Crucible
By designing a crucible with raw material barrel, the local carbonization problem caused by uneven heating of silicon carbide powder during crystal growth in PVT method is solved, and the high quality and structural integrity of silicon carbide single crystals are achieved.
Patent Information
- Application Number
- CN202421188182.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-05-28
AI Technical Summary
In the PVT method, silicon carbide powder is prone to local carbonization due to uneven heating during crystal growth, resulting in fluctuation of the C/Si ratio of the gas phase component, resulting in crystal structure defects and wrap defects.
A crucible is designed, including a raw material barrel and a crucible cover. The bottom of the raw material barrel is closed, the top opening is facing the crucible cover, and the inner diameter gradually increases from the bottom to form a slope wall to isolate the direct contact between the silicon carbide powder and the bottom and side wall of the crucible to achieve uniform heating.
Through this design, the silicon carbide powder is heated more uniformly during the crystal growth process, reducing local carbonization, stabilizing the C/Si ratio of the gas phase component, and improving the quality and structural integrity of the silicon carbide single crystal.
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Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of crystal growth, in particular to a crucible. Background Art
[0002] The physical vapor transport (PVT) method is a commonly used commercial method for growing silicon carbide crystals. However, due to the high crystal growth temperature, long cycle, and the difficulty in controlling the C / Si ratio of the gas phase components, the currently grown silicon carbide crystals still have many defects, such as polymorphic inclusions, inclusions, dislocations, stacking faults, etc. The key to obtaining high-quality large-size silicon carbide crystals is to achieve precise control of the PVT crystal growth process, among which the solid-gas-solid phase change and transport process are the difficulties of process control. Solid-phase silicon carbide powder is sublimated at high temperature into gas phase components such as Si(g), Si2C(g) and SiC2(g), and then these gas phase components are transported to the interface of crystal growth through the control of the axial temperature gradient.
[0003] During the entire crystal growth process, the C / Si ratio of the gas phase components and the stability of the transport of these components are always maintained, which is conducive to the continuous and stable accumulation of carbon silicon molecules on the surface of the silicon carbide seed crystal, maintaining the interlayer stacking mode of the 4H crystal form, stabilizing the crystal form and reducing the crystal structure defects and inclusion defects caused by fluctuations in the gas phase components.
[0004] The graphite crucible used for PVT crystal growth generally has a cylindrical cavity. The temperature field formed by heating will form a high-temperature zone in the cavity. Uneven heating of silicon carbide powder can easily lead to severe local carbonization, thereby disrupting the C / Si ratio during the solid-gas phase transition process, causing fluctuations in the gas phase composition and enrichment of the carbon source during the crystal growth process.
[0005] Therefore, how to achieve uniform heating and sublimation of solid-phase silicon carbide powder under the same temperature field conditions to avoid local overheating and carbonization is a key technical problem in achieving high-quality silicon carbide single crystal growth. Utility Model Content
[0006] The purpose of the utility model includes, for example, providing a crucible, which can make silicon carbide powder in a more uniform heating state and can effectively reduce the local carbonization of the powder during the crystal growth process.
[0007] The embodiments of the present invention can be implemented as follows:
[0008] In a first aspect, the utility model provides a crucible, the crucible comprising a crucible body and a crucible cover, the crucible body having a chamber, the crucible cover being arranged at one end of the crucible body to close the chamber, comprising:
[0009] A raw material barrel is located in the chamber; the raw material barrel has a bottom portion close to the bottom wall of the chamber and a top portion away from the bottom wall of the chamber, the bottom portion of the raw material barrel is closed and the top portion is open, and the inner diameter of the raw material barrel has an increasing trend from the bottom portion to the top portion of the raw material barrel;
[0010] The bottom of the raw material barrel is arranged on the bottom wall of the chamber, the opening of the top of the raw material barrel is arranged toward the crucible cover, and the side wall of the top of the raw material barrel abuts against the inner wall of the chamber.
[0011] In an optional embodiment, the inner diameter of the raw material barrel gradually increases from the bottom to the top of the raw material barrel; the slope of the inner wall of the raw material barrel is 40-50°.
[0012] In an optional embodiment, the raw material barrel includes a support block and a first barrel body; the support block is arranged on the bottom wall of the chamber; the first barrel body has a bottom close to the bottom wall of the chamber and a top away from the bottom wall of the chamber, and the bottom and top of the first barrel body both have openings; the bottom of the first barrel body is connected to the top of the support block close to the first barrel body, the top of the support block blocks the opening of the bottom of the first barrel body, the opening of the top of the first barrel body is arranged toward the crucible cover, and the side wall of the top of the first barrel body abuts against the inner wall of the chamber; along the direction from the bottom wall of the chamber to the crucible cover, the inner diameter of the first barrel body has an increasing trend.
[0013] In an optional embodiment, the inner diameter of the first cylinder gradually increases along the direction from the bottom wall of the chamber to the crucible cover; and the slope of the inner wall of the first cylinder is 40-50°.
[0014] In an optional embodiment, the height of the first cylinder in the direction from the bottom wall of the chamber to the crucible cover is 3-5 cm;
[0015] And / or, the support block has a height of 2-3 cm in the direction from the bottom wall of the chamber to the crucible cover.
[0016] In an optional embodiment, the top of the support block is snap-fitted with the opening at the bottom of the first cylinder.
[0017] In an optional embodiment, it further includes a bottom plate, which is located in the chamber and is arranged on the bottom wall of the chamber, the bottom plate covers the bottom wall of the chamber and is in contact with the bottom wall of the chamber; the bottom of the raw material barrel is arranged on the bottom plate;
[0018] and / or,
[0019] It also includes a second cylinder, which is sleeved in the chamber. The second cylinder has a top close to the crucible cover and a bottom away from the crucible cover. The top and bottom of the second cylinder are both provided with openings. The outer wall of the second cylinder is in contact with the inner wall of the chamber; the side wall of the top of the raw material cylinder abuts against the inner wall of the second cylinder.
[0020] In an optional embodiment, the crucible includes the bottom plate and the second cylinder, the bottom of the second cylinder is connected to the bottom plate, and the bottom plate blocks the opening at the bottom of the second cylinder to form a cylindrical structure with a closed bottom and an open top together with the second cylinder.
[0021] In an optional embodiment, the top of the second cylinder is spaced apart from the crucible cover;
[0022] The crucible also includes a guide tube, which is located in the chamber and arranged between the top of the second cylinder and the crucible cover; a seed crystal connection area is provided on the inner surface of the crucible cover; the guide tube has a top close to the crucible cover and a bottom away from the crucible cover, a guide outlet is provided at the top of the guide tube, and a guide inlet is provided at the bottom of the guide tube; the inner diameter of the guide tube has a decreasing trend along the direction from the guide inlet to the guide outlet; the bottom of the guide tube abuts against the top of the second cylinder, and the guide inlet is connected to the opening at the top of the second cylinder; the top of the guide tube abuts against the crucible cover, and the guide outlet faces the seed crystal connection area.
[0023] In an optional embodiment, at least one of the raw material cylinder, the base plate, the second cylinder and the guide cylinder is made of graphite material; and / or the surface of at least one of the base plate, the second cylinder and the guide cylinder is provided with a tantalum carbide coating; the thickness of the tantalum carbide coating is 2-3 mm.
[0024] The beneficial effects of the embodiments of the present utility model include, for example:
[0025] A raw material tube of a crucible is arranged in a chamber of the crucible, the bottom of the raw material tube is sealed and arranged on the bottom wall of the chamber and the top is provided with an opening facing the crucible cover, so that the raw material tube can be used as a place to carry silicon carbide powder. In the prior art, during the crystal growth process, compared with other parts of the crucible, the temperature near the bottom of the crucible is the highest and the heating time is the longest, which easily causes the powder in the bottom area to overheat and carbonize. The raw material tube can isolate the silicon carbide powder from the bottom of the crucible, and isolate the silicon carbide powder from the area near the bottom of the crucible side wall, so that the overall heating of the powder during the crystal growth process is more uniform, which is conducive to improving the stability and consistency of the silicon carbide powder sublimation process, thereby reducing the structural defects and inclusions of the crystal. Along the direction from the bottom to the top of the raw material tube, the inner diameter of the raw material tube has an increasing trend, which, on the one hand, makes the raw material tube have a smaller contact area with the bottom of the crucible to reduce overheating, so that the overall heating of the powder during the crystal growth process is more uniform, and on the other hand, it can ensure the stability of the powder during the charging process and improve the utilization rate of the raw materials. In summary, such a crucible has the advantages of simple structure, convenient operation, and excellent crystal growth effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] 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.
[0027] Figure 1 The figure is a schematic structural diagram of a crucible according to an embodiment of the utility model.
[0028] Icons: 100 - raw material cylinder; 110 - support block; 120 - first cylinder; 210 - second cylinder; 220 - bottom plate; 300 - flow guide cylinder; 301 - flow guide outlet; 302 - flow guide inlet; 21 - crucible body; 22 - crucible cover; 23 - chamber; 30 - seed crystal connection area; 40 - powder. DETAILED DESCRIPTION
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] Please refer to Figure 1 The present embodiment provides a crucible, which is applied to a crucible. The crucible includes a crucible body 21 and a crucible cover 22. The crucible body 21 has a chamber 23. The crucible cover 22 is disposed at one end of the crucible body 21 to close the chamber 23, including:
[0036] The raw material barrel 100 is located in the chamber 23; the raw material barrel 100 has a bottom close to the bottom wall of the chamber 23 and a top away from the bottom wall of the chamber 23, the bottom of the raw material barrel 100 is closed and the top is open, and the inner diameter of the raw material barrel 100 has an increasing trend from the bottom to the top of the raw material barrel 100;
[0037] The bottom of the raw material barrel 100 is disposed on the bottom wall of the chamber 23 , the opening of the top of the raw material barrel 100 is disposed toward the crucible cover 22 , and the side wall of the top of the raw material barrel 100 abuts against the inner wall of the chamber 23 .
[0038] Based on the cylindrical graphite crucible, such a crucible has a raw material barrel 100 added to the bottom of the crucible according to the high temperature zone morphology of the simulated temperature field, so that the silicon carbide powder 40 is always in a uniform heating state, which can effectively avoid local carbonization of the powder 40 during the crystal growth process. That is, the raw material barrel 100 serves as a place for crystal growth and also as a heat-insulating component for maintaining uniform temperature.
[0039] Optionally, the material of the raw material barrel 100 is graphite material. The raw material barrel 100 made of graphite material can reduce the overheating of the bottom of the crucible and ensure that the heat can act on the powder 40. At the same time, the graphite raw material barrel 100 has a heat equalization effect, which can improve the uneven heating of the silicon carbide powder 40, which can easily lead to serious local carbonization, thereby maintaining the C / Si ratio during the solid-gas phase transition process, avoiding fluctuations in gas phase components and enrichment of carbon sources during crystal growth, and thus improving the quality of crystal growth.
[0040] In an optional embodiment, the inner diameter of the raw material barrel 100 gradually increases from the crucible body 21 to the crucible cover 22. In this way, the inner wall of the raw material barrel 100 is formed into a straight extension shape, which not only simplifies the processing and manufacturing, but also ensures the uniform heating effect of the raw material barrel 100. In other embodiments of the utility model, the inner diameter of the raw material barrel 100 can be a step-by-step increase, which is just an example. Optionally, the slope α of the inner wall of the raw material barrel 100 is 40-50°. This slope range can be adjusted according to the different positions of the high temperature lines of the thermal field. The purpose is to isolate the area where the heat of the crucible wall is most concentrated, so that the overall heating of the powder 40 during the crystal growth process is more uniform. Specifically, the inner wall slope here refers to the angle formed between the inner wall and the bottom opening plane of the raw material barrel 100.
[0041] from Figure 1 It can also be seen that in an optional embodiment, the raw material barrel 100 includes a support block 110 and a first barrel 120; the support block 110 is arranged on the bottom wall of the chamber 23; the first barrel 120 has a bottom close to the bottom wall of the chamber 23 and a top away from the bottom wall of the chamber 23, and the bottom and top of the first barrel 120 both have openings; the bottom of the first barrel 120 is connected to the top of the support block 110 close to the first barrel 120, the top of the support block 110 blocks the opening at the bottom of the first barrel 120, the opening at the top of the first barrel 120 is arranged toward the crucible cover 22, and the side wall of the top of the first barrel 120 abuts against the inner side wall of the chamber 23; along the direction from the bottom wall of the chamber 23 to the crucible cover 22, the inner diameter of the first barrel 120 has an increasing trend. In this way, the raw material barrel 100 is arranged as a split structure, and such an arrangement is convenient for maintenance and disassembly and installation. It is not difficult to understand that in other embodiments of the present invention, the raw material barrel 100 can also be an integrally formed structure.
[0042] Furthermore, along the direction from the bottom wall of the chamber 23 to the crucible cover 22, the inner diameter of the first barrel 120 gradually increases; the slope α of the inner side wall of the first barrel 120 is 40-50°. That is, the inner wall of the first barrel 120 encloses a storage space for accommodating the powder 40, and the inner wall of the first barrel 120 extends straight. It is not difficult to understand that in other embodiments of the utility model, the inner diameter of the first barrel 120 can be increased in a step-by-step manner, which is only an example and is not limited here.
[0043] In an optional embodiment, the first barrel 120 is an annular plate. In this way, the outer wall of the plate encloses the first barrel 120 in a frustum shape, and the inner wall of the plate encloses the funnel mouth with a gradually increasing opening. Thereby, the first barrel 120 forms a funnel-shaped structure. That is, there is a distance between the outer wall of the first barrel 120 and the inner wall of the crucible, so that the heat insulation effect of the raw material barrel 100 is better. It should be noted that in other embodiments of the utility model, the first barrel 120 can also be a cylinder, and the outer peripheral wall of the first barrel 120 can be against the inner wall of the crucible. Along the central axis of the cylindrical first barrel 120, an inverted cone-shaped through-channel is opened in the first barrel 120.
[0044] The first barrel 120 separates the silicon carbide powder 40 from the bottom of the crucible, avoiding overheating and carbonization in this area, so that the overall heating of the powder 40 is more uniform during the crystal growth process; the first barrel 120 is a circular conical plate, and the outer diameter of the first barrel 120 is the same as the diameter of the support block 110.
[0045] Optionally, the height H of the first cylinder 120 in the direction from the bottom wall of the chamber 23 to the crucible cover 22 is 3-5 cm, which can be adjusted according to the different positions of the high temperature lines of the thermal field.
[0046] The support block 110 is used to separate the powder 40 from the bottom of the crucible, avoiding overheating and carbonization in this area, so that the overall heating of the powder 40 during the crystal growth process is more uniform. In this embodiment, the support block 110 is a circular graphite block, and the diameter of the support block 110 is the same as the bottom opening of the first cylinder 120. That is, the top of the support block 110 is clamped with the opening at the bottom of the first cylinder 120 to form a stable support structure. The height h of the support block 110 in the direction from the bottom wall of the chamber 23 to the crucible cover 22 is 2-3 cm, which can be adjusted according to the position of the high temperature line of the thermal field to achieve the best uniform heating effect for the powder 40.
[0047] from Figure 1 It can also be seen that in an optional embodiment, the crucible further includes a bottom plate 220 and a second cylinder 210.
[0048] The bottom plate 220 is located in the chamber 23 and is arranged on the bottom wall of the chamber 23. The bottom plate 220 covers the bottom wall of the chamber 23 and is in contact with the bottom wall of the chamber 23. The bottom of the raw material barrel 100 is arranged on the bottom plate 220. The arrangement of the bottom plate 220 can isolate the bottom of the crucible, thereby improving the heat insulation effect of the crucible.
[0049] The second barrel 210 is sleeved in the chamber 23. The second barrel 210 has a top close to the crucible cover 22 and a bottom away from the crucible cover 22. The top and bottom of the second barrel 210 are both provided with openings. The outer wall of the second barrel 210 is in contact with the inner wall of the chamber 23. The side wall of the top of the raw material barrel 100 abuts against the inner wall of the second barrel 210. The second barrel 210 can isolate the inner wall of the crucible, thereby preventing the graphite wall of the crucible from reacting with the gas phase components, and effectively maintaining the stability of the C / Si ratio during the crystal growth process.
[0050] Optionally, the bottom of the second barrel 210 is connected to the bottom plate 220, and the bottom plate 220 blocks the opening at the bottom of the second barrel 210, so as to enclose together with the second barrel 210 a cylindrical structure with a closed bottom and an open top. In this way, the second barrel 210 maintains abutting contact with the top opening of the raw material barrel 100 and the inner wall of the crucible, and the bottom plate 220 maintains abutting contact with the bottom of the raw material barrel 100 and the bottom wall of the crucible, so that while ensuring the heat insulation effect, the heat can be evenly transferred to the entire second barrel 210, which is conducive to ensuring that the silicon carbide powder 40 is always in a uniformly heated state.
[0051] It is easy to understand that in other embodiments of the present invention, the crucible may only include the bottom plate 220 or the second cylinder 210, that is, only the raw material cylinder 100 is isolated from the bottom wall of the chamber 23, or only the raw material cylinder 100 is isolated from the inner wall of the chamber 23.
[0052] In an optional embodiment, the bottom plate 220 and the second cylinder 210 are both made of graphite material. Tantalum carbide coatings are provided on the surfaces of the bottom plate 220 and the second cylinder 210. The thickness of the tantalum carbide coatings of the bottom plate 220 and the second cylinder 210 is 2-3 mm, which can provide sufficient structural strength while preventing the graphite wall of the crucible from reacting with the gas phase components, and effectively maintaining the stability of the C / Si ratio during the crystal growth process.
[0053] from Figure 1It can also be seen that in an optional embodiment, the top of the second barrel 210 is spaced apart from the crucible cover 22; a crucible also includes a guide tube 300; the guide tube 300 is located in the chamber 23 and is arranged between the top of the second barrel 210 and the crucible cover 22; a seed crystal connection area 30 is provided on the inner surface of the crucible cover 22; the guide tube 300 has a top close to the crucible cover 22 and a bottom away from the crucible cover 22, a guide outlet 301 is provided at the top of the guide tube 300, and a guide inlet 302 is provided at the bottom of the guide tube 300; along the direction from the guide inlet 302 to the guide outlet 301, the inner diameter of the guide tube 300 has a decreasing trend; the bottom of the guide tube 300 abuts against the top of the second barrel 210, and the guide inlet 302 is connected to the opening at the top of the second barrel 210; the top of the guide tube 300 abuts against the crucible cover 22, and the guide outlet 301 faces the seed crystal connection area 30. The guide tube 300 can guide the silicon carbide atmosphere to flow efficiently and quickly onto the seed crystal at the seed crystal connection area 30, thereby improving the crystal growth efficiency and ensuring the crystal quality.
[0054] In an optional embodiment, the guide tube 300 is made of graphite material. A tantalum carbide coating is provided on the surface of the guide tube 300. The thickness of the tantalum carbide coating of the guide tube 300 is 2-3 mm, which can provide sufficient structural strength while guiding the growth atmosphere to the seed crystal growth interface.
[0055] This embodiment adopts the PVT method to grow silicon carbide crystals. The specific growth process includes seed crystal pasting, crucible assembly, powder material 40 filling, crystal growth and other links. These links will be specifically described below.
[0056] A resin adhesive, including but not limited to phenolic resin, epoxy resin, etc., is used to bond the silicon carbide seed crystal to the seed crystal cap; further, the bonded seed crystal is subjected to hot pressing to remove the voids and bubbles therein. Preferably, carbon powder is added to the resin adhesive to reduce the voids after bonding. A graphite crucible is used, and its graphite block is isostatic graphite, which is characterized by high density and low cracking rate; preferably, asphalt glue is used as a filling adhesive for the graphite block.
[0057] Furthermore, the second cylinder 210 and the bottom plate 220 adapted to the inner diameter of the graphite crucible are stably placed inside the crucible, and the inner diameters are ensured to be consistent during assembly so that they do not shake inside the crucible.
[0058] The support block 110 is placed at the bottom of the tantalum carbide coated graphite piece, and the funnel-shaped first cylinder 120 is placed on top, ensuring that the funnel-shaped first cylinder 120 is placed horizontally.
[0059] During the loading process, the first cylinder 120 is inserted into the crucible from the top of the crucible, the bottom of the first cylinder 120 is inserted into the second cylinder 210, and the silicon carbide powder 40 is slowly added to the first cylinder 120 through the funnel, ensuring that the powder 40 added thereto fills the bottom of the funnel-shaped first cylinder 120 layer by layer, and gradually fills it to the specified filling height, and the surface is flattened with a flat shovel.
[0060] During growth: Place the graphite crucible (such as Figure 1 As shown), the whole is placed in an induction heating furnace and wrapped with graphite felt for heat preservation. After evacuation and filling with argon, the vacuum degree is reduced to 2-50mbar, and then the temperature of the machine is increased to 2100-2300℃. At this time, the area below the crucible wall is the area with the highest temperature in the high-temperature zone. The utility model isolates the high-temperature area from the powder 40 through the funnel-shaped first cylinder 120, thereby effectively avoiding the concentrated carbonization of this area. At the same time, due to the filling of the bottom raw material cylinder 100, the charging amount is reduced, and the utilization rate of the raw materials is further improved. At the same time, a tantalum carbide coating is used to isolate the graphite crucible wall growth chamber 23, thereby improving the stability of the gas phase components.
[0061] 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 crucible, comprising a crucible body and a crucible cover, wherein the crucible body has a chamber, and the crucible cover is arranged at one end of the crucible body to close the chamber, characterized in that: include: A raw material barrel (100) is located in the chamber (23); the raw material barrel (100) has a bottom portion close to the bottom wall of the chamber (23) and a top portion away from the bottom wall of the chamber (23); the bottom of the raw material barrel (100) is closed and the top is open; and the inner diameter of the raw material barrel (100) tends to increase from the bottom to the top of the raw material barrel (100); The bottom of the raw material barrel (100) is arranged on the bottom wall of the chamber (23), the opening of the top of the raw material barrel (100) is arranged toward the crucible cover (22), and the side wall of the top of the raw material barrel (100) abuts against the inner wall of the chamber (23).
2. A crucible according to claim 1, characterized in that: Along the direction from the bottom to the top of the raw material barrel (100), the inner diameter of the raw material barrel (100) gradually increases; The slope of the inner wall of the raw material barrel (100) is 40-50°.
3. A crucible according to claim 2, characterized in that: The raw material barrel (100) comprises a support block (110) and a first barrel body (120); The support block (110) is arranged on the bottom wall of the chamber (23); The first cylinder (120) has a bottom close to the bottom wall of the chamber (23) and a top away from the bottom wall of the chamber (23), and both the bottom and the top of the first cylinder (120) have openings; the bottom of the first cylinder (120) is connected to the top of the support block (110) close to the first cylinder (120), and the top of the support block (110) blocks the opening at the bottom of the first cylinder (120); the opening at the top of the first cylinder (120) is arranged toward the crucible cover (22), and the side wall of the top of the first cylinder (120) abuts against the inner wall of the chamber (23); along the direction from the bottom wall of the chamber (23) to the crucible cover (22), the inner diameter of the first cylinder (120) has an increasing trend.
4. A crucible according to claim 3, characterized in that: Along the direction from the bottom wall of the chamber (23) to the crucible cover (22), the inner diameter of the first cylinder (120) gradually increases; The slope of the inner wall of the first cylinder (120) is 40-50°.
5. A crucible according to claim 3, characterized in that: The height of the first cylinder (120) in the direction from the bottom wall of the chamber (23) to the crucible cover (22) is 3-5 cm; And / or, the height of the support block (110) in the direction from the bottom wall of the chamber (23) to the crucible cover (22) is 2-3 cm.
6. A crucible according to claim 5, characterized in that: The top of the support block (110) is snap-fitted to the opening at the bottom of the first cylinder (120).
7. A crucible according to any one of claims 1 to 6, characterized in that: It also includes a bottom plate (220), which is located in the chamber (23) and is arranged on the bottom wall of the chamber (23); the bottom plate (220) covers the bottom wall of the chamber (23) and is in contact with the bottom wall of the chamber (23); the bottom of the raw material barrel (100) is arranged on the bottom plate (220); and / or, The invention also comprises a second barrel (210) which is sleeved in the chamber (23); the second barrel (210) has a top close to the crucible cover (22) and a bottom far away from the crucible cover (22); the top and the bottom of the second barrel (210) are both provided with openings; the outer wall of the second barrel (210) is in contact with the inner wall of the chamber (23); the side wall of the top of the raw material barrel (100) abuts against the inner wall of the second barrel (210).
8. A crucible according to claim 7, characterized in that: The crucible comprises the bottom plate (220) and the second cylinder (210), the bottom of the second cylinder (210) is connected to the bottom plate (220), and the bottom plate (220) blocks the opening at the bottom of the second cylinder (210), so as to form a cylindrical structure with a closed bottom and an open top together with the second cylinder (210).
9. A crucible according to claim 8, characterized in that: The top of the second cylinder (210) is spaced apart from the crucible cover (22); The crucible further comprises a flow guide tube (300), the flow guide tube (300) being located in the chamber and arranged between the top of the second cylinder (210) and the crucible cover (22); a seed crystal connection area (30) is arranged on the inner surface of the crucible cover (22); the flow guide tube (300) has a top close to the crucible cover (22) and a bottom away from the crucible cover (22); a flow guide outlet (301) is arranged on the top of the flow guide tube (300), and a flow guide outlet (301) is arranged on the bottom of the flow guide tube (300); The invention relates to a flow inlet (302); the inner diameter of the flow guide tube (300) tends to decrease along the direction from the flow guide inlet (302) to the flow guide outlet (301); the bottom of the flow guide tube (300) abuts against the top of the second cylinder (210), and the flow guide inlet (302) is connected to the opening at the top of the second cylinder (210); the top of the flow guide tube (300) abuts against the crucible cover (22), and the flow guide outlet (301) faces the seed crystal connection area (30).
10. A crucible according to claim 9, characterized in that: At least one of the raw material cylinder (100), the bottom plate (220), the second cylinder body (210) and the guide cylinder (300) is made of graphite material; And / or, a tantalum carbide coating is provided on the surface of at least one of the bottom plate (220), the second cylinder (210) and the guide cylinder (300); and the thickness of the tantalum carbide coating is 2-3 mm.