A device for improving crystal edge quality

Abstract

The present invention relates to a device for improving the edge quality of a crystal, comprising a graphite crucible, wherein a rotating rod is sleeved on the top of the graphite crucible, a seed crystal holder is arranged on the inner side of the top of the graphite crucible, a seed crystal holder is arranged on the inner side of the seed crystal holder, the bottom end of the seed crystal holder is connected to a porous graphite with a pyrolytic carbon coating through an equal diameter ring, an anti-corrosion ring is arranged in the middle of the inner side of the graphite crucible, and the top of the anti-corrosion ring abuts against the porous graphite with a pyrolytic carbon coating. By placing a porous graphite ring with a pyrolytic carbon coating above the anti-corrosion ring, the pore size of the porous graphite ring is smaller than the size of carbon particles, and the carbon particles generated by the preferential sublimation and graphitization of powder in the high temperature area near the wall edge of the anti-corrosion ring and the crucible can be effectively filtered, and because the porous graphite ring has a pyrolytic carbon coating, it has a blocking effect on silicification corrosion, and will not form new carbon particle pollution due to its own graphite material, thereby improving the edge quality of the crystal.

Description

Technical Field

[0001] The invention belongs to the field of improving crystal edge quality, in particular to a device for improving crystal edge quality. Background Art

[0002] As a third-generation semiconductor material, 4H-type silicon carbide has the characteristics of large bandgap, low on-resistance, good heat dissipation and high saturated electron drift velocity. It is widely used in high-power, high-frequency and high-temperature electronic devices and has good development prospects. At present, the mainstream preparation of large-size commercial silicon carbide single crystals is mainly based on physical vapor transport method. The preparation process of this method is that the seed crystal is fixed on the top of the graphite crucible, and the silicon carbide raw material is placed under the graphite crucible. Most of them are silicon carbide powder or polycrystalline silicon carbide. The bottom raw material is decomposed and sublimated by heating. Driven by the axial temperature difference, the gas phase components that are subsequently sublimated are transported to the surface of the seed crystal with the airflow, and deposited and crystallized on the growth surface of the seed crystal. As the growth time increases, the growth interface gradually advances to the raw material area, and finally forms a silicon carbide ingot.

[0003] Chinese patent application CN117904718A provides a device and method for growing silicon carbide crystals, which prevents corrosion particles on the surface of graphite parts from entering the crystals by setting a relay ring made of pyrolytic graphite blocks above the growth crucible, thereby reducing defects such as carbon inclusions. The relay ring used is isostatic graphite, which has strong corrosion resistance. Although this method can reduce the carbon inclusions caused by the corrosion of the graphite parts themselves in the growth area, it cannot avoid the carbon particles floating into the crystals due to the graphitization of the powder in the high-temperature area of ​​the crucible side wall. And if there is no additional carbon source, the excess silicon-rich gas phase components in the early stage cannot fully react with the graphite parts, and it is easy to run to the seed crystal area and react with the seed crystal.

[0004] Unlike Chinese patent application CN113622016 A, which provides a device to place a graphite ring near the material surface to filter impurity particles generated by graphitization of raw materials, the present invention introduces an anti-corrosion ring, and places the graphite ring 7 on the anti-corrosion ring, which can further filter the heterogeneous particles generated by corrosion of graphite parts (mainly anti-corrosion rings), and is placed at a high position with a thicker adjustable thickness to avoid being too close to the silicon carbide raw material, causing bottom crystallization and affecting the crystal growth rate. Chinese patent applications CN 102534763 A and CN 113622016B respectively report filtering particulate matter generated by powder through porous graphite plates or porous graphite meshes, but graphite itself is also a carbon source, generating additional carbon particles. Although tantalum carbide coatings are used as baffles in some other strategies to avoid the generation of new carbon impurities, on the one hand, this type of coating structure has a greater impact on the temperature field inside the crucible and has a higher production cost. Unlike most graphite plates or graphite meshes used to filter carbon particles generated by high temperature of raw materials, this device also fully considers other carbon sources, such as particulate matter that may be generated by corrosion of graphite parts. At the same time, in terms of design, in order to reduce the generation of carbon particles, corrosion protection is introduced as an additional carbon source in the non-growth area to reduce the corrosion of graphite parts in the growth area and avoid the generation of carbon inclusions inside the crystal. In terms of materials, this paper uses isostatic graphite with a volume density of 1.9g / cm3 and a particle size of 10μm to make graphite rings. Graphite materials with high density and small particle size are not easily corroded by silicon-rich atmosphere components, which increases the difficulty of carbon particles aggregating into inclusions at the crystal growth site. In addition, the graphite ring has a pyrolytic carbon coating to avoid the introduction of new carbon impurities, while increasing the initial flux, effectively avoiding the corrosion defects often caused by insufficient atmosphere flux in the early stage, and thus a device for improving the edge quality of the crystal is proposed. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the following technical problems in the prior art: Graphite materials with high density and small particle size are not easily corroded by silicon-rich atmosphere components, which increases the difficulty of carbon particles aggregating into inclusions at the crystal growth site. In addition, the graphite ring has a pyrolytic carbon coating to avoid the introduction of new carbon impurities, while increasing the initial flux, effectively avoiding the corrosion defects often caused by insufficient atmosphere flux in the early stage.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a device for improving the edge quality of a crystal, comprising a graphite crucible, a rotating rod being sleeved on the top of the graphite crucible, a seed crystal holder being arranged on the inner side of the top of the graphite crucible, a seed crystal being arranged on the inner side of the seed crystal holder, the bottom end of the seed crystal holder being connected to porous graphite with a pyrolytic carbon coating via an equal-diameter ring, an anti-corrosion ring being arranged in the middle of the inner side of the graphite crucible, and the top of the anti-corrosion ring being in contact with the porous graphite with the pyrolytic carbon coating.

[0008] As a preferred technical solution of a device for improving the edge quality of a crystal, the graphite crucible is arranged inside a heating component, the heating component comprises a support frame, a telescopic coil, an active cavity, a coil slot and an outer cylinder, the middle of the outer cylinder is provided with an active cavity, the inner side of the active cavity is provided with a support frame, the edge of the outer cylinder is provided with a coil slot, the inner side of the coil slot is provided with a telescopic coil, and the graphite crucible is located inside the active cavity;

[0009] The active cavity can reduce the temperature loss in the graphite crucible.

[0010] As a preferred technical solution of a device for improving the edge quality of a crystal, a base frame is provided at the bottom of the inner side of the active cavity, a driving motor is provided in the middle of the base frame, a power output end of the driving motor is connected to the bottom end of a graphite crucible through a connecting shaft, and a plurality of bearing spheres are provided between the bottom end of the graphite crucible and the supporting frame;

[0011] Graphite crucible contains SiC raw material

[0012] The bearing ball can bear the weight of the graphite crucible and make the rotation of the graphite crucible smoother. The driving motor drives the graphite crucible to rotate through the lead screw.

[0013] As a preferred technical solution for a device for improving the edge quality of a crystal, the heating component further comprises a servo motor, a bottom frame, a wire connection frame, a bottom bracket and a limit rod, a plurality of servo motors are arranged in a circular array at the bottom of the outer cylinder, a screw rod is arranged at the power output end of the servo motor, a limit rod is arranged vertically in the coil slot, a movable frame is slidably connected to the upper part of the limit rod, a wire connection frame is arranged at one end of the movable frame, the wire connection frame is threadedly connected to the corresponding screw rod, a groove is provided at the other end of the movable frame, the groove is clamped with the telescopic coil, a bottom bracket is arranged at the bottom of the other end of the movable frame, the bottom bracket supports the telescopic coil, and a polyethylene strip is arranged at the center of the inner part of the telescopic coil;

[0014] The servo motor drives the lead screw to rotate, and the lead screw drives multiple lead frames to go up and down together. The elastic rope shortens, and the elastic force of the elastic rope pulls the telescopic coils together. The telescopic coils located in the two power supply components are compressed and the number of turns increases, which increases the magnetic field strength.

[0015] As a preferred technical solution for a device for improving the edge quality of a crystal, the inner side of the bearing sphere is a cavity, the inner wall of the cavity is attached to a wear-resistant layer, the inner side of the wear-resistant layer contains tantalum carbide, and the bearing sphere is egg-shaped;

[0016] The particle size of the tantalum carbide is 80-200 meshes.

[0017] The shape of the load-bearing sphere can provide a larger load-bearing area, and the shape of the load-bearing sphere can also better disperse the pressure, making it difficult for the load-bearing sphere to undergo a large deformation, thereby improving the stability of the device operation.

[0018] As a preferred technical solution for a device for improving the edge quality of a crystal, power supply components are provided at the top and the middle of the coil slot, the power supply components include a graphite contact layer, a connecting plate, a connecting column, a spring and a second movable slot, the outer cylinder is provided with two second movable slots near the inner wall of the coil slot, a connecting column is movably inserted in the second movable slot, the connecting columns are in groups of two and are connected to the same connecting plate, a spring is provided on the connecting column, and the spring extends into the second movable slot;

[0019] The graphite contact layer contacts the telescopic coil, and the connecting plate is connected to the circuit, so that the telescopic coil can be partially connected to the passage, so that a stably changing magnetic field can be generated through the telescopic coil.

[0020] As a preferred technical solution for a device for improving the edge quality of a crystal, a top groove is provided on the top of the outer cylinder, and a cover plate is inserted on the top of the top groove;

[0021] The cover plate closes the top groove and the active cavity.

[0022] As a preferred technical solution for a device for improving the edge quality of a crystal, the bottom of the graphite crucible and the inner bottom wall of the heat preservation tube are both provided with concave fitting grooves, and the fitting grooves are movably connected with the bearing spheres;

[0023] The fitting groove matches the outer peripheral shape of the bearing sphere, and the inner wall of the bearing sphere can perfectly fit the graphite crucible, so that the weight of the graphite crucible can be distributed non-centrally on each bearing sphere.

[0024] As a preferred technical solution of a device for improving the edge quality of a crystal, a guide cylinder is provided in the middle of the support frame, the guide cylinder is movably connected to a connecting shaft, and the material of the connecting shaft is non-metal;

[0025] The coil groove enables the connecting shaft to rotate stably.

[0026] As a preferred technical solution for a device for improving the edge quality of a crystal, a pull ring is provided on the telescopic coil, and two upper and lower adjacent pull rings are connected by an elastic rope.

[0027] The device for improving the edge quality of crystals of the present invention has the following beneficial effects: the effective number of turns of the telescopic coil connected to the circuit can be adjusted by the servo motor and the lead screw, the lead screw moves up and down with the multiple wire connecting frames, the elastic rope is shortened, the elastic force of the elastic rope pulls the telescopic coil closer, and the telescopic coil located at the two power supply components is compressed and the number of turns increases, so that the magnetic field strength becomes larger, even if the difference between the extreme values ​​of the changing magnetic field becomes larger, so that the crucible is heated more quickly;

[0028] By placing a porous graphite ring with a pyrolytic carbon coating above the anti-corrosion ring, the void size of the porous graphite ring is smaller than the size of the carbon particles, which can effectively filter the carbon particles produced by the preferential sublimation and graphitization of the powder in the high-temperature area of ​​the anti-corrosion ring and the edge of the crucible near the wall. In addition, because the porous graphite ring has a pyrolytic carbon coating, it has a blocking effect on silicification corrosion and will not form new carbon particle pollution due to its own graphite material, thereby improving the quality of the crystal edge. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0030] Figure 1 It is a front structural schematic diagram of the present invention;

[0031] Figure 2 It is a schematic diagram of the position structure of the bearing sphere and the graphite crucible of the present invention;

[0032] Figure 3 For the present invention Figure 1 A schematic diagram of the partially enlarged structure of part A;

[0033] Figure 4 For the present invention Figure 1 A schematic diagram of the partially enlarged structure of part B;

[0034] Figure 5 For the present invention Figure 1 A schematic diagram of the local enlarged structure of part C in the middle;

[0035] Figure 6 It is a schematic structural diagram of the positional relationship between the pull ring and the telescopic coil of the present invention.

[0036] Figure numerals: 1. seed crystal holder; 2. seed crystal; 3. equal diameter ring; 4. anti-corrosion ring; 5. SiC raw material; 6. graphite crucible; 7. porous graphite with pyrolytic carbon coating; 8. rotating rod; 9. insulation cylinder; 10. load-bearing roller; 11. servo motor; 12. outer cylinder; 13. top groove; 14. cover plate; 15. coil groove; 16. movable cavity; 17. annular fixing frame; 18. connecting shaft; 19. driving motor; 20. telescopic coil; 21. screw rod; 22. bottom frame; 23. fitting groove; 24. graphite contact layer; 25. connecting plate; 26. connecting column; 27. spring; 28. movable groove two; 29. ​​wire connection frame; 30. movable frame; 31. bottom bracket; 32. limit rod; 33. wear-resistant layer; 34. support frame; 35. guide cylinder; 36. elastic rope; 37. pull ring. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0040] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0041] like Figures 1 to 6 As shown, the present invention proposes a device for improving the edge quality of a crystal, comprising a graphite crucible 6, a rotating rod 8 being sleeved on the top of the graphite crucible 6, a seed crystal holder 1 being arranged on the inner side of the top of the graphite crucible 6, a seed crystal 2 being arranged on the inner side of the seed crystal holder 1, a porous graphite 7 with a pyrolytic carbon coating being connected to the bottom end of the seed crystal holder 1 through an equal-diameter ring 3, an anti-corrosion ring 4 being arranged in the middle of the inner side of the graphite crucible 6, and the top of the anti-corrosion ring 4 being in contact with the porous graphite 7 with a pyrolytic carbon coating.

[0042] The annular fixing frame 17 is disposed on the top of the coil slot 15 and connected to the top end of the telescopic coil 20 .

[0043] The graphite crucible 6 is arranged inside the heating component, and the heating component includes a support frame 34, a telescopic coil 20, an active cavity 16, a coil slot 15 and an outer tube 12. The active cavity 16 is opened in the middle of the outer tube 12, and the support frame 34 is arranged inside the active cavity 16. The coil slot 15 is opened at the edge of the outer tube 12, and the telescopic coil 20 is arranged inside the coil slot 15. The graphite crucible 6 is located inside the active cavity 16.

[0044] The active cavity 16 can reduce the temperature loss in the graphite crucible 6 .

[0045] A bottom frame 22 is provided at the bottom of the inner side of the active chamber 16, a driving motor 19 is provided in the middle of the bottom frame 22, a power output end of the driving motor 19 is connected to the bottom end of the graphite crucible 6 through a connecting shaft 18, and a plurality of bearing balls 10 are provided between the bottom end of the graphite crucible 6 and the supporting frame 34;

[0046] The bearing sphere 10 can bear the weight of the graphite crucible 6 and make the rotation of the graphite crucible 6 smoother. The driving motor 19 drives the graphite crucible 6 to rotate through the screw rod 21 .

[0047] The heating component further comprises a servo motor 11, a bottom frame 22, a threaded frame 29, a bottom bracket 31 and a limiting rod 32. The bottom circumferential array of the outer cylinder 12 comprises a plurality of servo motors 11. A threaded rod 21 is arranged at the power output end of the servo motor 11. A limiting rod 32 is vertically arranged in the coil slot 15. A movable frame 30 is slidably connected to the upper portion of the limiting rod 32. A threaded frame 29 is arranged at one end of the movable frame 30. The threaded frame 29 is threadedly connected to the corresponding threaded rod 21. A groove is provided at the other end of the movable frame 30. The groove is clamped with the telescopic coil 20. A bottom bracket 31 is arranged at the bottom of the other end of the movable frame 30. The bottom bracket 31 supports the telescopic coil 20. A polyethylene strip is arranged at the inner center of the telescopic coil 20.

[0048] The servo motor 11 rotates the lead screw 21, and the lead screw 21 moves up and down with the plurality of wire brackets 29, the elastic rope 36 shortens, and the elastic force of the elastic rope 36 pulls the telescopic coils 20 closer together, and the telescopic coils 20 located at the two power supply components are compressed and the number of turns increases, so that the magnetic field strength becomes larger.

[0049] The inner side of the bearing sphere 10 is a cavity, the inner wall of the cavity is attached to the wear-resistant layer 33, the inner side of the wear-resistant layer 33 contains tantalum carbide, and the bearing sphere 10 is egg-shaped;

[0050] The shape of the bearing sphere 10 can provide a larger bearing area, and the shape of the bearing sphere 10 can also better disperse the pressure, so that the bearing sphere 10 is not easy to deform greatly, thereby improving the stability of the device operation.

[0051] The bearing ball 10 is made of high temperature resistant and pressure resistant polyester thermoplastic elastic material.

[0052] The top and middle of the coil slot 15 are both provided with power supply components, which include a graphite contact layer 24, a connecting plate 25, a connecting column 26, a spring 27 and a movable groove 28. The inner wall of the outer cylinder 12 close to the coil slot 15 is provided with two movable grooves 28, and the movable grooves 28 are movably plugged with connecting columns 26. The connecting columns 26 are grouped in two and connected to the same connecting plate 25. The connecting columns 26 are provided with springs 27, and the springs 27 extend into the movable grooves 28.

[0053] The graphite contact layer 24 contacts the telescopic coil 20 , and the connecting plate 25 is connected to the circuit, so that the telescopic coil 20 can be partially connected to the passage, so that a stably changing magnetic field can be generated through the telescopic coil 20 .

[0054] A top groove 13 is formed on the top of the outer cylinder 12, and a cover plate 14 is inserted into the top of the top groove 13;

[0055] The cover plate 14 closes the top groove 13 and the active cavity 16 .

[0056] The bottom of the graphite crucible 6 and the inner bottom wall of the heat preservation tube 9 are both concavely provided with a fitting groove 23, and the fitting groove 23 is movably connected with the supporting ball 10;

[0057] The load-bearing sphere 10 is egg-shaped and has a thin shell structure. When bearing weight, it can transfer pressure downward and outward to adjacent parts.

[0058] The fitting groove 23 matches the outer peripheral shape of the bearing sphere 10 , and the inner wall of the bearing sphere 10 can perfectly fit with the graphite crucible 6 , so that the weight of the graphite crucible 6 can be distributed not concentratedly on each bearing sphere 10 .

[0059] A guide cylinder 35 is disposed in the middle of the support frame 34, and the guide cylinder 35 is movably connected to the connecting shaft 18, and the material of the connecting shaft 18 is non-metal;

[0060] The coil groove 15 enables the connecting shaft 18 to rotate stably.

[0061] The telescopic coil 20 is provided with a pull ring 37 , and two upper and lower adjacent pull rings 37 are connected by an elastic rope 36 .

[0062] The specific implementation method is as follows: 1. Thermal field assembly: All components are processed and assembled, and silicon carbide raw material 5 is filled at the bottom of the crucible. The powder particle size is 20-40 mesh, and the material surface is 95-100mm away from the seed crystal. A 2-3mm thick anti-corrosion ring 4 is placed on the upper part of the powder, and the height of the anti-corrosion ring is about 35-40mm. The graphite equal-diameter ring 3 and the porous graphite ring 7 with pyrolytic carbon coating are placed on the anti-corrosion ring 4. The inner diameter of the graphite equal-diameter ring matches the outer diameter of the porous graphite ring, and the outer diameter is adapted to the inner diameter of the upper part of the crucible. The assembly error does not exceed 0.1mm. The seed crystal holder 1 is placed on the upper part of the graphite equal-diameter ring 3, and the seed crystal 2 is glued to the bottom of the seed crystal holder 1. The outer diameter of the seed crystal holder 1 is adapted to the inner diameter of the crucible, and the lower part is assembled with the graphite equal-diameter ring 3. The seed crystal size can be selected according to actual needs;

[0063] 2. Crystal growth process:

[0064] a. Place the assembled thermal field structure into the heater. The furnace should be sealed intact. Check for leaks and evacuate the furnace. When the internal pressure drops to 0.5-5Pa, turn on the molecular pump to further evacuate to 5*10-3~5*10-2Pa.

[0065] b. Turn on the heating and temperature rise. When the upper and lower temperatures rise to about 1200°C, the heating rate is about 6°C / min. When the target temperature is reached, turn off the molecular pump, and the mechanical pump continues to pump air. The crucible starts to rotate at a rate of 2r / min.

[0066] c. Continue heating to 1600°C at a heating rate of 2-3°C / min. After reaching the target temperature, introduce protective gas Ar2 into the furnace chamber at a gas flow rate of 100-200ml / min, introduce N2 as a doping gas at a gas flow rate of 5-10ml / min, and set the pressure to 300mbar;

[0067] d. Target temperature 1800-2000°C, time 3h, pressure 100-200mbar;

[0068] e. The target temperature is 2100-2200℃ for the upper part and 2200-2300℃ for the lower part. The heating time is 10h. After reaching the target temperature, the pressure is reduced in stages from 100-200mbar to 50-100mbar for 1h; 50-100mbar to 25-50mbar for 1h; 25-50mbar to 5-10mbar for 5h. The temperature and pressure are kept for 90-110h.

[0069] f. Enter the cooling and pressure return stage, and the growth temperature is reduced to room temperature in 10 to 20 hours. The crucible rotation is turned off and the pressure is returned to 800 mbar. After the cooling is completed, the pressure inside the cavity is returned to atmospheric pressure;

[0070] g. Take out the crystal and complete the furnace opening.

[0071] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A device for improving the edge quality of a crystal, characterized in that: The invention comprises a graphite crucible (6), the top of which is sleeved with a rotating rod (8), a seed crystal holder (1) is arranged on the inner side of the top of the graphite crucible (6), a seed crystal (2) is arranged on the inner side of the seed crystal holder (1), the bottom end of the seed crystal holder (1) is connected to a porous graphite (7) with a pyrolytic carbon coating via an equal diameter ring (3), an anti-corrosion ring (4) is arranged in the middle of the inner side of the graphite crucible (6), and the top of the anti-corrosion ring (4) is in contact with the porous graphite (7) with a pyrolytic carbon coating.

2. The device for improving crystal edge quality according to claim 1, characterized in that: The graphite crucible (6) is arranged inside the heating component; The heating component comprises a support frame (34), a telescopic coil (20), a movable cavity (16), a coil slot (15) and an outer tube (12); the movable cavity (16) is provided in the middle of the outer tube (12); the inner side of the movable cavity (16) is provided with a support frame (34); the edge of the outer tube (12) is provided with a coil slot (15); the inner side of the coil slot (15) is provided with a telescopic coil (20); and the graphite crucible (6) is located on the inner side of the movable cavity (16).

3. The device for improving crystal edge quality according to claim 2, characterized in that: A base frame (22) is provided at the bottom of the inner side of the movable chamber (16), a driving motor (19) is provided in the middle of the base frame (22), a power output end of the driving motor (19) is connected to the bottom end of the graphite crucible (6) via a connecting shaft (18), and a plurality of bearing balls (10) are provided between the bottom end of the graphite crucible (6) and the support frame (34).

4. The device for improving crystal edge quality according to claim 1, characterized in that: The heating component further comprises a servo motor (11), a bottom frame (22), a threaded frame (29), a bottom bracket (31) and a limiting rod (32). The bottom circumference array of the outer cylinder (12) comprises a plurality of servo motors (11). The power output end of the servo motor (11) is provided with a threaded rod (21). A limiting rod (32) is vertically arranged in the coil slot (15). A movable frame (30) is slidably connected to the upper part of the limiting rod (32). A threaded frame (29) is provided at one end of the movable frame (30). The threaded frame (29) is threadedly connected to the corresponding threaded rod (21). A groove is provided at the other end of the movable frame (30). The groove is clamped with the telescopic coil (20). A bottom bracket (31) is provided at the bottom of the other end of the movable frame (30). The bottom bracket (31) supports the telescopic coil (20). A polyethylene strip is provided at the center of the inner part of the telescopic coil (20).

5. The device for improving crystal edge quality according to claim 3, characterized in that: The inner side of the load-bearing sphere (10) is a cavity, the inner wall of the cavity is in contact with the wear-resistant layer (33), the inner side of the wear-resistant layer (33) contains liquid, and the load-bearing sphere (10) is egg-shaped.

6. The device for improving crystal edge quality according to claim 1, characterized in that: The top and middle of the coil slot (15) are both provided with power supply components, and the power supply components include a graphite contact layer (24), a connecting plate (25), a connecting column (26), a spring (27) and a movable slot two (28). The inner wall of the outer cylinder (12) close to the coil slot (15) is provided with two movable slots two (28), and the movable slots two (28) are movably inserted with connecting columns (26). The connecting columns (26) are grouped in two and connected to the same connecting plate (25). A spring (27) is provided on the connecting column (26), and the spring (27) extends into the movable slot two (28).

7. The device for improving crystal edge quality according to claim 1, characterized in that: A top groove (13) is provided at the top of the outer cylinder (12), and a cover plate (14) is inserted into the top of the top groove (13).

8. The device for improving crystal edge quality according to claim 1, characterized in that: The bottom of the graphite crucible (6) and the inner bottom wall of the heat-insulating cylinder (9) are both concavely provided with fitting grooves (23), and the fitting grooves (23) are movably connected to the supporting spheres (10) in correspondence.

9. The device for improving crystal edge quality according to claim 1, characterized in that: A guide cylinder (35) is arranged in the middle of the support frame (34), and the guide cylinder (35) is movably connected to the connecting shaft (18), and the material of the connecting shaft (18) is non-metal.

10. The device for improving crystal edge quality according to claim 1, characterized in that: The telescopic coil (20) is provided with a pull ring (37), and two pull rings (37) adjacent to each other are connected via an elastic rope (36).

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