WO2020155669A1

WO2020155669A1 - Silicon carbide single crystal growth apparatus and silicon carbide single crystal preparation device

Info

Publication number: WO2020155669A1
Application number: PCT/CN2019/111081
Authority: WO
Inventors: 陈泽斌; 张洁; 廖弘基; 陈华荣
Original assignee: 福建北电新材料科技有限公司
Priority date: 2019-02-02
Filing date: 2019-10-14
Publication date: 2020-08-06
Also published as: CN109629001A

Abstract

A silicon carbide single crystal growth apparatus and a silicon carbide single crystal preparation device, relating to the field of crystal growth. The silicon carbide single crystal growth apparatus comprises a growth container, a growth base, and a slow air mechanism; an accommodating space is arranged at the bottom of the growth container, the inside of the accommodating space being configured for the placement of silicon carbide powder material; the growth base is arranged at the top part of the growth container and is configured for silicon carbide single crystals to grow on the growth base; the slow air mechanism is arranged in the growth container and is located at a position between the accommodating space and the growth base; and the slow air mechanism has a gas channel to enable growth atmosphere to pass through the gas channel and arrive at the growth base at the top part of the growth container. The silicon carbide single crystal preparation device comprises the aforementioned silicon carbide single crystal growth apparatus. The silicon carbide single crystals prepared using the present silicon carbide single crystal growth apparatus and silicon carbide single crystal preparation device have good quality and a high yield.

Description

Silicon carbide single crystal growth device and silicon carbide single crystal preparation equipment

Cross references to related applications

This application claims the priority of the Chinese patent application with the application number 201910108178.0 and the name "silicon carbide single crystal growth device and silicon carbide single crystal preparation equipment" submitted to the China Patent Office on February 2, 2019, the entire content of which is incorporated by reference Incorporated in this application.

Technical field

This application relates to the field of crystal growth, in particular to a silicon carbide single crystal growth device, and a silicon carbide single crystal preparation equipment including the silicon carbide single crystal growth device.

Background technique

Silicon carbide (SiC) single crystal material is an ideal substrate material for preparing high-temperature, high-frequency, high-power and radiation-resistant semiconductor devices, and is widely used in hybrid vehicles, high-voltage power transmission, LED lighting, aerospace and other fields. Silicon carbide single crystals hardly appear in a natural state, and silicon carbide single crystals can only be obtained by synthetic methods.

In the prior art, the silicon carbide single crystal is generally obtained by physical vapor deposition. The equipment for preparing silicon carbide single crystals according to this method includes a growth container, which is generally a crucible, and the material is generally graphite. It includes a growth container body and a growth container cover. The growth container cover can be closed on the growth container body, thereby A closed growth space is formed in the growth container. The bottom of the growth container is configured to place silicon carbide powder, and the top is provided with a growth base; the growth base is configured to fix a silicon carbide seed crystal and has a growth surface of a silicon carbide single crystal. The general process of the specific preparation of silicon carbide single crystal is as follows: firstly, the graphite growth container is heated by induction heating, and the temperature gradient of the graphite growth container is formed in the vertical direction, and the temperature at the bottom is high and the temperature at the top is low; When the temperature at the bottom of the graphite growth vessel reaches a certain temperature (for example, 2100°C) (and meets other corresponding conditions, such as low pressure, etc.), the silicon carbide powder will sublime to form a growth atmosphere for silicon carbide single crystals, and its gas phase components include gaseous Si , Si ₂ C and SiC ₂ etc., the gas phase composition will rise; when it rises to the top of the growth vessel, due to the lower temperature at the top, it will crystallize at the silicon carbide seed crystal to form a silicon carbide single crystal.

However, in the process of preparing silicon carbide single crystal as described above, the following problems may exist:

When silicon carbide powder is sublimated into gas, it will decompose in a non-stoichiometric ratio. Specifically, in the early stage of the growth of silicon carbide single crystals, the components of the growth atmosphere are rich in silicon; on the one hand, silicon droplets are easily formed on the growth surface, which will lead to the transformation of microtubes and polytypes; on the other hand, it will lead to silicon carbide powder The graphitization of the material will form carbon particles in the middle/mid-to-late growth period. These carbon particles will be blown up by the gas phase component and adhere to the crystal growth surface, resulting in the formation of carbon inclusions. In the later stage of growth, the components of the growth atmosphere are rich in carbon. When these carbon-rich vapor phase components rise to the crystal growth surface, silicon atoms in the grown silicon carbide single crystal will be precipitated, resulting in the surface of the silicon carbide single crystal Graphitization.

Summary of the invention

The purpose of this application is to provide a silicon carbide single crystal growth device and a silicon carbide single crystal preparation equipment including the silicon carbide single crystal growth device, so as to improve or alleviate the above technical problems in the prior art.

The silicon carbide single crystal growth device provided in the present application includes a growth container, a growth base, and a gas retarding mechanism; the bottom of the growth container is provided with an accommodating space, and the accommodating space is configured to place silicon carbide powder; The growth base is arranged on the top of the growth vessel and is configured to grow silicon carbide single crystals on the growth base; the gas retarding mechanism is arranged in the growth vessel and is located between the accommodating space and the growth base And the gas slowing mechanism has a gas channel so that the growth atmosphere can reach the growth base on the top of the growth vessel through the gas channel.

Wherein, the air damper mechanism is ring-shaped, the outer periphery of the air damper mechanism is in contact with the inner wall of the growth container, and the ring hole of the air damper mechanism forms the gas channel.

Wherein, along the vertical direction from bottom to top, the aperture of the ring hole of the air damper mechanism decreases.

Wherein, the number of gas channels on the air retarding mechanism is multiple, and the multiple gas channels are evenly distributed on the air retarding mechanism.

Wherein, the air slowing mechanism includes a plurality of blocks, and a gap forming a gas channel is formed between two adjacent blocks.

Wherein, the silicon carbide single crystal growth device further includes a flow guide mechanism, the flow guide mechanism is arranged in the growth container, and is located between the gas retarding mechanism and the growth base, configured to The gas generated by the powder sublimation is guided to the direction of the growth base.

Wherein, the lower end of the flow guiding mechanism is in contact with the air slowing mechanism; the guiding mechanism is provided with a flow guiding hole, the lower end of the guiding hole is connected with the gas channel of the air slowing mechanism, and the upper end faces The growth base.

Wherein, the surface of the air damper mechanism has a protective layer, and the material of the protective layer is tungsten carbide, niobium carbide or tantalum carbide.

Wherein, the surface of the guide mechanism has a protective layer, and the material of the protective layer is tungsten carbide, niobium carbide or tantalum carbide.

The silicon carbide single crystal preparation equipment provided by the present application includes the above-mentioned silicon carbide single crystal growth device.

This application has the following beneficial effects:

The silicon carbide single crystal growth device provided in the present application includes a growth container, a growth base, and a gas retarding mechanism with a gas channel, and the retarding mechanism is arranged between the accommodating space and the growth base. In this way, firstly in the early stage of the growth of silicon carbide single crystal, by forming silicon droplets at the gas retarding mechanism, on the one hand, the formation of silicon droplets on the growth surface of the growth base is reduced; on the other hand, the silicon droplets formed on the gas retarding mechanism The silicon carbide powder can be used for the growth and preparation of silicon carbide single crystals again, thereby increasing the yield of silicon carbide single crystals. Secondly, in the middle and late stages of the growth of the silicon carbide single crystal, carbon inclusions are formed on the air damper mechanism to reduce the formation of carbon inclusions on the growth surface of the growth base, thereby improving the quality of the obtained silicon carbide single crystals. Third, in the late growth stage of the silicon carbide single crystal, the carbon-rich gas produced by the sublimation of the silicon carbide powder can precipitate silicon atoms from the silicon carbide crystal formed in the early growth stage on the retarding mechanism. On the one hand, it can avoid the growth of the base. The silicon atoms in the silicon carbide single crystal grown on the growth surface of the silicon carbide are precipitated and carbonized, and the adhesion of carbon atoms on the growth surface of the growth base is reduced, thereby improving the quality of the silicon carbide single crystal; on the other hand, supplement The gas containing the silicon atoms can continue to form silicon carbide single crystals on the growth surface of the growth base, thereby increasing the yield of silicon carbide single crystals.

The silicon carbide single crystal preparation equipment provided in the present application includes the above-mentioned silicon carbide single crystal growth device. Therefore, it also has the beneficial effects of the above-mentioned silicon carbide single crystal growth device.

Description of the drawings

In order to more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the specific embodiments or the description of the prior art. Obviously, the appendix in the following description The drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic three-dimensional cross-sectional view of a silicon carbide single crystal growth device provided by this application in a first embodiment of the first embodiment;

FIG. 2 is a schematic plan view of the silicon carbide single crystal growth device shown in FIG. 1;

3 is a schematic diagram of the structure of a gas retarding mechanism in the silicon carbide single crystal growth device shown in FIG. 2;

4 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in a second embodiment of the first embodiment;

5 is a schematic plan view of the silicon carbide single crystal growth device shown in FIG. 4;

6 is a schematic diagram of the structure of a gas retarding mechanism in the silicon carbide single crystal growth device shown in FIG. 5;

FIG. 7 is a schematic structural diagram of a gas retarding mechanism in another embodiment of the first embodiment of the silicon carbide single crystal growth apparatus provided by this application;

FIG. 8 is a schematic structural diagram of a gas retarding mechanism in another embodiment of the first embodiment of the silicon carbide single crystal growth apparatus provided by this application;

FIG. 9 is a schematic structural diagram of a gas retarding mechanism in another embodiment of the first embodiment of the silicon carbide single crystal growth apparatus provided by this application;

FIG. 10 is a schematic structural diagram of a gas retarding mechanism in another embodiment of the first embodiment of the silicon carbide single crystal growth apparatus provided by this application;

FIG. 11 is a schematic structural diagram of a gas retarding mechanism in another embodiment of the first embodiment of the silicon carbide single crystal growth apparatus provided by this application;

12 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the first embodiment of the second embodiment;

FIG. 13 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the second embodiment of the second embodiment;

14 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the first embodiment of the third embodiment;

15 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the second embodiment of the third embodiment;

16 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the first embodiment of the fourth embodiment;

FIG. 17 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the second embodiment of the fourth embodiment;

18 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the third embodiment of the fourth embodiment;

19 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in one of the fourth embodiments of the fourth embodiment;

20 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in the second embodiment of the fourth embodiment;

21 is a schematic three-dimensional cross-sectional view of the silicon carbide single crystal growth device provided by this application in one of the fifth embodiments of the fourth embodiment;

FIG. 22 is a schematic three-dimensional cross-sectional view of the second embodiment of the fourth embodiment of the silicon carbide single crystal growth device provided by this application.

Icon: 10: growth container; 11: accommodation space; 12: protrusion; 13: growth container body; 14: upper side wall; 15: growth container cover; 16: lower growth container body; 17: upper growth container body ; 20: growth base; 30: slow air mechanism; 31: gas channel; 40: diversion mechanism; 41: diversion hole;

130: bottom wall; 131: lower side wall;

160: bottom wall; 161: lower side wall; 170: upper side wall; 171: growth container cover.

detailed description

The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

In the description of this application, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" appear ", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the pointed device or element must have a specific orientation Or it is constructed and operated in a specific orientation, so it cannot be understood as a limitation of the application. In addition, if the terms "first", "second" and "third" appear, they are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood under specific circumstances.

The present application provides a silicon carbide single crystal growth device, and multiple embodiments of the silicon carbide single crystal growth device are given below, so that those skilled in the art can realize the silicon carbide single crystal growth device.

(1) The first embodiment of the silicon carbide single crystal growth device

In the first embodiment of the silicon carbide single crystal growth device, as shown in FIG. 1, the silicon carbide single crystal growth device includes a growth vessel 10, a growth base 20 and a gas retarding mechanism 30. An accommodating space 11 is provided at the bottom of the growth container 10, and the accommodating space 11 is configured to place silicon carbide powder. The growth susceptor 20 is disposed on the top of the growth container 10 and is configured to grow silicon carbide single crystals on the growth susceptor 20. The air cushion mechanism 30 is arranged in the growth container 10 at a position between the accommodating space 11 and the growth base 20. The gas slowing mechanism 30 has a gas channel 31 so that the growth atmosphere can reach the growth base 20 on the top of the growth container 10 through the gas channel 31.

Specifically, in the first embodiment of the present embodiment, as shown in FIGS. 1, 2 and 3, the air cushion mechanism 30 is a ring-shaped workpiece, and its outer periphery is in contact with the inner wall of the growth container 10, and is The junction of the container 10 is fixedly arranged in the growth container 10. The connection between the outer periphery of the air damper mechanism 30 and the inner wall of the growth vessel 10 means that there is no obvious gap between the air damper mechanism 30 and the inner wall of the growth vessel 10 in the complete circumferential direction. Except for small gaps that may occur due to factors such as process level. The specific method of fixing between the air damper mechanism 30 and the growth container 10 is: the growth container 10 has a circumferential flange, as shown in FIG. 2, the air damper mechanism 30 is placed on the circumferential flange, so that the circumferential flange The damper mechanism 30 is supported toward the flange, so that the damper mechanism 30 is fixed in the growth container 10.

As shown in FIG. 2 and FIG. 3, the middle of the air damper mechanism 30 has a through ring hole, and the ring hole forms a gas channel 31. Here, the "middle" where the ring hole is located is not necessarily the exact center position of the air damper mechanism 30, and it may also be at an eccentric position. Of course, in this embodiment, it is preferable that the ring hole is located approximately at the center or at the exact center.

The process and principle of preparing a silicon carbide single crystal by the silicon carbide single crystal growth device in this embodiment will be described in detail below with reference to the accompanying drawings.

Firstly, an environment for realizing the growth of silicon carbide single crystals is constructed in the growth vessel 10, which mainly includes high temperature and low pressure. Taking temperature as an example, the temperature in the growth container 10 should generally reach above 2100° C., with a temperature gradient in the vertical direction, and the temperature at the bottom of the growth container 10 is high while the temperature at the top is low. It can be seen that the temperature at the air damper mechanism 30 is lower than the temperature at the accommodating space 11, and the temperature at the growth base 20 is lower than the temperature at the air damper mechanism 30 and the accommodating space 11.

After the growth container 10 has an environment that satisfies the growth of silicon carbide single crystals, under the influence of high temperature and low pressure, the silicon carbide powder placed in the accommodating space 11 at the bottom of the growth container 10 will sublime and generate gas. The gas phase composition of the gas includes Si and Si _x C _y .

As mentioned in the background technology section, when silicon carbide powder is sublimated to produce gas, the process is non-stoichiometric decomposition and sublimation. In the early stage of silicon carbide single crystal growth, the gas phase component of the generated gas is rich in silicon, that is, the gas phase component contains Si and Si _x C _y (x>y). During the ascending process of the gas, it will first pass through the position where the gas slowing mechanism 30 is located, and then continue to rise through the gas channel 31 on the gas slowing mechanism 30 to reach the growth base 20.

When passing through the air damper mechanism 30, since the temperature at the air damper mechanism 30 is lower than the temperature at the accommodating space 11, the silicon-rich gas phase component will be on the bottom surface of the air damper mechanism 30 when it comes into contact with the air damper mechanism 30. Silicon droplets are formed on the surface; at the same time, silicon carbide crystals are also crystallized.

Since the temperature at the growth susceptor 20 is lower, the gas phase components rising to the growth susceptor 20 will also crystallize and grow on the growth surface of the growth susceptor 20 to form a silicon carbide single crystal. In addition, since the temperature at the growth base 20 is lower than the temperature at the retarding mechanism 30, the crystal growth rate on the growth base 20 will be higher than the crystal growth rate on the retarding mechanism 30.

In the above process, silicon droplets are formed on the bottom surface of the gas retarder 30. On the one hand, this can reduce the proportion of silicon in the gas phase component, so that the gas channel 31 on the gas retarder 30 rises to the growth base 20 The gas phase composition is closer to the stoichiometric ratio of silicon carbide, thereby reducing or avoiding the formation of silicon droplets on the growth surface of the silicon carbide single crystal of the growth base 20. On the other hand, the silicon droplets formed on the bottom surface of the air damper mechanism 30 will also drip onto the silicon carbide powder under the action of gravity, supplementing the silicon carbide powder that has lost more silicon, so that it can be The middle and later stages of the growth of the silicon single crystal enable the silicon carbide powder to further generate Si _x C _y , which is used to grow the silicon carbide single crystal on the silicon carbide single crystal growth surface of the growth base 20, thereby improving the silicon carbide single crystal The output.

In the middle and late stages of silicon carbide single crystal growth, silicon carbide powder continues to sublimate to generate gas. However, because the gas produced by sublimation in the early stage of growth takes away a large amount of silicon atoms, the silicon carbide powder at this time is gradually graphitized. The fine carbon particles will be blown by the gas produced by sublimation and rise with the gas produced by sublimation. When ascending past the air damper mechanism 30, a part of carbon particles will be adhered and wrapped by the crystals grown at the bottom of the air damper mechanism 30 to form a carbon wrap. In this way, the carbon particles that continue to rise to the growth base 20 through the gas channel 31 are correspondingly reduced, thereby reducing the number of carbon inclusions on the silicon carbide single crystal grown on the growth base 20 and improving the obtained silicon carbide single crystal. Quality.

In the later stage of silicon carbide single crystal growth, the graphitization of silicon carbide powder will further develop. At this time, the gas phase composition of the gas produced by sublimation is rich in carbon. The carbon-rich gas will first come into contact with the retarding mechanism 30 during the ascent. When in contact with the retarding mechanism 30, the carbon-rich gas phase component will precipitate silicon atoms in the silicon carbide crystals formed on the bottom surface of the retarding mechanism 30, turning it into a vapor phase, thereby making the growth of silicon atoms in the atmosphere The partial pressure increases; the carbon atoms remain on the retarding mechanism 30. After contacting with the retarding mechanism 30, the gas continues to rise and reaches the growth base 20. Since silicon atoms are replenished when passing through the gas retarding mechanism 30, on the one hand, the gas reaching the growth base 20 can crystallize on the growth surface of the growth base 20 to form a silicon carbide single crystal; on the other hand, it can also avoid the growth base 20. The silicon atoms in the silicon carbide single crystal grown on the growth surface of the silicon carbide are precipitated and carbonized, and the adhesion of carbon atoms on the growth surface of the growth base 20 is reduced, thereby improving the quality of the silicon carbide single crystal.

The general process of preparing a silicon carbide single crystal by the silicon carbide single crystal growth device provided in this embodiment has been described above. Analyzing the process of preparing silicon carbide single crystal in this embodiment and comparing it with the process of preparing silicon carbide single crystal in the prior art, it can be seen that the method of preparing silicon carbide single crystal using the silicon carbide single crystal growth device in this embodiment has The following beneficial effects:

First, in the early stage of the growth of the silicon carbide single crystal, by forming silicon droplets at the gas retarding mechanism 30, on the one hand, the formation of silicon droplets on the growth surface of the growth base 20 is reduced; The silicon droplets are dripped onto the silicon carbide powder material and can be used again for the growth and preparation of silicon carbide single crystals, thereby increasing the yield of silicon carbide single crystals.

Secondly, in the middle and late stages of the growth of the silicon carbide single crystal, carbon inclusions are formed on the air damper mechanism 30 to reduce the formation of carbon inclusions on the growth surface of the growth susceptor 20, thereby improving the obtained silicon carbide single crystal. quality.

Third, in the late growth stage of the silicon carbide single crystal, the carbon-rich gas generated by the sublimation of the silicon carbide powder can precipitate silicon atoms from the silicon carbide crystal formed in the early growth stage on the gas retarding mechanism 30. On the one hand, it can avoid the growth of the base. The silicon atoms in the silicon carbide single crystal grown on the growth surface of the base 20 are precipitated and carbonized, and the adhesion of carbon atoms on the growth surface of the growth base 20 is reduced, thereby improving the quality of the silicon carbide single crystal; On the one hand, the gas supplemented with silicon atoms can continue to form silicon carbide single crystals on the growth surface of the growth base 20, thereby increasing the yield of silicon carbide single crystals.

In a modified embodiment of the above-mentioned first embodiment, the inside of the growth container 10 includes a plurality of protrusions, and the plurality of protrusions protrude from the inner wall of the growth container 10 into the growth container 10. When placing the air damper mechanism 30 in the growth container 10, unlike the first embodiment described above, the plurality of protrusions support the air damper mechanism 30 in a multi-point support manner, thereby realizing the air damper mechanism 30 and the growth container Fixed between 10.

In other modified embodiments of the foregoing first embodiment, the surface of the air damper mechanism 30 may also have a protective layer, and the material of the protective layer may specifically be tungsten carbide, niobium carbide or tantalum carbide, which is used to increase the air damper mechanism 30 Service life.

In the second embodiment of the present embodiment, as shown in FIGS. 4 to 6, compared with the above-mentioned first embodiment, along the vertical direction from bottom to top, the aperture of the ring hole of the air damper mechanism 30 decreases. This arrangement on the one hand facilitates the gas generated by the sublimation of the silicon carbide powder to flow toward the top of the growth vessel 10, thereby promoting the growth process of the silicon carbide single crystal, and it also facilitates the gravity effect of the silicon droplets formed on the gas retarding mechanism 30. Drop down onto the silicon carbide powder.

In this embodiment, the damper mechanism 30 is not limited to the ring-shaped workpiece in the first and second embodiments described above. In other embodiments of this embodiment, the air damper mechanism 30 may also be a structure other than a ring structure.

For example, in the embodiment shown in FIG. 7, the air damper mechanism 30 has a disc shape, and a plurality of through holes are provided thereon, and the through holes serve as the gas passage 31.

For another example, in the embodiment shown in FIG. 8, the air cushioning mechanism 30 is a plurality of plate-shaped mechanisms located in the same plane, and the plurality of plate-shaped structures have gaps between them, and the gaps serve as the gas channels 31. On the basis of the embodiment shown in FIG. 8, as a modified embodiment, as shown in FIG. 9, the plurality of plate-shaped mechanisms may also be provided with through holes, and the through holes also serve as gas channels 31.

For another example, in the embodiment shown in FIG. 10, the air cushioning mechanism 30 includes a plurality of plate-shaped mechanisms which are arranged at intervals in the vertical direction, and there will be gaps between the plurality of plate-like mechanisms arranged at intervals. , The gap is used as a gas channel 31. Similar to the embodiment shown in FIG. 9 above, on the basis of the embodiment shown in FIG. 10, as a modified embodiment, as shown in FIG. 11, the plurality of plate-shaped mechanisms may also be provided with through holes, and the through holes serve as The gas channel 31 allows the growth atmosphere formed during the growth of the silicon carbide single crystal to rise to the top position of the growth container 10 through the through hole.

(2) The second embodiment of the silicon carbide single crystal growth device

In the second embodiment of the silicon carbide single crystal growth device, the silicon carbide single crystal growth device also includes a growth vessel 10, a growth base 20 and a gas retarding mechanism 30, and its structure and function are substantially the same as in the first embodiment described above. Regarding the similarities between this embodiment and the above-mentioned first embodiment, since it has been described in detail in the above-mentioned first embodiment, it will not be repeated here. The following describes the differences between this embodiment and the above-mentioned first embodiment.

As shown in FIG. 12, in this embodiment, the accommodating space 11 is annular. Specifically, there is a protrusion 12 at the bottom of the growth container 10, and there is a gap between the protrusion 12 and the inner side wall of the growth container 10, and the protrusion 12 and the inner side of the growth container 10 The annular accommodation space 11 is formed between the walls. It should be noted here that the position of the protruding body 12 only needs to satisfy the gap between the outer side wall and the inner side wall of the growth container 10 to form the annular accommodation space 11. Therefore, the position of the protruding body 12 is only The "relative" center position of the bottom of the growth container 10. Of course, in a preferred case, the protrusion 12 may be located at the center of the bottom of the growth container 10.

In the first example of this embodiment, as shown in FIG. 12, the protrusion 12 is a cylindrical member, and the material thereof is specifically graphite. Specifically, there is a groove corresponding to the cylindrical member at the bottom of the growth container 10, and the cylindrical member is installed and fixed in the groove, so that there is a gap between the outer side wall of the cylindrical member and the inner side wall of the growth container 10 A ring-shaped space is formed between the accommodating space 11.

As shown in FIG. 12, in this embodiment, the air damper mechanism 30 is a ring-shaped workpiece, and the air damper mechanism 30 is higher than the protruding body 12 in the vertical direction; thus, between the air damper mechanism 30 and the protruding body 12 A gap is formed, and the gap is used for the gas generated by the sublimation of the silicon carbide powder placed in the containing space 11 to pass through and flow toward the top of the growth container 10.

In this embodiment, a protrusion 12 is provided at the bottom of the growth container 10. Compared with the prior art, the area occupied by the protrusion 12 cannot accommodate silicon carbide powder, which can avoid The silicon carbide powder in the central area of the bottom of the growth vessel 10 is condensed together to form a ceramic body with a very dense structure, which leads to the waste of silicon carbide powder, which brings about the beneficial effect of saving silicon carbide powder.

In addition, in this embodiment, the protruding body 12 and the annular hole on the air damper mechanism 30 at least partially overlap in the vertical direction. In a preferred case, the two can be completely overlapped in the vertical direction. This arrangement can reduce the area occupied by the silicon carbide powder that is not blocked by the air cushion mechanism 30 in the vertical direction, so that all the silicon carbide powder materials placed in the accommodation space 11 are in the vertical direction by the air cushion mechanism 30. Blocking; thus can reduce or avoid the gas generated by the sublimation of silicon carbide powder material directly flow to the growth base 20 on the top of the growth vessel 10 without the retarding mechanism 30 (forming silicon droplets, crystallization or precipitation of silicon atoms, etc.) This is beneficial to the maximum realization of the beneficial effects obtained in the first embodiment.

In a modified embodiment of the above-mentioned first embodiment, the protrusion 12 and the growth container 10 may also be an integral structure.

In other modified embodiments of the above-mentioned first embodiment, the protruding body 12 may also be cylindrical, conical, truncated or polygonal. It should be noted that in the embodiment when the protrusion 12 is in the shape of a cone or truncated cone, in order to provide a gap between the air damper mechanism 30 and the protrusion 12, the air damper mechanism 30 is provided with a higher convex Outer body 12; the restriction on the height of the air damper mechanism 30 and the protrusion 12 here means that the air damper mechanism 30 is higher than the protrusion 12 as a whole, and does not mean that the bottom surface of the air damper mechanism 30 is absolutely higher than the cone Cone-shaped tip or truncated cone-shaped top surface, including the case where the bottom surface of the air damper mechanism 30 is lower than the conical tip or truncated cone-shaped top surface, but there is a gap between the air damper mechanism 30 and the conical or truncated cone shape .

In other modified embodiments of the foregoing first embodiment, the material of the protrusion 12 may also be molybdenum.

In other modified embodiments of the above-mentioned first embodiment, the surfaces of the protrusions 12 and the air damper mechanism 30 may also have a protective layer. The material of the protective layer may specifically be tungsten carbide, niobium carbide or tantalum carbide, which can increase the convexity. The service life of the body 12 and the air cushion mechanism 30.

In the second embodiment of this embodiment, as shown in FIG. 13, the gas channel 31 on the air damper mechanism 30 includes a through hole, and the position of the through hole is an area on the air damper mechanism 30 corresponding to the accommodation space 11 That is to say, the area corresponding to the protrusion 12 in the vertical direction on the air damper mechanism 30 is not provided with a gas channel 31. Therefore, in this embodiment, the protrusions 12 can be in contact with each other in the vertical direction, and the contact will not hinder the flow of the gas generated by the sublimation of the silicon carbide powder in the accommodating space 11 toward the top of the growth container 10 .

Of course, in other modified embodiments of the second embodiment, there may still be a gap between the protruding body 12 and the air cushion mechanism 30, so that the gas generated by the sublimation of the silicon carbide powder in the accommodation space 11 can be more smoothly Flow toward the top of the growth container 10.

(3) The third embodiment of the silicon carbide single crystal growth device

In the third embodiment of the silicon carbide single crystal growth device, the silicon carbide single crystal growth device also includes a growth vessel 10, a growth base 20 and a gas retarding mechanism 30, and its structure and function are roughly the same as those in the first and second embodiments. the same. Regarding the similarities between this embodiment and the above-mentioned first and second embodiments, since it has been described in detail in the above-mentioned first and second embodiments, it will not be repeated here. The following describes the differences between this embodiment and the above-mentioned first and second embodiments.

In this embodiment, as shown in FIG. 14, the silicon carbide single crystal growth device further includes a flow guide mechanism 40, which is arranged in the growth container 10 and is located between the air damper mechanism 30 and the growth base 20. It is configured to guide the gas generated by the sublimation of silicon carbide powder to the direction of the growth base 20.

In this embodiment, when the gas generated by the sublimation of the silicon carbide powder flows upward through the retarding mechanism 30, the flow guiding mechanism 40 guides the part of the gas to the growth base 20, so that the part of the gas is at the growth base 20. Accumulation can reduce the diffusion of this part of the gas and increase the gas density at the growth susceptor 20, thereby helping to increase the growth rate of the silicon carbide single crystal on the growth surface of the growth susceptor 20.

In the first preferred embodiment of this embodiment, the lower end of the diversion mechanism 40 is in contact with the damper mechanism 30; the diversion mechanism 40 is provided with a diversion hole 41, and the lower end of the diversion hole 41 is in contact with the damper mechanism 30. The gas channels 31 are connected, and the upper end faces the growth base 20. This arrangement makes the gas channel 31 and the diversion hole on the diversion mechanism 40 directly connect, and there is no gap between the two, which can prevent the gas from diffusing between the damper mechanism 30 and the diversion mechanism 40, and can be better and Directing the gas to the growth susceptor 20 more directly helps maximize the beneficial effect of increasing the growth rate of the silicon carbide single crystal on the growth surface of the growth susceptor 20 in this embodiment.

In other modified embodiments of the above-mentioned first embodiment, the surface of the flow guiding mechanism 40 may also have a protective layer, and the material of the protective layer may specifically be tungsten carbide, niobium carbide or tantalum carbide. Service life.

In the second preferred embodiment of this embodiment, as shown in FIG. 15, the flow guiding mechanism 40 and the air damper mechanism 30 can also be an integral structure, so that when it is installed in the growth container 10, only one installation process is required. The installation can be achieved.

(4) Fourth embodiment of silicon carbide single crystal growth device

In the fourth embodiment of the silicon carbide single crystal growth device, the silicon carbide single crystal growth device also includes a growth vessel 10, a growth base 20 and a gas retarding mechanism 30, and may also include a flow guiding mechanism 40, which has the same structure and function as the above-mentioned The first, second and third embodiments are roughly the same. Regarding the similarities between this embodiment and the above-mentioned first, second and third embodiments, since they have been described in detail in the above-mentioned first, second and third embodiments, they will not be repeated here. The following describes the differences between this embodiment and the above-mentioned first, second and third embodiments.

In the first example of this embodiment, as shown in FIG. 16, the growth container 10 includes a growth container body 13 mainly composed of a bottom wall 130 and a lower side wall 131, and an upper side wall 14 and a growth container cover 15. The upper side wall 14 is mounted on the lower side wall 131, and the growth container cover 15 is configured to cover the upper side wall 14. As shown in FIG. The growth container body 13, the upper side wall 14 and the growth container cover 15 form a closed space for growing a silicon carbide single crystal.

As mentioned in the background art section, in the process of preparing silicon carbide single crystals, the gas generated by the sublimation of silicon carbide powder will not only grow silicon carbide single crystals on the growth surface of the growth base 20, but also in the surrounding area, That is, the top wall of the closed space in the growth container 10 and the junction with the side wall deposit and crystallize. In the prior art, the crystals formed in these regions will hinder the process of opening the growth container cover and taking out the silicon carbide single crystal after the silicon carbide single crystal is prepared, and cutting tools have to be used to open the growth container cover. And separation.

In this embodiment, after the process of preparing the silicon carbide single crystal is completed, the upper side wall 14 and the lower side wall 131 are separated at the junction between the two, thereby opening the growth container body 13, the upper side wall 14 and the growth A closed space formed by the container lid 15. Since the junction of the upper side wall 14 and the lower side wall 131 is at a certain distance from the growth vessel cover 15, there are fewer crystals formed by crystallization, or will not be corroded by gas phase components or crystals will not appear, so that The upper side wall 14 and the lower side wall 131 are conveniently separated to avoid the use of equipment cutting, thereby reducing the probability of damage to the growth container 10, and also reducing the occurrence of personal injury caused by equipment cutting.

Moreover, for the separated growth container body 13, it can also be used for the next silicon carbide single crystal preparation process. When the silicon carbide single crystal is prepared next time, only a new upper side wall 14 needs to be installed on the growth container body 13 And the growth container cover 15 can form a new enclosed space on the basis of the growth container body 13 for the next process of preparing silicon carbide single crystal.

Since the gas phase components generally only erode the top of the growth vessel 10, the growth vessel body 13 located at the bottom is less eroded or not eroded. Therefore, for the growth container body 13 after separation, the residue of the silicon carbide powder in the containing space 11 is removed and cleaned, and then it can be used in the next preparation process of silicon carbide single crystal. Reduce the cost of equipment required to produce multiple silicon carbide single crystals. Specifically, in this embodiment, the ratio of the height of the upper side wall 14 to the height of the lower side wall 131 ranges from 1:2.5 to 1:5, preferably 1:3.

In the second example of the present embodiment, as shown in FIG. 17, the growth container 10 includes a lower growth container body 16 mainly composed of a bottom wall 160 and a lower side wall 161, and mainly composed of an upper side wall 170 and a growth container cover. 171 formed the upper growth container body 17. Specifically, the lower growth container body 16 includes a bottom wall 160 and a lower side wall 161, and the bottom wall 160 and the lower side wall 161 serve as the main body of the lower growth container body 16. The bottom wall 160 and the lower side wall 161 may be an integral structure. Or a split structure that is installed and fixed together. The upper growth container body 17 includes an upper side wall 170 and a growth container cover 171, and the upper side wall 170 and the growth container cover 171 serve as the main body of the upper growth container cover, and the upper side wall 170 and the growth container cover 171 are an integral structure.

The upper side wall 170 of the upper growth container body 17 is installed and covered on the lower side wall 161 of the lower growth container body 16 so that the upper growth container body 17 and the lower growth container body 16 form a closed space for growing silicon carbide single crystals.

In this embodiment, similar to the above-mentioned first embodiment, after the process of preparing the silicon carbide single crystal is completed, the upper sidewall 160 and the lower sidewall 161 are separated at the junction of the two, that is, the upper growth The separation of the container body 17 and the lower growth container body 16 can achieve the same technical effect as the above-mentioned first embodiment, which will not be repeated here.

In the third embodiment of this embodiment, on the basis of the first and second embodiments, the connecting surface of the upper side wall and the lower side wall is an inclined surface, and is inclined downward from the inside to outside direction of the growth container 10, As shown in Figure 18. Obviously, the inclination direction of the junction is opposite to the gas flow direction in the growth vessel 10, so that when the gas generated by the sublimation of silicon carbide powder in the growth vessel 10 flows from bottom to top, the gas passing through the upper side wall and Leakage occurs at the junction of the lower side walls.

The fourth embodiment of this embodiment is based on the above-mentioned third embodiment and combines the above-mentioned first and second embodiments. As shown in FIG. 19, the guide mechanism 40 is connected to the lower end of the upper side wall and the lower side wall. The upper ends are connected to cover the joint between the upper side wall and the lower side wall. This arrangement can reduce or avoid the occurrence of gas leakage through the junction of the upper side wall and the lower side wall.

When this embodiment is combined with the above-mentioned third embodiment, as shown in FIG. 20, the occurrence of gas leakage through the junction of the upper side wall and the lower side wall can be further reduced or avoided.

The fifth embodiment of this embodiment is based on the above-mentioned first embodiment and combines the above-mentioned first and second embodiments. As shown in FIG. 21, the air cushion mechanism 30 is connected to the lower end of the upper side wall and the lower side wall. The upper ends are connected to cover the joint between the upper side wall and the lower side wall. This arrangement can reduce or avoid the occurrence of gas leakage through the junction of the upper side wall and the lower side wall.

When this embodiment is combined with the above-mentioned third embodiment, as shown in FIG. 22, it is possible to further reduce or avoid the occurrence of gas leakage through the junction of the upper side wall and the lower side wall.

The present application also provides a silicon carbide single crystal preparation equipment. In its embodiment, the silicon carbide single crystal growth device in the above embodiment of the silicon carbide single crystal preparation equipment, and further includes a heating device configured to heat the growth container, Equipment such as thermal insulation structure configured to make the growth container form a temperature gradient in the vertical direction.

The silicon carbide single crystal preparation equipment provided by the present application includes the silicon carbide single crystal growth device in the foregoing embodiments, and therefore, it also has the beneficial effects of the silicon carbide single crystal growth devices in the foregoing multiple embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application range.

Claims

A device for silicon carbide single crystal growth, which is characterized by comprising a growth container, a growth base and a gas retarding mechanism;

An accommodating space is provided at the bottom of the growth container, and the accommodating space is configured to place silicon carbide powder;

The growth base is arranged on the top of the growth container and is configured to grow silicon carbide single crystals on the growth base;

The gas retarding mechanism is arranged in the growth container at a position between the accommodating space and the growth base; and the gas retarding mechanism has a gas channel so that the growth atmosphere can pass through the gas channel Reach the growth base at the top of the growth container.
The silicon carbide single crystal growth device according to claim 1, wherein the air retarding mechanism is ring-shaped, the outer periphery of the air retarding mechanism is in contact with the inner wall of the growth vessel, and the air retarding mechanism The annular hole forms the gas passage.
4. The silicon carbide single crystal growth device according to claim 2, wherein the diameter of the annular hole of the air cushion mechanism decreases in a vertical direction from bottom to top.
The silicon carbide single crystal growth device according to claim 1, wherein the number of gas channels on the gas retarding mechanism is multiple, and the multiple gas channels are evenly distributed on the gas retarding mechanism.
The silicon carbide single crystal growth device according to claim 1, wherein the gas retarding mechanism comprises a plurality of blocks, and there is a gap forming a gas channel between two adjacent blocks.
The silicon carbide single crystal growth device according to claim 1, wherein the silicon carbide single crystal growth device further comprises a diversion mechanism, and the diversion mechanism is arranged in the growth container and is located in the slow The gas mechanism and the growth base are configured to guide the gas generated by the sublimation of the silicon carbide powder to the direction of the growth base.
The silicon carbide single crystal growth device according to claim 6, wherein the lower end of the flow guiding mechanism is in contact with the air damper mechanism; the flow guiding mechanism is provided with a flow guiding hole, and the guiding hole The lower end is connected with the gas channel of the gas retarding mechanism, and the upper end faces the growth base.
The silicon carbide single crystal growth device according to claim 1, wherein the surface of the gas damper has a protective layer, and the material of the protective layer is tungsten carbide, niobium carbide or tantalum carbide.
The silicon carbide single crystal growth device according to claim 6 or 7, wherein the surface of the flow guide mechanism has a protective layer, and the material of the protective layer is tungsten carbide, niobium carbide or tantalum carbide.
A silicon carbide single crystal preparation equipment, characterized in that it comprises the silicon carbide single crystal growth device according to any one of claims 1-9.