Novel silicon carbide crystal growth crucible

Abstract

The utility model discloses a novel silicon carbide crystal growth crucible, which relates to the technical field of silicon carbide crystal growth and comprises a lower crucible and an upper crucible, a cavity of the upper crucible is opposite to a cavity of the lower crucible, an upper temperature measuring point is arranged at the top of the upper crucible, a lower temperature measuring point is arranged at the bottom of the lower crucible, and a boss is further arranged in the lower crucible. And the periphery of the boss and the inner wall of the lower crucible can form an annular groove structure. The utility model solves the technical problems that the silicon carbide crystal growth crucible in the prior art is relatively strong in dependence on the whole crucible and is not favorable for improving the growth size of the silicon carbide crystal.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon carbide crystal growth, in particular to a novel crucible for silicon carbide crystal growth. Background Art

[0002] Silicon carbide crystal growth is mostly carried out using the physical vapor transport (PVT) method using a crystal growth furnace. The crystal growth furnace must be equipped with special gases with specific proportions of multiple components and be carried out in a certain relative vacuum atmosphere. The temperature of the crystal growth crucible must be strictly and stably controlled during the production process to ensure that the growing raw materials can smoothly achieve silicon carbide sublimation and crystallization.

[0003] At present, there are two main heating methods used in crystal growth furnaces, namely induction heating crucible type and resistance heating crucible type. Among them, the induction heating crucible type realizes the sublimation and crystallization process of raw materials by electromagnetically heating the crystal growth crucible; during the whole process, there is a certain difference between the temperature at the center of the crucible and the temperature at the periphery, especially the crucible structure should not be too large, otherwise it will lead to an increase in the difference, and the yield around the ingot will be significantly deviated from the middle, resulting in uneven crystal growth, inclusions, microtubes, dislocations and other defects, which seriously affect the overall crystal quality. The resistance heating crucible type indirectly heats the material by heating the crystal growth crucible with resistance. Its heating structure is also limited by the different temperature requirements of the material during the crystal growth sublimation / crystallization process, so that the crucible structure must ensure a strict size structure, which is difficult to upgrade and expand, so that the size of the long crystal cannot be qualitatively improved.

[0004] Therefore, the existing silicon carbide crystal growth crucible is highly dependent on the crucible as a whole, which is not conducive to increasing the growth size of the silicon carbide crystal. Utility Model Content

[0005] The embodiment of the present application provides a novel silicon carbide crystal growth crucible to solve the technical problem in the prior art that the silicon carbide crystal growth crucible has a strong dependence on the crucible as a whole, which is not conducive to increasing the growth size of the silicon carbide crystal.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions: a new type of silicon carbide crystal growth crucible, including a lower crucible and an upper crucible, the chamber of the upper crucible is arranged opposite to the chamber of the lower crucible, the top of the upper crucible has an upper temperature measuring point, the bottom of the lower crucible has a lower temperature measuring point, and a boss is also provided in the lower crucible, and the outer periphery of the boss and the inner wall of the lower crucible can form an annular groove structure.

[0007] Since the overall structure includes an upper crucible and a lower crucible, the top of the upper crucible and the bottom of the lower crucible have an upper temperature measuring point and a lower temperature measuring point respectively, so the upper crucible and the lower crucible can be heated independently, and the temperature can be accurately controlled in combination with their respective temperature measuring points, so that the sublimation and crystallization process of the raw materials can better meet the process requirements; and a boss is provided inside the lower crucible, which can help to transfer heat to the raw materials more evenly, thereby facilitating the expansion of the growth size of the silicon carbide crystal.

[0008] Furthermore, the upper crucible is a resistance heating crucible, and the lower crucible is an electromagnetic heating crucible. The resistance heating method can provide a more stable temperature, and the temperature control is more precise, and it is easier to achieve precise temperature gradient control to meet the needs of the crystallization area; the electromagnetic heating method can provide more uniform heating, and the heating efficiency is higher, and the raw materials can be heated to the required temperature faster to meet the needs of the raw material area.

[0009] Furthermore, a magnetic induction coil is provided on the outer ring of the lower crucible, and a cylindrical sleeve is provided between the magnetic induction coil and the lower crucible, and the upper edge of the cylindrical sleeve is supported on the bottom of the upper crucible; by using the cylindrical sleeve as a supporting structure, the upper crucible can be separated from the lower crucible, thereby improving the stability and safety of the upper crucible.

[0010] Furthermore, an exhaust hole is formed between the bottom of the upper crucible and the top of the cylindrical sleeve; these excess crystal molecules can be discharged in time through the exhaust hole to ensure that the molecules in the crystal growth area are arranged in an orderly manner, thereby improving the crystal quality.

[0011] Furthermore, a plurality of exhaust holes are provided and are evenly arranged along the circumferential direction.

[0012] Furthermore, the boss is cylindrical and has a coaxial center with the lower crucible.

[0013] It can be seen from the above technical solutions that the utility model has at least the following technical effects or advantages:

[0014] Since the overall structure of the utility model includes an upper crucible and a lower crucible, the top of the upper crucible and the bottom of the lower crucible have an upper temperature measuring point and a lower temperature measuring point respectively, the upper crucible and the lower crucible can be heated independently, and the temperature can be accurately controlled in combination with their respective temperature measuring points, so that the sublimation and crystallization process of the raw materials can better meet the process requirements; and a boss is provided inside the lower crucible, which can help to transfer heat to the raw materials more evenly, thereby facilitating the expansion of the growth size of the silicon carbide crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the utility model, the following is a brief introduction to the drawings required for the description. 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:

[0016] Figure 1 It is a schematic diagram of the structure of a silicon carbide crystal growth crucible in the prior art;

[0017] Figure 2 The utility model is a schematic diagram of the overall structure of the utility model.

[0018] Explanation of the accompanying reference numerals: 1. lower crucible, 2. upper crucible, 3. raw material area, 4. crystallization area, 5. upper temperature measuring point, 6. lower temperature measuring point, 7. boss, 8. magnetic induction coil, 9. cylindrical sleeve, 10. exhaust hole. DETAILED DESCRIPTION

[0019] In order to better understand the improvements made by the present invention relative to the prior art, before describing the specific implementation methods of the present invention in detail, the prior art mentioned in the background art is first described in conjunction with the drawings.

[0020] Figure 1 The structure of a crucible for growing silicon carbide crystals in the prior art is shown. As shown in the figure, when in use, the raw material is placed inside a crucible, and the crucible is heated by electromagnetic or electrical resistance to sublimate and crystallize the raw material. The raw material needs to be sublimated and crystallized in a crucible, and these two processes have different temperature requirements for the material, so the crucible size requirements are very strict.

[0021] Moreover, the existing crucibles for growing silicon carbide crystals have a certain difference in the center temperature compared to the peripheral temperature. When the crucible structure size is larger, the difference between the temperature at the center of the crucible and the peripheral temperature will be more obvious. Therefore, the crucible must ensure a strict size structure, which will make it difficult to upgrade and expand the crucible, and the growth size of the silicon carbide crystal cannot be qualitatively improved.

[0022] The implementation of the utility model is to improve the existing silicon carbide crystal growth crucible, which is highly dependent on the crucible as a whole and is not conducive to increasing the growth size of the silicon carbide crystal. The specific implementation is described in detail below.

[0023] like Figure 2As shown, in this embodiment, the novel silicon carbide crystal growth crucible includes a lower crucible 1 and an upper crucible 2, the chamber of the upper crucible 2 faces downward, the chamber of the lower crucible 1 faces upward, and the chamber of the upper crucible 2 and the chamber of the lower crucible 1 can together constitute a crystal growth chamber. The crystal growth chamber includes a raw material area 3, a sublimation area and a crystallization area 4. Among them, the raw material area 3 is the interior of the chamber of the lower crucible 1, the crystallization area 4 is located at the top of the chamber of the upper crucible 2, and the sublimation area is located between the raw material area 3 and the crystallization area 4.

[0024] Specifically in this embodiment, the upper crucible 2 is a resistance heating crucible, the lower crucible 1 is an electromagnetic heating crucible, and the top of the upper crucible 2 has an upper temperature measuring point 5, and the bottom of the lower crucible 1 has a lower temperature measuring point 6. Therefore, the raw material area 3 and the crystallization area 4 can be independently controlled according to the temperatures of the upper temperature measuring point 5 and the lower temperature measuring point 6, respectively, so that the material sublimation and crystallization process is more in line with the process requirements. Among them, the upper crucible 2 uses resistance heating to provide a more stable temperature, and the temperature control is more accurate, and it is easier to achieve accurate temperature gradient control to meet the needs of the crystallization area. The lower crucible 1 uses electromagnetic heating to provide more uniform heating, and the heating efficiency is higher, and the raw materials can be heated to the required temperature faster to meet the needs of the raw material area.

[0025] More specifically, a boss 7 is further provided inside the lower crucible 1, and the boss 7 is cylindrical and coaxial with the lower crucible 1. Thus, an annular groove structure can be formed between the outer periphery of the boss 7 and the inner wall of the lower crucible 1, which not only increases the contact area between the raw material and the lower crucible 1, improves the heating efficiency, and reduces energy consumption, but also helps to transfer heat to the raw material more evenly, which is conducive to expanding the growth size of silicon carbide crystals.

[0026] On the other hand, Figure 2 As shown, in this embodiment, a magnetic induction coil 8 is provided on the outer outer ring of the lower crucible 1, and a cylindrical sleeve 9 is provided between the magnetic induction coil 8 and the lower crucible 1, and the upper edge of the cylindrical sleeve 9 is supported on the bottom of the upper crucible 2. Thus, the upper crucible 2 can be separated from the lower crucible 1 by using the cylindrical sleeve 9 as a supporting structure, thereby improving the stability and safety of the upper crucible 2. In addition, an exhaust hole 10 is formed between the bottom of the upper crucible 2 and the top of the cylindrical sleeve 9, and a plurality of exhaust holes 10 are provided and evenly arranged in the circumferential direction. During the growth of silicon carbide crystals, some crystal molecules may not be able to participate in the crystal arrangement in time, resulting in defects inside the crystal. These excess crystal molecules can be discharged in time through the exhaust holes 10 to ensure that the molecules in the crystal growth area are arranged in an orderly manner, thereby improving the crystal quality.

[0027] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "vertical", "horizontal", etc. (if any) indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the purpose of describing the present invention and do not require that the present invention must be constructed or operated in a specific position, and therefore cannot be understood as a limitation on the present invention. The terms "connected" and "connected" in the present invention should be understood in a broad sense, for example, it can be connected or detachably connected; it can be directly connected or indirectly connected through an intermediate component. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in their embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novelties disclosed herein.

Claims

1. A new type of silicon carbide crystal growth crucible, characterized in that: The invention comprises a lower crucible (1) and an upper crucible (2), wherein the chamber of the upper crucible (2) is arranged opposite to the chamber of the lower crucible (1), the top of the upper crucible (2) is provided with an upper temperature measuring point (5), the bottom of the lower crucible (1) is provided with a lower temperature measuring point (6), and a boss (7) is further provided in the lower crucible (1), and the outer periphery of the boss (7) and the inner wall of the lower crucible (1) can form an annular groove structure.

2. A new type of silicon carbide crystal growth crucible according to claim 1, characterized in that: The upper crucible (2) is a resistance heating crucible, and the lower crucible (1) is an electromagnetic heating crucible.

3. A new type of silicon carbide crystal growth crucible according to claim 2, characterized in that: The outer ring of the lower crucible (1) is provided with a magnetic induction coil (8), and a cylindrical sleeve (9) is provided between the magnetic induction coil (8) and the lower crucible (1), and the upper edge of the cylindrical sleeve (9) is supported on the bottom of the upper crucible (2).

4. A new type of silicon carbide crystal growth crucible according to claim 3, characterized in that: An exhaust hole (10) is formed between the bottom of the upper crucible (2) and the top of the cylindrical sleeve (9).

5. A new type of silicon carbide crystal growth crucible according to claim 4, characterized in that: A plurality of exhaust holes (10) are provided and are evenly arranged along the circumferential direction.

6. A novel silicon carbide crystal growth crucible according to any one of claims 1 to 5, characterized in that: The boss (7) is cylindrical and has a coaxial center with the lower crucible (1).

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