Silicon carbide crystal growth container and silicon carbide crystal growth equipment having the same.

Abstract

This utility model discloses a silicon carbide crystal growth container and a silicon carbide crystal growth device having the same. The silicon carbide crystal growth container includes: a container body; a protrusion disposed on the inner bottom surface of the container body and protruding upward; and an inert metal mesh disposed on the outer surface of the protrusion and the inner surface of the container body. The silicon carbide crystal growth container according to the embodiment of this utility model has the advantages of uniform heating and high crystal yield.

Description

Technical Field

[0001] This utility model relates to the field of silicon carbide crystal growth technology, and more specifically, to a silicon carbide crystal growth container and a silicon carbide crystal growth device having the silicon carbide crystal growth container. Background Technology

[0002] In the physical vapor transport (PVT) method for silicon carbide crystal growth, uneven thermal field distribution and large radial temperature gradients are common problems. This leads to a significant temperature difference between the crystal edges and the center, resulting in uneven crystal growth and causing crystal facet depressions, edge polycrystalline structures, and cracks. Furthermore, in the later stages of crystal growth, the crucible is prone to corrosion. Corrosion particles from the crucible's inner wall can enter the growth atmosphere, causing defects such as inclusions, dislocations, and micropipes, which are detrimental to the growth of high-quality, large-size silicon carbide crystals. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a silicon carbide crystal growth container, which has advantages such as uniform heating and high crystal yield.

[0004] This invention also proposes a silicon carbide crystal growth device having the aforementioned silicon carbide crystal growth container.

[0005] To achieve the above objectives, a silicon carbide crystal growth container is provided according to an embodiment of the first aspect of the present invention. The silicon carbide crystal growth container includes: a container body; a protrusion disposed on the inner bottom surface of the container body and protruding upward; and an inert metal mesh disposed on the outer surface of the protrusion and the inner surface of the container body.

[0006] The silicon carbide crystal growth container according to the embodiments of this utility model has the advantages of uniform heating and high crystal yield.

[0007] In addition, the silicon carbide crystal growth container according to the above embodiments of this utility model may also have the following additional technical features:

[0008] According to one embodiment of the present invention, one of the lower surface of the protrusion and the inner bottom surface of the container body is provided with a threaded portion and the other is provided with a threaded hole, wherein the threaded portion is threadedly engaged in the threaded hole.

[0009] According to one embodiment of the present invention, the connection between the upper surface of the protrusion and the outer peripheral surface is rounded.

[0010] According to one embodiment of the present invention, the inert metal mesh includes: an inner mesh body covering the protrusion; and an outer mesh body covering the inner circumferential surface and the inner bottom surface of the container body and overlapping with the inner mesh body.

[0011] According to one embodiment of the present invention, the mesh count of the inner mesh is less than or equal to the mesh count of the outer mesh.

[0012] According to one embodiment of the present invention, the inner mesh has a mesh count of 50-70, the outer mesh has a mesh count of 70-100, and the thickness of the inner mesh and the outer mesh is 1-3 mm.

[0013] According to one embodiment of the present invention, the silicon carbide crystal growth container further includes: an upper filter element; a lower filter element, wherein the lower filter element is provided with a lower airflow through hole, and the diameter of the lower airflow through hole is equal to that of the protrusion.

[0014] According to one embodiment of the present invention, the diameter of the protrusion is 70-80 mm and the height of the protrusion protruding from the inner bottom surface of the container body is 20-30 mm.

[0015] According to one embodiment of the present invention, the protrusion is a graphite part and the inert metal mesh is a tantalum mesh.

[0016] According to a second aspect of the present invention, a silicon carbide crystal growth apparatus is provided, the silicon carbide crystal growth apparatus including the silicon carbide crystal growth container according to a first aspect of the present invention.

[0017] The silicon carbide crystal growth apparatus according to the embodiments of the present invention has advantages such as uniform heating and high crystal yield by utilizing the silicon carbide crystal growth container described in the first aspect of the present invention.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a cross-sectional view of a silicon carbide crystal growth container according to an embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional view of a silicon carbide crystal growth container according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the protrusion of the silicon carbide crystal growth container according to an embodiment of the present invention.

[0023] Reference numerals: 1. Silicon carbide crystal growth container; 10. Container body; 11. Threaded hole; 20. Protrusion; 21. Threaded part; 22. Rounded corner; 30. Inert metal mesh; 31. Inner mesh body; 32. Outer mesh body; 40. Lower filter element; 41. Lower airflow through hole; 50. Upper filter element; 51. Upper airflow through hole; 60. Liner ring; 70. Inert particle layer; 80. Graphite ring; 81. Growth space; 90. Container cover; 2. Silicon carbide powder; 3. Seed crystal. Detailed Implementation

[0024] This application is based on the findings and understanding of the following facts and issues:

[0025] In the physical vapor transport (PVT) method for silicon carbide crystal growth, uneven thermal field distribution and large radial temperature gradients are common problems. This leads to a significant temperature difference between the crystal edges and the center, resulting in uneven crystal growth and causing crystal facet depressions, edge polycrystalline structures, and cracks. Furthermore, in the later stages of crystal growth, the crucible is prone to corrosion. Corrosion particles from the crucible's inner wall can enter the growth atmosphere, causing defects such as inclusions, dislocations, and micropipes, which are detrimental to the growth of high-quality, large-size silicon carbide crystals.

[0026] Specifically, in the physical vapor transport (PVT) method for silicon carbide crystal growth, induction heating has advantages such as simple structure, energy saving and low maintenance cost. However, for large-size silicon carbide crystals, due to the skin effect, the high-frequency current is concentrated on the surface of the crucible, which can easily lead to uneven thermal field distribution and large radial temperature gradient.

[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0028] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] The silicon carbide crystal growth container 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0031] like Figures 1-3 As shown, the silicon carbide crystal growth container 1 according to an embodiment of the present invention includes a container body 10, a protrusion 20, and an inert metal mesh 30.

[0032] The protrusion 20 is provided on the inner bottom surface of the container body 10 and protrudes upward (the vertical direction is shown by the arrow in the figure). The inert metal mesh 30 is provided on the outer surface of the protrusion 20 and the inner surface of the container body 10.

[0033] Specifically, the silicon carbide crystal growth container 1 is a silicon carbide growth container using the physical vapor transport method. The silicon carbide crystal growth container 1 also includes a container lid 90 and a graphite ring 80. The graphite ring 80 is located at the upper end of the container body 10, and the container lid 90 is placed on top of the graphite ring 80. The container lid 90 and the radially inner side of the graphite ring 80 define a growth space 81 for crystal growth. The container body 10 is suitable for holding silicon carbide powder 2, and the container lid 90 is suitable for bonding seed crystals 3. The container body 10 can be a crucible, and the container lid 90 can be a crucible lid.

[0034] The protrusion 20 can be located in the middle of the inner bottom surface of the container body 10, preferably at the radial center of the inner bottom surface of the container body 10 and coaxial with the inner bottom surface of the container body 10.

[0035] According to the silicon carbide crystal growth container 1 of this utility model embodiment, by providing a protrusion 20, which is provided on the inner bottom surface of the container body 10, the protrusion 20 can radiate heat evenly to the surroundings when heated during the silicon carbide crystal growth process. Compared with silicon carbide crystal growth containers in related technologies, this can improve the temperature uniformity inside the container body 10, reduce the radial temperature gradient, reduce the radial temperature difference of the seed crystal 3, improve the uniformity of crystal growth, avoid the occurrence of crystal surface depression, edge polycrystalline, cracks, etc., and improve the reliability and yield of crystal growth.

[0036] Furthermore, by setting an inert metal mesh 30, which is located on the outer surface of the protrusion 20 and the inner surface of the container body 10, compared with silicon carbide crystal growth containers in related technologies, the inert metal mesh 30 can block corrosion particles on the inner peripheral wall of the container body 10 from entering the crystal growth atmosphere. This helps to reduce defects such as inclusions, dislocations, and microtubes in silicon carbide crystals, thereby facilitating the growth of high-quality, large-size silicon carbide crystals and improving the reliability and yield of crystal growth.

[0037] Therefore, the silicon carbide crystal growth container 1 according to the present invention has the advantages of uniform heating and high crystal yield.

[0038] The silicon carbide crystal growth container 1 according to a specific embodiment of the present invention is described below with reference to the accompanying drawings.

[0039] In some specific embodiments of this utility model, such as Figures 1-3 As shown, the silicon carbide crystal growth container 1 according to an embodiment of the present invention includes a container body 10, a protrusion 20, and an inert metal mesh 30.

[0040] Advantageously, such as Figure 1 and Figure 3 As shown, one of the lower surface of the protrusion 20 and the inner bottom surface of the container body 10 is provided with a threaded portion 21, and the other is provided with a threaded hole 11. The threaded portion 21 is threaded into the threaded hole 11. Specifically, the figure shows a technical solution in which the threaded portion 21 is provided on the protrusion 20 and the threaded hole 11 is provided on the container body 10. This allows the container body 10 and the protrusion 20 to be manufactured separately, reducing the difficulty of setting the protrusion 20 on the container body 10 and reducing the manufacturing difficulty of the silicon carbide crystal growth container 1.

[0041] Of course, the protrusion 20 can also be integrally formed on the container body 10 to reduce the assembly process.

[0042] More advantageously, such as Figure 1 and Figure 3 As shown, the connection between the upper surface of the protrusion 20 and the outer peripheral surface is rounded at the corner 22. Specifically, the radius of the corner 22 is 3-5 mm. This not only makes the heat radiation from the protrusion 20 more uniform, thereby reducing the concentration of thermal stress in the container body 10 and further improving the temperature uniformity inside the container body 10, but also helps to mitigate the corrosion of the protrusion 20 during the heating process.

[0043] Specifically, such as Figure 1 and Figure 2 As shown, the inert metal mesh 30 includes an inner mesh body 31 and an outer mesh body 32. The inner mesh body 31 covers the protrusion 20. The outer mesh body 32 covers the inner circumferential surface and the inner bottom surface of the container body 10 and overlaps with the inner mesh body 31. Since the inner mesh body 31 needs to adapt to the shape of the protrusion 20, manufacturing the inner mesh body 31 and the outer mesh body 32 separately can reduce the manufacturing difficulty of the inner mesh body 31 and the outer mesh body 32, thereby reducing the manufacturing difficulty of the inert metal mesh 30.

[0044] Of course, the inner mesh body 31 and the outer mesh body 32 can also be integrally formed to reduce the number of parts and simplify the assembly process.

[0045] More specifically, the mesh count of the inner mesh 31 is less than or equal to the mesh count of the outer mesh 32. Since the inner radial center of the container body 10 is less prone to corrosion, having a mesh count of the outer mesh 32 greater than or equal to that of the inner mesh 31 not only improves the blocking effect on corrosive particles but also facilitates a reduction in the overall cost of the inert metal mesh 30.

[0046] Optionally, the inner mesh 31 has a mesh count of 50-70, the outer mesh 32 has a mesh count of 70-100, and the thickness of both the inner and outer meshes is 1-3 mm. Preferably, the inner mesh 31 has a mesh count of 65, the outer mesh 32 has a mesh count of 80, and the thickness of both is 1.5 mm. Specifically, the silicon carbide powder 2 has a mesh count of 8-40. By using an inert metal mesh 30 with a mesh count of 50-100, contact between the silicon carbide powder 2 and the peripheral wall of the container body 10 can be avoided during loading, thereby reducing corrosion of the container body 10 during crystal growth.

[0047] Furthermore, such as Figure 1 As shown, the diameter D of the protrusion 20 is 70-80 mm. This ensures that the radial temperature difference of the seed crystal 3 during the heating and growth process is 4-5 degrees Celsius per centimeter, thereby guaranteeing the micro-protrusion growth of silicon carbide crystals, which helps to reduce stress concentration and dislocations.

[0048] The protrusion 20 extends 20 out of the bottom surface of the container body 10 at a height h of 20-30 mm. This ensures that the silicon carbide powder 2 is supplied in sufficient quantities while improving temperature uniformity.

[0049] Furthermore, the protrusion 20 is made of graphite. This gives the protrusion 20 good thermal conductivity, facilitating heat radiation and improving heat uniformity within the container body 10. The inert metal mesh 30 is made of tantalum. This gives the inert metal mesh 30 good high-temperature stability, preventing it from affecting the silicon carbide crystal growth process.

[0050] Figure 1 A silicon carbide crystal growth container 1 according to some examples of the present invention is shown. For example... Figure 1 As shown, the silicon carbide crystal growth container 1 also includes an upper filter 50 and a lower filter 40. The lower filter 40 has a lower airflow through-hole 41, the diameter of which is equal to the diameter of the protrusion 20. Specifically, the lower filter 40 is located above the silicon carbide powder 2. The lower filter 40 and the upper filter 50 are spaced apart in the vertical direction and their edges are supported and positioned by a bushing 60. An inert particle layer 70 is filled between the upper filter 50 and the lower filter 40. The upper filter 50 has an upper airflow through-hole 51, the diameter of which is larger than the diameter of the lower airflow through-hole 41. The lower airflow through-hole 41, the upper airflow through-hole 51, and the protrusion 20 are coaxially arranged. By setting the lower filter 40, the inert particle layer 70, and the upper filter 50, the gaseous components can be filtered. The purified silicon carbide gas enters the growth space 81 and is transported to the growth surface of the seed crystal 3 for crystallization, which helps to reduce inclusion defects in the silicon carbide crystal. By making the diameter of the upper airflow through-hole 51 larger than the diameter of the lower airflow through-hole 41, the annular area of ​​the lower filter element 40 is larger, which can block more inclusions from the silicon carbide powder 2. Furthermore, the coaxial arrangement of the lower airflow through-hole 41, the upper airflow through-hole 51, and the protrusion 20 facilitates a more stable ascent of the gas phase components. This allows the lower filter element 40, the inert particle layer 70, and the upper filter element 50 to continuously and progressively block inclusions, effectively filtering out the generated micro-inclusions, reducing the inclusion content in the silicon carbide single crystal, and thus improving the quality of the silicon carbide single crystal. By making the diameter of the lower airflow through-hole 41 equal to the diameter of the protrusion 20, the gas phase components generated by the silicon carbide powder 2 directly above the protrusion 20 can easily pass through the lower airflow through-hole 41, further improving the uniformity of crystal growth.

[0051] Specifically, the surface of the liner 60 is coated with a tantalum carbide layer with a thickness of 30 micrometers. This prevents gas from entering the inert particle layer 70 from corroding the liner 60 and the container body 10, and helps reduce the possibility of corrosion particles from the liner 60 and the container body 10 entering the silicon carbide crystal and causing inclusion defects.

[0052] The inert particle layer 70 can be a tantalum particle layer with a particle size of 2 mm, and the height of the inert particle filling layer is 25 mm.

[0053] The quality characterization results of the 8-inch silicon carbide single crystals grown using the silicon carbide crystal growth container 1 according to the present invention are shown in the table below:

[0054] Silicon carbide crystal performance parameters Example Crystal diameter 206 Crystal thickness (mm) 22 Multitype none Resistivity (ohms*cm) 0.02 Microtubule density (ea / cm2) 0.03 Visually estimate the total area of ​​the carbon inclusions (observed under strong light). ≤0.15％ Total area of ​​the six-sided cavity (observed under strong light) ≤0.02％ Total dislocation density (ea / cm2) 1900

[0055] It can be seen that the silicon carbide single crystal grown using the silicon carbide crystal growth container 1 according to the present invention has a low cumulative area of ​​carbon inclusions, a low cumulative area of ​​hexagonal voids, and a low total dislocation density, which meets the existing requirements for large-size, high-quality silicon carbide crystals.

[0056] The silicon carbide crystal growth apparatus according to an embodiment of the present invention is described below. The silicon carbide crystal growth apparatus according to an embodiment of the present invention includes a silicon carbide crystal growth container 1 according to the above embodiment of the present invention.

[0057] The silicon carbide crystal growth equipment according to the embodiments of the present invention has the advantages of uniform heating and high crystal yield by utilizing the silicon carbide crystal growth container 1 according to the above embodiments of the present invention.

[0058] Other components and operations of the silicon carbide crystal growth apparatus according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A silicon carbide crystal growth container, characterized by, include: Container body; A protrusion is provided on the inner bottom surface of the container body and protrudes upward; An inert metal mesh is disposed on the outer surface of the protrusion and the inner surface of the container body.

2. The silicon carbide crystal growth vessel of claim 1, wherein, The lower surface of the protrusion and the inner bottom surface of the container body are provided with a threaded portion on one and a threaded hole on the other, and the threaded portion is threadedly engaged in the threaded hole.

3. The silicon carbide crystal growth vessel of claim 1, wherein, The connection between the upper surface of the protrusion and the outer peripheral surface is rounded.

4. The silicon carbide crystal growth vessel of claim 1, wherein, The inert metal mesh includes: An inner mesh body that covers the protrusion; An outer mesh body covers the inner circumferential surface and the inner bottom surface of the container body and overlaps with the inner mesh body.

5. The silicon carbide crystal growth vessel of claim 4, wherein, The number of meshes in the inner network body is less than or equal to the number of meshes in the outer network body.

6. The silicon carbide crystal growth vessel of claim 5, wherein, The inner mesh has a mesh count of 50-70, the outer mesh has a mesh count of 70-100, and the thickness of both the inner and outer meshes is 1-3 mm.

7. The silicon carbide crystal growth vessel of claim 1, wherein, Also includes: Upper filter element; The lower filter element has a lower airflow passage hole, the diameter of which is equal to that of the protrusion.

8. The silicon carbide crystal growth vessel of claim 1, wherein, The diameter of the protrusion is 70-80 mm and the height of the protrusion from the bottom surface of the container body is 20-30 mm.

9. The silicon carbide crystal growth vessel of claim 1, wherein, The protrusion is a graphite part, and the inert metal mesh is a tantalum mesh.

10. A silicon carbide crystal growth apparatus, characterized by, Includes a silicon carbide crystal growth container according to any one of claims 1-9.

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