SiC crystal growth thermal insulation equipment and method thereof

Abstract

The invention discloses SiC crystal growth thermal insulation equipment and a method thereof, and relates to the technical field of silicon carbide crystal growth, the SiC crystal growth thermal insulation equipment comprises a thermal insulation barrel, the thermal insulation barrel comprises an upper cover, a base and a barrel body, the barrel body is an open cylindrical barrel, the upper cover and the base are respectively fixed at openings at two ends of the barrel body, a crucible is arranged in the thermal insulation barrel, and the crucible is arranged in the thermal insulation barrel. Raw materials and seed crystals are contained in the crucible, and the outer wall of the crucible is tightly attached to the inner side wall of the heat preservation barrel to guarantee the stability of the crucible. An upper cover, a base and a barrel body of the heat preservation barrel are formed by processing graphite hard felt, a mounting groove is formed in the heat preservation barrel and located below the base, lifting equipment used for driving the heat preservation barrel and a crucible to ascend and descend is mounted in the mounting groove, and a rotating mechanism is used for driving the heat preservation barrel and the crucible to rotate, so that a raw material temperature field in the crucible is more uniform, and crystal shaping is facilitated; a regular convex polyhedron is formed, and crystal form stability is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of silicon carbide crystal growth, and in particular to a SiC crystal growth heat preservation device and a method thereof. Background Art

[0002] As an important third-generation semiconductor material, silicon carbide (SiC) crystal has broad application prospects in power electronics, radio frequency devices, high-temperature devices, etc. due to its excellent properties such as wide bandgap, high breakdown electric field, high thermal conductivity, and high electron saturation mobility. However, the growth process of SiC crystal is extremely complex and has extremely high requirements for the growth environment. In particular, the temperature field and material transmission rate need to be precisely controlled during the crystal growth process to ensure the quality and growth efficiency of the crystal.

[0003] In the growth process of SiC crystals, the physical vapor transport method (PVT method) is usually used, that is, the SiC raw material is sublimated at high temperature and transferred to the surface of the seed crystal through the vapor phase for crystal growth. This process needs to be carried out in a specific temperature field, and the uniformity and stability of the temperature field directly affect the growth quality of the crystal and the integrity of the crystal structure. Existing SiC crystal growth equipment usually uses a graphite crucible as a growth container, and the outside of the crucible is coated with insulation material to maintain the stability of the temperature field. However, traditional insulation materials such as graphite soft felt are difficult to rotate and accurately position the crucible during the growth process due to their soft material and inability to solidify, resulting in uneven temperature field, which in turn affects the quality of crystal growth.

[0004] Specifically, in the prior art, the crucible covered with graphite soft felt is prone to deviate from the center of the quartz cavity during the heating process due to the inability to accurately control the position, resulting in inconsistent distances between the crucible wall and the quartz wall. Since there is circulating cooling water (temperature is about 20°C) in the quartz wall, the temperature of the crucible part close to the quartz wall is lower, while the temperature of the part away from the quartz wall is higher. This temperature difference will lead to inconsistent sublimation and transmission rates of SiC raw materials, and then make SiC molecules preferentially deposited on the side close to the cooling water, resulting in uneven growth of the crystal surface, with one side high and the other side low. This not only affects the growth quality of the crystal, but may also cause interruptions in the crystal growth process, reducing production efficiency and crystal yield.

[0005] In addition, during the heating process, the existing SiC crystal growth equipment usually controls the temperature field by raising and lowering the crucible. However, due to the excellent thermal conductivity of the graphite crucible, the SiC raw material near the crucible wall will sublime first and decompose rapidly, causing the SiC vapor pressure on the surface of the raw material pile to increase rapidly, inhibiting subsequent material transmission and even interrupting the growth process. Therefore, how to achieve rapid and stable temperature rise in the early stage of crystal growth and avoid interruption of the transmission channel caused by high-speed sublimation in the early stage is a problem that needs to be solved in the existing technology. Summary of the invention

[0006] The present invention provides a SiC crystal growth insulation device and method thereof, aiming to solve the problems mentioned in the above-mentioned prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions: A SiC crystal growth insulation device comprises an insulation barrel, the insulation barrel comprises an upper cover, a base and a barrel body, the barrel body is an open cylindrical barrel, the upper cover and the base are respectively fixed at the openings at both ends of the barrel body, a crucible is arranged in the insulation barrel, the crucible contains raw materials and seed crystals, and the outer wall of the crucible is closely attached to the inner wall of the insulation barrel to ensure the stability of the crucible; The upper cover, base and barrel body of the heat preservation barrel are formed by graphite hard felt. The heat preservation barrel is provided with a mounting groove below the base, and a lifting device for driving the heat preservation barrel and the crucible to rise and fall is installed in the mounting groove. The lifting device includes a driving motor, an output end of the driving motor is connected to a rotating shaft, an outer sleeve of the rotating shaft is sleeved with a limiting sleeve, and the rotating shaft and the limiting sleeve are connected by a bearing, a spiral groove is provided on the surface of the rotating shaft, a sliding sleeve is slidably connected inside the limiting sleeve, the sliding sleeve is arranged between the rotating shaft and the limiting sleeve, a positioning slider is arranged on the sliding sleeve, and the positioning slider is slidably arranged in the spiral groove, one side of the rotating shaft is connected to a rotating mechanism via a clutch assembly, and the rotating mechanism is used to drive the rotation of the insulation barrel and the crucible.

[0008] As an optional solution of the SiC crystal growth insulation equipment described in the present invention, the clutch assembly includes a positioning groove opened on the driving motor housing, the positioning groove is arranged on a circle of the driving motor output shaft, the limiting sleeve is integrally connected with a protruding ring at one end of the rotating shaft, the protruding ring is arranged in a cylindrical shape, a ring sleeve is slidably arranged on the protruding ring, a positioning protrusion is arranged on one side of the ring sleeve, and the positioning protrusion and the positioning groove are matched and clamped with each other.

[0009] As an optional solution of the SiC crystal growth insulation device of the present invention, a chamfered surface is provided on one side of the ring sleeve, a mounting shaft is provided on one side of the ring sleeve, an eccentric wheel is installed on the mounting shaft, the eccentric wheel and the chamfered surface on the ring sleeve match each other, a handle is connected to one end of the mounting shaft, and a locking mechanism is provided on one side of the mounting shaft; The locking mechanism comprises a ring groove formed on the outer surface of the mounting shaft, a ratchet groove is arranged in the ring groove, a spring sheet is arranged on one side of the mounting shaft, a clamping block is arranged on the spring sheet, and the clamping block and the ratchet groove are matched and clamped with each other.

[0010] As an optional solution of the SiC crystal growth insulation device of the present invention, the rotating mechanism includes a guide rod connected to the other end of the sliding sleeve, and the guide rod passes through the limit sleeve, the other end of the guide rod is threadedly connected to an adjustment rod, and the other end of the adjustment rod is connected and fixed to the mounting groove below the base; The guide rod is provided with a limiting sliding groove, the limiting sleeve is provided with a protrusion matching the limiting sliding groove, and the protrusion is slidably arranged in the limiting sliding groove.

[0011] As an optional solution of the SiC crystal growth insulation equipment described in the present invention, the crucible includes a crucible body, a crucible cover and a crystallizer installed on the crucible body, the SiC raw material is loaded in the crucible, the seed crystal is fixed on the crystallizer of the crucible cover, the bottom of the crucible body is provided with a U-shaped protrusion structure, the lower side of the U-shaped protrusion structure is a hollow structure, the outer end opening of the U-shaped protrusion structure is smaller than the inner end opening diameter, the upper surface of the base is provided with an insertion part matching the U-shaped protrusion structure, and the insertion part is inserted into the hollow of the U-shaped protrusion structure.

[0012] As an optional solution of the SiC crystal growth insulation equipment described in the present invention, a crystal growth furnace quartz furnace is arranged on the outside of the insulation barrel, an electromagnetic induction coil is arranged on the outside of the crystal growth furnace quartz furnace, the crystal growth furnace quartz furnace is a double-layer quartz glass furnace, and circulating cooling water is filled in the middle of the double-layer quartz glass furnace, the crystal growth furnace quartz furnace.

[0013] As an optional solution for the SiC crystal growth insulation equipment described in the present invention, a flange is provided on the lower surface of the upper cover, a groove for embedding the crucible cover is provided on the flange, a circle of grooves is provided on the side of the groove, and a sealing protrusion is provided on one side of the groove.

[0014] A method for SiC crystal growth insulation equipment, the method is as follows: a. Place the crucible containing raw materials and seed crystals in an insulation barrel, close to the side wall of the insulation barrel; b. Fix the insulation barrel including the upper cover, base and barrel body on the outside of the crucible to ensure the stability of the crucible; c. Start the drive motor. The heat preservation barrel and the crucible can be raised, lowered or rotated under the control of the clutch assembly. The height can be adjusted according to the electromagnetic induction coil set outside the crystal growth furnace quartz furnace; d. The crucible is rotated evenly in the quartz furnace of the crystal growth furnace. The crucible rotates evenly, and the entire temperature field is more uniform for the SiC raw material in the crucible, which is helpful for crystal shaping, forming a regular convex polyhedron, and promoting crystal stability.

[0015] Technical effects and advantages of the present invention: 1. In order to control the temperature of the crucible in this case, it is necessary to control the position of the crucible at the induction coil. When the crucible needs to be driven up and down, it is only necessary to fix the limit sleeve and drive the motor to drive the rotation of the rotating shaft. Since a spiral groove is provided on the rotating shaft, the slider on the sliding sleeve can slide in the spiral groove, thereby driving the sliding sleeve to move up and down. The sliding sleeve drives the crucible to move up and down, making it convenient to adjust the position of the crucible.

[0016] 2. In this case, when the crucible needs to be rotated, the handle can be turned to drive the installation shaft to rotate, and the installation shaft then drives the eccentric wheel to rotate. The eccentric wheel contacts the beveled surface on the ring sleeve, so when the eccentric wheel rotates, the ring sleeve can be pressed to move. The spring allows the positioning protrusion under the ring sleeve to disengage from the positioning groove, so that the limit sleeve is not fixed. The driving motor can drive the rotation of the rotating mechanism, thereby driving the crucible. The crucible is inductively heated during the rotation process, and the crucible rotates. For the raw material in the crucible, the entire temperature field is more uniform, which is conducive to the crystal shaping, forming a regular convex polyhedron, and promoting the stability of the crystal form.

[0017] 3. A U-shaped protruding structure is provided at the bottom of the crucible body. The U-shaped protruding structure makes the bottom of the crucible body protrude upward, thereby reducing the distance between the position where the SiC raw material is placed at the bottom of the crucible body and the crucible wall, so that the heat of the crucible wall can be quickly transferred to the SiC raw material, and the SiC raw material is heated more evenly in the crucible body. In addition, the outside of the U-shaped protruding structure is a hollow structure. At the same time, when the insulation barrel is covered on the outside of the crucible, the insertion part on the base can be inserted into the hollow structure. Since the diameter of one end of the insertion part is larger than the diameter of the other end, the insertion part is not easy to fall off after being inserted into the hollow structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a partial cross-sectional structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the structure of the heat preservation barrel of the present invention; Figure 4 This is a schematic diagram of the internal structure of the heat preservation barrel of the present invention; Figure 5 It is a schematic diagram of the cross-sectional structure of the heat preservation barrel and the crucible of the present invention; Figure 6 For the present invention Figure 5 The enlarged structural diagram at A in the middle; Figure 7 It is a schematic diagram of the structure of the clutch assembly of the present invention; Figure 8 For the present invention Figure 7 The enlarged structural diagram at B in the middle; Fig. 9It is a schematic diagram of the three-dimensional structure of the lifting device of the present invention; Fig.10 It is a schematic diagram of the three-dimensional structure of the locking mechanism of the present invention; Fig.11 It is a schematic diagram of the locking mechanism structure of the present invention.

[0019] Description of the numbers in the figure: 1. Insulated barrel; 11. Upper cover; 111. Flange; 112. Embedded groove; 113. Clamping groove; 114. Sealing protrusion; 12. Base; 121. Mounting groove; 122. Insertion part; 13. Barrel body; 2. Crucible; 21. Crucible body; 22. Crucible cover; 23. U-shaped protruding structure; 3. Lifting device; 31. Driving motor; 32. Rotating shaft; 33. Limiting sleeve; 34. Spiral groove; 35. Sliding sleeve; 36. Positioning slider; 37. Clutch assembly; 371. Positioning groove; 372. Projecting ring; 373. Ring sleeve; 374. Positioning protrusion; 375. Beveled surface; 376. Mounting shaft; 377. Eccentric wheel; 378. Turning handle; 38. Rotating mechanism; 381. Guide rod; 382. Adjusting rod; 383. Limiting slide groove; 384. Protrusion; 39. Locking mechanism; 391. Ring groove; 392. Ratchet groove; 393. Shrapnel; 394. Block; 4. Crystal growth furnace quartz furnace; 5. Electromagnetic induction coil. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 Please refer to the attached Figure 1 and Figure 2 , a SiC crystal growth insulation equipment, including an insulation barrel 1, the insulation barrel 1 includes an upper cover 11, a base 12 and a barrel body 13, the barrel body 13 is an open cylindrical barrel, the upper cover 11 and the base 12 are respectively fixed at the openings at both ends of the barrel body 13, the upper cover 11, the base 12 and the barrel body 13 of the insulation barrel 1 are formed by graphite hard felt, the insulation barrel 1 is equipped with a crucible 2, the crucible 2 is filled with raw materials and seed crystals, and the outer wall of the crucible 2 is close to the inner wall of the insulation barrel 1; The outer side of the crucible 2 is coated with a heat-insulating material. In the prior art, the heat-insulating material is generally coated with graphite soft felt. However, the graphite soft felt is soft. Since the soft felt cannot solidify, the crucible 2 is in a static state during the entire crystal growth process. Due to the soft felt, the domestic process cannot realize the rotation of the crucible 2 with material. During the heating process, if the crucible 2 cannot be placed in the center of the quartz cavity, part of the crucible wall will be close to the quartz wall, and part of the crucible wall will be far away from the quartz wall. Since the circulating cooling water on the quartz wall is only about 20°C, this will cause the temperature field in the crucible to change, the transmission rate of the powder is inconsistent, and the SiC molecules will preferentially deposit on the side close to the cooling water, resulting in one side of the crystal plane being high and the other side being low, thereby affecting the growth of the SiC crystal; In the present application, the upper cover 11, the base 12 and the barrel body 13 in the heat preservation barrel 1 are formed by graphite hard felt, and the upper cover 11, the base 12 and the barrel body 13 are tightly fitted and fixed to the crucible 2, which can effectively prevent the crucible 2 from shaking due to unstable contact with the heat preservation barrel 1 during the rotation process, thereby ensuring the stability of the crucible 2.

[0022] Example 2 Please refer to the attached Figure 3-11 The insulation barrel 1 is provided with a mounting groove 121 below the base 12, and a lifting device 3 for driving the insulation barrel 1 and the crucible 2 to rise and fall is installed in the mounting groove 121; The lifting device 3 includes a driving motor 31, which is installed in the crystal growth furnace quartz furnace 4. A rotating shaft 32 is connected to the output end of the driving motor 31. A limiting sleeve 33 is sleeved on the outer side of the rotating shaft 32, and the rotating shaft 32 and the limiting sleeve 33 are connected through a bearing. A spiral groove 34 is provided on the surface of the rotating shaft 32. A sliding sleeve 35 is slidably connected inside the limiting sleeve 33. The sliding sleeve 35 is arranged between the rotating shaft 32 and the limiting sleeve 33. A positioning slider 36 is arranged on the sliding sleeve 35. The positioning slider 36 is slidably arranged in the spiral groove 34. One side of the rotating shaft 32 is connected to a rotating mechanism 38 through a clutch assembly 37. The rotating mechanism 38 is used to drive the rotation of the insulation barrel 1 and the crucible 2.

[0023] When the crucible 2 is heated by the induction coil, the crucible 2 is located at a height within the induction coil and is affected by the heating of the induction coil. When the crucible 2 is completely placed in the induction coil, the heating effect is good. When a part of the crucible 2 is placed in the induction coil, an obvious temperature difference can be made in the crucible 2. The crystal growth process is achieved by utilizing the temperature difference in the crucible 2. The principle of crystal growth is: SiC wafers are used as seed crystals, and SiC powder is placed in a graphite crucible as a growth raw material. By controlling the growth temperature in the crucible, the growth raw material is decomposed into gas phase components and then transported to the seed crystal driven by the axial temperature gradient inside the graphite crucible to crystallize and grow SiC crystals.

[0024] However, due to the excellent thermal conductivity of the graphite crucible, the temperature near the crucible wall is higher than the center temperature. The SiC raw material near the crucible wall will decompose first, and the decomposition rate is the fastest, and then sublimate along the wall to the seed crystal, and then the entire raw material pile will begin to react. The rapid rate at the beginning will also cause the SiC vapor pressure decomposed on the surface of the raw material pile to be greater than the equilibrium pressure, inhibiting transmission, the raw material will stop decomposing, and the growth will be interrupted. Therefore, for the initial heating stage of crystal growth, rapid and stable heating to the temperature at which the raw material sublimates is beneficial to prevent high-rate sublimation in the initial stage and avoid interruption of the transmission channel.

[0025] In the present application, in order to control the temperature of the crucible 2, it is necessary to control the position of the crucible 2 at the induction coil. When it is necessary to drive the crucible 2 to rise and fall, it is only necessary to fix the limit sleeve 33 and drive the motor 31 to drive the rotation of the rotating shaft 32. Since a spiral groove 34 is provided on the rotating shaft 32, the slider 36 on the sliding sleeve 35 can slide in the spiral groove 34, thereby driving the sliding sleeve 35 to rise and fall. The sliding sleeve 35 drives the crucible 2 to rise and fall, which facilitates the adjustment of the position of the crucible 2.

[0026] Specifically, the clutch assembly 37 includes a positioning groove 371 opened on the outer casing of the driving motor 31, the positioning groove 371 is set on a circle of the output shaft of the driving motor 31, the limiting sleeve 33 is sleeved on one end of the rotating shaft 32 and is integrally connected with a protruding ring 372, the protruding ring 372 is cylindrically set, a ring sleeve 373 is slidably set on the protruding ring 372, a spring is sleeved under the ring sleeve 373, and a positioning protrusion 374 is set on one side of the ring sleeve 373, and the positioning protrusion 374 and the positioning groove 371 are matched and clamped with each other. A beveled surface 375 is provided on one side of the ring sleeve 373, and a mounting shaft 376 is provided on one side of the ring sleeve 373. An eccentric wheel 377 is installed on the mounting shaft 376, and the eccentric wheel 377 matches the beveled surface 375 on the ring sleeve 373. A turning handle 378 is connected to one end of the mounting shaft 376, and a locking mechanism 39 is provided on one side of the mounting shaft 376; the locking mechanism 39 includes a circle of annular groove 391 provided on the outer surface of the mounting shaft 376, and a ratchet groove 392 is provided in the annular groove 391. A spring piece 393 is provided on one side of the mounting shaft 376, and a clamping block 394 is provided on the spring piece 393. The clamping block 394 and the ratchet groove 392 are matched and clamped with each other, and the locking mechanism 39 is installed in the outer shell of the crystal growth furnace quartz furnace 4.

[0027] During the heating process of the crucible 2, if the temperature is controlled only by lifting and lowering, the distance between the SiC raw material and the crucible wall is different, which easily leads to temperature differences. The SiC raw material is heated quickly when it is close to the crucible wall, and it is heated slowly when it is far away. In order to make the temperature of the crucible 2 more uniform during the heating process, the entire crucible assembly can be rotated during the crystal growth process; When the crucible 2 needs to be rotated, the handle 378 can be turned to drive the installation shaft 376 to rotate, and the installation shaft 376 then drives the eccentric wheel 377 to rotate. The eccentric wheel 377 contacts the beveled surface 375 on the ring sleeve 373, so when the eccentric wheel 377 rotates, the ring sleeve 373 can be pressed to move. The spring allows the positioning protrusion 374 under the ring sleeve 373 to disengage from the positioning groove 371, so that the limiting sleeve 33 is not fixed, and the driving motor 31 can drive the rotation of the rotating mechanism 38, thereby driving the rotation of the crucible 2. The crucible 2 is inductively heated during the rotation process, and the crucible 2 rotates. For the raw material in the crucible 2, the entire temperature field is more uniform, which is conducive to crystal shaping, forming a regular convex polyhedron, and promoting crystal stability.

[0028] In a specific implementation, the rotating mechanism 38 includes a guide rod 381 connected to the other end of the sliding sleeve 35, and the guide rod 381 passes through the limiting sleeve 33, and the other end of the guide rod 381 is threadedly connected to the adjusting rod 382, ​​and the other end of the adjusting rod 382 is connected and fixed to the mounting groove 121 below the base 12; A limiting sliding groove 383 is provided on the guide rod 381 , and a protrusion 384 matching the limiting sliding groove 383 is provided on the limiting sleeve 33 , and the protrusion 384 is slidably disposed in the limiting sliding groove 383 .

[0029] By rotating the adjusting rod 382 , the distance between the guide rod 381 and the base 12 can be adjusted to accommodate crucibles 2 of different sizes.

[0030] Example 3 Please refer to the attached Figure 4 , Figure 5 and Figure 6 The crucible 2 includes a crucible body 21, a crucible cover 22 and a crystallizer mounted on the crucible body 21. The SiC raw material is mounted in the crucible 2, and the seed crystal is fixed on the crystallizer of the crucible cover 22. The bottom of the crucible body 21 is provided with a U-shaped protrusion structure 23. The lower side of the U-shaped protrusion structure 23 is a hollow structure. The outer end opening of the U-shaped protrusion structure 23 is smaller than the inner end opening diameter. The upper surface of the base 12 is provided with an insertion portion 122 matching the U-shaped protrusion structure 23. The insertion portion 122 is inserted into the hollow of the U-shaped protrusion structure 23. A crystal growth furnace quartz furnace 4 is arranged on the outside of the heat preservation barrel 1. An electromagnetic induction coil 5 is arranged on the outside of the crystal growth furnace quartz furnace 4. The crystal growth furnace quartz furnace 4 is a double-layer quartz glass furnace, and circulating cooling water is filled in the middle of the double-layer quartz glass furnace. The lower surface of the upper cover 11 is provided with a flange 111, and the flange 111 is provided with an embedding groove 112 for embedding the crucible cover 22. The flange 111 is provided with a circle of grooves 113 on the side of the embedding groove 112, and a sealing protrusion 114 is provided on one side of the groove 113 of the flange 111.

[0031] After the heat preservation barrel 1 covers the crucible 2, since the outer surface of the crucible 2 is relatively smooth, the heat preservation barrel 1 is easy to fall off after being connected to the crucible 2, which greatly affects the subsequent heating treatment of the crucible 2. The present application provides a U-shaped protruding structure 23 at the bottom of the crucible body 21. The U-shaped protruding structure 23 makes the bottom of the crucible body 21 protrude upward, reduces the distance between the position where the SiC raw material is placed at the bottom of the crucible body 21 and the wall of the crucible 2, so that the heat of the crucible 2 wall can be quickly transferred to the SiC raw material, and the SiC raw material is heated more evenly in the crucible body 21. In addition, the outside of the U-shaped protruding structure 23 is a hollow structure. At the same time, when the heat preservation barrel 1 is covered on the outside of the crucible 2, the insertion part 122 on the base 12 can be inserted into the hollow structure. Since the diameter of one end of the insertion part 122 is larger than the diameter of the other end, the insertion part 122 is not easy to fall off after being inserted into the hollow structure. In addition, in order to prevent the upper cover 11 from falling, after the upper cover 11 is covered on the crucible cover 22, the crucible cover 22 is inserted into the flange 111 of the upper cover 11, and the sealing protrusion 114 provided on the flange 111 enters into the slot 113 under the action of the extrusion force. Since the sealing protrusion 114 always has an outward force, the upper cover 11 can be clamped on the crucible cover 22.

[0032] Example 4 A method for SiC crystal growth insulation equipment, the method is as follows: a. Place the crucible 2 containing the raw materials and seed crystals in a heat preservation barrel, close to the side wall of the heat preservation barrel; b. Fix the heat preservation barrel 1 including the upper cover 11, the base 12 and the barrel body 13 on the outside of the crucible 2 to ensure the stability of the crucible 2; c. Start the driving motor 31. The heat preservation barrel 1 and the crucible 2 can be raised or lowered or rotated under the control of the clutch assembly 37. The height can be adjusted by the electromagnetic induction coil 5 disposed outside the crystal growth furnace quartz furnace 4; d. The crucible 2 is rotated evenly in the crystal growth furnace quartz furnace 4. The crucible 2 rotates evenly, and the entire temperature field is more uniform for the SiC raw material in the crucible 2, which is helpful for crystal shaping, forming a regular convex polyhedron, and promoting crystal stability.

[0033] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A SiC crystal growth insulation device, comprising an insulation barrel, characterized in that: The heat preservation barrel comprises an upper cover, a base and a barrel body, the barrel body is an open cylindrical barrel, the upper cover and the base are respectively fixed at the openings at both ends of the barrel body, a crucible is installed in the heat preservation barrel, the crucible is filled with raw materials and seed crystals, and the outer wall of the crucible is closely attached to the inner wall of the heat preservation barrel to ensure the stability of the crucible; The upper cover, base and barrel body of the heat preservation barrel are formed by graphite hard felt. The heat preservation barrel is provided with a mounting groove below the base, and a lifting device for driving the heat preservation barrel and the crucible to rise and fall is installed in the mounting groove. The lifting device includes a driving motor, an output end of the driving motor is connected to a rotating shaft, an outer sleeve of the rotating shaft is sleeved with a limiting sleeve, and the rotating shaft and the limiting sleeve are connected by a bearing, a spiral groove is provided on the surface of the rotating shaft, a sliding sleeve is slidably connected inside the limiting sleeve, the sliding sleeve is arranged between the rotating shaft and the limiting sleeve, a positioning slider is arranged on the sliding sleeve, and the positioning slider is slidably arranged in the spiral groove, one side of the rotating shaft is connected to a rotating mechanism via a clutch assembly, and the rotating mechanism is used to drive the rotation of the insulation barrel and the crucible.

2. The SiC crystal growth insulation equipment according to claim 1, characterized in that: The clutch assembly includes a positioning groove opened on the driving motor housing, the positioning groove is arranged on a circle of the driving motor output shaft, the limiting sleeve is integrally connected with a protruding ring at one end of the rotating shaft, the protruding ring is arranged in a cylindrical shape, a ring sleeve is slidably arranged on the protruding ring, a positioning protrusion is arranged on one side of the ring sleeve, and the positioning protrusion and the positioning groove are matched and clamped with each other.

3. The SiC crystal growth insulation equipment according to claim 3, characterized in that: A chamfered surface is provided on one side of the ring sleeve, a mounting shaft is provided on one side of the ring sleeve, an eccentric wheel is installed on the mounting shaft, the eccentric wheel and the chamfered surface on the ring sleeve match each other, a turning handle is connected to one end of the mounting shaft, and a locking mechanism is provided on one side of the mounting shaft; The locking mechanism comprises a ring groove formed on the outer surface of the mounting shaft, a ratchet groove is arranged in the ring groove, a spring sheet is arranged on one side of the mounting shaft, a clamping block is arranged on the spring sheet, and the clamping block and the ratchet groove are matched and clamped with each other.

4. The SiC crystal growth insulation equipment according to claim 3, characterized in that: The rotating mechanism includes a guide rod connected to the other end of the sliding sleeve, and the guide rod passes through the limiting sleeve, the other end of the guide rod is threadedly connected to an adjusting rod, and the other end of the adjusting rod is connected and fixed to the mounting groove below the base; The guide rod is provided with a limiting sliding groove, the limiting sleeve is provided with a protrusion matching the limiting sliding groove, and the protrusion is slidably arranged in the limiting sliding groove.

5. The SiC crystal growth insulation equipment according to claim 1, characterized in that: The crucible includes a crucible body, a crucible cover and a crystallizer installed on the crucible body, SiC raw material is installed in the crucible, and seed crystal is fixed on the crystallizer of the crucible cover. The bottom of the crucible body is provided with a U-shaped protrusion structure, the lower side of the U-shaped protrusion structure is a hollow structure, the outer end opening of the U-shaped protrusion structure is smaller than the inner end opening diameter, and the upper surface of the base is provided with an insertion part matching the U-shaped protrusion structure, and the insertion part is inserted into the hollow of the U-shaped protrusion structure.

6. The SiC crystal growth insulation equipment according to claim 1, characterized in that: A crystal growth furnace quartz furnace is arranged on the outside of the heat preservation barrel, an electromagnetic induction coil is arranged on the outside of the crystal growth furnace quartz furnace, the crystal growth furnace quartz furnace is a double-layer quartz glass furnace, and circulating cooling water is filled in the middle of the double-layer quartz glass furnace.

7. The SiC crystal growth insulation equipment according to claim 1, characterized in that: The lower surface of the upper cover is provided with a flange, the flange is provided with an embedding groove for embedding the crucible cover, the flange is provided with a circle of clamping grooves on the side of the embedding groove, and the flange is provided with a sealing protrusion on one side of the clamping groove.

8. A method for implementing the SiC crystal growth insulation equipment according to any one of claims 1 to 7, characterized in that: Here’s how: a. Place the crucible containing raw materials and seed crystals in an insulation barrel, close to the side wall of the insulation barrel; b. Fix the insulation barrel including the upper cover, base and barrel body on the outside of the crucible to ensure the stability of the crucible; c. Start the drive motor. The heat preservation barrel and the crucible can be raised, lowered or rotated under the control of the clutch assembly. The height can be adjusted according to the electromagnetic induction coil set outside the crystal growth furnace quartz furnace; d. The crucible is rotated evenly in the quartz furnace of the crystal growth furnace. The crucible rotates evenly, and the entire temperature field is more uniform for the SiC raw material in the crucible, which is helpful for crystal shaping, forming a regular convex polyhedron, and promoting crystal stability.

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