Seed crystal support and crucible for PVT process

Abstract

The utility model relates to a seed crystal support and a crucible for a PVT process. The seed crystal support comprises a body and a disc-shaped groove formed in the body, an annular protrusion (4) is formed on the top face (2) of the groove, and a gap is formed between the annular protrusion (4) and the inner side wall of the groove so that the groove can be divided into an inner cavity and an annular outer cavity (6). A through hole (5) penetrating through the inner side wall and the outer side wall of the annular protrusion is formed in the annular protrusion. According to the invention, the problem of crystal form inclusion caused by non-uniform supersaturation distribution in the crucible can be reduced, so that the yield of single crystals is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of crystal preparation, and particularly to a seed crystal holder and a crucible for PVT process. Background Art

[0002] In the existing silicon carbide crystal growth crucible device, a high-temperature resistant material gas flow duct and a nested graphite cylinder can be introduced. The nested graphite cylinder is in threaded fit with the crucible, and the gas flow duct is embedded in the graphite cylinder. During the crystal growth process by the PVT method, the gas jet output port of the gas flow duct is located near the facet area to achieve a uniform supersaturation distribution on the crystal growth surface. However, the existing crucible structure will cause the uniformity of the temperature field inside the crucible to be damaged and the gas flow field to operate disorderly, thereby increasing the crystal ingot defects and the serious crystal ingot deviation degree. Summary of the Utility Model

[0003] The purpose of the present disclosure is to provide a seed crystal holder and a crucible for PVT process, so as to reduce the problem of crystal form inclusion caused by uneven supersaturation distribution in the crucible, and further improve the single crystal yield.

[0004] To achieve the above object, in the first aspect of the present disclosure, a seed crystal holder for PVT process is provided. The seed crystal holder includes a body and a disc-shaped groove formed in the body; a ring-shaped protrusion is formed on the top surface of the groove, and there is a gap between the ring-shaped protrusion and the inner side wall of the groove to divide the groove into an inner cavity and an annular outer cavity; the ring-shaped protrusion is formed with a through hole penetrating its inner side wall and outer side wall.

[0005] Optionally, the ring-shaped protrusion is coaxially arranged with the groove; the outer side wall of the ring-shaped protrusion is arranged with an equal diameter along the direction away from the top surface.

[0006] Optionally, the body includes a top support and a side wall formed at the edge of the top support; a fillet is formed at the connection between the inner surface of the side wall and the top surface of the groove.

[0007] Optionally, the fillet radius of the fillet is (R 1 -R 2 ) / 2, where R 1 is the inner diameter of the groove, and R 2 is the outer diameter of the ring-shaped protrusion.

[0008] Optionally, the through hole is inclined downward from the inner side wall to the outer side wall of the ring-shaped protrusion;

[0009] The distance between the opening center of the through hole on the inner side wall of the ring-shaped protrusion and the top surface is 2-4 mm.

[0010] Optionally, the included angle between the axis of the through hole and the axis of the disc-shaped groove is 30° to 45°; the hole diameter of the through hole is 3 to 4 mm.

[0011] Optionally, the height of the annular protrusion is 14 to 16 mm; the maximum width of the annular protrusion at the top surface is 9.5 to 10.5 mm;

[0012] The inner diameter of the disc-shaped groove is 5 to 6 mm larger than the outer diameter of the annular protrusion.

[0013] Optionally, the top surface of the inner cavity is formed as a seed crystal bonding surface for bonding a silicon carbide seed crystal; the through hole is used to face the facet of the silicon carbide seed crystal;

[0014] The inner diameter of the annular protrusion is 6 to 10 mm larger than the diameter of the silicon carbide seed crystal.

[0015] Optionally, a plurality of the through holes are provided on the annular protrusion, and the plurality of through holes are arranged at intervals along a ring.

[0016] Optionally, the annular protrusion includes an arc-shaped opening area, the through holes are distributed in the opening area, and the central angle corresponding to the opening area is 119° to 121°.

[0017] Optionally, the opening area includes a central section, and a first section and a second section located on both sides of the central section; wherein the number of through holes in the central section is 4 per 20°, the number of through holes in the first section is 3 per 20°, and the number of through holes in the second section is 2 per 20°.

[0018] Optionally, the central angle corresponding to the central section is 39° to 40°, and the central angles corresponding to the first section and the second section are the same.

[0019] The second aspect of the present disclosure provides a crucible for a PVT process, which includes the seed crystal holder described in the first aspect of the present disclosure.

[0020] Through the above technical solutions, the present disclosure provides a seed crystal holder and a crucible for a PVT process. The annular protrusion of the seed crystal holder is provided with through holes, which has little influence on the overall structure of the seed crystal holder, and can ensure uniform temperature field distribution and stable and orderly fluid field operation inside the crucible. In the PVT process, the supersaturation rate of the single crystal growth surface corresponding to the position of the through hole can be effectively reduced, and problems such as crystal form inclusions caused by uneven supersaturation distribution can be reduced, thereby improving the yield of single crystals. The crucible provided by the present disclosure adopts a seed crystal holder with through holes. Compared with the prior art that introduces other structures inside the crucible to destroy the temperature field and the gas flow field, the present disclosure makes less adjustment to the inside of the existing crucible.

[0021] Other features and advantages of the present disclosure will be described in detail in the following detailed description section. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings:

[0023] Figure 1 is a schematic cross-sectional view of the seed crystal holder structure provided by the present disclosure;

[0024] Figure 2 is a schematic diagram of the through-hole distribution of the seed crystal holder provided by the present disclosure;

[0025] Figure 3 is a top view of the through-hole distribution of the seed crystal holder provided by the present disclosure;

[0026] Figure 4 is a schematic diagram of the internal gas flow movement in the crucible provided by the present disclosure;

[0027] Figure 5 is a schematic diagram of the crucible structure provided by the present disclosure.

[0028] REFERENCE NUMERALS

[0029] 1 - support top, 2 - top surface, 3 - silicon carbide seed crystal, 4 - annular protrusion, 5 - through hole, 6 - outer chamber, 7 - side wall. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following provides a detailed description of the specific embodiments of the present disclosure. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present disclosure, and are not used to limit the present disclosure.

[0031] It should be understood that in the description of the present disclosure, the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present disclosure and simplifying the description, and do 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 thus should not be construed as a limitation to the present disclosure. In the description of the present disclosure, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0032] It should be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "arranged", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; 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 communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood through specific situations.

[0033] The first aspect of the present disclosure provides a seed crystal holder for PVT process, as Figure 1 shown. The seed crystal holder includes a body and a disc-shaped groove formed in the body; a ring-shaped protrusion 4 is formed on the top surface 2 of the groove, and there is a gap between the ring-shaped protrusion 4 and the inner side wall of the groove to divide the groove into an inner cavity and an annular outer cavity 6; the ring-shaped protrusion is formed with a through hole 5 penetrating its inner side wall and outer side wall.

[0034] The present disclosure provides a seed crystal holder for PVT process. The ring-shaped protrusion of the seed crystal holder is provided with a through hole, which has little influence on the overall structure of the seed crystal holder, and can ensure the uniform distribution of the temperature field inside the crucible and the stable and orderly operation of the fluid field. In the PVT process, the supersaturation rate of the single crystal growth surface corresponding to the position of the through hole can be effectively reduced, and problems such as crystal form inclusions caused by uneven supersaturation distribution can be reduced, thereby improving the yield of single crystals.

[0035] The inventors of the present disclosure found in the research that:

[0036] If the supersaturation in a certain area is too high during the crystal growth process, it is easy to cause the transformation of the growth mode from spiral growth to two-dimensional growth, and finally lead to defects such as phase transformation. At the same time, the supersaturation rate increases with the increase of the temperature gradient and the saturation vapor pressure. Therefore, the seed crystal holder provided by the present disclosure forms a ring-shaped protrusion inside the body, and the ring-shaped protrusion is provided with a through hole. In the PVT process, as Figure 4 shown, the sublimated raw materials are transported upward with the carrier gas to the upper part including the seed crystal area. Part of the carrier gas carrying the raw materials reaches the facets and edge areas of the single crystal growth surface. Affected by the structure of the ring-shaped protrusion and the through hole, a part of the raw materials will be transported outside the ring-shaped protrusion with the carrier gas and enter the outer cavity. Then, the carrier gas entering the outer cavity will flow smoothly along the inner wall of the outer cavity downward and participate in the next round of carrier gas rising. This process realizes the effective regulation of the local gas flow field while ensuring the influence on the overall gas flow field distribution. Beneficially, the regulated gas flow still orderly converges into the overall gas flow field, and the supersaturation rate of the single crystal growth surface at this position can be effectively reduced.

[0037] In a specific embodiment, as Figure 1As shown, the annular protrusion 4 is coaxially arranged with the groove; the inner sidewall of the annular protrusion 4 expands in diameter in a direction away from the top surface, and the outer sidewall of the annular protrusion is arranged with an equal diameter in a direction away from the top surface. In the present disclosure, the outer sidewall of the annular protrusion is of equal diameter in the vertical direction and forms a cylindrical shape, whereby a uniformly spaced annular outer chamber can be formed between the outer sidewall of the annular protrusion and the inner sidewall of the groove, which is beneficial to gas flow; and the inner sidewall of the annular protrusion expands in diameter in a direction away from the top surface, that is, expands in diameter from top to bottom in the vertical direction, which is also beneficial to providing a growth space for the crystal grown by PVT.

[0038] In one embodiment, the body includes a supporting top 1 and a sidewall 7 formed at the edge of the supporting top; a fillet is formed at the connection between the inner surface of the sidewall 7 and the top surface of the groove; as Figure 1 shown, in the top region of the outer chamber 6, that is, between the sidewall 7 of the body and the outer sidewall of the annular protrusion, it is connected by a fillet, and the fillet helps the air flow entering the outer chamber 6 through the through hole to flow downward along the smooth inner wall, improving the smoothness of the air flow.

[0039] In a specific embodiment, the fillet radius of the fillet is (R 1 -R 2 ) / 2, where R 1 is the inner diameter of the groove, and R 2 is the outer diameter of the annular protrusion 4. In the present disclosure, the diameter of the fillet is set according to the inner diameter of the inner sidewall of the groove and the outer diameter of the outer sidewall of the annular protrusion, which is more beneficial to improving the smoothness of the downward flow of the air flow entering the outer chamber.

[0040] In a preferred embodiment, the through hole 5 is inclined downward from the inner sidewall to the outer sidewall of the annular protrusion. In the present disclosure, the opening position of the through hole on the inner sidewall of the annular protrusion is higher than the opening position of the through hole on the outer sidewall of the annular protrusion, which helps the air flow inside the annular protrusion to flow smoothly downward and into the outer chamber.

[0041] In a specific embodiment, the distance between the center of the opening of the through hole 5 on the inner sidewall of the annular protrusion and the top surface 2 is 2 to 4 mm, including but not limited to 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm. In the present disclosure, the top surface 2 is used for seed crystal bonding. By controlling the distance between the opening position of the through hole on the inner sidewall of the annular protrusion and the top surface, it helps to avoid supersaturation of the crystal growth surface corresponding to the through hole.

[0042] In a specific embodiment, the included angle between the axis of the through hole 5 and the axis of the disc-shaped groove is 30 to 45°, including but not limited to 30°, 32°, 34°, 36°, 38°, 40°, 42°, 44°, 45°; the hole diameter of the through hole 5 is 3 to 4 mm, including but not limited to 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm. The arrangement of the through hole provided in this embodiment is conducive to the gas in the inner cavity of the annular protrusion flowing to the outer cavity.

[0043] In a specific embodiment, the height of the annular protrusion is 14 to 16 mm, including but not limited to 14 mm, 14.2 mm, 14.4 mm, 14.6 mm, 14.8 mm, 15 mm, 15.2 mm, 15.4 mm, 15.6 mm, 15.8 mm, 16 mm; the maximum width of the annular protrusion at the top surface is 9.5 to 10.5 mm, including but not limited to 9.5 mm, 9.6 mm, 9.8 mm, 10 mm, 10.2 mm, 10.4 mm, 10.5 mm.

[0044] In a specific embodiment, the diameter of the inner side wall of the disc-shaped groove is 10 to 12 mm larger than the diameter of the outer side wall of the annular protrusion, including but not limited to 10 mm, 10.2 mm, 10.4 mm, 10.6 mm, 10.8 mm, 11 mm, 11.2 mm, 11.4 mm, 11.6 mm, 11.8 mm, 12 mm; then the distance between the inner side wall of the disc-shaped groove and the outer side wall of the annular protrusion (i.e., the ring width of the annular outer cavity) is 5 to 6 mm.

[0045] In one embodiment, as Figures 2 - 3 shown, the top surface of the inner cavity forms a seed crystal bonding surface for bonding the silicon carbide seed crystal 3; the through hole 5 is used to face the facet of the silicon carbide seed crystal 3. Since the facet and its edge position region of the ingot have a higher supersaturation ratio compared to other regions, it is easy to undergo a transformation from spiral growth to two-dimensional growth in the growth mode, and eventually lead to defects such as phase transformation. In the present disclosure, setting the through hole to face the facet of the seed crystal is more conducive to adjusting the gas flow saturation degree in the seed crystal facet area and its vicinity, and effectively reducing the supersaturation ratio of the single crystal growth surface at this position.

[0046] In a specific embodiment, the inner diameter of the annular protrusion 4 is 6 to 10 mm larger than the diameter of the silicon carbide seed crystal 3, including but not limited to 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm. In the present disclosure, the size of the seed crystal can be 6 inches or 8 inches. In the present disclosure, the inner diameter of the annular protrusion 4 is larger than the diameter of the silicon carbide seed crystal 3, which can provide space for subsequent crystal growth.

[0047] In a specific embodiment, as Figure 1 shown, the top of the inner side wall of the annular protrusion 4 is in the same plane as the top surface 2 of the groove.

[0048] In one embodiment, a plurality of through holes 5 are provided on the annular protrusion 4, and the plurality of through holes 5 are arranged at intervals along the ring. In the present disclosure, the more the number of through holes, the more the air flow is exported, and it is more beneficial to reduce the supersaturation rate of the single crystal growth surface.

[0049] In a specific embodiment, the annular protrusion 4 includes an arc-shaped opening area, and a plurality of the through holes are distributed in the opening area, and the central angle corresponding to the opening area is 119-121°. As Figures 2 - 3 shown, the seed crystal holder provided by the present disclosure is provided with a plurality of through holes in a section area (opening area) of the annular protrusion. In the PVT process, the facet area of the seed crystal is arranged corresponding to the opening area.

[0050] In a preferred embodiment, as Figures 2 - 3 shown, the opening area includes a central section, and a first section and a second section located on both sides of the central section; wherein the number of through holes in the central section is 4 per 20°, the number of through holes in the first section is 3 per 20°, and the number of through holes in the second section is 2 per 20°. Preferably, the through holes in the central section are evenly distributed; the through holes in the first section and the second section are evenly distributed. From Figures 2 - 3 it can be seen that in the annular area of the opening area, the through holes in the central section in the middle part are more closely distributed, and the distribution of the through holes on the left and right sides of the central section is sparser than that of the through holes in the central section. In the actual PVT process, the facet of the seed crystal corresponds to the central section, that is, the closer to the facet and its edge area, the higher the density, which is more beneficial to controlling the gas to avoid supersaturation.

[0051] In a specific embodiment, the central angle corresponding to the central section is 39-40°, and the central angles corresponding to the first section and the second section are the same. For example, the central angle corresponding to the entire opening area is 90°, the central angle corresponding to the central section is 30°, and the central angles corresponding to the first section and the second section are 30° respectively. Setting the central angles of the central area, the first section and the second section according to this embodiment can correspond to the facet area and its edge area of the silicon carbide seed crystal.

[0052] In the application of the seed crystal holder provided by the present disclosure in the PVT process, the facet area of the cut seed crystal is opposed to the central section of the through hole to bond the seed crystal to the seed crystal surface, and with the axis of the [000-1] crystal orientation of the seed crystal pointing to the (11-20) crystal plane direction side as the axis, and this axis coincides with the central axis of the central section of the seed crystal holder provided by the present disclosure. Taking the central angle corresponding to the entire opening area as 90° and the central angle corresponding to the central section as 30° as an example, as Figure 3As shown, within the range of 0° to 15° on the left side of the central axis to 0° to 15° on the right side of the central axis (a total of 30°) corresponds to the central section of the seed crystal holder, and a plurality of through holes 5 are equally spaced within the central section; within the range of 15° to 45° (a total of 30°) on the left side (the first section) of the central axis and within the range of 15° to 45° (a total of 30°) on the right side (the second section) of the central axis, a plurality of through holes are equally spaced respectively, and the spacing of the through holes in the central section is smaller than the spacing of the through holes in the first section and the second section, that is, the closer to the small surface and its edge area, the higher the density of the through holes.

[0053] In the present disclosure, the thickness of the top 1 of the seed crystal holder and the seed crystal holder wall are determined according to the size of the produced ingot and the performance of the crystal growth furnace. The thickness of the top 1 is calculated according to the following formula (1):

[0054] Formula (1); where Δ is the maximum thickness of the effective heating of the crucible top, ρ is the resistivity of the crucible, μ r is the relative magnetic permeability, and f is the frequency of the induction power supply. Among them, when determining the thickness of the top 1, it should also be considered that the resistivity of the crucible increases with the increase of temperature, so that Δ also gradually increases. Therefore, the value of Δ should not be too small, otherwise the heating efficiency will decrease.

[0055] In the present disclosure, the outer diameter of the crucible (D 外 ) can be obtained according to the empirical formula (the following formula (2)):

[0056] Formula (2).

[0057] At the same time, through D 外 and the value of Δ, the inner diameter D 内 of the inner wall of the crucible can be determined.

[0058] The second aspect of the present disclosure provides a crucible for the PVT process, which includes the seed crystal holder described in the first aspect of the present disclosure.

[0059] In the present disclosure, the setting method of the seed crystal holder in the crucible is a conventional method in the art, such as screw connection. The structure of the crucible in the present disclosure is also a conventional device structure in the art.

[0060] Example 1

[0061] This example provides a seed crystal holder for the PVT process, and the structure of the seed crystal holder is as Figures 1 - 3 shown.

[0062] The seed crystal holder includes a main body and a disc-shaped groove formed in the main body; a ring-shaped protrusion 4 is formed on the top surface 2 of the groove, the ring-shaped protrusion 4 is coaxially arranged with the groove and has a gap with the inner side wall of the groove to divide the groove into an inner cavity and an annular outer cavity 6; the inner side wall of the ring-shaped protrusion expands in diameter in a direction away from the top surface; the ring-shaped protrusion is formed with a through hole 5 penetrating its inner side wall and outer side wall;

[0063] The main body includes a support top 1 and a side wall 7 formed at the edge of the support top; a fillet is formed at the connection of the inner surface of the side wall 7 and the top surface of the groove; the fillet radius of the fillet is R 1 -R 2 / 2, where R 1 is the inner diameter of the groove, and R 2 is the outer diameter of the ring-shaped protrusion 4;

[0064] The through hole 5 slopes downward from the inner side wall to the outer side wall of the ring-shaped protrusion 4; the distance from the opening center of the through hole 5 on the inner side wall of the ring-shaped protrusion to the top surface 2 is 2 to 4 mm;

[0065] The included angle between the axis of the through hole 5 and the axis of the disc-shaped groove is 30 to 45°; the hole diameter of the through hole 5 is 3 to 4 mm;

[0066] The inner side wall of the ring-shaped protrusion 4 expands in diameter in a direction away from the top surface, and the outer side wall of the ring-shaped protrusion is arranged with an equal diameter in a direction away from the top surface;

[0067] The height of the ring-shaped protrusion is 14 to 16 mm; the maximum width of the ring-shaped protrusion 4 at the top surface 2 is 9.5 to 10.5 mm;

[0068] The inner diameter of the disc-shaped groove is 10 to 12 mm larger than the outer diameter of the ring-shaped protrusion 4;

[0069] The top surface of the inner cavity is formed as a seed crystal bonding surface for bonding a silicon carbide seed crystal 3; the through hole 5 is used to face the facet of the silicon carbide seed crystal 3;

[0070] The inner diameter of the ring-shaped protrusion 4 is 6 to 10 mm larger than the diameter of the silicon carbide seed crystal 3; a plurality of the through holes 5 are provided on the ring-shaped protrusion 4, and the plurality of through holes 5 are arranged at intervals along the ring;

[0071] The ring-shaped protrusion 4 includes an arc-shaped opening area, and a plurality of the through holes are distributed in the opening area, and the central angle corresponding to the opening area is 90°;

[0072] The opening area includes a central section, as well as a first section and a second section located on both sides of the central section; wherein the number of through-holes in the central section is 4 per 20°, the number of through-holes in the first section is 3 per 20°, and the number of through-holes in the second section is 2 per 20°; in the central section, a total of 9 through-holes are evenly distributed, and a total of 8 through-holes are evenly distributed in the first section and the second section; the central angle corresponding to the central section is 30°, and the central angles corresponding to the first section and the second section are the same, each being 30° respectively.

[0073] The working principle of the seed crystal holder for growing large-size silicon carbide single crystals by the PVT method provided in this embodiment is as follows: The seed crystal holder provided in the present disclosure introduces a through-hole structure with a smaller diameter, which basically does not affect the overall structure of the seed crystal holder, ensuring a uniform temperature field distribution and a smooth and orderly operation of the fluid field inside the crucible. During the production process, as Figure 4 shown, the sublimated raw materials are transported upward with the carrier gas to the upper part including the seed crystal area. Some of the carrier gas carrying the raw materials reaches the facets and edge areas of the single crystal growth surface on the seed crystal bonding surface. Affected by the structure of the annular protrusion and the through-holes, a part of the raw materials will be transported outside the annular protrusion with the carrier gas and enter the outer chamber. Then, the carrier gas entering the outer chamber will flow smoothly downward along the smooth inner wall and participate in the next round of carrier gas rising. This process effectively regulates the local gas flow field while ensuring the influence on the overall gas flow field distribution. Beneficially, the adjusted gas flow still orderly converges into the overall gas flow field. The more the number of through-holes, the more the gas flow export volume, effectively reducing the supersaturation rate of the single crystal growth surface at this position.

[0074] During the process of growing silicon carbide crystals by the PVT method, using the seed crystal holder provided in the present disclosure will help reduce problems such as crystal form inclusions caused by uneven supersaturation distribution, thereby improving the yield of single crystals. In addition, the seed crystal holder provided in the present disclosure is not only applicable to the growth of the (0001) crystal plane, but also applicable to the production of silicon carbide single crystals including 6 inches and 8 inches.

[0075] The preferred embodiments of the present disclosure have been described in detail above. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0076] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any appropriate manner. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0077] In addition, any combination can be made among various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A seed crystal holder for PVT process, characterized in that: The seed crystal holder comprises a body and a disc-shaped groove formed in the body; an annular protrusion (4) is formed on the top surface (2) of the groove, and the annular protrusion (4) is spaced from the inner side wall of the groove so as to divide the groove into an inner chamber and an annular outer chamber (6); the annular protrusion is formed with a through hole (5) penetrating the inner side wall and the outer side wall thereof.

2. The seed crystal holder according to claim 1, characterized in that: The annular protrusion (4) is coaxially arranged with the groove; and the outer side wall of the annular protrusion (4) is arranged with equal diameter in a direction away from the top surface.

3. The seed crystal holder according to claim 1, characterized in that: The body comprises a support top (1) and a side wall (7) formed at the edge of the support top; a fillet is formed at the connection between the inner surface of the side wall (7) and the top surface of the groove.

4. The seed crystal holder according to claim 3, characterized in that: The fillet radius of the fillet is (R1-R2) / 2, wherein R1 is the inner diameter of the groove, and R2 is the outer diameter of the annular protrusion (4).

5. The seed crystal holder according to claim 1, characterized in that: The through hole (5) is inclined downward from the inner wall to the outer wall of the annular protrusion (4); The distance between the opening center of the through hole (5) on the inner side wall of the annular protrusion and the top surface (2) is 2 to 4 mm.

6. The seed crystal holder according to claim 5, characterized in that: The angle between the axis of the through hole (5) and the axis of the disc-shaped groove is 30-45°; the diameter of the through hole (5) is 3-4 mm.

7. The seed crystal holder according to claim 1, characterized in that: The height of the annular protrusion is 14-16 mm; the maximum width of the annular protrusion (4) at the top surface (2) is 9.5-10.5 mm; The inner diameter of the disc-shaped groove is 5 to 6 mm larger than the outer diameter of the annular protrusion (4).

8. The seed crystal holder according to claim 1, characterized in that: The top surface of the inner chamber is formed as a seed crystal bonding surface for bonding the silicon carbide seed crystal (3); the through hole (5) is used to face the small surface of the silicon carbide seed crystal (3); The inner diameter of the annular protrusion (4) is 6 to 10 mm larger than the diameter of the silicon carbide seed crystal (3).

9. The seed crystal holder according to claim 1, characterized in that: The annular protrusion (4) is provided with a plurality of through holes (5), and the plurality of through holes (5) are arranged at intervals along a ring shape.

10. The seed crystal holder according to claim 9, characterized in that: The annular protrusion (4) comprises an arc-shaped opening area, the through holes are distributed in the opening area, and the central angle corresponding to the opening area is 119-121°.

11. The seed crystal holder according to claim 10, characterized in that: The opening area includes a central segment, and a first segment and a second segment located on both sides of the central segment; wherein the number of through holes in the central segment is 4 per 20°, the number of through holes in the first segment is 3 per 20°, and the number of through holes in the second segment is 2 per 20°.

12. The seed crystal holder according to claim 11, characterized in that: The central angle corresponding to the central segment is 39-40°, and the central angles corresponding to the first segment and the second segment are the same.

13. A crucible for PVT process, characterized in that: A seed crystal holder comprising any one of claims 1 to 12.

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