Crucible assembly
The crucible assembly with a ring groove and stone graphite ring addresses graphite dispersion issues, enhancing silicon carbide crystal quality and yield by isolating graphite powder, thus improving production efficiency and reducing costs.
Patent Information
- Application Number
- CN202422324923.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-09-24
AI Technical Summary
In the prior art, graphite pulverization separation of crucible components during the growth of silicon carbide crystals leads to the problem of reducing the yield and utilization of silicon carbide crystals.
A crucible assembly is designed, including a crucible body and a crucible cover. A first ring groove is provided with an open end of the crucible body and a second ring groove is provided on the graphite ring. By reducing heat conduction and isolating the graphite purifier, the chance of graphite purifier being brought to the crystal surface is reduced.
The yield and utilization rate of silicon carbide crystals are improved, production costs are reduced, and the quality of the crystals is improved.
Smart Images
Figure CN223103134U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of silicon carbide crystal preparation, and more specifically, to a crucible assembly. Background Technique
[0002] As a third-generation semiconductor material, silicon carbide has outstanding advantages several times that of silicon-based semiconductor materials and is widely used in fields such as power semiconductor devices and microwave radio frequency devices. In addition, there is also a certain market demand for silicon carbide moissanite jewelry. At present, the Physical Vapor Transport (PVT) method is a commonly used method for growing silicon carbide crystals. The PVT method mainly heats silicon carbide powder to above 2300 degrees Celsius by induction heating in a closed growth chamber close to vacuum, so that it sublimates to produce reaction gases of various gas components such as Si, Si2C, and SiC2. These reaction gases form atomic deposition on the surface of the silicon carbide seed crystal at the top of the growth chamber and gradually grow into single-crystal silicon carbide.
[0003] During the growth process, as the temperature gradient continuously increases, the graphite on the crucible assembly will powder and separate. When the graphite powder detaches from the graphite body, it will be carried by the sublimated Si and C atomic gas flows to the crystallization surface to form carbon encapsulation, which will reduce the yield and utilization rate of silicon carbide crystals.
[0004] Therefore, how to improve the yield and utilization rate of silicon carbide crystals has become a technical problem that needs to be solved urgently by those skilled in the art. Content of the Utility Model
[0005] In view of this, the purpose of the utility model is to provide a crucible assembly to improve the yield and utilization rate of silicon carbide crystals.
[0006] To achieve the above purpose, the utility model provides the following technical solutions:
[0007] A crucible assembly includes a crucible body and a crucible cover;
[0008] A first annular groove is formed on the end surface of the open end of the crucible body. The first annular groove is coaxially arranged with the cavity of the crucible body, and its inner diameter is less than or equal to the inner diameter of the cavity of the crucible body, and its outer diameter is less than the outer diameter of the crucible body. The end surface of the first annular groove facing the crucible cover is an annular step surface;
[0009] The crucible cover is used to be arranged at the open end of the crucible body, and both the crucible body and the crucible cover are made of graphite.
[0010] Optionally, in the above crucible assembly, a graphite ring is further included. The graphite ring is made of graphite and is used to be arranged between the crucible body and the crucible cover. One end of the graphite ring is used to abut against the end face of the open end of the crucible body, and the other end is connected to the crucible cover;
[0011] A second ring groove is formed on the end face of the graphite ring facing away from the crucible cover. The second ring groove is coaxially arranged with the graphite ring, and the inner diameter of the second ring groove is larger than the inner diameter of the graphite ring, and the outer diameter is smaller than the outer diameter of the graphite ring.
[0012] Optionally, in the above crucible assembly, the second ring groove divides the end face of the graphite ring facing away from the crucible cover into a first ring band and a second ring band. The first ring band is located inside the second ring groove, and the second ring band is located outside the second ring groove;
[0013] In the depth direction of the crucible body, the second ring band abuts against the end face of the open end of the crucible body and is opposite to the annular step surface. The second ring groove and the first ring band are both arranged in a staggered manner with respect to the annular step surface; or, in the depth direction of the crucible body, the second ring band abuts against the end face of the open end of the crucible body, a part of the second ring groove is opposite to the annular step surface, and the other part of the second ring groove and the first ring band are both arranged in a staggered manner with respect to the annular step surface.
[0014] Optionally, in the above crucible assembly, the groove width of the second ring groove is 6 mm - 9 mm, and the groove depth is 20 mm - 40 mm; and / or,
[0015] The ring width of the first ring band is greater than or equal to 4 mm.
[0016] Optionally, in the above crucible assembly, a crucible body fitting ring platform is arranged on the end face of the open end of the crucible body. The crucible body fitting ring platform is coaxially arranged with the cavity of the crucible body, and the inner diameter of the crucible body fitting ring platform is larger than the outer diameter of the annular step surface, and the outer diameter is equal to the outer diameter of the crucible body;
[0017] A first fitting groove for fitting and cooperating with the crucible body fitting ring platform is arranged at one end of the graphite ring away from the crucible cover.
[0018] Optionally, in the above crucible assembly, the crucible body fitting ring platform and the crucible body are of an integral structure.
[0019] Optionally, in the above crucible assembly, the crucible body fitting ring platform is in threaded fit with the first fitting groove.
[0020] Optionally, in the above crucible assembly, a second fitting groove is arranged at one end of the graphite ring facing away from the crucible body;
[0021] The crucible cover is provided with a cover body fitting boss for fitting into the second fitting groove, and the end face of the cover body fitting boss facing the crucible body is used for pasting a seed crystal.
[0022] Optionally, in the above crucible assembly, the cover body fitting boss and the crucible cover are of an integral structure.
[0023] Optionally, in the above crucible assembly, the ring width of the annular stepped surface is greater than or equal to 3 mm.
[0024] The crucible assembly provided by the present utility model comprises a crucible body and a crucible cover. A first ring groove is formed on the end face of the open end of the crucible body. The first ring groove is coaxially arranged with the cavity of the crucible body, and its inner diameter is less than or equal to the inner diameter of the cavity of the crucible body, and its outer diameter is less than the outer diameter of the crucible body, so that the end face of the first ring groove facing the crucible cover forms an annular stepped surface. The crucible cover is used to be arranged at the open end of the crucible body, and both the crucible body and the crucible cover are made of graphite.
[0025] The first ring groove is formed at a part of the crucible body that is prone to pulverization. After the first ring groove is formed on the crucible body, the degree of pulverization during the first three uses of the crucible body is reduced. The reason is that the setting of the first ring groove reduces the heat conduction effect of the crucible body on the silicon carbide raw material, thereby reducing the degree of pulverization of the graphite of the crucible body. In addition, the setting of the first ring groove enables a part of the pulverized graphite powder of the crucible body to fall on the annular stepped surface, isolating it from the silicon carbide raw material, reducing the probability of the graphite powder falling off and being carried to the crystal crystallization surface along with the C and Si sublimation gases, and further reducing the production of inclusions in the later stage of the silicon carbide crystal.
[0026] Compared with the prior art, the crucible assembly provided by the present utility model has a simple structure, improves the quality of the prepared silicon carbide crystal, simultaneously improves the yield and utilization rate of the silicon carbide crystal, and reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0028] Figure 1 is a schematic structural view of the crucible assembly disclosed in the embodiment of the present utility model Figure 1 ;
[0029] Figure 2 is a schematic structural view of the crucible body disclosed in the embodiment of the present utility model;
[0030] Figure 3 Schematic structural diagram of the crucible lid disclosed in the embodiment of the present utility model;
[0031] Figure 4 Schematic structural diagram of the graphite ring disclosed in the embodiment of the present utility model;
[0032] Figure 5 Schematic structure of the crucible assembly disclosed in the embodiment of the present utility model Figure 2 .
[0033] Among them, 100 is the crucible body, 110 is the first annular groove, 111 is the annular stepped surface, and 120 is the crucible body mounting ring platform;
[0034] 200 is the crucible lid, and 210 is the lid body mounting boss;
[0035] 300 is the graphite ring, 301 is the first annular band, 302 is the second annular band, 310 is the second annular groove, 320 is the first mounting groove, and 330 is the second mounting groove;
[0036] 400 is the seed crystal;
[0037] 500 is the silicon carbide raw material. Specific embodiments
[0038] The core of the present utility model is to disclose a crucible assembly to improve the yield and utilization rate of silicon carbide crystals.
[0039] Hereinafter, the embodiments will be described with reference to the drawings. In addition, the embodiments shown below do not limit the content of the utility model described in the claims in any way. In addition, all the contents of the configurations shown in the following embodiments are not limited to those necessary for the solution of the utility model described in the claims. It should be noted that for the convenience of description, only the parts related to the relevant utility model are shown in the drawings. Without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.
[0040] Combined with Figures 1 - 5 , the crucible assembly disclosed in the present utility model includes a crucible body 100 and a crucible lid 200. A first annular groove 110 is formed on the end surface of the open end of the crucible body 100. The first annular groove 110 is coaxially arranged with the cavity of the crucible body 100, and its inner diameter is less than or equal to the inner diameter of the cavity of the crucible body 100, and its outer diameter is less than the outer diameter of the crucible body 100, so that the end surface of the first annular groove 110 facing the crucible lid 200 forms an annular stepped surface 111. The crucible lid 200 is used to be arranged at the open end of the crucible body 100, and both the crucible body 100 and the crucible lid 200 are made of graphite.
[0041] According to the test, for each use of the crucible body 100 without the first annular groove 110, the thickness of the crucible body 100 decreases by about 0.3 mm - 0.8 mm. As the number of uses increases, the pulverization degree of the crucible body 100 shows a decreasing trend. In the first three uses of the crucible body 100, the probability of macroscopically large particles wrapping in the middle and later stages of the silicon carbide crystal accounts for 60% - 100%, and the wrapping area accounts for 5% - 30% or even higher. As the number of uses of the crucible body 100 increases, the probability of macroscopically large particles wrapping in the middle and later stages shows a downward trend.
[0042] The first annular groove 110 is opened at the part of the crucible body 100 that is prone to pulverization. After the first annular groove 110 is opened on the crucible body 100, the degree of pulverization of the crucible body 100 during the first three uses is reduced. The reason is that the setting of the first annular groove 110 reduces the heat conduction effect of the crucible body 100 on the silicon carbide raw material 500, thereby reducing the pulverization degree of the graphite of the crucible body 100. In addition, the setting of the first annular groove 110 enables a part of the graphite powder pulverized from the crucible body 100 to fall on the annular step surface 111, isolating it from the silicon carbide raw material 500, reducing the probability of the graphite powder being carried to the crystal crystallization surface by the C and Si sublimation gases after falling off, and thus reducing the output of the silicon carbide crystal wrapping in the middle and later stages.
[0043] Compared with the prior art, the structure of the present utility model is simple, improving the quality of the prepared silicon carbide crystal, while also enhancing the yield and utilization rate of the silicon carbide crystal and reducing the production cost.
[0044] It should be noted that in the present utility model, the crucible body 100 is described by taking a regular cylindrical shape as an example, that is, the inner diameter and outer diameter dimensions of the cavities at all parts of the crucible body 100 are the same. For some crucible bodies 100 with irregular shapes, the dimensions of the crucible body 100 in the present utility model all refer to the dimensions at the open end of the crucible body 100.
[0045] In a specific embodiment disclosed by the present utility model, the crucible assembly further includes a graphite ring 300. The graphite ring 300 is made of graphite and is used to be arranged between the crucible body 100 and the crucible cover 200. One end of the graphite ring 300 abuts against the end surface of the open end of the crucible body 100, and the other end is used to connect with the crucible cover 200. The graphite ring 300 and the crucible body 100 and the crucible cover 200 are all coaxially arranged. Due to the uneven heating of the silicon carbide raw material 500 in the crucible body 100, the temperature of the silicon carbide raw material 500 closer to the side wall of the crucible body 100 is higher, and the corresponding gaseous Si generated by the sublimation of the silicon carbide raw material 500 is more. Along the depth direction of the crucible body 100, the graphite ring 300 corresponds to the silicon carbide raw material 500 near the side wall of the crucible body 100 in the crucible body 100, and the generated gaseous Si can be formed on the graphite ring 300 without being brought onto the seed crystal 400, ensuring the yield and utilization rate of the prepared silicon carbide crystal.
[0046] Specifically, when preparing a silicon carbide crystal, the crucible cover 200 with the seed crystal 400 attached and the graphite ring 300 are assembled to obtain an assembly; the silicon carbide raw material 500 is loaded into the cavity of the crucible body 100; the assembly is assembled with the crucible body 100; the crucible assembly is placed into a growth furnace for low-pressure high-temperature growth; after the growth is completed and the crucible assembly is taken out after natural cooling, a silicon carbide crystal is obtained, and the assembly process is simple and the operation is convenient.
[0047] Combined with Figure 4 , a second ring groove 310 is formed on the end face of the graphite ring 300 facing away from the crucible cover 200. The second ring groove 310 is coaxially arranged with the graphite ring 300, and the inner diameter of the second ring groove 310 is larger than the inner diameter of the graphite ring 300, and the outer diameter is smaller than the outer diameter of the graphite ring 300. The second ring groove 310 is used to reduce the heat conduction of the graphite ring 300, thereby reducing the degree of pulverization of the graphite on the graphite ring 300 and reducing the probability that the graphite powder on the graphite ring 300 is carried by the sublimated Si and C atomic gas flows to the crystallization surface to form carbon encapsulation.
[0048] Further, it is defined that the second ring groove 310 divides the end face of the graphite ring 300 facing away from the crucible cover 200 into a first ring band 301 and a second ring band 302. The first ring band 301 is located inside the second ring groove 310, and the second ring band 302 is located outside the second ring groove 310. Then, along the depth direction of the crucible body 100, the second ring band 302 abuts against the end face of the open end of the crucible body 100 and is opposite to the annular step surface 111. The second ring groove 310 and the first ring band 301 are both arranged out of alignment with the annular step surface 111, so that the graphite powder on the annular step surface 111 can sublimate onto the second ring band 302 of the graphite ring 300. Alternatively, along the depth direction of the crucible body 100, the second ring band 302 abuts against the end face of the open end of the crucible body 100, a part of the second ring groove 310 is opposite to the annular step surface 111, and the other part of the second ring groove 310 and the first ring band 301 are both arranged out of alignment with the annular step surface 111, so that the graphite powder on the annular step surface 111 can sublimate into the second ring groove 310 of the graphite ring 300.
[0049] Among them, the groove depth, groove width of the second ring groove 310 and the width of the annular step surface 111 all affect the heat conduction performance of the graphite. According to the experimental verification of different groove depths and widths of the second ring groove 310, when other parameters remain unchanged, separately increasing the groove depth or groove width of the second ring groove 310 has an obvious improvement effect on the macroscopic large particle encapsulation in the middle and late stages of the prepared silicon carbide crystal. When the growth power is appropriately increased, the generation probability of macroscopic large particle encapsulation in the middle and late stages can be reduced to about 10%-15%.
[0050] Exemplarily, combined with Figure 4, the groove width b of the second annular groove 310 is 6 mm - 9 mm, and the groove depth c is 20 mm - 40 mm. The annular width d of the first annular band 301 is greater than or equal to 4 mm to reduce the risk of fracture of the graphite ring 300 during the growth process. Combining Figure 2 , the annular width of the annular step surface 111 is greater than or equal to 3 mm.
[0051] In one embodiment, to ensure the sealed connection between the graphite ring 300 and the crucible body 100, combining Figure 2 , an embedded ring platform 120 of the crucible body is provided on the end surface of the open end of the crucible body 100. The embedded ring platform 120 of the crucible body is coaxially arranged with the cavity of the crucible body 100, and the inner diameter of the embedded ring platform 120 of the crucible body is greater than the outer diameter of the annular step surface 111, and the outer diameter is equal to the outer diameter of the crucible body 100; correspondingly, combining Figure 4 and Figure 5 , a first embedded groove 320 for embedding the embedded ring platform 120 of the crucible body is provided at one end of the graphite ring 300 away from the crucible cover 200.
[0052] During assembly, the first embedded groove 320 is embedded into the embedded ring platform 120 of the crucible body. The embedded ring platform 120 of the crucible body and the crucible body 100 are of an integral structure. The embedded ring platform 120 of the crucible body and the first embedded groove 320 can be in threaded fit.
[0053] To facilitate the positioning and installation of the graphite ring 300 and the crucible cover 200, combining Figure 4 , a second embedded groove 330 is provided at one end of the graphite ring 300 facing away from the crucible body 100; combining Figure 3 , a cover body embedded boss 210 for embedding into the second embedded groove 330 is provided on the crucible cover 200. The end surface of the cover body embedded boss 210 facing the crucible body 100 is used for pasting the seed crystal 400, and silicon carbide crystals are generated on the seed crystal 400 after the sublimation of the silicon carbide raw material 500.
[0054] Among them, the cover body embedded boss 210 and the crucible cover 200 are of an integral structure.
[0055] In one embodiment disclosed by the present utility model, a first annular groove 110 is provided on the crucible body 100, and a second annular groove 310 is provided on the graphite ring 300. The first annular groove 110 and the first annular groove 110 can reduce the heat conduction of graphite during the crystal growth process, thereby reducing the pulverization degree of graphite. Compared with the crucible assembly without the first annular groove 110 and the second annular groove 310, the macro large particle inclusion in the middle and later stages of the silicon carbide crystal prepared by the crucible assembly disclosed by the present utility model can be reduced to within 5%, greatly reducing the inclusion effect and improving the quality of the prepared silicon carbide crystal.
[0056] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. The specific technical means in some embodiments can be partially or wholly incorporated into another embodiment on the premise that it is not explicitly excluded by another embodiment. Therefore, the present utility model will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A crucible assembly, characterized in that, It includes a crucible body (100) and a crucible cover (200); On the end face of the open end of the crucible body (100), a first annular groove (110) is provided. The first annular groove (110) is coaxially arranged with the cavity of the crucible body (100), and its inner diameter is less than or equal to the inner diameter of the cavity of the crucible body (100), and its outer diameter is less than the outer diameter of the crucible body (100). The end face of the first annular groove (110) facing the crucible cover (200) is an annular stepped surface (111); The crucible cover (200) is used to be arranged at the open end of the crucible body (100), and both the crucible body (100) and the crucible cover (200) are made of graphite material.
2. The crucible assembly according to claim 1, characterized in that, It further includes a graphite ring (300). The graphite ring (300) is made of graphite material and is used to be arranged between the crucible body (100) and the crucible cover (200). One end of the graphite ring (300) is used to abut against the end face of the open end of the crucible body (100), and the other end is connected to the crucible cover (200); On the end face of the graphite ring (300) facing away from the crucible cover (200), a second annular groove (310) is provided. The second annular groove (310) is coaxially arranged with the graphite ring (300), and the inner diameter of the second annular groove (310) is greater than the inner diameter of the graphite ring (300), and the outer diameter is less than the outer diameter of the graphite ring (300).
3. The crucible assembly according to claim 2, wherein The second annular groove (310) divides the end face of the graphite ring (300) facing away from the crucible cover (200) into a first annular band (301) and a second annular band (302). The first annular band (301) is located inside the second annular groove (310), and the second annular band (302) is located outside the second annular groove (310); Along the depth direction of the crucible body (100), the second annular band (302) abuts against the end face of the open end of the crucible body (100) and is opposite to the annular stepped surface (111). The second annular groove (310) and the first annular band (301) are both arranged in a staggered manner with respect to the annular stepped surface (111); or, along the depth direction of the crucible body (100), the second annular band (302) abuts against the end face of the open end of the crucible body (100), a part of the second annular groove (310) is opposite to the annular stepped surface (111), and the other part of the second annular groove (310) and the first annular band (301) are both arranged in a staggered manner with respect to the annular stepped surface (111).
4. The crucible assembly according to claim 3, wherein, The groove width of the second annular groove (310) is 6 mm - 9 mm, and the groove depth is 20 mm - 40 mm; and / or, The annular width of the first annular band (301) is greater than or equal to 4 mm.
5. The crucible assembly according to claim 2, characterized in that, On the end face of the open end of the crucible body (100), a crucible body installation ring platform (120) is provided. The crucible body installation ring platform (120) is coaxially arranged with the cavity of the crucible body (100), and the inner diameter of the crucible body installation ring platform (120) is greater than the outer diameter of the annular stepped surface (111), and the outer diameter is equal to the outer diameter of the crucible body (100); One end of the graphite ring (300) away from the crucible cover (200) is provided with a first fitting groove (320) for fittingly engaging with the fitting ring platform (120) of the crucible body.
6. The crucible assembly according to claim 5, characterized in that, The fitting ring platform (120) of the crucible body and the crucible body (100) are of an integral structure.
7. The crucible assembly according to claim 5, wherein, The fitting ring platform (120) of the crucible body is in threaded fit with the first fitting groove (320).
8. The crucible assembly according to claim 2, wherein, One end of the graphite ring (300) facing away from the crucible body (100) is provided with a second fitting groove (330); The crucible cover (200) is provided with a cover body fitting boss (210) for being embedded in the second fitting groove (330), and the end face of the cover body fitting boss (210) facing the crucible body (100) is used for pasting a seed crystal (400).
9. The crucible assembly according to claim 8, wherein, The cover body fitting boss (210) and the crucible cover (200) are of an integral structure.
10. The crucible assembly according to claim 1, characterized in that, The ring width of the annular stepped surface (111) is greater than or equal to 3 mm.