnace liquid phase method and gas phase method being compatible at the same time.

[0061] Although the present invention has been specifically demonstrated and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes may be made to the present invention in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A silicon carbide single crystal furnace with a replaceable growth chamber, comprising a furnace body, characterized in that: It also includes a first lifting and rotating system, a second lifting and rotating system, and a replaceable growth chamber assembly; A furnace cover is provided on the top of the furnace body, and a closable opening is provided at the center of the furnace cover; The first lifting and rotating system is arranged above the furnace body; The second lifting and rotating system is arranged below the furnace body, and is provided with a turntable, a rotating rod, and a crucible lifting and rotating device, the upper part of the rotating rod is connected to the turntable, and the lower part of the rotating rod is connected to the crucible lifting and rotating device, which is used to drive the turntable to perform lifting and rotating motion; The replaceable growth chamber components are respectively installed in the furnace body, and the replaceable growth chamber components are respectively provided with a graphite crucible, an insulation layer, and an induction coil. A crucible cover is provided on the top of the graphite crucible. The insulation layer includes a first insulation layer, a second insulation layer, and a third insulation layer. The first insulation layer is stacked on the top of the crucible cover, the second insulation layer is wrapped on the outside of the graphite crucible, and the third insulation layer is padded under the graphite crucible. The third insulation layer is installed on the turntable to realize that the turntable drives the graphite crucible to rotate up and down; the induction coil is sleeved on the periphery of the insulation layer and fixed to the bottom of the furnace body; The replaceable growth chamber assembly includes at least one growth chamber for TSSG and one growth chamber for PVT: The TSSG growth chamber is used for growing silicon carbide single crystals by a liquid phase method. When the TSSG growth chamber is used, the closable opening of the furnace cover is opened, and the TSSG growth chamber is further provided with a seed crystal lifting rod, the lower end of which is provided with a seed crystal tray for bonding seed crystals, and the upper end of the seed crystal lifting rod is connected to the first lifting and rotating system, so as to drive the seed crystal tray to rotate up and down; The PVT growth chamber is used for growing silicon carbide single crystals by a vapor phase method. When the PVT growth chamber is used, the closable opening of the furnace cover is closed.

2. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 1, characterized in that: The first insulation layer of the TSSG growth chamber and the center of the crucible cover are both provided with through holes, and the seed crystal lifting rod passes through the closable opening of the furnace cover and extends into the interior of the graphite crucible through the through holes.

3. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 2, characterized in that: The first lifting and rotating system is provided with a lifting frame, a first positioning screw, a first lifting motor, a first rotating motor, and a furnace top. The first positioning screw is provided with a first slider that can perform longitudinal movement. The first lifting motor is connected to the first slider to control the first slider to perform longitudinal movement. The first rotating motor is connected to the seed crystal lifting rod to control the seed crystal lifting rod to perform rotational movement. A first flexible bellows and an infrared thermometer are provided on the furnace top. The upper part of the seed crystal lifting rod passes through the furnace top and extends into the first flexible bellows to ensure the airtightness of the single crystal furnace. A first magnetic fluid is provided above the first flexible bellows to improve the airtightness of the single crystal furnace. The infrared thermometer is used to detect the internal temperature of the graphite crucible.

4. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 3, characterized in that: The furnace top is provided with a first through hole and a second through hole, the second through hole is provided with a glass window, the infrared thermometer is fixed above the glass window, the upper part of the seed crystal lifting rod passes through the first through hole and extends into the first flexible bellows, and the infrared thermometer irradiates the interior of the graphite crucible of the TSSG growth chamber through the second through hole, the closable opening of the furnace cover, the first insulation layer and the through hole of the crucible cover to detect the internal temperature of the graphite crucible.

5. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 1, characterized in that: The crucible lifting and rotating device is provided with a second rotating motor, a second flexible bellows, a second magnetic fluid, a second lifting motor, a second slider, and a second positioning screw. The second rotating motor is connected to the rotating rod to control the rotating rod to rotate; the lower end of the rotating rod is connected to the second magnetic fluid through the second flexible bellows, and the second lifting motor is connected to the second magnetic fluid to control the rotating rod to move longitudinally. A lifting nut is provided on the second positioning screw. The second lifting motor drives the lifting nut to perform longitudinal lifting movement on the second positioning screw by controlling the longitudinal movement of the second slider, thereby controlling the lifting movement of the rotating rod and the turntable.

6. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 1, characterized in that: The furnace body is provided with a gas circuit system for vacuum extraction and maintaining air pressure, and the replaceable growth chamber assembly is respectively provided with an air inlet and an air extraction port, and the air inlet and the air outlet are connected to the gas circuit system; the gas circuit system is provided with a gate valve and a vacuum pump, and the gate valve extends into the replaceable growth chamber assembly to introduce inert gas, and the vacuum pump includes an exhaust pump and a pressure regulating pump, so as to perform vacuum extraction and air pressure regulation on the replaceable growth chamber assembly.

7. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 6, characterized in that: The furnace body is also provided with a cooling water system. A water pipe is passed through the interior of the induction coil. The water pipe is connected to the cooling water system to cool and protect the induction coil.

8. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 1, characterized in that: The induction coil is fixed to the bottom of the furnace body through a support rod.

9. The silicon carbide single crystal furnace with replaceable growth chamber according to claim 1, characterized in that: The materials of the second thermal insulation layer and the third thermal insulation layer are soft graphite felt and / or hard graphite felt, and the material of the first thermal insulation layer is soft graphite felt.

10. The silicon carbide single crystal furnace with replaceable growth chamber according to any one of claims 1 to 9, characterized in that: The outer side of the furnace body is provided with a steel pad for lifting the furnace cover.

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