Silicon carbide crystal growth crucible
By designing a uniform ventilation system for raw material support seats and porous graphite plates in the silicon carbide crystal growth crucible, the problem of charred and poor crystal growth of silicon carbide powder is solved, and a higher raw material utilization rate and a more uniform and flat crystal growth effect are achieved.
Patent Information
- Application Number
- CN202421905802.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-08-07
AI Technical Summary
After the existing silicon carbide crystal crucibles grow crystals, the silicon carbide powder is prone to burn and stick to the bottom of the crucible, resulting in waste of raw materials and low crystal growth quality. The crystal growth results on the crucible cover are not ideal, the crystal thickness uniformity is poor, the flatness is not high, and there are many defects.
A silicon carbide long crystal crucible is designed, including a crucible body, a crucible cover, a raw material support base, a porous graphite plate and a relay ring. The raw material support base is used to carry silicon carbide powder so that it is spaced from the bottom surface of the crucible main body. The porous graphite plate is located above the raw material support base. The relay ring is located between the porous graphite plate and the crucible cover, and is uniformly ventilated to improve the crystal growth quality.
By isolating the raw material support seat from the bottom surface of the crucible body, the powder burning is reduced, and the raw material utilization rate and crystal growth quality are improved. The uniform ventilation design of porous graphite plates improves the uniformity and flatness of crystal growth and reduces crystal defects.
Smart Images
Figure CN222861710U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of crystal growth equipment, in particular to a silicon carbide crystal growth crucible. Background Art
[0002] The existing silicon carbide crystal growth crucible generally places silicon carbide powder at the bottom of the crucible, and heats the crucible to evaporate the silicon carbide powder onto the crucible cover to achieve crystal growth. However, such a crucible structure often has the following problems:
[0003] 1. After the crystal growth, when you open the crucible, you will find that a lot of silicon carbide powder is burnt and tightly adhered to the bottom of the crucible. These burnt silicon carbide powders are not used for crystal growth, which not only causes a waste of raw materials and low crystal growth quality, but also has a significant adverse effect on the service life of the crucible;
[0004] 2. The crystal growth results on the crucible cover are not ideal. The uniformity of the crystal thickness is poor, the crystal surface is not flat, and there are many defects, which makes it difficult to increase the thickness of the final usable crystal. Utility Model Content
[0005] The purpose of the utility model includes providing a silicon carbide crystal growth crucible, which can improve the phenomenon of silicon carbide powder burning, improve the raw material utilization rate and the uniformity of crystal growth.
[0006] The embodiments of the present invention can be implemented as follows:
[0007] In a first aspect, the utility model provides a silicon carbide crystal growth crucible, which includes a crucible body, a crucible cover, a raw material support seat, a porous graphite plate and a relay ring;
[0008] The crucible cover is closed on the crucible body, the raw material support seat is installed at the bottom of the crucible body, the raw material support seat is used to carry silicon carbide powder so that the silicon carbide powder is spaced apart from the bottom surface of the crucible body, the porous graphite plate is arranged in the crucible body and above the raw material support seat, the relay ring is arranged between the porous graphite plate and the crucible cover, and the porous graphite plate is used to allow gas to pass evenly and grow crystals on the crucible cover.
[0009] In an optional embodiment, the raw material support seat is T-shaped as a whole, and the top surface of the raw material support seat and the inner wall surface of the crucible body form a cavity for accommodating silicon carbide powder.
[0010] In an optional embodiment, the raw material support seat includes a cylindrical column and a support plate. The cylindrical column is a hollow structure and is supported between the bottom of the crucible body and the support plate. The top surface of the support plate is used to carry silicon carbide powder.
[0011] In an optional embodiment, a convex portion is provided on the bottom surface of the support plate, and the convex portion is used to cooperate with the hollow cylindrical column.
[0012] In an alternative embodiment, the diameter of the porous graphite plate is larger than the inner diameter of the relay ring.
[0013] In an optional embodiment, a crystal growth portion protruding toward the inside of the relay ring is provided in the middle of the crucible cover, and the bottom surface of the crystal growth portion is the crystal growth surface.
[0014] In an optional embodiment, there is a gap between the surface of the crystal growth portion and the inner surface of the relay ring, and the gap forms a pressure relief channel for the gas.
[0015] In an optional embodiment, the inner diameter a of the relay ring near the porous graphite plate is smaller than the inner diameter b of the relay ring near the crucible cover, and the outer diameter c of the crystal growth part is larger than the inner diameter a and smaller than the inner diameter b.
[0016] In an optional embodiment, the pressure relief channel includes a gap A between the bottom surface of the crystal growth portion and the inner end surface of the relay ring and a gap B between the outer side surface of the crystal growth portion and the inner side surface of the relay ring.
[0017] In an optional embodiment, the top surface of the crucible cover has a groove, and thermal insulation cotton is arranged in the groove. A vertical through hole is opened in the center of the thermal insulation cotton, and the through hole is used for the light of the thermometer to pass through.
[0018] The beneficial effects of the silicon carbide crystal growth crucible provided by the embodiment of the utility model include:
[0019] 1. By arranging a raw material support seat for carrying silicon carbide powder at the bottom of the crucible body, the silicon carbide powder is spaced from the bottom surface of the crucible body, so as to avoid the silicon carbide powder at the bottom directly bearing the high temperature of the bottom surface of the crucible body, improve the scorching of the silicon carbide powder at the bottom, make more silicon carbide powder normally used for crystal growth, improve the utilization rate of raw materials and the quality of crystal growth, reduce the situation of scorched silicon carbide powder adhering to the inner wall of the crucible body, and improve the service life of the crucible;
[0020] 2. By arranging a porous graphite plate between the relay ring and the raw material support seat, the gas generated by the evaporation of the silicon carbide powder can pass through the porous graphite plate evenly, making the gas reaching the crucible cover for crystal growth more uniform, which is conducive to forming crystals with uniform thickness, improving the flatness of the crystal surface, and reducing crystal defects. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.
[0022] Figure 1 A schematic diagram of the appearance structure of a silicon carbide crystal growth crucible provided in an embodiment of the utility model;
[0023] Figure 2 A schematic diagram of the full cross-section structure of a silicon carbide crystal growth crucible provided in an embodiment of the utility model;
[0024] Figure 3 for Figure 2 A magnified schematic diagram of the local M in the figure.
[0025] Icons: 1-crucible body; 2-crucible cover; 21-groove; 22-crystal growth part; 3-insulation cotton; 31-through hole; 4-raw material support seat; 41-cylindrical column; 42-support plate; 43-convex part; 5-relay ring; 6-porous graphite plate. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. 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.
[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0029] In the description of the present utility model, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the utility model product is usually placed when used. It is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present utility model.
[0030] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.
[0031] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.
[0032] Please refer to Figure 1 and Figure 2 This embodiment provides a silicon carbide crystal growth crucible, which includes a crucible body 1, a crucible cover 2, insulation cotton 3, a raw material support seat 4, a porous graphite plate 6 and a relay ring 5.
[0033] The crucible cover 2 is covered on the crucible body 1, and the raw material support seat 4 is installed at the bottom of the crucible body 1. The raw material support seat 4 is used to carry silicon carbide powder, so that the silicon carbide powder and the bottom surface of the crucible body 1 are spaced apart to avoid the silicon carbide powder at the bottom directly being subjected to the high temperature of the bottom surface of the crucible body 1, improve the burning condition of the silicon carbide powder at the bottom, make more silicon carbide powder normally used for crystal growth, improve the utilization rate of raw materials and the quality of crystal growth, reduce the situation of the burnt silicon carbide powder adhering to the inner wall of the crucible body 1, and increase the service life of the crucible.
[0034] Specifically, the raw material support seat 4 is T-shaped as a whole. The top surface of the raw material support seat 4 and the inner wall surface of the crucible body 1 form a cavity for accommodating silicon carbide powder. The raw material support seat 4 includes a cylindrical column 41 and a support plate 42. The cylindrical column 41 is a hollow structure and is supported between the bottom of the crucible body 1 and the support plate 42. The top surface of the support plate 42 is used to carry silicon carbide powder. Among them, the hollow cylindrical column 41 can reduce the contact area between the cylindrical column 41 and the support plate 42, so that the bottom surface of the support plate 42 is basically in contact with the gas. In this way, the bottom surface of the support plate 42 receives the same heat transfer efficiency from the crucible body 1, and the heat is more uniform, and the silicon carbide powder is also heated more uniformly.
[0035] The bottom surface of the support plate 42 is provided with a convex portion 43, which is used to cooperate with the hollow cylindrical column 41. In this way, the relative misalignment or shaking of the support plate 42 and the cylindrical column 41 can be avoided, the stability of the crystal growth is improved, and the assembly difficulty can be reduced.
[0036] In other embodiments, a plurality of columns evenly spaced apart may be provided to support the support plate 42 , wherein the columns may be solid or hollow.
[0037] The porous graphite plate 6 is arranged in the crucible body 1 and is located above the raw material support seat 4. The relay ring 5 is arranged between the porous graphite plate 6 and the crucible cover 2. The porous graphite plate 6 is used to allow the gas (including volatile gas molecules such as Si, Si2C and SiC2) to pass through evenly and grow crystals on the crucible cover 2, so that the gas reaching the crucible cover 2 for crystal growth is more uniform, which is conducive to forming crystals with uniform thickness, improving the flatness of the crystal surface, and reducing crystal defects.
[0038] As the crystal grows, the silicon carbide powder (including silicon powder and carbon powder) tends to be enriched with carbon particles in the crucible, and the porous graphite plate 6 can filter the impurity particles with larger particle sizes, so that the content of impurity particles reaching the crucible cover 2 is reduced, and the final crystal has less inclusions, which is beneficial to improving the quality of the crystal. Preferably, the porous graphite plate 6 is a graphite plate with uniform thickness and uniform pore distribution.
[0039] Specifically, the material of the porous graphite plate 6 can be low-density graphite. For example, the material of the porous graphite plate 6 is a material with a density less than or equal to 1.8 g / cm 3 of graphite.
[0040] The diameter of the porous graphite plate 6 is larger than the inner diameter of the relay ring 5. In this way, the gas entering the relay ring 5 is homogenized by the porous graphite plate 6, which is beneficial to ensure the quality of crystal growth.
[0041] In this embodiment, the porous graphite plate 6 is also conducive to improving the overall temperature of the raw material area and improving the axial and radial temperature uniformity, promoting the full sublimation and utilization of the raw material; the porous graphite plate 6 reduces the overall gas mass transfer rate, the gas flow rate changes less with time, and the entire growth process is more stable. At the same time, the porous graphite plate 6 also effectively suppresses the occurrence of excessive mass transfer at the edge of the crucible cover 2. At the same time, the thermal insulation effect of the porous graphite plate 6 reduces the occurrence of recrystallization in the upper part of the raw material to a certain extent. Therefore, the porous graphite plate 6 can improve the crystal growth environment and optimize the crystal quality.
[0042] The top surface of the crucible cover 2 has a groove 21, and a heat-insulating cotton 3 is arranged in the groove 21, which is conducive to improving the uniformity and stability of the temperature of the crystal growth zone on the bottom surface of the crucible cover 2 and improving the quality of crystal growth. A vertical through hole 31 is opened in the center of the heat-insulating cotton 3, and the through hole 31 is used for the light of the temperature measuring instrument to pass through, which is conducive to real-time monitoring of the temperature of the crystal growth zone on the bottom surface of the crucible cover 2.
[0043] Please refer to Figure 2 and Figure 3 The middle part of the crucible cover 2 is provided with a crystal growth part 22 protruding into the inside of the relay ring 5, and the bottom surface of the crystal growth part 22 is the crystal growth surface. The inner diameter a of the end of the relay ring 5 close to the porous graphite plate 6 is smaller than the inner diameter b of the end of the relay ring 5 close to the crucible cover 2, and the outer diameter c of the crystal growth part 22 is larger than the inner diameter a and smaller than the inner diameter b. There is a gap between the surface of the crystal growth part 22 and the inner surface of the relay ring 5, and the gap forms a pressure relief channel for gas, so that the gas will not accumulate too much at the edge position of the crystal growth part 22 (that is, the position close to the inner surface of the relay ring 5), so that the outer peripheral surface of the growing crystal is relatively smooth, without obvious burrs or concave-convex areas, and the quality of crystal growth is improved.
[0044] Specifically, the pressure relief channel includes a gap A between the bottom surface of the crystal growth portion 22 and the inner end surface of the relay ring 5 and a gap B between the outer side surface of the crystal growth portion 22 and the inner side surface of the relay ring 5. Figure 3 From the cross-section of the silicon carbide crystal growth crucible, the vertical section of the pressure relief channel is L-shaped, the gap extending horizontally at the bottom is gap A, and the gap extending vertically at the top is gap B. When the gas concentration at the edge of the crystal growth part 22 is high, it will diffuse outward through gap A and gap B in turn, avoiding the high gas concentration in the corner area between the edge of the crystal growth part 22 and the inner side of the relay ring 5, ensuring the uniformity of the overall crystal growth. Among them, the entrance of the L-shaped pressure relief channel is gap A, and the extension direction of gap A is basically perpendicular to the diffusion direction of the gas from bottom to top, so that the gas diffused from bottom to top will not directly enter the pressure relief channel and be discharged, avoiding the gas concentration at the edge of the crystal growth part 22 being too low.
[0045] The beneficial effects of the silicon carbide crystal growth crucible provided by the embodiment of the utility model include:
[0046] 1. By arranging a raw material support seat 4 for carrying silicon carbide powder at the bottom of the crucible body 1, the silicon carbide powder is spaced apart from the bottom surface of the crucible body 1, so as to avoid the silicon carbide powder at the bottom directly bearing the high temperature of the bottom surface of the crucible body 1, improve the scorching of the silicon carbide powder at the bottom, make more silicon carbide powder normally used for crystal growth, improve the utilization rate of raw materials and the quality of crystal growth, reduce the situation of scorched silicon carbide powder adhering to the inner wall of the crucible body 1, and improve the service life of the crucible;
[0047] 2. By arranging a porous graphite plate 6 between the relay ring 5 and the raw material support seat 4, the gas generated by the evaporation of the silicon carbide powder can pass through the porous graphite plate 6 evenly, so that the gas reaching the crucible cover 2 for crystal growth is more uniform, which is conducive to forming crystals with uniform thickness, improving the flatness of the crystal surface, and reducing crystal defects;
[0048] 3. By forming a gap between the surface of the crystal growth part 22 of the crucible cover 2 and the inner surface of the relay ring 5 as a gas pressure relief channel, the gas will not accumulate too much at the edge of the crystal growth part 22, so that the outer peripheral surface of the growing crystal is smoother without obvious burrs or concave-convex areas, thereby improving the quality of crystal growth.
[0049] The above are only specific implementations of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.
Claims
1. A silicon carbide crystal growth crucible, characterized in that: The silicon carbide crystal growth crucible comprises a crucible body (1), a crucible cover (2), a raw material support seat (4), a porous graphite plate (6) and a relay ring (5); The crucible cover (2) is covered on the crucible body (1); the raw material support seat (4) is installed at the bottom of the crucible body (1); the raw material support seat (4) is used to carry silicon carbide powder so that the silicon carbide powder is spaced apart from the bottom surface of the crucible body (1); the porous graphite plate (6) is arranged in the crucible body (1) and above the raw material support seat (4); the relay ring (5) is arranged between the porous graphite plate (6) and the crucible cover (2); the porous graphite plate (6) is used to allow gas to pass evenly and grow crystals on the crucible cover (2).
2. The silicon carbide crystal growth crucible according to claim 1, characterized in that: The raw material support seat (4) is T-shaped as a whole, and the top surface of the raw material support seat (4) and the inner wall surface of the crucible body (1) form a cavity for accommodating the silicon carbide powder.
3. The silicon carbide crystal growth crucible according to claim 2, characterized in that: The raw material support seat (4) comprises a cylindrical column (41) and a support plate (42); the cylindrical column (41) is a hollow structure and is supported between the bottom of the crucible body (1) and the support plate (42); the top surface of the support plate (42) is used to carry the silicon carbide powder.
4. The silicon carbide crystal growth crucible according to claim 3, characterized in that: The bottom surface of the support plate (42) is provided with a convex portion (43), and the convex portion (43) is used to cooperate with the hollow cylindrical column (41).
5. The silicon carbide crystal growth crucible according to claim 1, characterized in that: The diameter of the porous graphite plate (6) is greater than the inner diameter of the relay ring (5).
6. The silicon carbide crystal growth crucible according to claim 1, characterized in that: A crystal growth portion (22) protruding toward the inside of the relay ring (5) is provided in the middle of the crucible cover (2), and the bottom surface of the crystal growth portion (22) is a crystal growth surface.
7. The silicon carbide crystal growth crucible according to claim 6, characterized in that: There is a gap between the surface of the crystal growing portion (22) and the inner surface of the relay ring (5), and the gap forms a pressure relief channel for the gas.
8. The silicon carbide crystal growth crucible according to claim 7, characterized in that: The inner diameter a of the end of the relay ring (5) close to the porous graphite plate (6) is smaller than the inner diameter b of the end of the relay ring (5) close to the crucible cover (2), and the outer diameter c of the crystal growth part (22) is larger than the inner diameter a and smaller than the inner diameter b.
9. The silicon carbide crystal growth crucible according to claim 8, characterized in that: The pressure relief channel comprises a gap A between the bottom surface of the crystal growth portion (22) and the inner end surface of the relay ring (5), and a gap B between the outer side surface of the crystal growth portion (22) and the inner side surface of the relay ring (5).
10. The silicon carbide crystal growth crucible according to claim 1, characterized in that: The top surface of the crucible cover (2) has a groove (21), a heat-insulating cotton (3) is arranged in the groove (21), a vertical through hole (31) is opened at the center of the heat-insulating cotton (3), and the through hole (31) is used for allowing light from a thermometer to pass through.