Crucible for crystal growth

Abstract

The utility model discloses a crucible for crystal growth, which comprises a first forming part, a first communicating part and a second forming part which are connected in sequence. The first forming part is provided with a first forming cavity, the first communicating part is provided with a first communicating cavity communicating with the first forming cavity, the second forming part is provided with a second forming cavity communicating with the first communicating cavity, and the radial size of the second forming cavity is larger than that of the first forming cavity. The radial size of the first communicating cavity is gradually increased in the arrangement direction of the first forming part and the second forming part, and the radial sizes of the two ends of the first communicating cavity are the same as the radial sizes of the first forming cavity and the second forming cavity correspondingly. According to the crucible, crystal growth can be carried out in the first forming cavity and the second forming cavity, meanwhile, due to the fact that the radial size of the second forming cavity is larger than that of the first forming cavity, the crucible can grow crystals of two sizes, when crystals of various diameters are prepared, various crucibles do not need to be used, and the preparation cost is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of crystal growth, and in particular relates to a crucible for crystal growth. Background Art

[0002] Compound semiconductors are widely used in optical communications, high-frequency millimeter-wave devices, optoelectronic integrated circuits, and solar cells for outer space. The main compound semiconductors currently include gallium arsenide, indium phosphide, silicon carbide, gallium oxide, gallium nitride, sapphire, etc. These compound semiconductors need to be grown into crystals first, then cut into wafers, and then cut, polished, and washed to become qualified substrates. In the crystal growth process, a crucible is needed as a carrier. Traditional crucibles can only grow crystals of equal diameter. When preparing crystals of multiple diameters, multiple crucibles are needed, which is costly. Utility Model Content

[0003] The technical problem to be solved by the present application is that: currently, when preparing crystals of various diameters, various crucibles need to be used. In order to solve this technical problem, a low-cost crucible for crystal growth is provided that can prepare crystals of various diameters.

[0004] The technical solution proposed in this application is:

[0005] A crucible for crystal growth, comprising:

[0006] A first molding portion having a first molding cavity;

[0007] A first connecting portion, one end of which is connected to the first molding portion, and the first connecting portion has a first connecting cavity that is connected to the first molding cavity;

[0008] A second molding portion, one end of which is connected to an end of the first connecting portion away from the first molding portion, and the second molding portion has a second molding cavity connected to the first connecting cavity;

[0009] Among them, the opening of the crucible is located at one end of the second molding cavity away from the first connecting cavity, the radial dimension of the second molding cavity is larger than the radial dimension of the first molding cavity, the radial dimension of the first connecting cavity gradually increases along the arrangement direction of the first molding part and the second molding part, and the radial dimensions at both ends of the first connecting cavity are respectively the same as the radial dimensions of the first molding cavity and the second molding cavity.

[0010] Furthermore, the crystal growth crucible further includes a second connecting portion and a third forming portion;

[0011] The second communicating portion is connected to an end of the second molding portion away from the first communicating portion, and the second communicating portion has a second communicating cavity communicating with the second molding cavity;

[0012] The third molding part is connected to an end of the second communicating part away from the second molding part, and the third molding part has a third molding cavity communicating with the second communicating cavity;

[0013] The opening of the crucible is located at an end of the third molding cavity away from the second connecting cavity, and the radial dimension of the third molding cavity is greater than the radial dimension of the second molding cavity.

[0014] Furthermore, the radial dimension of the second connecting cavity gradually increases along the arrangement direction of the first molding parts and the second molding parts, and the radial dimensions of both ends of the second connecting cavity are respectively the same as the radial dimensions of the second molding cavity and the third molding cavity.

[0015] Furthermore, the second connecting cavity is in a truncated cone shape, and a cone angle of the second connecting cavity is 90° to 120°.

[0016] Further, the crucible further comprises a seed crystal part and a third connecting part, the seed crystal part has a seed crystal cavity, one end of the third connecting part is connected to the seed crystal part, and the other end is connected to the first forming part, the first connecting part is connected to an end of the first forming part away from the third connecting part, and the third connecting part has a third connecting cavity connected to the seed crystal cavity and the first forming cavity;

[0017] Wherein, the radial dimension of the first forming cavity is larger than the radial dimension of the seed crystal cavity.

[0018] Furthermore, the radial dimension of the third connecting cavity gradually increases along the arrangement direction of the first forming part and the second forming part, and the radial dimensions of both ends of the third connecting cavity are respectively the same as the radial dimensions of the seed crystal cavity and the first forming cavity.

[0019] Furthermore, the third connecting cavity is in a truncated cone shape, and a cone angle of the third connecting cavity is 90° to 120°.

[0020] Furthermore, the first connecting cavity is in a truncated cone shape, and a cone angle of the first connecting cavity is 90° to 120°.

[0021] Furthermore, the material of the crucible is one of boron nitride, quartz, graphite, copper, aluminum, silver, iridium, iron and platinum.

[0022] Furthermore, the height of the first forming part and the second forming part is 80-100 mm.

[0023] By using the above-mentioned crucible for crystal growth, crystal growth can be performed in both the first molding cavity and the second molding cavity. At the same time, since the radial dimension of the second molding cavity is larger than the radial dimension of the first molding cavity, the crucible can grow crystals of two sizes. When preparing crystals of various diameters, it is not necessary to use various crucibles, thereby reducing the preparation cost. In addition, the first molding cavity and the second molding cavity are connected through the gradually changing first connecting cavity, so that in the process of growing a large diameter crystal from a small diameter crystal, the crystal can be smoothly and gradually overgrown, thereby reducing the formation of twins and improving the yield rate of the crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. They are used to explain the present application together with the embodiments of the present application and do not constitute a limitation of the present application.

[0025] Figure 1 A schematic diagram of the structure of a crucible provided in one embodiment of the present application;

[0026] Figure 2 for Figure 1 Schematic diagram of the internal structure of the crucible shown.

[0027] Description of labels:

[0028] 100, crucible; 110, first molding part; 120, first connecting part; 130, second molding part; 111, first molding cavity; 121, first connecting cavity; 131, second molding cavity; 140, second connecting part; 150, third molding part; 141, second connecting cavity; 151, third molding cavity; 160, seed crystal part; 170, third connecting part; 161, seed crystal cavity; 171, third connecting cavity. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a crucible 100 for crystal growth. The crucible 100 includes a first forming portion 110 , a first connecting portion 120 and a second forming portion 130 .

[0032] The first molding part 110 , the first connecting part 120 and the second molding part 130 are connected in sequence. The first molding part 110 has a first molding cavity 111 , the first connecting part 120 has a first connecting cavity 121 connected to the first molding cavity 111 , and the second molding part 130 has a second molding cavity 131 connected to the first connecting cavity 121 .

[0033] Among them, the opening of the crucible is located at one end of the second molding cavity 131 away from the first connecting cavity 121, the radial dimension of the second molding cavity 131 is larger than the radial dimension of the first molding cavity 111, the radial dimension of the first connecting cavity 121 gradually increases along the arrangement direction of the first molding part 110 and the second molding part 130, and the radial dimensions at both ends of the first connecting cavity 121 are respectively the same as the radial dimensions of the first molding cavity 111 and the second molding cavity 131.

[0034] It should be explained that the radial dimensions of the two ends of the first connecting cavity 121 are respectively the same as the radial dimensions of the first molding cavity 111 and the second molding cavity 131, that is, the radial dimension of the end of the first connecting cavity 121 communicating with the first molding cavity 111 is the same as the radial dimension of the first molding cavity 111, and the radial dimension of the end of the first connecting cavity 121 communicating with the second molding cavity 131 is the same as the radial dimension of the second molding cavity 131. In addition, it can be understood that the first molding cavity 111 and the second molding cavity 131 are both equal-diameter cavities, that is, the molding cavities are cylindrical.

[0035] By using the above-mentioned crucible for crystal growth, crystal growth can be performed in both the first molding cavity 111 and the second molding cavity 131. At the same time, since the radial dimension of the second molding cavity 131 is larger than the radial dimension of the first molding cavity 111, the crucible can grow crystals of two sizes. When preparing crystals of various diameters, it is not necessary to use various crucibles, thereby reducing the preparation cost. In addition, the first molding cavity 111 and the second molding cavity 131 are connected through the gradually changing first connecting cavity 121, which can make the crystal grow smoothly and gradually in the process of growing a large diameter crystal from a small diameter crystal, reduce the formation of twins, and improve the yield rate of the crystal.

[0036] Specific to Figure 2 In the embodiment shown, the first connecting cavity 121 is truncated cone-shaped, and the taper angle of the first connecting cavity 121 is 90° to 120°, so as to further reduce the formation of twins and improve the yield of crystals. It should be explained that the taper angle of the truncated cone-shaped first connecting cavity 121 is the angle between two generatrixes on the axial section.

[0037] It needs to be further explained that the angle of the cone angle of the first connecting cavity 121 will affect the yield rate of the crystal in the second molding cavity 131. Since the solid-liquid interface is less affected by the surface tension during the growth of large-diameter crystals, its solid-liquid interface is easily turned into a concave surface and twins are generated. Therefore, the cone angle of the first connecting cavity 121 is reduced, which can slow down the rapid formation of the solid-liquid interface, thereby increasing the solid-liquid surface tension, forming a convex surface, reducing the formation of twins, and improving the yield rate of the crystal. In this embodiment, preferably, the cone angle of the first connecting cavity 121 is 90°~100°.

[0038] In one embodiment, the crucible further includes a second connecting portion 140 and a third forming portion 150, wherein the second connecting portion 140 is connected to an end of the second forming portion 130 away from the first connecting portion 120, and the third forming portion 150 is connected to an end of the second connecting portion away from the second forming portion 130. The second connecting portion 140 has a second connecting cavity 141 connected to the second forming cavity 131, and the third forming portion 150 has a third forming cavity 151 connected to the second connecting cavity 141.

[0039] The opening of the crucible is located at one end of the third forming cavity 151 away from the second connecting cavity 141. The radial dimension of the third forming cavity 151 is greater than the radial dimension of the second forming cavity 131. Thus, in this embodiment, the crucible can grow crystals of three diameters at one time. It is understandable that in other embodiments, more connecting parts and forming parts can be provided, which is not limited here.

[0040] Furthermore, the radial dimension of the second connecting cavity 141 gradually increases along the arrangement direction of the first molding part 110 and the second molding part 130, and the radial dimensions at both ends of the second connecting cavity 141 are respectively the same as the radial dimensions of the second molding cavity 131 and the third molding cavity 151, so as to reduce the formation of twins in the process of growing crystals in the third molding cavity 151 and improve the yield of crystals in the third molding cavity 151.

[0041] Specific to Figure 2 In the illustrated embodiment, the second communication cavity 141 is truncated cone-shaped, and the cone angle of the second communication cavity 141 is 90° to 120°. It is understandable that the preferred range of the cone angle of the second communication cavity 141 is the same as that of the first communication cavity 121, which will not be described in detail.

[0042] In one embodiment, the crucible further includes a seed crystal part 160 and a third connecting part 170, one end of the third connecting part 170 is connected to the seed crystal cavity 161, and the other end is connected to the first molding part 110, and the first connecting part 120 is connected to an end of the first molding part 110 away from the third connecting part 170. The seed crystal part 160 has a seed crystal cavity 161, and the third connecting part 170 has a third connecting cavity 171 connected to the seed crystal cavity 161 and the first molding cavity 111.

[0043] The radial dimension of the first forming cavity 111 is greater than the radial dimension of the seed crystal cavity 161. When growing a crystal, a seed crystal can be placed in the seed crystal cavity 161 to guide the crystal to grow along a preset crystal direction angle. It should also be noted that the inner wall of the seed crystal cavity 161 is required to be smooth and free of burrs to further ensure that the crystal direction of the crystal meets the requirements.

[0044] Furthermore, the radial dimension of the third connecting cavity 171 gradually increases along the arrangement direction of the first molding part 110 and the second molding part 130, and the radial dimensions of the two ends of the third connecting cavity 171 are respectively the same as the radial dimensions of the seed crystal cavity 161 and the first molding cavity 111. Similarly, it can be known that the provision of the third connecting cavity 171 can reduce the formation of twins during the process of growing crystals in the first molding cavity 111, thereby improving the yield rate of the crystals in the first molding cavity 111.

[0045] Specific to Figure 2 In the illustrated embodiment, the third communication cavity 171 is truncated cone-shaped, and the cone angle of the third communication cavity 171 is 90° to 120°. The preferred range of the cone angle of the third communication cavity 171 is the same as that of the first communication cavity 121, which will not be described in detail.

[0046] In combination with the above embodiments, it can be determined that the radial dimensions of the multiple molding cavities in the crucible are different, and the provision of multiple connecting cavities can slow down the formation of the solid-liquid interface during the crystal growth process, increase the tension of the solid-liquid surface, form a convex surface, avoid the formation of twins in the corresponding molding cavity, and improve the crystal yield.

[0047] In one embodiment, the end of the seed crystal part 160 away from the third connecting part 170 is an open end, that is, the seed crystal cavity 161 runs through both ends of the seed crystal part 160, so as to facilitate the removal of the remaining seed crystal after the crystal growth is completed, so that the crucible can be reused.

[0048] In one embodiment, the material of the crucible is one of boron nitride, quartz, graphite, copper, aluminum, silver, iridium, iron and platinum. Further, the height of the crucible is 400-450 mm, and the wall thickness of the crucible is 0.3-1 mm.

[0049] In one embodiment, the heights of the first molding portion 110 , the second molding portion 130 , and the third molding portion 150 are all 80-100 mm.

[0050] It is understandable that in Figure 2 In the embodiment shown, in order to match the crystal growth furnace, the height of the crucible is fixed, and when the radial dimensions of the seed crystal cavity 161, the first molding cavity 111, the second molding cavity 131 and the third molding cavity 151 are fixed, the smaller the cone angle of the connecting cavity and the higher the height of the connecting cavity, the smaller the height of the corresponding molding cavity.

[0051] In order to facilitate understanding of the function of the connecting cavity, the following two embodiments are used for comparison and explanation:

[0052] Example 1

[0053] The crucible is made of boron nitride with a thickness of 0.3 mm. The diameter of the seed crystal cavity 161 is 4 mm and the height is 30 mm. The cone angle of the third connecting cavity 171 is 90°, the cone angle of the first connecting cavity 121 is 90°, and the cone angle of the second connecting cavity 141 is 90°. The radial dimension of the first forming part 110 is 50 mm, the radial dimension of the second forming part 130 is 76 mm, and the radial dimension of the third forming part 150 is 100 mm. The height of the three forming parts is 95 mm.

[0054] Example 2

[0055] The crucible is made of boron nitride with a thickness of 0.3 mm. The diameter of the seed crystal cavity 161 is 4 mm and the height is 30 mm. The cone angle of the third connecting cavity 171 is 95°, the cone angle of the first connecting cavity 121 is 95°, and the cone angle of the second connecting cavity 141 is 95°. The radial dimension of the first forming part 110 is 50 mm, the radial dimension of the second forming part 130 is 76 mm, and the radial dimension of the third forming part 150 is 100 mm. The height of the three forming parts is 98 mm.

[0056] Example 3

[0057] The crucible is made of boron nitride with a thickness of 0.3 mm. The diameter of the seed crystal cavity 161 is 4 mm and the height is 30 mm. The cone angle of the third connecting cavity 171 is 120°, the cone angle of the first connecting cavity 121 is 120°, and the cone angle of the second connecting cavity 141 is 120°. The radial dimension of the first forming part 110 is 50 mm, the radial dimension of the second forming part 130 is 76 mm, and the radial dimension of the third forming part 150 is 100 mm. The heights of the three forming parts are all 100 mm.

[0058] Comparative Example

[0059] The crucible is made of boron nitride with a thickness of 0.6 mm. The diameter of the seed crystal cavity 161 is 6 mm and the height is 30 mm. The cone angle of the third connecting cavity 171 is 150°, the cone angle of the first connecting cavity 121 is 150°, and the cone angle of the second connecting cavity 141 is 150°. The radial dimension of the first forming part 110 is 50 mm, the radial dimension of the second forming part 130 is 76 mm, and the radial dimension of the third forming part 150 is 100 mm. The height of the three forming parts is 105 mm.

[0060] Gallium arsenide single crystals were grown using the crucibles in the embodiment and the comparative example, and the single crystal yields are shown in the following table:

[0061]

[0062] The effective crystal height is the crystal height*crystal yield. In addition, as mentioned above, since the crucible always needs to match the crystal growth furnace, the total height of the crucible is fixed.

[0063] When the total height of the crucible remains unchanged, the smaller the cone angle of the connecting cavity, the higher the height of the connecting cavity, and the shorter the height of the forming portion. Therefore, the smaller the cone angle of the connecting cavity, even if the crystal yield is higher, the height of the forming portion will be reduced accordingly, which will affect the effective crystal height. Combined with the above table, it can be seen that the crystal yield is higher in Example 1 and Example 2. At this time, the cone angles of the connecting cavity are 90° and 95° respectively. Considering the comprehensive crystal yield and the effective crystal height, the effective crystal height is optimal when the cone angle of the connecting cavity is 95°. Therefore, the most preferred cone angle of the connecting cavity is 95°.

[0064] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A crucible for crystal growth, characterized in that: include: A first molding portion having a first molding cavity; A first connecting portion, one end of which is connected to the first molding portion, and the first connecting portion has a first connecting cavity that is connected to the first molding cavity; a second molding portion, one end of which is connected to an end of the first connecting portion away from the first molding portion, and the second molding portion has a second molding cavity connected to the first connecting cavity; The opening of the crucible is located at one end of the second molding cavity away from the first connecting cavity, the radial dimension of the second molding cavity is larger than the radial dimension of the first molding cavity, the radial dimension of the first connecting cavity gradually increases along the arrangement direction of the first molding part and the second molding part, and the radial dimensions of the two ends of the first connecting cavity are respectively the same as the radial dimensions of the first molding cavity and the second molding cavity; The crystal growth crucible further includes a second connecting portion and a third forming portion; The second communicating portion is connected to an end of the second molding portion away from the first communicating portion, and the second communicating portion has a second communicating cavity communicating with the second molding cavity; The third molding part is connected to an end of the second communicating part away from the second molding part, and the third molding part has a third molding cavity communicating with the second communicating cavity; Wherein, the opening of the crucible is located at one end of the third molding cavity away from the second connecting cavity, and the radial dimension of the third molding cavity is greater than the radial dimension of the second molding cavity; The radial dimension of the second connecting cavity gradually increases along the arrangement direction of the first forming part and the second forming part, and the radial dimensions of both ends of the second connecting cavity are respectively the same as the radial dimensions of the second forming cavity and the third forming cavity; The second connecting cavity is in a truncated cone shape, and a cone angle of the second connecting cavity is 90° to 120°.

2. The crystal growth crucible according to claim 1, characterized in that: The crucible further includes a seed crystal part and a third connecting part, the seed crystal part has a seed crystal cavity, one end of the third connecting part is connected to the seed crystal part, and the other end is connected to the first forming part, the first connecting part is connected to an end of the first forming part away from the third connecting part, and the third connecting part has a third connecting cavity connected to the seed crystal cavity and the first forming cavity; Wherein, the radial dimension of the first forming cavity is larger than the radial dimension of the seed crystal cavity.

3. The crystal growth crucible according to claim 2, characterized in that: The radial dimension of the third connecting cavity gradually increases along the arrangement direction of the first forming part and the second forming part, and the radial dimensions of both ends of the third connecting cavity are respectively the same as the radial dimensions of the seed crystal cavity and the first forming cavity.

4. The crystal growth crucible according to claim 2, characterized in that: The third connecting cavity is in a truncated cone shape, and a cone angle of the third connecting cavity is 90° to 120°.

5. The crystal growth crucible according to claim 1, characterized in that: The first connecting cavity is in a truncated cone shape, and a cone angle of the first connecting cavity is 90° to 120°.

6. The crystal growth crucible according to claim 1, characterized in that: The material of the crucible is one of boron nitride, quartz, graphite, copper, aluminum, silver, iridium, iron and platinum.

7. The crystal growth crucible according to claim 1, characterized in that: The height of the first molding part and the second molding part is 80-100 mm.

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