Crucible powder heat conduction bearing disc for silicon carbide crystal growth
By setting bumps on the thermally conductive bearing plate of the crucible powder grown in silicon carbide crystals, changing the flow direction of the heating air flow, the problem of unbalanced temperature gradient is solved, the internal stress and dislocation of the crystal are reduced, and the crystal growth rate and mass are improved.
Patent Information
- Application Number
- CN202422187174.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-06
AI Technical Summary
During the growth of silicon carbide crystals, how to reasonably control the temperature gradient to improve the crystal growth rate and ensure the quality of the crystal, especially in high temperature environments, it is difficult to achieve temperature gradient equalization.
A crucible powder thermally conductive bearing disk for silicon carbide crystal growth is designed. By setting bumps on the disk body to change the flow direction of the heating gas flow, the graphitized raw materials are covered on the surface of the carrier disk, and the ungraphitized raw materials are covered on the surface of the graphitized raw materials to reduce internal stress and dislocation of the crystal.
Effectively reduce internal stress of crystals, reduce dislocations, improve crystal quality and thickness, achieve temperature gradient equalization, and improve crystal growth rate and quality.
Smart Images
Figure CN223074316U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of crystal growth furnaces, and particularly to a crucible powder heat-conducting bearing plate for silicon carbide crystal growth. Background Technique
[0002] The growth of silicon carbide crystals needs to be carried out in a high-temperature environment above 2,000 °C. The growth conditions are very harsh, and the growth process is difficult to monitor in real time. To ensure the quality of crystal growth, it is necessary to precisely control the growth temperature and pressure through the thermal field. Among them, the thermal field is the most critical part in the PVT silicon carbide single crystal furnace, and the thermal field design determines the accuracy of temperature control.
[0003] In a resistance heating type PVT growth system, the side heater around the crucible is the main heat source, and the top holes are the main heat dissipation channels. There is strong radiative heat transfer between the surface of the raw material and the surface of the seed crystal / crystal. Therefore, there are obvious lateral and longitudinal temperature gradients in the raw material area, that is, the temperature of the peripheral area of the raw material > the temperature of the central area > the temperature of the surface of the raw material. And the temperature gradient in the raw material area is closely related to the ultimate growth rate of the crystal. Increasing the temperature gradient in the raw material area can improve the crystal growth rate, but if the temperature gradient exceeds a certain threshold, it will lead to a decrease in the growth rate or even growth interruption. Therefore, how to reasonably control the temperature gradient is the key to obtaining high-quality silicon carbide crystals. Content of the Utility Model
[0004] The purpose of the utility model is to provide a crucible powder heat-conducting bearing plate for silicon carbide crystal growth to solve the problems raised in the above background technique.
[0005] To achieve the above purpose, the utility model provides the following technical solutions:
[0006] A crucible powder heat-conducting bearing plate for silicon carbide crystal growth, including a disk body, the disk body is fixed in the crucible, the disk body is provided with bumps, the top of the bumps is an arc surface, and there is a gap between the top of the bumps and the top of the crucible.
[0007] In a possible implementation manner, the bump includes a column body and a head, the column body is connected to the disk body, and the head is placed at one end of the column body away from the disk body.
[0008] Optionally, an installation groove is opened on the disk body, and the column body is inserted into the installation groove.
[0009] Optionally, there are at least two bumps, and the bumps are evenly distributed at equal intervals.
[0010] In a possible implementation, the bump includes a protruding portion, a buffer portion, and a connecting portion. The connecting portion is connected to the disk body, the buffer portion is disposed between the protruding portion and the connecting portion, and the top of the protruding portion is an arc surface.
[0011] Optionally, the slope of the protruding portion is greater than the slope of the buffer portion.
[0012] Optionally, both the buffer portion and the connecting portion are annular, and the diameter of the circular ring of the connecting portion is greater than the diameter of the circular ring of the buffer portion.
[0013] In a possible implementation, the disk body is connected to the bottom of the crucible through a support frame.
[0014] Compared with the prior art, the present utility model has the following advantages:
[0015] By providing bumps on the carrier disk, the flow direction of the heating gas flow in the crucible can be changed, so that the graphitized raw materials cover the surface of the carrier disk, and the ungraphitized raw materials cover the surface of the graphitized raw materials, greatly reducing the internal stress of the crystal and reducing the dislocation of the crystal. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;
[0017] Figure 2 is a schematic structural diagram of another embodiment of the present utility model.
[0018] In the figure: 10, disk body; 11, installation groove; 20, bump; 21, head; 22, column; 23, protruding portion; 24, connecting portion; 25, buffer portion; 30, support frame; 40, crucible. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] To further elaborate on the technical means and effects adopted by the present utility model to achieve the predetermined utility model purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and effects according to the present utility model as follows.
[0020] Embodiment 1, as Figure 1 shown, a crucible powder heat-conducting carrier disk for silicon carbide crystal growth includes a disk body 10. The disk body 10 is fixed in a crucible 40. A bump 20 is provided on the disk body 10. The top of the bump 20 is an arc surface, and there is a gap between the top of the bump 20 and the top of the crucible 40. In the present application, the top of the bump 20 does not contact the top of the crucible 40. In this way, during the heating process of the crucible 40, the gas flow at the top can flow freely, and the inside of the crucible 40 will not be cut into multiple sub-heating chambers due to the bump 20.
[0021] It should be noted that in this application, the heating method adopted is the side heating method commonly used in silicon carbide growth, that is, the heat sources are located on both sides of the crucible 40.
[0022] In this embodiment, the bump 20 includes a column 22 and a head 21. The column 22 is connected to the disk body 10, and the head 21 is placed at one end of the column 22 away from the disk body 10. Among them, the head 21 and the column 22 can be assembled in a split manner or integrally formed. The preferred solution is to be integrally formed.
[0023] Among them, the shape of the head 21 can be a spherical segment structure similar to a warhead shape, and the top surface of the head 21 is an arc surface. This structure can effectively change the air flow direction in the crucible 40, so that the silicon carbide seed crystal adjusts the gas phase component equilibrium pressure through the radial temperature change at the crystal growth interface, makes the crystal plane grow into a stable isothermal line shape, greatly reduces the internal stress of the crystal, obtains the best crystal with a slightly convex morphology, reduces the microtube density and various dislocation defects, and improves the thickness and quality of the crystal.
[0024] Specifically, when using a traditional carrier plate for silicon carbide crystal growth, raw material graphitization, gas phase transport, and porosity / permeability evolution all occur at the near sidewall close to the heat source. In this application, however, raw material graphitization and porosity / permeability evolution are realized on the disk body 10 of the carrier plate, and gas phase transport is carried out in the remaining raw materials above the graphitized raw materials. That is to say, during the heating process of this application, the remaining raw materials are always above the graphitized raw materials and no longer contact the carrier plate. In this way, the temperature gradients of the temperature at the peripheral region, the central region, and the surface of the raw materials can be reduced.
[0025] In order to better install the bump 20 onto the disk body 10, an installation groove 11 is formed on the disk body 10, and the column 22 is inserted into the installation groove 11.
[0026] Furthermore, there are at least two bumps 20, and the bumps 20 are equally spaced from each other. Using multiple bumps 20 can better disperse the raw materials into the space formed between the bumps 20, thereby further reducing the temperature gradient during the growth process of the silicon carbide crystal.
[0027] Embodiment 2, as Figure 2 shown, in this embodiment, the composition of the bump 20 is different from that in Embodiment 1.
[0028] Specifically, the bump 20 includes a raised portion 23, a buffer portion 25, and a connecting portion 24. The connecting portion 24 is connected to the disk body 10. The buffer portion 25 is disposed between the raised portion 23 and the connecting portion 24. The top of the raised portion 23 is an arc surface. Both the buffer portion 25 and the connecting portion 24 are annular. The diameter of the ring of the connecting portion 24 is greater than the diameter of the ring of the buffer portion 25. The slope of the raised portion 23 is greater than the slope of the buffer portion 25. In this embodiment, the structure of the bump 20 is similar to a contour line structure, that is, the raised portion 23 is equivalent to a mountain ridge, the connecting portion 24 is equivalent to the bottom of a mountain, and the highest point of the raised portion 23 is an arc surface. In this way, the air flow generated by heating will change its flow direction when it encounters the raised portion 23, so as to ensure that the crystal plane grows into a stable temperature.
[0029] The raised portion 23 can quickly slide the raw material towards the disk body 10. When the raw material slides onto the buffer portion 25, since the slope of the buffer portion 25 is smaller than that of the raised portion 23, the raw material begins to deposit on the buffer portion 25 and finally slides onto the connecting portion 24. By adopting the setting method of the bump 20 in this embodiment, it can be ensured that during the growth of silicon carbide, the graphitized raw material always covers the surface of the bump 20, and the non-graphitized raw material covers the surface of the graphitized raw material. In this way, it can be ensured that during the growth of silicon carbide crystals, the temperature gradient is balanced.
[0030] For the first embodiment and the second embodiment, the bottom of the disk body 10 and the crucible 40 can both be connected through the support frame 30. Thus, the carrier disk can be more firmly fixed in the crucible 40.
[0031] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inner", "front", "center", "both ends", "left and right", "front and back", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0032] In the present invention, unless otherwise clearly defined and limited, the terms "installation", "setting", "connection", "fixation", "swivel connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0033] As described above, it is only the preferred embodiment of the present utility model, and there is no limitation to the present utility model in any form. Although the present utility model has been disclosed as above with the preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to equivalent embodiments of equivalent changes by using the above-disclosed technical content within the scope of the technical solution of the present utility model. However, as long as it does not depart from the content of the technical solution of the present utility model, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model still fall within the scope of the technical solution of the present utility model.
Claims
1. A crucible powder heat-conducting bearing plate for silicon carbide crystal growth, characterized in that, It includes a disk body (10), the disk body (10) is fixed in a crucible (40), a convex block (20) is provided on the disk body (10), the top of the convex block (20) is an arc surface, and there is a gap between the top of the convex block (20) and the top of the crucible (40).
2. The crucible powder heat-conducting and load-bearing disk for silicon carbide crystal growth according to claim 1, wherein The convex block (20) includes a column body (22) and a head (21), the column body (22) is connected to the disk body (10), and the head (21) is placed at one end of the column body (22) away from the disk body (10).
3. The crucible powder heat-conducting and load-bearing disk for silicon carbide crystal growth according to claim 2, characterized in that, An installation groove (11) is formed on the disk body (10), and the column body (22) is inserted into the installation groove (11).
4. The crucible powder heat-conducting and load-bearing disk for silicon carbide crystal growth according to claim 2, characterized in that There are at least two convex blocks (20), and the convex blocks (20) are equally spaced from each other.
5. The crucible powder heat-conducting and load-bearing disc for silicon carbide crystal growth according to claim 1, wherein, The convex block (20) includes a convex portion (23), a buffer portion (25) and a connecting portion (24), the connecting portion (24) is connected to the disk body (10), the buffer portion (25) is arranged between the convex portion (23) and the connecting portion (24), and the top of the convex portion (23) is the arc surface.
6. The crucible powder heat-conducting and load-bearing disk for silicon carbide crystal growth according to claim 5, wherein The slope of the convex portion (23) is greater than the slope of the buffer portion (25).
7. The crucible powder heat-conducting and load-bearing disk for silicon carbide crystal growth according to claim 5, characterized in that, Both the buffer portion (25) and the connecting portion (24) are annular, and the diameter of the ring of the connecting portion (24) is greater than the diameter of the ring of the buffer portion (25).
8. The crucible powder heat-conducting and load-bearing disc for silicon carbide crystal growth according to claim 1, wherein The bottom of the disk body (10) and the crucible (40) are connected by a support frame (30).