Silicon carbide crystal growing device

Abstract

The utility model discloses a silicon carbide crystal growing device which comprises a first crucible, a second crucible, a porous graphite cylinder, a graphite cylinder, a partition plate, an exhaust component, a seed crystal mounting component and a heat preservation component, the second crucible is coaxially arranged in the first crucible, a second crucible cover covers the upper part of the second crucible, and a through hole is formed in the second crucible cover; the porous graphite cylinder is coaxially mounted in the second crucible; the graphite cylinder is coaxially mounted on the inner side of the porous graphite cylinder, a set gap is formed between the graphite cylinder and the porous graphite cylinder, and the graphite cylinder, the porous graphite cylinder and the second crucible are the same in height; the partition plate is arranged in the graphite cylinder, and the partition plate can be corroded, fractured and sunk in the crystal growth process; the exhaust component covers the upper part of the first crucible; the seed crystal mounting assembly is arranged at the upper part of the exhaust assembly; the seed crystal is mounted on the inner wall of the seed crystal mounting assembly; the heat preservation assembly wraps the outer sides of the crucible, the exhaust assembly and the seed crystal mounting assembly.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a silicon carbide crystal growth apparatus. Background Technology

[0002] Related technologies indicate that silicon carbide crystals are grown using the physical vapor transport (PTV) method. During crystal growth, due to the "skin effect" of induction heating or the heat conduction effect of resistance heating, the upper part of the crucible center remains in a lower temperature crystallization region. Within this region, a large amount of aggregated 6H-SiC ceramic material exists. The position of the high-temperature region does not change with crystal growth; its relative position depends only on the position and power of the electromagnetic induction coil relative to the crucible, as well as the thermal insulation performance of the crucible.

[0003] As the crystal grows, the crystal growth interface moves towards the high-temperature region, meaning the temperature of the crystal growth interface continuously increases. Therefore, to maintain high crystal quality, the high-temperature region needs to be shifted relatively downwards. This is typically achieved by moving the position of the electromagnetic induction coil or the stage (used to support the crucible). Thus, during crystal growth, the high-temperature region gradually decreases, which is beneficial for crystal growth with higher crystal quality. However, this also increases the formation and crystallinity of the 6H-SiC ceramic body, especially when the temperature at the bottom of the crucible is high and the crystal growth interface temperature is low. The 6H-SiC ceramic body forms a denser structure. The formation of the ceramic body prevents some powder source from being utilized, reducing the powder source utilization rate. In addition, the ceramic body blocks the straight-line rise of silicon carbide gas, which needs to rise from around the ceramic body to the crystal growth region. Therefore, this ultimately results in a concave crystal growth surface, affecting the crystal growth quality. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a silicon carbide crystal growth apparatus that can improve the utilization rate of powder source and produce silicon carbide crystals with flat crystal growth surfaces.

[0005] A silicon carbide crystal growth apparatus according to this utility model includes a first crucible, a second crucible, a porous graphite cylinder, a graphite cylinder, a partition, an exhaust assembly, a seed crystal mounting assembly, and a heat preservation assembly. The second crucible is coaxially placed inside the first crucible, with its outer wall tightly against the inner wall of the first crucible. A second crucible lid is placed on the top of the second crucible, and the second crucible lid has a through hole. The porous graphite cylinder is coaxially installed inside the second crucible, and its outer wall and the inner wall of the second crucible together define a first loading space. The graphite cylinder is coaxially installed inside the porous graphite cylinder, and a set gap exists between the graphite cylinder and the porous graphite cylinder. The graphite cylinder, the porous graphite cylinder, and the second crucible are all connected together. The heights are the same; the partition is disposed inside the graphite cylinder, and the partition can be corroded and fractured during the crystal growth process, dividing the graphite cylinder into an upper loading space and a lower loading space; the venting assembly covers the upper part of the first crucible, and the bottom of the venting assembly is in close contact with the upper surface of the second crucible cover; the seed crystal mounting assembly is disposed above the venting assembly, and the inner wall of the seed crystal mounting assembly, the inner side wall of the venting assembly, and the outer wall of the crucible cover together define the crystal growth area, and the seed crystal is mounted on the inner wall of the seed crystal mounting assembly; the heat insulation assembly wraps around the outside of the crucible, the venting assembly, and the seed crystal mounting assembly, and the top wall of the heat insulation assembly has a set gap with the top wall of the seed crystal mounting assembly.

[0006] Preferably, the upper part of the venting assembly of this utility model extends radially outward to form an extension portion, and the venting assembly covers the upper part of the first crucible through the extension portion. There is a certain gap between the outer side wall of the venting assembly and the inner side wall of the first crucible. The upper part of the venting assembly defines an annular groove for accommodating the seed crystal mounting assembly, and venting holes are provided on both the side wall of the venting assembly and the extension portion.

[0007] Preferably, the seed crystal mounting assembly of this utility model includes a seed crystal mounting plate and an annular graphite pressure plate. The seed crystal mounting plate is installed in the annular groove, and the annular graphite pressure plate is placed on the upper part of the seed crystal mounting plate. The width of the annular graphite pressure plate is the same as the width of the annular groove. The seed crystal is installed on the lower surface of the seed crystal mounting plate. The lower surface of the seed crystal mounting plate and the inner wall of the exhaust assembly together define the crystal growth area.

[0008] Preferably, the partition of this utility model includes a main body component and a connecting component. The connecting component is connected to the outside of the main body component. The partition is installed inside the second crucible through the connecting component. The main body component has through holes evenly distributed on it. The thickness of the partition component is greater than the thickness of the connecting component. The connecting component can be corroded and broken during the crystal growth process.

[0009] Preferably, the partition of this utility model includes a main body component and a connecting component, and multiple main body components and connecting components are provided and spaced apart. The partition is connected to the inner wall of the second crucible through the outermost connecting component. The main body component has through holes evenly distributed on it, and the thickness of the partition component is greater than the thickness of the connecting component.

[0010] Preferably, the main component of the partition of this utility model has a thickness of 10-15mm, the connecting part has a thickness of 4-6mm, and the vertical height of the lower loading space is 50-70mm.

[0011] Preferably, the silicon carbide powder contained in the first loading space and the upper loading space of this invention has a particle size of 10-20 mesh and a purity of 99.999%; the silicon carbide powder contained in the upper loading space has a particle size of 30-40 mesh and a purity of 99.999%; and the silicon carbide powder above the second crucible lid has a particle size of 80-100 mesh and a purity of 99.9999999%.

[0012] Preferably, the diameter of the round holes on the porous graphite cylinder of this utility model is 2.5-3mm, the distance between the round holes is 1.5mm, the outer diameter of the porous graphite cylinder is 120-140mm, the wall thickness is 10-15mm, and the diameter of the through hole is 2mm.

[0013] Preferably, the graphite cylinder of this utility model has an outer diameter of 100-120mm and a wall thickness of 5mm.

[0014] Preferably, the first crucible, the second crucible, the porous graphite cylinder, and the graphite cylinder of this utility model are all made of graphite material.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) This invention divides the interior of the crucible into multiple loading spaces using a porous graphite cylinder, a graphite tube, and a partition. The partition separates the interior of the graphite cylinder into upper and lower loading spaces. The upper loading space is located away from the low-temperature zone, where ceramic bodies are prone to form. During crystal growth, the partition of this invention corrodes and breaks over time. After breakage, the main body of the partition moves downward, and the silicon carbide powder in the upper loading space also moves downward with the main body to a position closer to the high-temperature zone, thus avoiding the formation of ceramic bodies in the upper loading space and improving the utilization rate of the powder. In addition, the silicon carbide gas is not affected by ceramic bodies during its ascent and does not need to rise from the side to the crystal growth interface, which helps to improve the flatness of the crystal growth surface and avoids the technical problem of concave crystal growth surfaces, thereby improving the quality of crystal growth.

[0017] 2) In this invention, only the silicon carbide powder above the partition collapses and moves downward, resulting in a small collapse area and minimal impact on the interior of the powder source. This further avoids carbon encapsulation and is beneficial to improving the growth quality of the crystal. This invention further reduces the impact of changes within the powder source on crystal growth by sacrificing some of the material.

[0018] 3) In this invention, the silicon carbide powder near the high-temperature zone (the area near the side wall and bottom of the second crucible) has a relatively large particle size and low purity requirements, while the silicon carbide powder far from the high-temperature zone has a small particle size and high purity. The silicon carbide powder above the second crucible lid has the smallest particle size and the highest purity. The silicon carbide powder here can filter the silicon carbide gas sublimating from below, improving the cleanliness of the silicon carbide gas. At the same time, it can neutralize the carbon element in the silicon carbide gas, avoid carbon encapsulation defects, and improve the crystal growth quality. Therefore, the silicon carbide powder in the second crucible of this invention does not have high requirements for particle size and purity, reducing the cost of raw materials and thus reducing production costs.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional schematic diagram of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional schematic diagram of the exhaust assembly and seed crystal assembly of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic cross-sectional view of the partition plate of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0024] Figure 5 This is a cross-sectional schematic diagram of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the interface of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic cross-sectional view of the partition plate of a silicon carbide crystal growth apparatus according to an embodiment of the present invention;

[0027] Figure label:

[0028] 100: Silicon carbide crystal growth apparatus; 101: Electromagnetic induction coil;

[0029] 10: Exhaust assembly; 11: Extension; 111: Exhaust port;

[0030] 20: First crucible; 21: First loading space;

[0031] 30: First crucible; 31: Second crucible lid;

[0032] 40: Porous graphite cylinder;

[0033] 50: Graphite cylinder; 51: Upper loading space; 52: Lower loading space; 53: Partition; 531: Main component; 5311: Through hole; 532: Connecting component;

[0034] 70: Seed crystal mounting component; 71: Seed crystal mounting plate; 72: Graphite pressure plate;

[0035] 80: Seed crystal;

[0036] 90: Thermal insulation components; Detailed Implementation

[0037] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0038] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0039] Example 1

[0040] The following is for reference. Figures 1 to 5The silicon carbide crystal growth apparatus 100 according to an embodiment of the present invention includes a first crucible 20, a second crucible 30, a porous graphite cylinder 40, a graphite cylinder 50, a partition 53, an exhaust assembly 10, a seed crystal mounting assembly 70, a heat preservation assembly, and an electromagnetic induction coil 10. The second crucible 30 is coaxially placed inside the first crucible 20, with its outer wall tightly attached to the inner wall of the first crucible 20. A second crucible cover 31 covers the upper part of the second crucible 30, and the second crucible cover 31 has a through hole 5311, which allows silicon carbide gas to rise uniformly to the crystal growth area. The porous graphite cylinder 40 is coaxially installed inside the second crucible 30, and its outer wall and the inner wall of the second crucible 30 together define a first loading space 21. The graphite cylinder 50 is coaxially installed inside the porous graphite cylinder 40. Inside the graphite cylinder 40, there is a certain gap between the graphite cylinder 50 and the porous graphite cylinder 40, which is conducive to the upward transport of the decomposed and sublimated gas phase components of silicon carbide powder located in the high-temperature zone (the area near the inner wall of the second crucible 30), which is beneficial to improving the crystal growth rate. In this embodiment, the graphite cylinder 50, the porous graphite cylinder 40, and the second crucible 30 have the same height. The partition 53 is set inside the graphite cylinder 50. The partition 53 can be corroded and fractured and sink during the crystal growth process. The partition 53 divides the graphite cylinder 50 into an upper loading space 51 and a lower loading space 52. The exhaust assembly 10 covers the upper part of the first crucible 20, and the bottom of the exhaust assembly 10 is in close contact with the upper surface of the second crucible cover 31. The exhaust assembly 10 is mainly used to exhaust excess gas in the crucible and reduce the impact of excess gas on the crystal growth quality. The seed crystal mounting assembly 70 is positioned above the venting assembly 10. The inner wall of the seed crystal mounting assembly 70, the inner side wall of the venting assembly 10, and the outer wall of the crucible lid together define the crystal growth area. The seed crystal 80 is mounted on the inner wall of the seed crystal mounting assembly 70. A heat insulation assembly 90 surrounds the crucible, the venting assembly 10, and the seed crystal mounting assembly 70, with a certain gap between the top wall of the heat insulation assembly 90 and the top wall of the seed crystal mounting assembly 70 to facilitate gas exhaust. In this embodiment, the first crucible 20, the second crucible 30, the porous graphite cylinder 40, and the graphite cylinder 50 are all made of graphite material.

[0041] refer to Figure 1 and Figure 3 As shown, in some embodiments, the venting assembly 10 of this invention has an annular structure. An extension 11 extends radially outward from the upper part of the venting assembly 10, covering the upper part of the first crucible 20 via the extension 11. A certain gap exists between the outer wall of the venting assembly 10 and the inner wall of the first crucible 20. An annular groove for accommodating the seed crystal mounting assembly 70 is defined on the upper part of the venting assembly 10. Venting holes 111 are provided on both the side wall of the venting assembly 10 and the extension 11. In this embodiment, the venting holes 111 can expel interference from excess components from the crystal growth area, thus avoiding adverse factors such as excessive components leading to rapid initial growth, uncontrollable crystal weight gain, and decreased crystal quality.

[0042] refer to Figure 1 and Figure 3 As shown, in some embodiments, the seed crystal mounting assembly 70 of this utility model includes a seed crystal 80 mounting plate 71 and an annular graphite pressure plate 72. The seed crystal 80 mounting plate 71 is installed in an annular groove, and the annular graphite pressure plate 72 is placed on the upper part of the seed crystal 80 mounting plate 71. The width of the annular graphite pressure plate 72 is the same as the width of the annular groove. The seed crystal 80 is installed on the lower surface of the seed crystal 80 mounting plate 71. The lower surface of the seed crystal 80 mounting plate 71 and the inner wall of the exhaust assembly 10 together define the crystal growth area.

[0043] refer to Figure 4 As shown, in some embodiments, the partition 53 of this invention includes a main body component 531 and a connecting component 532. The connecting component 532 is connected to the outside of the main body component 531, and the partition 53 is installed inside the second crucible 30 through the connecting component 532. The main body component 531 has through holes 5311 evenly distributed on it. The thickness of the partition 53 component is greater than the thickness of the connecting component 532, and the connecting component 532 can be corroded and broken during the crystal growth process. Preferably, in this embodiment, the thickness of the main body component 531 of the partition 53 is 10-15 mm, the thickness of its connecting part is 4-6 mm, and the vertical height of the lower loading space 52 is 50-70 mm. In this embodiment, the connecting portion of the partition 53 is relatively thin. As the crystal growth time progresses, the connecting portion gradually corrodes and breaks. After the connecting portion breaks, the main component 531 sinks, and the silicon carbide powder in the upper loading space 51 moves down to the high-temperature zone, avoiding the formation of ceramic bodies. On the one hand, this improves the utilization rate of silicon carbide powder; on the other hand, during the ascent of silicon carbide gas, with less obstruction from ceramic bodies, the silicon carbide gas can rise linearly and uniformly to the crystal growth interface, ensuring the flatness of the crystal growth surface. At the same time, the downward movement of this part of the silicon carbide powder to the high-temperature zone is beneficial to increasing the decomposition rate of this part of the silicon carbide powder, thereby increasing the crystal growth rate.

[0044] refer to Figure 2 As shown, in some embodiments, the silicon carbide powder contained in the first loading space 21 and the upper loading space 51 of this invention has a particle size of 10-20 mesh and a purity of 99.999%; the silicon carbide powder contained in the upper loading space 51 has a particle size of 30-40 mesh and a purity of 99.999%; and the silicon carbide powder above the second crucible lid 31 has a particle size of 80-100 mesh and a purity of 99.9999999%. Because the silicon carbide powder above the second crucible lid 31 in this embodiment has a small particle size and high purity, it can filter out impurities in the sublimated silicon carbide gas. Therefore, the requirements for the particle size and purity of the silicon carbide powder in the second crucible 30 are not high, reducing the cost of powder usage and thus reducing the production cost for enterprises. In addition, the silicon carbide powder above the second crucible lid 31 can also neutralize the carbon element in the sublimated silicon carbide gas, avoiding carbon encapsulation and effectively improving the crystal growth quality.

[0045] In some embodiments, the diameter of the circular holes on the porous graphite cylinder 40 is 2.5-3 mm, the distance between the circular holes is 1.5 mm, the outer diameter of the porous graphite cylinder 40 is 120-140 mm, its wall thickness is 10-15 mm, and the diameter of the through hole 5311 is 2 mm. The outer diameter of the graphite cylinder 50 is 100-120 mm, and its wall thickness is 5 mm. This embodiment, on the one hand, facilitates the entry of silicon carbide gas in the first loading space 21 through the circular holes into the gap between the porous graphite cylinder 40 and the graphite cylinder 50, and then rises to the crystal growth area through the through hole 5311 of the second crucible cover 31, accelerating the rising rate of the silicon carbide gas and effectively improving the crystal growth rate. On the other hand, it facilitates a more uniform rise of the silicon carbide gas to the crystal growth interface, effectively improving the crystal growth quality. Of course, the diameter of the circular holes, the outer diameter of the porous graphite cylinder 50, and the wall thickness can also be set according to actual conditions.

[0046] Based on the above apparatus, the method for growing silicon carbide crystals is as follows:

[0047] 1) Achieve high vacuum in 1 hour, and perform vacuum leak detection in 1 hour;

[0048] 2) The pressure rises to 800 mbar within 5 minutes, and the Ar flow rate is 600 sccm;

[0049] 3) Within 20 minutes, the power increases to 5 kW, the pressure to 800 mBr, and the Ar flow rate to 80 sccm;

[0050] 4) Within 30 minutes, the power increases to 15 kW, the pressure to 800 mBr, and the Ar flow rate to 80 sccm;

[0051] 5) Power maintained at 15 kW for 1 hour, pressure reduced to 5 MPabr, Ar flow rate 80 sccm;

[0052] 6) Within 150 hours, the power increases to 15.20kw, the pressure is maintained at 5mabr, the Ar flow rate is 80sccm, the N2 flow rate is 8sccm, and the electromagnetic induction coil 10 moves downward 22.5mm relative to the thermal field.

[0053] Example 2

[0054] Compared to Example 1, this embodiment further reduces the impact of powder falling and moving downwards on the interior of the powder source, further avoids carbon encapsulation, and improves the growth quality of the crystal. The difference between this embodiment and Example 1 is as follows:

[0055] refer to Figure 6 and Figure 7As shown, the partition 53 in this embodiment includes a main body component 531 and connecting components 532. Multiple main body components 531 and connecting components 532 are provided and spaced apart. The partition 53 is connected to the inner wall of the second crucible 30 through the outermost connecting component 532. Through holes 5311 are evenly distributed on the main body component 531. The thickness of the partition 53 component is greater than the thickness of the connecting component 532. In this embodiment, the main body component 531 and connecting components 532 of the partition 53 are spaced apart. When the connecting component 532 is corroded and broken, the main body component 531 sinks. However, due to the large number of main body components 531, the small area of ​​each main body component 531, and the different fracture times of each connecting component 532, the sinking time of the main body component 531 varies accordingly. Therefore, the amount of silicon carbide powder that sinks with a single main body component 531 is small, resulting in minimal impact on the interior of the powder source. Furthermore, the repeated small-scale sinking of silicon carbide powder has almost no impact on the interior of the silicon carbide powder, further avoiding carbon encapsulation and improving the growth quality of silicon carbide crystals.

[0056] Other components of the silicon carbide crystal growth apparatus 100 according to embodiments of the present invention, such as the crucible, the heat preservation component 90, and the electromagnetic induction coil 10, as well as their operation, are known to those skilled in the art and will not be described in detail here.

[0057] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0059] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0060] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A silicon carbide crystal growth apparatus, characterized in that, include First crucible; The second crucible is coaxially placed inside the first crucible, with the outer side wall of the second crucible tightly attached to the inner side wall of the first crucible. The upper part of the second crucible is covered with a second crucible lid, which has a through hole. A porous graphite cylinder is coaxially installed inside the second crucible, and the outer wall of the porous graphite cylinder and the inner wall of the second crucible together define a first loading space. A graphite tube is coaxially mounted inside a porous graphite tube, and there is a set gap between the graphite tube and the porous graphite tube. The graphite tube, the porous graphite tube, and the second crucible are of the same height. A partition is disposed inside the graphite cylinder. The partition can be corroded and fractured during the crystal growth process, and the partition divides the graphite cylinder into an upper loading space and a lower loading space. An exhaust assembly is provided, which covers the upper part of the first crucible and the bottom of the exhaust assembly is in close contact with the upper surface of the second crucible cover. A seed crystal mounting assembly is disposed on the upper part of the venting assembly. The inner wall of the seed crystal mounting assembly, the inner side wall of the venting assembly, and the outer wall of the crucible cover together define a crystal growth area. The seed crystal is mounted on the inner wall of the seed crystal mounting assembly. A heat insulation component is provided, which is wrapped around the crucible, the venting component and the seed crystal mounting component, and the top wall of the heat insulation component has a set gap with the top wall of the seed crystal mounting component.

2. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The venting assembly is a ring structure, with an extension extending radially outward from the upper part of the venting assembly. The venting assembly covers the upper part of the first crucible through the extension. There is a certain gap between the outer side wall of the venting assembly and the inner side wall of the first crucible. The upper part of the venting assembly defines an annular groove for accommodating the seed crystal mounting assembly. Venting holes are provided on both the side wall of the venting assembly and the extension.

3. The silicon carbide crystal growth apparatus according to claim 2, characterized in that, The seed crystal mounting assembly includes a seed crystal mounting plate and an annular graphite pressure plate. The seed crystal mounting plate is installed in the annular groove, and the annular graphite pressure plate is placed on the upper part of the seed crystal mounting plate. The width of the annular graphite pressure plate is the same as the width of the annular groove. The seed crystal is installed on the lower surface of the seed crystal mounting plate. The lower surface of the seed crystal mounting plate and the inner wall of the exhaust assembly together define the crystal growth area.

4. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The partition includes a main body and a connecting part. The connecting part is connected to the outside of the main body. The partition is installed inside the second crucible through the connecting part. The main body has through holes evenly distributed on it. The thickness of the partition part is greater than the thickness of the connecting part. The connecting part can be corroded and broken during the crystal growth process.

5. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The partition includes a main body component and a connecting component. Multiple main body components and connecting components are provided and spaced apart. The partition is connected to the inner wall of the second crucible through the outermost connecting component. The main body component has through holes evenly distributed on it. The thickness of the partition component is greater than the thickness of the connecting component.

6. A silicon carbide crystal growth apparatus according to claim 4 or 5, characterized in that, The main body of the partition has a thickness of 10-15mm, the connecting part has a thickness of 4-6mm, and the vertical height of the lower loading space is 50-70mm.

7. The silicon carbide crystal growth apparatus according to claim 6, characterized in that, The silicon carbide powder contained in the first loading space and the upper loading space has a particle size of 10-20 mesh and a purity of 99.999%; the silicon carbide powder contained in the upper loading space has a particle size of 30-40 mesh and a purity of 99.999%; and the silicon carbide powder above the second crucible lid has a particle size of 80-100 mesh and a purity of 99.9999999%.

8. The silicon carbide crystal growth apparatus according to claim 7, characterized in that, The diameter of the round holes on the porous graphite cylinder is 2.5-3mm, the distance between the round holes is 1.5mm, the outer diameter of the porous graphite cylinder is 120-140mm, the wall thickness is 10-15mm, and the diameter of the through hole is 2mm.

9. A silicon carbide crystal growth apparatus according to claim 7, characterized in that, The graphite cylinder has an outer diameter of 100-120 mm and a wall thickness of 5 mm.

10. A silicon carbide crystal growth apparatus according to claim 1, characterized in that, The first crucible, the second crucible, the porous graphite tube, and the graphite tube are all made of graphite material.

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