A single crystal growth furnace for growing silicon carbide crystals

Abstract

The present invention discloses a single crystal growth furnace for growing silicon carbide crystals. The present invention relates to the technical field of silicon carbide crystal growth, and comprises a furnace body, which is made of high-purity alumina ceramic material and has excellent high temperature resistance. A furnace cover is installed on the flange on the top of the furnace body, an auxiliary furnace chamber is fixedly connected to the middle of the furnace cover surface, a lifting component is installed on the top of the auxiliary furnace chamber, a visual sensor is installed on the side flange of the furnace cover surface, an atmosphere component is installed on the side of the furnace cover surface away from the visual sensor, a temperature storage component is fixedly installed in the middle of the side of the furnace cover facing the furnace body, and a ceramic heater is installed in the middle of the inner side of the furnace body. The single crystal growth furnace for growing silicon carbide crystals fills the entire furnace body with silicon source and carbon source by using a short pipe and a thick ring pipe, so that the atmosphere is evenly distributed on the inner side of the furnace body, and a clear division and independent control of the temperature field inside the furnace body are achieved, and the temperature field inside the furnace body is precisely controlled.

Description

Technical Field

[0001] The invention relates to the technical field of silicon carbide crystal growth, in particular to a single crystal growth furnace for growing silicon carbide crystals. Background Art

[0002] Silicon carbide (SiC) crystals, due to their exceptional physical and chemical properties, such as high hardness, high thermal conductivity, wide bandgap, high electron saturation velocity, and high breakdown electric field, have become an important material for high-power electronic devices and high-temperature semiconductor devices. Silicon carbide is widely used in power electronics, light-emitting diodes (LEDs), high-frequency microwave devices, and high-temperature coatings. In the power electronics sector, SiC crystals are particularly suitable for fabricating high-efficiency, low-loss devices such as MOSFETs, JBS diodes, and IGBTs. These devices hold significant potential in applications such as electric vehicles, renewable energy systems (such as solar and wind power), smart grids, and industrial power supplies. Currently, SiC crystal growth is primarily achieved using physical vapor transport (PVT). PVT is a high-temperature vapor phase growth technique that heats and sublimates a SiC source material, followed by crystallization onto a lower-temperature substrate to form a SiC single crystal. However, conventional SiC crystal growth furnaces face several technical challenges during the growth process. These challenges include uneven temperature distribution, difficulty in atmosphere control, and high energy consumption, which limit the growth of high-quality, large-scale SiC crystals. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: A single crystal growth furnace for growing silicon carbide crystals, comprising a furnace body, wherein the furnace body is made of high-purity alumina ceramic material and has excellent high-temperature resistance, a furnace cover is installed on the top flange of the furnace body, an auxiliary furnace chamber is fixedly connected to the middle of the surface of the furnace cover, a lifting assembly is installed on the top of the auxiliary furnace chamber, a visual sensor is installed on the side flange of the furnace cover surface for monitoring the state of the melt inside the furnace body, an atmosphere assembly is installed on the side of the furnace cover surface away from the visual sensor, the atmosphere assembly is used to control the atmosphere composition and flow rate in the growth chamber, and maintain the stability and uniform flow of the atmosphere in the growth chamber, a heat storage assembly is fixedly installed in the middle of the side of the furnace cover facing the furnace body, and a ceramic heater is installed in the middle of the inner side of the furnace body;

[0004] The atmosphere component includes a straight pipe, two circulation components are connected to the surface of the straight pipe, a double-ring sleeve is installed between the furnace body and the furnace cover, the surface of the double-ring sleeve is connected to a lower connecting pipe in a centrally symmetrical shape, the top of the straight pipe is threadedly connected to a first valve head, and the end of the straight pipe away from the first valve head is connected to a back-suction pump;

[0005] The heat storage component includes a flat gourd body, and the flat gourd body is fixedly connected to the furnace cover. A concentric circle tube is embedded on the inner wall of the flat gourd body. A nozzle is installed at the embedded position of the concentric circle tube and the flat gourd body, and the nozzle is installed in a circular array on the surface of the concentric circle tube.

[0006] Preferably, the inner wall of the furnace body is covered with a silicon carbide coating, a rotating motor is installed in the middle of the bottom of the furnace body, and three heating spiral rings are installed in the inner wall of the ceramic heater at equal intervals along the axis direction of the ceramic heater. They are divided into upper, middle and lower layers and installed in the ceramic heater, dividing the space surrounded by the ceramic heater into three equal parts for heating, and the input end of the heating spiral ring passes through the furnace body and is connected to an external heating system, and the heating system is connected to a temperature controller for real-time monitoring and adjustment of the temperature in the growth chamber, wherein the heating spiral ring adopts inductive heating, and an exhaust valve pipe is connected to the outer surface of the furnace body and near the bottom side in a centrally symmetrical shape for discharging inert gas, and a temperature sensor is installed on the middle flange of the outer surface of the auxiliary furnace chamber, and the temperature sensor adopts a thermocouple to achieve high-precision temperature measurement, and a crucible is installed inside the furnace body and in the middle of the inner side of the ceramic heater, and the crucible is made of graphite material with high thermal conductivity to ensure uniform heat transfer during the growth of silicon carbide crystals, and a support ring frame is installed at the bottom of the ceramic heater to provide precise temperature control and rapid heating and cooling capabilities through the ceramic heater.

[0007] Preferably, a water-cooled electrode is inserted into the bottom inner side of the furnace body, and the water-cooled electrode is inserted into the furnace body in a circular array, and the support ring frame is inserted into the furnace body through the water-cooled electrode. An electric heating ring is installed on the inner side of the furnace body, and a turntable is installed at the bottom of the crucible. The electric heating ring is installed between the turntable and the furnace body. The electric heating ring is used to heat and keep the bottom of the turntable warm. An insulation sleeve is fixedly connected to the middle of the bottom of the furnace body, and the insulation sleeve is fitted to the output end of the rotating motor.

[0008] Preferably, the furnace cover is fixedly connected to a suspension rod on one side facing the furnace body, and the end of the suspension rod facing away from the furnace cover is connected to a thick ring tube, which is installed parallel to the top of the crucible through the suspension rod, and a valve is installed in the middle of the connection between the auxiliary furnace chamber and the furnace cover.

[0009] Preferably, there are two pairs of lower connecting pipes, one pair of lower connecting pipes passes through the furnace cover and is connected to the circulation component, and the other pair of lower connecting pipes is threadedly connected to the furnace cover. The first valve head is used for external silicon source, and the second valve head is fixedly connected to the surface of the straight pipe, and the second valve head is used for external carbon source.

[0010] Preferably, a thermal insulation pipe is connected to the surface of the straight pipe and the portion radially perpendicular to the first valve head and the second valve head, and the output end of the back-suction pump is connected to a short pipe and a branch pipe. There are two branch pipes, and the two branch pipes are connected to the output end of the back-suction pump in a centrally symmetrical manner, and the short pipe is connected to the middle between the two branch pipes. The short pipe is threadedly connected to the thick ring pipe, and the branch pipe passes through the heat storage component and is connected to the concentric circle pipe. The thick ring pipe is horizontally installed between the heat storage component and the valve through the short pipe and the hanger.

[0011] Preferably, the end of the lower connecting pipe away from the double ring sleeve is connected to a telescopic tube, the double ring sleeve is lifted and installed with the furnace cover through the telescopic tube on the lower connecting pipe, and the double ring sleeve is hoisted on the top of the crucible through the cooperation of the lower connecting pipe and the telescopic tube.

[0012] Preferably, the circulation component includes a flange pipe, and the flange pipe is fixedly installed with the furnace cover, a micro hydraulic rod is installed in a circular array on the top of the flange pipe, the output end of the micro hydraulic rod is connected to a straight rod, the middle thread of the top of the flange pipe is connected to the circulation pipe, the circulation pipe is threadedly connected to the insulation pipe, the surface of the circulation pipe is covered with an insulation neck sleeve, and the surface of the circulation pipe is covered with an insulation sleeve, the insulation sleeve is installed between the insulation neck sleeve and the insulation pipe, and between the insulation neck sleeve and the flange pipe, and the insulation sleeve is used to shield and insulate the part of the circulation pipe surface not covered by the insulation neck sleeve;

[0013] Guide joints are installed at equal intervals on the surface of the straight rod, and the straight rod is connected with the thermal insulation neck sleeve. The guide joints are installed at the position where the straight rod and the thermal insulation neck sleeve penetrate, and the guide joints are fixedly connected to the thermal insulation neck sleeve. A soft cover is connected to the bottom of the thermal insulation neck sleeve. The soft cover and the thermal insulation neck sleeve are both hollow structures, and the diameter of the trumpet-shaped structure on the top of the thermal insulation neck sleeve is larger than the diameter of the soft cover.

[0014] Preferably, a heat-insulating layer is installed on the side of the thermal insulation neck sleeve facing away from the soft cover and the side of the soft cover facing away from the thermal insulation neck sleeve. A soft sealing ring is installed on the side of the thermal insulation neck sleeve facing away from the soft cover. The soft sealing ring is fitted with the soft cover at the bottom of the other thermal insulation neck sleeve. The surface of the double-ring sleeve is connected to a nozzle in a circular array, and the axis of the nozzle is obliquely downward pointing towards the crucible.

[0015] Preferably, the flat gourd body is a hollow structure and is through-through at the axis, the auxiliary furnace chamber is connected to the furnace body through the valve and the flat gourd body, and the outer surface of the flat gourd body and the direction facing the furnace cover are embedded with fan plates in a circular array, the fan plates are hinged to the flat gourd body, and the nozzles pass through the flat gourd body and correspond one-to-one to the fan plates. A wide band ring is fixedly connected to the surface of the concentric circle tube, and the wide band ring is a hollow structure.

[0016] The present invention provides a single crystal growth furnace for growing silicon carbide crystals, which has the following beneficial effects:

[0017] 1. The single crystal growth furnace for growing silicon carbide crystals can successively activate the back-suction pump to transport the silicon source and the carbon source to the inside of the furnace body and the furnace cover respectively through the insulation tube, the telescopic tube, the lower connecting tube, the double-ring sleeve and the nozzle. The double-ring sleeve and the nozzle connected to the surface thereof are used to realize the annular balanced and close-range transportation of the silicon source and the carbon source inside the furnace body and directly above the furnace cover. The silicon source and the carbon source can be directly transported to the inside of the furnace cover and its vicinity, and then the silicon source and the carbon source are filled into the entire furnace body through the use of the short connecting tube and the thick ring tube, so that the atmosphere is evenly distributed inside the furnace body.

[0018] Second, the single crystal growth furnace for growing silicon carbide crystals can control the specific hoisting height of the double-ring sleeve directly above the crucible by adjusting the telescopic tube, so as to adapt to the use of crucibles of different heights and sizes.

[0019] 3. The single crystal growth furnace for growing silicon carbide crystals can, during the period of internal circulation of the atmosphere using the atmosphere component, activate the retraction of the micro hydraulic rod, expand the top of the insulation neck sleeve and the soft cover, and directly expose the surface of the circulation pipe blocked by the two to the air. In this way, the indirect consumption and release of excess heat energy inside the furnace body can be achieved, and the temperature inside the furnace body and the furnace cover can be assisted by the heating system connected to the heating spiral ring.

[0020] 4. The single crystal growth furnace for growing silicon carbide crystals uses an insulating neck sleeve and a soft cover to wrap and shield the surface of the circulation tube. The hollow structure of the insulating neck sleeve and the soft cover can be used to form a layer of insulating protection cavity on the surface of the circulation tube. Combined with the thermal insulation effect of the insulation layer, it can effectively avoid the problem of heat loss on the surface of the circulation tube during the atmosphere circulation guidance, and avoid interference with the internal temperature of the furnace body and the furnace cover during the atmosphere circulation guidance.

[0021] 5. The single crystal growth furnace for growing silicon carbide crystals heats the inner side of the furnace body by means of a heating spiral ring combined with a ceramic heater and an electric heating ring. The inner cavity of the furnace body is divided into an outer insulation layer by the ceramic heater and into upper, middle and lower layers by the heating spiral ring. The temperature field of these three equally divided heating layers is spatially evenly distributed, and the bottom layer where the turntable is located and supplemented by the electric heating ring realizes a clear division and independent control of the temperature field inside the furnace body, thereby realizing precise control of the temperature field inside the furnace body.

[0022] 6. The single crystal growth furnace for growing silicon carbide crystals can form a ring-shaped temperature protection field between the furnace body and the external environment through the ceramic heater to avoid the interference of external temperature changes on the temperature field inside the furnace cover. The electric heating ring controls the independent temperature field at the bottom of the turntable to compensate for the constant temperature field at the bottom of the crucible supported by the turntable. The auxiliary heating spiral ring maintains the constant temperature field inside the crucible. At the same time, it also avoids the interference of external factors from the bottom of the furnace body on the temperature field at the bottom of the crucible, comprehensively ensuring the safety during crystal growth and the stability of the temperature field.

[0023] 7. The single crystal growth furnace for growing silicon carbide crystals uses a support ring frame to lift the ceramic heater and heating spiral ring to the same height as the turntable; water-cooled electrodes are used to cool down the subsequent shutdown; and the design of the insulation sleeve extends the insulation structure length of the rotating motor through the connection between the furnace body and the turntable to avoid the risk of temperature loss here.

[0024] 8. The single crystal growth furnace for growing silicon carbide crystals can utilize the lifted fan plate as an expansion area of ​​contact between the flat gourd body and the internal space of the furnace body during the period when the atmosphere is circulated and guided inside the furnace body through the atmosphere component and the temperature storage component, so as to further increase the total amount of heat conduction generated by the flat gourd body itself from the furnace body, so that the inner side of the flat gourd body can be in a relatively stable temperature field state, ensuring that the flat gourd body can pull the crystal, especially after the valve is opened, the temperature field between the auxiliary furnace chamber and the furnace body can be quickly balanced under the excessive compensation of the temperature field of the flat gourd body, avoiding excessive temperature difference between the auxiliary furnace chamber and the furnace body and affecting the crystal quality.

[0025] 9. The single crystal growth furnace for growing silicon carbide crystals has a flat gourd-shaped structure: the flat gourd-shaped design can extend the extension length of the auxiliary furnace chamber on the inner side of the furnace body in a variable direction, thereby reducing the structural design height of the auxiliary furnace chamber in the middle part of the top surface of the furnace cover, reducing the overall space occupied by the furnace cover, and facilitating the convenient installation of the furnace cover and furnace body in the workplace. At the same time, it can effectively extend the crystal pulling path guided by the auxiliary furnace chamber into the inner space of the furnace body, and can quickly wrap and protect the crystal being pulled inside the flat gourd body, thereby ensuring the safety and quality of the crystal production operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the external structure of a single crystal growth furnace for growing silicon carbide crystals according to the present invention;

[0027] Figure 2 Schematic diagram of the internal structure of the furnace body of the present invention;

[0028] Figure 3 This is a schematic diagram of the partial assembly structure of the heating spiral ring through the ceramic heater and the furnace body of the present invention;

[0029] Figure 4 Schematic diagram of the bottom structure of the furnace body of the present invention;

[0030] Figure 5 This is a schematic diagram of the assembly structure of the atmosphere component and the furnace cover of the present invention;

[0031] Figure 6 This is a schematic diagram of the assembly structure of the straight pipe and the branch pipe of the present invention;

[0032] Figure 7 This is a schematic diagram of the assembly structure of the lower connecting pipe and the double-ring casing of the present invention;

[0033] Figure 8 This is a schematic diagram of the partial assembly structure of the flat gourd body and the concentric ring tubes of the present invention;

[0034] Figure 9 This is a schematic diagram of the internal structure of the flat gourd body of the present invention;

[0035] Figure 10 This is a schematic diagram of the overall structure of the lower pipe of the present invention;

[0036] Figure 11 It is a schematic diagram of the partial structure of the lower connecting pipe of the present invention;

[0037] Figure 12 It is a cross-sectional view of the thermal insulation neck cover of the present invention.

[0038] In the figure: 1. furnace body; 2. furnace cover; 3. auxiliary furnace chamber; 4. lifting assembly; 5. visual sensor; 7. atmosphere assembly; 8. rotating motor; 9. temperature storage assembly; 10. ceramic heater; 11. heating screw ring; 12. exhaust valve pipe; 13. temperature sensor; 14. crucible; 15. support ring frame; 16. water-cooled electrode; 17. electric heating ring; 18. turntable; 101. insulation cover; 22. suspension rod; 23. thick ring pipe; 31. valve; 71. straight pipe; 72. circulation assembly; 73. lower pipe; 74. double ring sleeve Pipe; 75, first valve head; 76, second valve head; 77, insulation pipe; 78, back-suction pump; 79, short pipe; 710, branch pipe; 731, telescopic pipe; 721, circulation pipe; 722, insulation sleeve; 723, insulation neck sleeve; 724, flange pipe; 725, micro hydraulic rod; 726, straight rod; 727, guide joint; 728, insulation layer; 729, soft sealing ring; 7210, soft cover; 741, nozzle; 91, flat gourd body; 92, concentric circle pipe; 93, nozzle; 94, fan plate; 95, wide band ring. DETAILED DESCRIPTION

[0039] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are chosen and described to better illustrate the principles of the invention and its practical application, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for specific applications.

[0040] The first embodiment, as Figures 1 to 12 As shown, the present invention provides a technical solution: a single crystal growth furnace for growing silicon carbide crystals, comprising a furnace body 1, the furnace body 1 being made of high-purity alumina ceramic material and having excellent high-temperature resistance, a furnace cover 2 being mounted on a flange on the top of the furnace body 1, a secondary furnace chamber 3 being fixedly connected to the middle of the surface of the furnace cover 2, a lifting assembly 4 being mounted on the top of the secondary furnace chamber 3, a visual sensor 5 being mounted on a side flange on the surface of the furnace cover 2 for monitoring the state of the melt inside the furnace body 1, an atmosphere assembly 7 being mounted on the side of the surface of the furnace cover 2 away from the visual sensor 5, the atmosphere assembly 7 being used to control the atmosphere composition and flow rate in the growth chamber and maintain a stable and uniform flow of the atmosphere in the growth chamber, a temperature storage assembly 9 being fixedly mounted on the middle of a side of the furnace cover 2 facing the furnace body 1, and a ceramic heater 10 being mounted on the middle of the inner side of the furnace body 1;

[0041] The atmosphere assembly 7 includes a straight pipe 71, with two circulation assemblies 72 connected to the surface of the straight pipe 71. A double-ring sleeve 74 is installed between the furnace body 1 and the furnace cover 2. The double-ring sleeve 74 is centrally symmetrically connected to the lower connecting pipe 73. The top of the straight pipe 71 is threadedly connected to a first valve head 75. The end of the straight pipe 71 away from the first valve head 75 is connected to a back-suction pump 78.

[0042] The heat storage component 9 includes a flat gourd body 91, and the flat gourd body 91 is fixedly connected to the furnace cover 2. A concentric circle tube 92 is embedded in the inner wall of the flat gourd body 91. A nozzle 93 is installed at the embedded part of the concentric circle tube 92 and the flat gourd body 91, and the nozzle 93 is installed in a circular array on the surface of the concentric circle tube 92.

[0043] A water-cooled electrode 16 is inserted at the bottom of the inner side of the furnace body 1, and the water-cooled electrode 16 is inserted on the furnace body 1 in a circular array, and the support ring frame 15 is inserted with the furnace body 1 through the water-cooled electrode 16. An electric heating ring 17 is installed on the inside of the furnace body 1, and a turntable 18 is installed at the bottom of the crucible 14. The electric heating ring 17 is installed between the turntable 18 and the furnace body 1. The electric heating ring 17 is used to heat and keep the bottom of the turntable 18 warm. An insulation sleeve 101 is fixedly connected to the middle of the bottom of the furnace body 1, and the insulation sleeve 101 is fitted to the output end of the rotating motor 8.

[0044] A hanger 22 is fixedly connected to the side of the furnace cover 2 facing the furnace body 1, and a thick ring tube 23 is connected to the end of the hanger 22 facing away from the furnace cover 2. The thick ring tube 23 is installed parallel to the top of the crucible 14 through the hanger 22, and a valve 31 is installed in the middle of the connection between the auxiliary furnace chamber 3 and the furnace cover 2.

[0045] There are two pairs of lower connecting pipes 73. One pair of lower connecting pipes 73 passes through the furnace cover 2 and is connected to the circulation component 72. The other pair of lower connecting pipes 73 is threadedly connected to the furnace cover 2. The first valve head 75 is used for external silicon source. The second valve head 76 is fixedly connected to the surface of the straight pipe 71. The second valve head 76 is used for external carbon source.

[0046] An insulation pipe 77 is connected to the surface of the straight pipe 71 and the portion radially perpendicular to the first valve head 75 and the second valve head 76. The output end of the back-suction pump 78 is connected to a short pipe 79 and a branch pipe 710. There are two branch pipes 710, and the two branch pipes 710 are connected to the output end of the back-suction pump 78 in a centrally symmetrical shape, and the short pipe 79 is connected to the middle part between the two branch pipes 710. The short pipe 79 is threadedly connected to the thick ring pipe 23. The branch pipe 710 passes through the heat storage component 9 and is connected to the concentric ring pipe 92. The thick ring pipe 23 is horizontally installed between the heat storage component 9 and the valve 31 through the short pipe 79 and the hanger 22.

[0047] One end of the lower connecting pipe 73 away from the double-ring sleeve 74 is connected to a telescopic tube 731. The double-ring sleeve 74 is lifted and lowered with the furnace cover 2 through the telescopic tube 731 on the lower connecting pipe 73. The double-ring sleeve 74 is hoisted at the top of the crucible 14 through the cooperation of the lower connecting pipe 73 and the telescopic tube 731.

[0048] The circulation component 72 includes a flange pipe 724, and the flange pipe 724 is fixedly installed with the furnace cover 2. A micro hydraulic rod 725 is installed in a circular array on the top of the flange pipe 724. The output end of the micro hydraulic rod 725 is connected to a straight rod 726. The middle of the top of the flange pipe 724 is threadedly connected to the circulation pipe 721. The circulation pipe 721 is threadedly connected to the insulation pipe 77. The surface of the circulation pipe 721 is covered with an insulation neck sleeve 723, and the surface of the circulation pipe 721 is covered with an insulation sleeve 722. The insulation sleeve 722 is installed between the insulation neck sleeve 723 and the insulation pipe 77, and between the insulation neck sleeve 723 and the flange pipe 724. The insulation sleeve 722 is used to shield and insulate the part of the surface of the circulation pipe 721 covered by the insulation neck sleeve 723;

[0049] Guide joints 727 are installed at equal intervals on the surface of the straight rod 726. The straight rod 726 is connected to the thermal insulation neck sleeve 723 through the guide joints 727. The guide joints 727 are installed at the position where the straight rod 726 and the thermal insulation neck sleeve 723 pass through, and the guide joints 727 are fixedly connected to the thermal insulation neck sleeve 723. A soft cover 7210 is connected to the bottom of the thermal insulation neck sleeve 723. The soft cover 7210 and the thermal insulation neck sleeve 723 are both hollow structures. The diameter of the trumpet-shaped structure at the top of the thermal insulation neck sleeve 723 is larger than the diameter of the soft cover 7210.

[0050] The side of the thermal insulation neck sleeve 723 facing away from the soft cover 7210 and the side of the soft cover 7210 facing away from the thermal insulation neck sleeve 723 are both installed with an insulation layer 728. A soft sealing ring 729 is installed on the side of the thermal insulation neck sleeve 723 facing away from the soft cover 7210. The soft sealing ring 729 is installed in a fit with the soft cover 7210 at the bottom of the other thermal insulation neck sleeve 723. The surface of the double-ring sleeve 74 is in a circular array shape and is connected to a nozzle 741. The axis of the nozzle 741 points obliquely downward toward the crucible 14.

[0051] During use, the heating spiral ring 11 in the ceramic heater 10 is heated simultaneously by an external heating system, and combined with the activation of the ceramic heater 10, annular waste heat is generated around the crucible 14, and then the silicon source is externally connected through the first valve head 75, and the carbon source is externally connected to the second valve head 76, and the back-suction pump 78 is activated to jointly transport the silicon source and the carbon source into the thick ring tube 23 through the short pipe 79, and then the atmosphere is transported to the crucible 14 through the thick ring tube 23. At this time, the ceramic heater 10, the heating spiral ring 11 and the electric heating ring 17 are heated at the same time to increase the internal temperature of the furnace body 1, and the temperature sensor 13 monitors the internal temperature of the auxiliary furnace chamber 3. When the temperature inside the auxiliary furnace chamber 3 reaches the preset value, it is determined that the internal temperature of the furnace body 1 at this time reaches the preset threshold, and the growth of the crystal can begin.

[0052] During this period, the first valve head 75 and the second valve head 76 can be closed, the micro hydraulic rod 725 can be activated to extend, and the straight rod 726 can be driven to be blocked and pushed upward by the guide joint 727, so that the top of each adjacent thermal insulation neck sleeve 723 is wrapped around the soft cover 7210 above it, and the surface of the circulation pipe 721 is shielded and surrounded by the thermal insulation layer 728, forming an insulation sleeve continuous with the thermal insulation sleeve 722, avoiding heat loss when the atmosphere circulates inside the circulation pipe 721; at this time, the back-suction pump 78 can be activated, and the atmosphere at the inner edge of the furnace body 1 is sucked into the circulation pipe 721 by means of the nozzle 741 on the surface of the double-ring sleeve 74, the lower connecting pipe 73 and the communication between the telescopic pipe 731 and the flange pipe 724. The atmosphere is finally transported into the inner side of the concentric tube 92 through the branch tube 710 and ejected through the nozzle 93 connected to the surface of the concentric tube 92, thereby pushing open the fan plate 94 covering the top of the flat gourd body 91 under the action of gravity, so that the fan plate 94 rotates around the hinged part with the flat gourd body 91 to open a certain inclination angle, so as to re-inject the atmosphere into the inner side of the furnace body 1 and the furnace cover 2, completing the circulation of the atmosphere inside the furnace body 1 and the furnace cover 2, so that the atmosphere component 7 can be combined with the heat storage component 9 to circulate the atmosphere in the furnace body 1 and the furnace cover 2, so that the atmosphere can be evenly filled in every corner of the furnace body 1 and the furnace cover 2, and the atmosphere is evenly distributed inside the furnace body 1 and the furnace cover 2, thereby improving the growth quality of the crystal.

[0053] By means of the atmosphere reflux transported from the surface of the heat storage component 9 with the aid of the atmosphere component 7, the atmosphere ejected from the nozzle 93 can be used for gaseous contact heat conduction with the fan plate 94, the contact heat conduction of the annular flow of the atmosphere inside the wide band ring 95, and the contact conduction between the concentric ring tube 92 and the inner wall of the flat gourd body 91 can be used, so that the flat gourd body 91 can automatically conduct and collect the heat carried by the atmosphere during the atmosphere circulation process, and enrich and temporarily store the heat inside the flat gourd body 91, so that when the crystal is subsequently vertically lifted by the lifting component 4, the crystal can be continuously kept warm, ensuring the constant temperature requirement of the crystal during the lifting period, and at the same time realizing the transfer and reuse of surplus heat inside the furnace body 1 and the furnace cover 2, reducing energy consumption while achieving the safety guarantee of the crystal quality during the crystal pulling process.

[0054] And the flat gourd-shaped design of the flat gourd body 91 itself can also be used to extend the extension length of the auxiliary furnace chamber 3 on the inner side of the furnace body 1 in disguised form, and can reduce the structural design height of the auxiliary furnace chamber 3 in the middle part of the top surface of the furnace cover 2, reduce the overall occupied space of the furnace cover 2, and facilitate the convenient installation of the furnace cover 2 and the furnace body 1 in the work site. At the same time, it can also effectively extend the crystal pulling path guided by the auxiliary furnace chamber 3 to the inner space of the furnace body 1, and can quickly wrap and protect the crystal being pulled inside the flat gourd body 91, thereby ensuring the safety and quality of the crystal production operation.

[0055] During the atmosphere input, the back-suction pump 78 can be activated in turn to transport the silicon source and the carbon source to the inside of the furnace body 1 and the furnace cover 2 respectively through the insulation tube 77, the telescopic tube 731, the lower connecting pipe 73, the double-ring sleeve 74 and the nozzle 741. The double-ring sleeve 74 and the nozzle 741 connected to its surface can be used to realize the annular balanced and close-range transportation of the silicon source and the carbon source inside the furnace body 1, just above the furnace cover 2. The silicon source and the carbon source can be directly transported to the inside of the furnace cover 2 and its vicinity, and then the silicon source and the carbon source are filled in the entire furnace body 1 through the use of the short connecting pipe 79 and the thick ring pipe 23, so that the atmosphere is evenly distributed inside the furnace body 1.

[0056] The specific hoisting height of the double-ring sleeve 74 directly above the crucible 14 can be controlled by adjusting the telescopic tube 731 , so as to adapt to the use of crucibles 14 of different heights and sizes.

[0057] In addition, during the period of internal circulation of the atmosphere by the atmosphere component 7, the micro hydraulic rod 725 can be activated to retract, the top of the thermal insulation neck sleeve 723 and the soft cover 7210 can be unfolded, and the surface of the circulation pipe 721 blocked by the two can be directly exposed to the air. In this way, the indirect consumption and release of excess heat energy inside the furnace body 1 can be achieved, and the temperature inside the furnace body 1 and the furnace cover 2 can be assisted by the heating system connected to the heating screw ring 11.

[0058] While using the thermal insulation neck sleeve 723 and the soft cover 7210 to wrap and shield the surface of the circulation pipe 721, the hollow structure of the thermal insulation neck sleeve 723 and the soft cover 7210 can be utilized to form a thermal insulation protection cavity on the surface of the circulation pipe 721. Combined with the thermal insulation effect of the thermal insulation layer 728, the problem of heat loss on the surface of the circulation pipe 721 during the atmosphere circulation guidance can be effectively avoided, thereby avoiding interference with the internal temperature of the furnace body 1 and the furnace cover 2 during the atmosphere circulation guidance.

[0059] The second embodiment, based on the first embodiment, see Figures 1 to 4As shown, the inner wall of the furnace body 1 is covered with a silicon carbide coating to improve the corrosion resistance of the furnace body 1. A rotating motor 8 is installed in the middle of the bottom of the furnace body 1. Three heating spiral rings 11 are installed at equal intervals in the inner wall of the ceramic heater 10 along the axial direction of the ceramic heater 10. They are divided into upper, middle and lower layers and installed in the ceramic heater 10. The space surrounded by the ceramic heater 10 is divided into three equal parts for heating. The input end of the heating spiral ring 11 passes through the furnace body 1 and is connected to an external heating system. The heating system is connected to a temperature controller for real-time monitoring and adjustment of the temperature in the growth chamber. The heating spiral ring 11 adopts induction heating, and the furnace body 1 is external. An exhaust valve pipe 12 is connected to the surface in a centrally symmetrical manner near the bottom edge for discharging the inert gas. A temperature sensor 13 is installed on the middle flange of the outer surface of the auxiliary furnace chamber 3. The temperature sensor 13 adopts a thermocouple to achieve high-precision temperature measurement and is used to monitor the internal temperature of the auxiliary furnace chamber 3. A crucible 14 is installed on the inner side of the furnace body 1 and in the middle of the inner side of the ceramic heater 10. The crucible 14 is made of graphite material with high thermal conductivity to ensure uniform heat transfer during the growth of silicon carbide crystals. A support ring frame 15 is installed at the bottom of the ceramic heater 10 to provide precise temperature control and rapid heating and cooling capabilities.

[0060] When in use, the heating spiral ring 11 is combined with the ceramic heater 10 and the electric heating ring 17 to heat the inside of the furnace body 1, so that the inner cavity of the furnace body 1 is divided into an outer insulation layer by the ceramic heater 10, and is divided into an upper, middle and lower layer by the heated spiral ring 11. The temperature field space of these three equal parts is evenly distributed in the heating layer, and the bottom layer where the turntable 18 is located, which is supplemented by the electric heating ring 17, is located. This realizes a clear division and independent control of the temperature field inside the furnace body 1, and realizes precise control of the temperature field inside the furnace body; during this period, the ceramic heater 10 can be used to A ring-shaped temperature protection field is formed between the furnace body 1 and the external environment to avoid the interference of external temperature changes on the temperature field inside the furnace cover 2. The electric heating ring 17 controls the independent temperature field at the bottom of the turntable 18 to compensate for the constant temperature field at the bottom of the crucible 14 supported by the turntable 18. The auxiliary heating spiral ring 11 maintains the constant temperature field inside the crucible 14. At the same time, it also avoids the interference of external factors from the bottom of the furnace body 1 on the temperature field at the bottom of the crucible 14, and comprehensively guarantees the safety during crystal growth and the stability of the temperature field.

[0061] The ceramic heater 10 and the heating spiral ring 11 are lifted to the same height as the turntable 18 by the support ring frame 15; the water-cooled electrode 16 plays a role in cooling the subsequent shutdown; and the design of the insulation sleeve 101 extends the insulation structure length of the rotating motor 8 through the connection between the furnace body 1 and the turntable 18, avoiding the hidden danger of temperature loss here.

[0062] The third embodiment, based on the first and second embodiments, see Figure 8 and Figure 9 As shown, the flat gourd body 91 is a hollow structure and is through-through at the axis. The auxiliary furnace chamber 3 is connected to the furnace body 1 through the valve 31 and the flat gourd body 91. The outer surface of the flat gourd body 91 is equipped with a circular array of fan plates 94 facing the furnace cover 2. The fan plates 94 are hinged to the flat gourd body 91. The nozzles 93 pass through the flat gourd body 91 and correspond one to one with the fan plates 94. A wide band ring 95 is fixedly connected to the surface of the concentric circle tube 92, and the wide band ring 95 is a hollow structure.

[0063] During use, the atmosphere can be circulated and guided inside the furnace body 1 through the atmosphere component 7 and the heat storage component 9, and the lifted fan plate 94 can be used as an enlarged area of ​​contact between the flat gourd body 91 and the internal space of the furnace body 1 to further increase the total amount of heat conduction generated by the flat gourd body 91 itself from the furnace body 1, so that the inside of the flat gourd body 91 can be in a relatively stable temperature field state, ensuring that the flat gourd body 91 can pull the crystal, especially after the valve 31 is opened, the temperature field between the auxiliary furnace chamber 3 and the furnace body 1 can be quickly balanced under the compensatory transition of the temperature field of the flat gourd body 91, avoiding the temperature difference between the auxiliary furnace chamber 3 and the furnace body 1 being too large and affecting the crystal quality.

[0064] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without making creative efforts should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention shall be implemented in accordance with conventional means in the field unless otherwise specified or limited.

Claims

1. A single crystal growth furnace for growing silicon carbide crystals, comprising a furnace body (1), wherein the furnace body (1) is made of high-purity alumina ceramic material, a furnace cover (2) is installed on the top flange of the furnace body (1), an auxiliary furnace chamber (3) is fixedly connected to the middle of the surface of the furnace cover (2), a lifting assembly (4) is installed on the top of the auxiliary furnace chamber (3), and a visual sensor (5) is installed on the side flange of the surface of the furnace cover (2), characterized in that: An atmosphere component (7) is installed on the side of the furnace cover (2) away from the visual sensor (5), a temperature storage component (9) is fixedly installed in the middle of a side of the furnace cover (2) facing the furnace body (1), and a ceramic heater (10) is installed in the middle of the inner side of the furnace body (1); The atmosphere component (7) comprises a straight tube (71), the surface of which is connected to two circulation components (72), a double-ring sleeve (74) is installed between the furnace body (1) and the furnace cover (2), the surface of which is centrally symmetrically connected to a lower connecting pipe (73), the top of the straight tube (71) is threadedly connected to a first valve head (75), and one end of the straight tube (71) away from the first valve head (75) is connected to a back-suction pump (78); The heat storage component (9) comprises a flat gourd body (91), and the flat gourd body (91) is fixedly connected to the furnace cover (2), a concentric circle tube (92) is embedded on the inner wall of the flat gourd body (91), a nozzle (93) is installed at the embedded part of the concentric circle tube (92) and the flat gourd body (91), and the nozzle (93) is installed in a circular array on the surface of the concentric circle tube (92); The inner wall of the furnace body (1) is covered with a silicon carbide coating, a rotating motor (8) is installed in the middle of the bottom of the furnace body (1), three heating spiral rings (11) are installed at equal intervals in the inner wall of the ceramic heater (10) along the axial direction of the ceramic heater (10), and are divided into upper, middle and lower layers and installed in the ceramic heater (10), and the input end of the heating spiral ring (11) passes through the furnace body (1) and is connected to an external heating system, wherein the heating spiral ring (11) adopts inductive heating, the outer surface of the furnace body (1) and the position near the bottom side are centrally symmetrically connected to the exhaust valve pipe (12), the middle flange of the outer surface of the auxiliary furnace chamber (3) is installed, a crucible (14) is installed on the inner side of the furnace body (1) and located in the middle of the inner side of the ceramic heater (10), and the crucible (14) is made of graphite material, and a support ring frame (15) is installed at the bottom of the ceramic heater (10).

2. The single crystal growth furnace for growing silicon carbide crystal according to claim 1, characterized in that: A water-cooled electrode (16) is inserted into the bottom of the inner side of the furnace body (1), and the water-cooled electrode (16) is inserted into the furnace body (1) in a circular array shape, and the support ring frame (15) is inserted into the furnace body (1) through the water-cooled electrode (16). An electric heating ring (17) is installed on the inner side of the furnace body (1), a turntable (18) is installed at the bottom of the crucible (14), and the electric heating ring (17) is installed between the turntable (18) and the furnace body (1). A heat preservation sleeve (101) is fixedly connected to the middle of the bottom of the furnace body (1), and the heat preservation sleeve (101) is mounted on the output end of the rotating motor (8).

3. The single crystal growth furnace for growing silicon carbide crystal according to claim 2, characterized in that: A suspension rod (22) is fixedly connected to one side of the furnace cover (2) facing the furnace body (1); a thick annular tube (23) is connected to one end of the suspension rod (22) facing away from the furnace cover (2); the thick annular tube (23) is installed in parallel with the top of the crucible (14) through the suspension rod (22); and a valve (31) is installed in the middle of the connection between the auxiliary furnace chamber (3) and the furnace cover (2).

4. The single crystal growth furnace for growing silicon carbide crystal according to claim 3, characterized in that: The number of the lower connecting pipes (73) is two pairs, one pair of the lower connecting pipes (73) passes through the furnace cover (2) and is connected to the circulation component (72), and the other pair of the lower connecting pipes (73) is threadedly connected to the furnace cover (2), and the first valve head (75) is used for externally connecting a silicon source. The surface of the straight pipe (71) is fixedly connected with a second valve head (76), and the second valve head (76) is used for externally connecting a carbon source.

5. The single crystal growth furnace for growing silicon carbide crystal according to claim 4, characterized in that: A heat-insulating pipe (77) is connected to the surface of the straight pipe (71) and at a position radially perpendicular to the first valve head (75) and the second valve head (76). The output end of the back-suction pump (78) is connected to a short pipe (79) and a branch pipe (710). There are two branch pipes (710), and the two branch pipes (710) are connected to the output end of the back-suction pump (78) in a centrally symmetrical manner. The short pipe (79) is connected to the middle between the two branch pipes (710). The short pipe (79) is threadedly connected to the thick ring pipe (23). The branch pipe (710) passes through the heat storage component (9) and is connected to the concentric ring pipe (92). The thick ring pipe (23) is horizontally installed between the heat storage component (9) and the valve (31) through the short pipe (79) and the suspension rod (22).

6. The single crystal growth furnace for growing silicon carbide crystal according to claim 5, characterized in that: One end of the lower connecting pipe (73) away from the double-ring sleeve (74) is connected to a telescopic pipe (731); the double-ring sleeve (74) is installed to be lifted and lowered with the furnace cover (2) via the telescopic pipe (731) on the lower connecting pipe (73); and the double-ring sleeve (74) is hoisted at the top of the crucible (14) by the cooperation of the lower connecting pipe (73) and the telescopic pipe (731).

7. The single crystal growth furnace for growing silicon carbide crystal according to claim 6, characterized in that: The circulation component (72) comprises a flange pipe (724), and the flange pipe (724) is fixedly installed with the furnace cover (2); a micro hydraulic rod (725) is installed in a circular array on the top of the flange pipe (724); the output end of the micro hydraulic rod (725) is connected to a straight rod (726); a circulation pipe (721) is threadedly connected to the middle of the top of the flange pipe (724); the circulation pipe (721) is threadedly connected to the insulation pipe (77); a thermal insulation neck sleeve (723) is sleeved on the surface of the circulation pipe (721); and a thermal insulation sleeve (722) is sleeved on the surface of the circulation pipe (721); the thermal insulation sleeve (722) is installed between the thermal insulation neck sleeve (723) and the insulation pipe (77), and between the thermal insulation neck sleeve (723) and the flange pipe (724); The surface of the straight rod (726) is provided with guide joints (727) at equal intervals, the straight rod (726) is connected through the thermal insulation neck sleeve (723), the guide joints (727) are installed at the portion where the straight rod (726) and the thermal insulation neck sleeve (723) are connected through, and the guide joints (727) and the thermal insulation neck sleeve (723) are fixedly connected, a soft cover (7210) is connected to the bottom of the thermal insulation neck sleeve (723), the soft cover (7210) and the thermal insulation neck sleeve (723) are both hollow structures, and the diameter of the trumpet-shaped structure at the top of the thermal insulation neck sleeve (723) is greater than the diameter of the soft cover (7210).

8. The single crystal growth furnace for growing silicon carbide crystal according to claim 7, characterized in that: A heat insulation layer (728) is installed on one side of the thermal insulation neck sleeve (723) facing away from the soft cover (7210) and on one side of the soft cover (7210) facing away from the thermal insulation neck sleeve (723). A soft sealing ring (729) is installed on the side of one side of the thermal insulation neck sleeve (723) facing away from the soft cover (7210). The soft sealing ring (729) is fitted with the soft cover (7210) at the bottom of the other thermal insulation neck sleeve (723). The surface of the double-ring sleeve (74) is connected to a nozzle (741) in a circular array shape, and the axis of the nozzle (741) is obliquely downwardly directed toward the crucible (14).

9. The single crystal growth furnace for growing silicon carbide crystal according to claim 8, characterized in that: The flat gourd body (91) is a hollow structure and is vertically connected at the axis. The auxiliary furnace chamber (3) is connected to the furnace body (1) through the valve (31) and the flat gourd body (91). The outer surface of the flat gourd body (91) is equipped with a fan plate (94) in a circular array in the direction facing the furnace cover (2). The fan plate (94) is hinged to the flat gourd body (91). The nozzle (93) passes through the flat gourd body (91) and corresponds to the fan plate (94) one by one. The surface of the concentric circle tube (92) is fixedly connected with a wide band ring (95), and the wide band ring (95) is a hollow structure.

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