Synthesis crucible of silicon carbide powder

Abstract

The utility model discloses a synthesis crucible for silicon carbide powder, which at least comprises an outer crucible, an inner crucible and an inner crucible, the inner crucible is arranged in the outer crucible, an opening is formed in one side of the inner crucible, the opening direction of the inner crucible is the same as that of the outer crucible, the inner crucible comprises a first branch part and a second branch part, and a gap is formed between the first branch part and the second branch part; the inner crucible cover is detachably arranged on the opening of the inner crucible; and the boss is arranged on one side, far away from the inner crucible cover, of the inner crucible. According to the synthesis crucible provided by the utility model, the axial temperature gradient and the radial temperature gradient between the raw materials in the crucible can be reduced, the temperature uniformity between the raw materials is improved, and silicon carbide powder with uniform particle size is synthesized.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor material preparation, in particular to a synthetic crucible for silicon carbide powder. Background Art

[0002] As one of the third-generation wide bandgap semiconductor materials, silicon carbide single crystal material has excellent properties such as high thermal conductivity, high breakdown voltage, extremely high carrier mobility, and high chemical stability. Therefore, it is suitable for making high-frequency, high-power electronic devices and optoelectronic devices that work under high temperature and strong radiation conditions. It is widely used in national defense, high technology, industrial production, power supply and substation fields.

[0003] As the raw material for the growth of silicon carbide single crystals, the purity, particle size, crystal form and quality uniformity of silicon carbide powder affect the quality of silicon carbide crystals. However, during the synthesis of silicon carbide powder, the thermal field inside the crucible is unstable, resulting in uneven particle size of the synthesized silicon carbide powder. Utility Model Content

[0004] The utility model aims to provide a synthesis crucible for silicon carbide powder, which can reduce the axial temperature gradient and radial temperature gradient between raw materials inside the crucible, improve the temperature uniformity between the raw materials, and synthesize silicon carbide powder with uniform particle size.

[0005] In order to achieve the above-mentioned purpose and other related purposes, the utility model is implemented through the following technical solutions.

[0006] The utility model provides a synthetic crucible for silicon carbide powder, which at least comprises:

[0007] an outer crucible, wherein one side of the outer crucible is open;

[0008] An inner crucible is arranged in the outer crucible, one side of the inner crucible is open, the opening direction of the inner crucible is the same as the opening direction of the outer crucible, the inner crucible comprises a first subsection and a second subsection, and a gap is arranged between the first subsection and the second subsection;

[0009] an inner crucible cover, detachably disposed on the opening of the inner crucible; and

[0010] The boss is arranged on a side of the inner crucible away from the inner crucible cover.

[0011] In an embodiment of the present invention, the inner crucible further includes a third section, the third section is disposed on a side close to the inner crucible cover, and the third section is connected to the first section and the second section.

[0012] In an embodiment of the present invention, the inner crucible and the outer crucible are coaxial.

[0013] In an embodiment of the present invention, the first sub-portion and the second sub-portion are symmetrically arranged on both sides of the axis of the outer crucible.

[0014] In one embodiment of the present invention, in the axial direction, the ratio of the height of the first section to the height of the inner crucible is (2-3):4.

[0015] In an embodiment of the present invention, in a direction perpendicular to the axis, the ratio of the gap between the first section and the second section to the radial dimension of the inner crucible is 1:(3-4).

[0016] In an embodiment of the present invention, the boss is symmetrically arranged on the first sub-portion and the second sub-portion with the axis as the center, and the boss is located between the inner crucible and the outer crucible.

[0017] In an embodiment of the present invention, at least one boss is disposed on each of the first sub-portion and the second sub-portion.

[0018] In an embodiment of the present invention, the boss is a cylindrical structure, a prismatic structure or a hexahedral structure.

[0019] In an embodiment of the present invention, a distance is set between the outer crucible and the inner crucible, and the distance is 2-5 mm.

[0020] In summary, the utility model provides a synthesis crucible for silicon carbide powder, which can reduce the axial temperature gradient and radial temperature gradient between the raw materials inside the crucible, improve the temperature uniformity between the raw materials, and synthesize silicon carbide powder with uniform particle size. Moreover, the synthesis crucible provided by the utility model can facilitate the loading and removal of raw materials, reducing the workload of operators.

[0021] Of course, any method of implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a schematic diagram of a synthesis crucible for silicon carbide powder in one embodiment of the utility model.

[0024] Figure 2Schematic diagram of an inner crucible in one embodiment of the utility model.

[0025] Figure 3 It is a planar structural diagram of the inner crucible and the boss in one embodiment of the utility model.

[0026] Figure 4 This is a plan view of the structure of the inner crucible in another embodiment of the present invention.

[0027] Marking Description:

[0028] 100, outer crucible; 200, inner crucible; 201, first subsection; 202, second subsection; 203, third subsection; 300, inner crucible cover; 400, boss; 500, raw material. DETAILED DESCRIPTION

[0029] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations. The details in the present invention can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0031] In the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application 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, and therefore cannot be understood as a limitation on the present application. In addition, if the terms "first" and "second" appear, they are only used for description and distinction purposes, and cannot be understood as indicating or implying relative importance.

[0032] In the large-scale synthesis of silicon carbide powder, it is necessary to increase the volume of the crucible to expand the output of silicon carbide powder. The expansion of the crucible volume is not only to increase the height of the crucible, but also to increase the diameter of the crucible. However, as the diameter of the crucible increases, the distance from the crucible wall to the center of the crucible increases, resulting in an increase in the temperature difference between the crucible wall as a heat source and the center of the crucible, that is, an increase in the radial gradient inside the crucible. The powder near the crucible wall is severely carbonized due to the high temperature, while the powder in the center of the crucible has a low temperature and a small particle size. The synthetic crucible provided by the utility model can reduce the axial temperature gradient and radial temperature gradient between the raw materials inside the crucible, improve the temperature uniformity between the raw materials, and synthesize silicon carbide powder with uniform particle size.

[0033] See also Figures 1 to 4 As shown, the utility model provides a synthesis crucible for silicon carbide powder, for example, including an outer crucible 100, an inner crucible 200, an inner crucible cover 300 and a boss 400. The inner crucible 200 is arranged in the outer crucible 100, and the raw material 500 is filled in the inner crucible 200. The inner crucible 200 includes a first subsection 201 and a second subsection 202, and a gap is arranged between the first subsection 201 and the second subsection 202. The boss 400 is arranged on the side of the inner crucible 200 away from the inner crucible cover 300. By arranging the gap between the first subsection 201 and the second subsection 202, the heat transfer area of ​​the inner crucible 200 can be increased, and the side walls of the first subsection 201 and the second subsection 202 in the gap relative to each other can provide heat for the raw material 500 in the central area of ​​the inner crucible 200, thereby improving the temperature uniformity of the raw material 500 in the radial direction of the crucible. Moreover, by connecting the outer crucible 100 and the inner crucible 200 through the boss 400, the heat of the outer crucible 100 can be easily radiated into the bottom of the inner crucible 200 and diffused into the inner crucible 200, which is conducive to adjusting the axial temperature gradient of the raw material 500. The synthetic crucible provided by the utility model can improve the temperature uniformity between the raw materials 500 in the crucible, and can be widely used in the synthesis process of various powders to reduce the influence of uneven temperature distribution on the synthetic powder. In this embodiment, the crucible is described by taking the synthesis of silicon carbide powder as an example.

[0034] See also Figure 1 As shown, in one embodiment of the utility model, one side of the outer crucible 100 is open to facilitate the placement of the inner crucible 200 in the outer crucible 100. The outer crucible 100 serves as a heating element to provide heat to the inner crucible 200 and the raw material 500 in the inner crucible 200 to synthesize silicon carbide powder. In this embodiment, the shape of the outer crucible 100 is, for example, a hexahedron, a prism or a cylinder, and the inner diameter, outer diameter, height and thickness of the outer crucible 100 can be selected according to actual needs.

[0035] See also Figure 1 to Figure 2As shown, in one embodiment of the utility model, the inner crucible 200 is arranged in the outer crucible 100. The wall thickness of the inner crucible 200 is, for example, less than the wall thickness of the outer crucible 100, the inner crucible 200 and the outer crucible 100 are, for example, coaxial, one side of the inner crucible 200 is, for example, open, and the opening direction of the inner crucible 200 is, for example, the same as the opening direction of the outer crucible 100, so as to facilitate the filling of the raw material 500 into the inner crucible 200. In this embodiment, the ratio of the height of the outer crucible 100 to the height of the inner crucible 200 is, for example, (1.15-1.25):1, so that the outer crucible 100 can completely surround the inner crucible 200 to avoid the loss of heat in the outer crucible 100. In this embodiment, a spacing is set between the outer crucible 100 and the inner crucible 200, for example, the spacing is 2-5 mm, so that the heat on the outer crucible 100 is radiated into the inner crucible 200.

[0036] See also Figures 1 to 4 As shown, in one embodiment of the utility model, the inner crucible 200 includes, for example, a first sub-section 201, a second sub-section 202 and a third sub-section 203. The first sub-section 201 and the second sub-section 202 are symmetrically distributed on both sides of the axis of the outer crucible 100, the first sub-section 201 and the second sub-section 202 are connected on the side close to the opening of the outer crucible 100, and a gap is set between the first sub-section 201 and the second sub-section 202 on the side away from the opening of the outer crucible 100. In the axial direction of the outer crucible 100, the ratio of the height of the first sub-section 201 to the height of the inner crucible 200 is, for example, (2-3):4, and in the direction perpendicular to the axis of the outer crucible 100, the ratio of the gap between the first sub-section 201 and the second sub-section 202 to the radial dimension of the inner crucible 200 is 1:(3-4). Specifically, the height of the inner crucible 200 is, for example, 400-600 mm, and for example, 500 mm. In the direction perpendicular to the axis of the outer crucible 100, the length of the inner crucible 200 is, for example, 400-500 mm, and for example, 450 mm. The height of the first subsection 201 is, for example, 200-450 mm, and the gap between the first subsection 201 and the second subsection 202 is, for example, 100-167 mm. By providing a gap between the first subsection 201 and the second subsection 202, the heat transfer area of ​​the inner crucible 200 can be increased, and the heat of the outer crucible 100 can be transferred to the side walls opposite to the first subsection 201 and the second subsection 202 in the gap, and the side walls can transfer heat to the raw material 500 in the central area of ​​the inner crucible 200, reduce the axial temperature gradient of the raw material 500, and improve the uniformity of the heat field distribution in the inner crucible 200.

[0037] See also Figure 1 to Figure 2As shown, in one embodiment of the present invention, the third subsection 203 is disposed on a side of the first subsection 201 and the second subsection 202 away from the boss 400, and the third subsection 203 is connected to the first subsection 201 and the second subsection 202. If the side of the first subsection 201 close to the opening of the inner crucible 200 and the side of the second subsection 202 close to the opening of the inner crucible 200 are not connected, the volume of the gap between the first subsection 201 and the second subsection 202 will be increased. Although the heat transfer area of ​​the inner crucible 200 can be further increased and the temperature uniformity of the raw materials 500 in the inner crucible 200 can be further improved, the volume of the inner crucible 200 will be reduced, and the amount of raw materials 500 that can be accommodated in the inner crucible 200 will be reduced. Therefore, the synthetic crucible provided by the present invention, by setting a gap between the first section 201 and the second section 202, and connecting the first section 201 and the second section 202 on one side close to the opening of the inner crucible 200 through the third section 203, can improve the uniformity of heat distribution between the raw materials 500 inside the inner crucible 200 while avoiding a significant reduction in the volume of the inner crucible 200, thereby ensuring that the amount of raw materials 500 loaded inside the inner crucible 200 is not too little.

[0038] See also Figure 3 As shown, in one embodiment of the present invention, the shape of the inner crucible 200 is, for example, a cylinder, and the end of the inner crucible 200 away from the opening of the outer crucible 100 is recessed into the inner crucible 200 by a preset distance to form a hole. In this embodiment, the hole is, for example, a cylinder. In other embodiments, the hole is, for example, a tetrahedron or a prism, etc. The present invention does not limit the shape of the hole. In this embodiment, the two parts of the cylinder with a hole that are symmetrical about the radial diameter are defined as a first subsection 201 and a second subsection 202, respectively, and the first subsection 201 and the second subsection 202 are connected.

[0039] See also Figure 4 As shown, in another embodiment of the utility model, the first division 201 and the second division 202 are independent cylinders, a gap is provided between the cylinders, and a third division 203 is provided at the same end of the first division 201 and the second division 202. The third division 203 is, for example, a third cylinder, and the third cylinder is connected to the first division 201 and the second division 202.

[0040] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, the inner crucible cover 300 is detachably disposed on the opening of the inner crucible 200 to seal the raw material 500 inside the inner crucible 200. While maintaining the internal temperature of the inner crucible 200, impurities can be prevented from entering the inner crucible 200, thereby protecting the purity of the raw material 500.

[0041] See also Figure 1 to Figure 2As shown, in one embodiment of the present invention, the synthesis crucible further includes a connection structure (not shown in the figure), which connects the inner crucible 200 and the inner crucible cover 300 to seal the raw material 500 and heat inside the inner crucible 200. The connection structure is, for example, one of the connection structures such as threaded connection, stepped clamping or pin connection.

[0042] See also Figure 1 to Figure 2 As shown, in one embodiment of the utility model, the boss 400 is arranged on the side of the inner crucible 200 away from the inner crucible cover 300. In this embodiment, with the axis of the inner crucible 200 as the center, the boss 400 is symmetrically arranged on the first subsection 201 and the second subsection 202, and the boss 400 is located between the outer crucible 100 and the inner crucible 200. Among them, the boss 400 is at least two, for example, and 4-8. In this embodiment, the boss 400 is two, for example, and one boss 400 is respectively arranged on the outer side of the first subsection 201 and the second subsection 202. Through the boss 400, the inner crucible 200 can be placed inside the outer crucible 100, and the heat of the outer crucible 100 can be radiated into the bottom of the inner crucible 200 through the boss 400, and diffused in the axial direction of the inner crucible 200, which is conducive to reducing the axial temperature gradient between the raw materials 500 inside the inner crucible 200 and improving the particle size uniformity of the synthesized silicon carbide powder.

[0043] See also Figure 3 As shown, in another embodiment of the present invention, there are four bosses 400, for example, two bosses 400 are respectively arranged on the outer sides of the first subsection 201 and the second subsection 202, and the bosses 400 on the first subsection 201 and the second subsection 202 are symmetrically distributed with the axis of the inner crucible 200 as the center, so as to improve the stability of the inner crucible 200 placed in the outer crucible 100, and also improve the efficiency of the heat of the outer crucible 100 radiating to the bottom of the inner crucible 200. Among them, the boss 400 is, for example, a cylindrical structure, and the ratio of the diameter of the boss 400 to the diameter of the inner crucible 200 is, for example, 1: (3-4), so as to stably support the inner crucible 200. In other embodiments, the boss 400 is, for example, a prismatic structure or a hexahedral structure, etc. The present invention does not limit the specific structure of the boss 400, which can be selected according to actual needs.

[0044] See also Figures 1 to 3As shown, the utility model provides a synthetic crucible for silicon carbide powder, wherein a mixed raw material 500 of carbon powder and silicon powder is loaded into the first subsection 201, the second subsection 202 and the third subsection 203, and the raw materials 500 react with each other in the inner crucible 200 to synthesize silicon carbide powder. Through the gap between the first subsection 201 and the second subsection 202, the heat transfer area of ​​the inner crucible 200 is expanded, and the heat of the outer crucible 100 can be transferred to the side walls opposite to the first subsection 201 and the second subsection 202 in the gap, and the side walls can transfer heat to the raw material 500 in the central area of ​​the inner crucible 200, thereby reducing the axial temperature gradient of the raw material 500. Moreover, through the boss 400, the heat of the outer crucible 100 can be radiated into the bottom of the inner crucible 200 and diffused in the axial direction of the inner crucible 200, thereby reducing the axial temperature gradient between the raw materials 500 inside the inner crucible 200. Therefore, the synthesis crucible provided by the present invention can improve the temperature uniformity of the raw materials 500 inside the inner crucible 200, thereby synthesizing silicon carbide powder with uniform particle size.

[0045] In summary, the utility model proposes a synthetic crucible for silicon carbide powder. By arranging a boss between an inner crucible and an outer crucible, and arranging a gap between a first section and a second section of the inner crucible, the axial temperature gradient and the radial temperature gradient between the raw materials inside the inner crucible can be reduced, the thermal field distribution inside the crucible can be adjusted, the temperature uniformity between the raw materials can be improved, and silicon carbide powder with uniform particle size can be synthesized.

[0046] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that the particular features, structures, or characteristics described in conjunction with the embodiment are included in at least one embodiment of the utility model, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the utility model may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the utility model embodiments described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the utility model.

[0047] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the concept of the utility model, such as the technical solution formed by replacing the above-mentioned features with the technical features with similar functions disclosed in this application (but not limited to). In addition to the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present utility model, the remaining technical features will not be repeated here.

Claims

1. A synthetic crucible for silicon carbide powder, characterized in that: At least: an outer crucible, wherein one side of the outer crucible is open; an inner crucible, arranged in the outer crucible, one side of the inner crucible is open, the opening direction of the inner crucible is the same as the opening direction of the outer crucible, the inner crucible comprises a first subsection and a second subsection, a gap is arranged between the first subsection and the second subsection; An inner crucible cover is detachably disposed on the opening of the inner crucible; as well as The boss is arranged on a side of the inner crucible away from the inner crucible cover.

2. The synthesis crucible according to claim 1, characterized in that: The inner crucible further includes a third section, which is disposed on a side close to the inner crucible cover and communicates with the first section and the second section.

3. The synthesis crucible according to claim 1, characterized in that: The inner crucible is coaxial with the outer crucible.

4. The synthesis crucible according to claim 3, characterized in that: The first section and the second section are symmetrically arranged on both sides of the axis.

5. The synthesis crucible according to claim 3, characterized in that: In the axial direction, the ratio of the height of the first section to the height of the inner crucible is (2-3):

4.

6. The synthesis crucible according to claim 3, characterized in that: In a direction perpendicular to the axis, a ratio of a gap between the first section and the second section to a radial dimension of the inner crucible is 1:(3-4).

7. The synthesis crucible according to claim 3, characterized in that: The boss is symmetrically arranged on the first sub-portion and the second sub-portion with the axis as the center, and the boss is located between the inner crucible and the outer crucible.

8. The synthesis crucible according to claim 7, characterized in that: At least one boss is disposed on each of the first section and the second section.

9. The synthesis crucible according to claim 7, characterized in that: The boss is a cylindrical structure, a prism structure or a hexahedral structure.

10. The synthesis crucible according to claim 1, characterized in that: A distance is set between the outer crucible and the inner crucible, and the distance is 2-5 mm.

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