Large-size crystal growth device and method

Abstract

The embodiment of the invention provides a large-size crystal growth device and method, and relates to the technical field of silicon carbide crystal growth. According to the large-size crystal growth method, the large-size crystal growth device is used for growing silicon carbide crystals, and the large-size crystal growth device comprises a crucible, a seed crystal, a flow guide part and a heating assembly. A porous graphite plate is arranged in the crucible, the porous graphite plate divides the crucible into a first chamber and a second chamber which are arranged in the axial direction, the first chamber is located on the upper side of the second chamber, and the first chamber and the second chamber are both used for containing silicon carbide powder. The flow guide part and the inner wall of the second cavity form a flow guide channel, the flow guide channel is provided with an inlet and an outlet, the inlet faces the porous graphite plate, and the outlet faces the outer side of the seed crystal. According to the special arrangement mode of the heating piece, the crystal growth atmosphere after sublimation of the silicon carbide powder in the first cavity can flow to the outer side of the seed crystal from the outlet under the guide of the flow guide channel, so that diameter-expanding growth of the silicon carbide crystal on the seed crystal is realized, and the large-diameter silicon carbide crystal is prepared.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide crystal growth technology, and more specifically, to a large-size crystal growth apparatus and method. Background Technology

[0002] Physical vapor transport (PVT) for growing silicon carbide crystals is a technique that uses gaseous substances as raw materials or transport media to grow crystals. It involves transporting solid silicon carbide powder to a designated location after high-temperature sublimation under a controlled atmosphere, and then growing silicon carbide crystals on a substrate (such as a seed crystal). The inventors have discovered that in related silicon carbide crystal growth devices, it is difficult to achieve efficient diameter expansion growth of silicon carbide crystals. Summary of the Invention

[0003] The present invention aims to provide a large-size crystal growth apparatus and method that can realize the diameter expansion growth of silicon carbide crystals, for example, from 6 inches to 8 inches, and from 8 inches to 12 inches, to prepare large-diameter silicon carbide crystals.

[0004] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a large-size crystal growth apparatus, comprising: The crucible contains a porous graphite plate that divides it into a first chamber and a second chamber arranged along the axial direction. The first chamber is located above the second chamber. Both the first and second chambers are used to contain silicon carbide powder. Seed crystal, the seed crystal is located in the second chamber and is located above the silicon carbide powder in the second chamber; The flow guide is connected to the side of the porous graphite plate near the second chamber. The flow guide is annular and located between the seed crystal and the inner wall of the second chamber. The flow guide and the inner wall of the second chamber form a flow channel with an inlet and an outlet. The inlet faces the porous graphite plate and the outlet faces the outside of the seed crystal. The heating assembly includes a first heating element and a second heating element, wherein the first heating element is disposed in a first chamber and the second heating element is disposed in a second chamber; In the first chamber, the crystal growth atmosphere after the silicon carbide powder sublimates can flow from the outlet to the outside of the seed crystal under the guidance of the flow channel.

[0005] In an optional embodiment, a first heating element is disposed above the crucible for heating the first chamber; The second heating element is located on the lower side of the crucible for heating the second chamber.

[0006] In an optional embodiment, the flow guide includes a flow guide shroud, the inner wall of the second chamber and the outer wall of the flow guide shroud together define a first flow channel, the end of the first flow channel near the porous graphite plate is the inlet, the flow guide shroud is disposed on the side of the porous graphite plate located in the second chamber, the end of the flow guide shroud away from the porous graphite plate has a first flow guide wall, and the radial dimension of the first flow guide wall gradually decreases in the direction near the porous graphite plate.

[0007] In an optional embodiment, a second flow guide wall is provided on the inner peripheral wall of the crucible, which is opposite to the first flow guide wall. The second flow guide wall is annular, and its radial dimension gradually decreases in the direction close to the porous graphite plate. The second flow guide wall is opposite to the first flow guide wall and together defines a second flow channel. The first flow channel and the second flow channel are connected and together form a flow guide channel. The end of the second flow channel away from the first flow channel is the outlet.

[0008] In an optional embodiment, the second chamber has a receiving groove for containing silicon carbide powder, the opening end of the receiving groove is connected to the opening end of the second guide wall, and the receiving groove is coaxial with the seed crystal.

[0009] In an optional embodiment, at least one of the first guide wall and the second guide wall is provided with a tantalum carbide layer.

[0010] The upper end of the outer peripheral wall of the flow guide is provided with external threads, and the porous graphite plate is provided with threaded holes for connection with the flow guide.

[0011] In an optional embodiment, the large-size crystal growth apparatus includes a connecting block disposed on one side of the porous graphite plate located in the second chamber. The connecting block is located inside the flow guide shroud, and a seed crystal is installed on the side of the connecting block away from the porous graphite plate. The outer wall of the connecting block and the inner peripheral wall of the flow guide shroud are spaced apart and together form a preset chamber.

[0012] In an optional embodiment, the connecting block includes a first connecting portion and a second connecting portion. The radial dimension of the first connecting portion is larger than that of the second connecting portion and is relatively close to the porous graphite plate. The outer peripheral wall of the first connecting portion abuts against the inner wall of the guide shroud, and a preset cavity is formed between the outer wall of the second connecting portion and the inner wall of the guide shroud.

[0013] In an optional embodiment, the crucible includes a body and a crucible lid, and the large-size crystal growth apparatus also includes a connecting column located in the middle of the first chamber. One end of the connecting column passes through a porous graphite plate and is connected to a connecting block, and the other end of the connecting column is connected to the crucible lid.

[0014] In a second aspect, the present invention provides a method for growing large-size crystals, wherein silicon carbide crystals are grown using the large-size crystal growth apparatus of any of the foregoing embodiments, the method comprising: Silicon carbide powder is filled into the first and second chambers; The first heating element is controlled to heat the first chamber, and the second heating element is controlled to heat the second chamber, so that the crystal growth atmosphere after the silicon carbide powder sublimation in the first chamber enters the guide channel through the porous graphite plate and flows from the outlet to the outside of the seed crystal, and the crystal growth atmosphere after the silicon carbide powder sublimation in the second chamber flows to the growth surface of the seed crystal.

[0015] The beneficial effects provided by the embodiments of the present invention include: The embodiments of the present invention provide a large-size crystal growth apparatus and method. The large-size crystal growth method is applied to the large-size crystal growth apparatus for growing silicon carbide crystals. The large-size crystal growth apparatus includes a crucible, a seed crystal, a flow guide, and a heating assembly. A porous graphite plate is disposed inside the crucible, dividing the crucible into a first chamber and a second chamber arranged axially. The first chamber is located above the second chamber, and both the first and second chambers are used to contain silicon carbide powder. The flow guide and the inner wall of the second chamber form a flow channel, which has an inlet and an outlet. The inlet faces the porous graphite plate, and the outlet faces the outside of the seed crystal. The heating assembly includes a first heating element and a second heating element. The first heating element is disposed corresponding to the first chamber, and the second heating element is disposed corresponding to the second chamber. The crystal growth atmosphere after the silicon carbide powder in the first chamber sublimates can flow from the outlet to the outside of the seed crystal under the guidance of the flow channel, thereby realizing the diameter expansion growth of the silicon carbide crystal on the seed crystal to prepare a large-diameter silicon carbide crystal. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the large-size crystal growth apparatus provided in this embodiment; Figure 2 This is a schematic diagram of the growth of silicon carbide crystals in the large-size crystal growth apparatus provided in this embodiment; Figure 3 for Figure 2 A magnified view of a portion of the image.

[0018] Icons: 1-Large-size crystal growth apparatus; 110-Body; 120-Cruise lid; 130-Connecting column; 140-Second guide wall; 100-Cruise; 101-First chamber; 102-Second chamber; 1011-First flow channel; 1012-Second flow channel; 1014-Outlet; 1015-Inlet; 1020-Preset chamber; 103-Receiving tank; 200-Guide component; 210-First guide wall; 300-Connecting block; 310-First connecting part; 320-Second connecting part; 400-Boss; 500-Seed crystal; 600-Porous graphite plate; 710-First heating element; 720-Second heating element; 2-Silicon carbide powder; 3-Silicon carbide crystal. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] In the process of silicon carbide crystal growth in related technologies, a heating element is set outside the crucible to provide a thermal field for the growth of silicon carbide crystals inside the crucible. This causes the crystal growth atmosphere after the silicon carbide powder in the crucible to flow upwards to the growth surface of the seed crystal, thereby depositing silicon carbide on the seed crystal. However, this method can only grow silicon carbide crystals of a certain size and makes it difficult to achieve rapid diameter expansion growth of silicon carbide crystals.

[0026] To address the aforementioned problems, this invention provides a large-size crystal growth apparatus that divides the crucible 100 into an axially arranged first chamber 101 and a second chamber 102 by providing a porous graphite plate 600 inside the crucible 100. A flow guide 200 forms a flow channel with the second chamber 102. The inlet of the flow guide channel faces the porous graphite plate 600, and the outlet 1014 of the flow guide channel faces the outside of the seed crystal 500. A first heating element 710 and a second heating element 720 are independently provided on the upper and lower sides of the crucible 100, respectively, to independently construct a thermal field. By controlling the first heating element 710 and the second heating element 720, the temperature on the growth surface of the seed crystal 500 is kept to a relatively low level. This allows the growth atmosphere of the silicon carbide powder 2 after sublimation in the first chamber 101 to flow downward through the guide element 200 to the seed crystal 500, and the growth atmosphere of the silicon carbide powder 2 after sublimation in the second chamber 102 to flow upward to the seed crystal 500, thereby achieving crystal diameter expansion growth.

[0027] The following describes in detail, with reference to the accompanying patent drawings, the specific structure of a large-size crystal growth apparatus provided by an embodiment of the present invention and the corresponding technical effects it brings.

[0028] Please refer to Figures 1-3The large-size crystal growth apparatus 1 provided in this embodiment of the invention includes a crucible 100, a seed crystal 500, a flow guide 200, and a heating assembly. A porous graphite plate 600 is disposed inside the crucible 100, dividing the crucible 100 into a first chamber 101 and a second chamber 102 arranged along the axial direction. The first chamber 101 is located above the second chamber 102. Both the first chamber 101 and the second chamber 102 are used to contain silicon carbide powder 2. The seed crystal 500 is located inside the second chamber 102 and above the silicon carbide powder 2 within the second chamber 102. A flow guide 200 and a porous graphite plate 600 are connected to each other on one side of the second chamber 102. The flow guide 200 is annular and located between the seed crystal 500 and the inner wall of the second chamber 102, forming a flow channel. The flow channel has an inlet 1015 and an outlet 1014. The inlet 1015 faces the porous graphite plate 600, and the outlet 1014 faces the outside of the seed crystal 500. The heating assembly includes a first heating element 710 and a second heating element 720. The first heating element 710 is disposed corresponding to the first chamber 101, and the second heating element 720 is disposed corresponding to the second chamber 102. After the silicon carbide powder 2 in the first chamber 101 is sublimated, the crystal growth atmosphere can flow from the outlet 1014 to the outside of the seed crystal 500 under the guidance of the flow channel, so as to realize the diameter expansion growth of silicon carbide crystal 3 on the seed crystal 500, thereby preparing a large-diameter silicon carbide crystal 3.

[0029] As is easily understood, the first chamber 101 is equipped with a first heating element 710, and the second chamber 102 is equipped with a second heating element 720. This allows the silicon carbide powder 2 in the first chamber 101 and the second chamber 102 to be heated independently, forming independent thermal fields. Furthermore, by controlling the first heating element 710, the heating efficiency of the first chamber 101 is made lower than that of the second chamber 102, and the temperature on the growth surface of the seed crystal 500 is kept relatively low. As a result, the growth atmosphere after the silicon carbide powder 2 sublimates in the first chamber 101 flows downward through the guide element 200 to the seed crystal 500, while the growth atmosphere after the silicon carbide powder 2 sublimates in the second chamber 102 flows upward to the seed crystal 500.

[0030] The crystal growth atmosphere after sublimation of silicon carbide powder 2 in the second chamber 102 mainly provides raw materials for the axial growth of silicon carbide crystal 3. The crystal growth atmosphere after sublimation in the first chamber 101, guided by the flow channel, flows to the outside of the seed crystal 500, mainly providing raw materials for the radial growth of the silicon carbide crystal 3 grown on the seed crystal 500. This achieves the diameter expansion growth of the silicon carbide crystal 3 to prepare a large-diameter silicon carbide crystal 3.

[0031] It should be noted that during the growth of silicon carbide crystal 3, the axial growth rate of the crystal can be slightly higher than the radial growth rate by adjusting the first heating element 710 and the second heating element 720. By setting the first heating element 710 and the second heating element 720, the thermal fields of the first chamber 101 and the second chamber 102 can be independently adjusted. Under the action of the flow guide 200, diameter expansion growth can be achieved during the growth of silicon carbide crystal 3, thereby producing a large-diameter silicon carbide crystal 3.

[0032] In this embodiment, since the first chamber 101 and the second chamber 102 are arranged at intervals in the axial direction, when the first chamber 101 and the second chamber 102 are heated independently, the temperature at the seed crystal 500 can be kept at a relatively low temperature. This facilitates the downward flow of the sublimated crystal growth atmosphere in the first chamber 101 and the flow guide 200 to the outside of the seed crystal 500.

[0033] In detail, in this embodiment, the first heating element 710 is disposed above the crucible 100 to heat the upper first chamber 101, and the second heating element 720 is disposed below the crucible 100 to heat the lower second chamber 102.

[0034] Specifically, the first heating element 710 and the second heating element 720 are spaced apart along the axial direction of the crucible 100, and the first heating element 710 and the second heating element 720 are respectively located at both ends of the crucible 100 along the axial direction, so as to independently heat the first chamber 101 and the second chamber 102. By utilizing the heating efficiency of the first heating element 710 and the second heating element 720, the temperature at the seed crystal 500 can be kept relatively low, thereby ensuring that the sublimated crystal growth atmosphere in the first chamber 101 flows downward and flows to the outside of the seed crystal 500 under the guidance of the flow guide 200, so as to provide a growth basis for the diameter expansion growth of the silicon carbide crystal 3.

[0035] Similarly, the first heating element 710 can be controlled so that the heating efficiency of the first chamber 101 is lower than that of the second chamber 102, so that the radial growth rate of the silicon carbide crystal 3 is slightly lower than the axial growth rate of the silicon carbide crystal 3. The axial growth is slightly faster than the radial growth, which helps to maintain the crystal growth interface in a slightly convex shape and can also grow a thicker silicon carbide crystal 3.

[0036] It should be noted that the porous graphite plate 600 in this embodiment can be understood as a graphite plate made of porous graphite. Since the graphite plate made of porous graphite itself has pores, it is easy for the growth atmosphere to pass through. By independently controlling the first heating element 710 and the second heating element 720, the temperature of the growth surface of the seed crystal 500 is relatively low, so that the sublimated gas in the first chamber 101 can flow downward through the pores to the guide channel.

[0037] To ensure that the porous graphite plate 600 is stably installed inside the crucible 100, a boss 400 is provided on the inner wall of the crucible 100, and the porous graphite plate 600 is placed on the boss 400, wherein the boss 400 can be annular boss 400.

[0038] In detail, the flow guide 200 includes a flow guide shroud. The inner wall of the second chamber 102 and the outer wall of the flow guide shroud together define a first flow channel 1011. The end of the first flow channel 1011 near the porous graphite plate 600 is the inlet 1015. The flow guide shroud is disposed on one side of the porous graphite plate 600 located in the second chamber 102. The end of the flow guide shroud away from the porous graphite plate 600 has a first flow guide wall 210. In the direction near the porous graphite plate 600, the radial dimension of the first flow guide wall 210 gradually decreases. That is, in the direction near the middle of the crucible 100, the first flow guide wall 210 is inclined upward, thereby guiding the sublimated crystal growth atmosphere in the first chamber 101 to the outside of the seed crystal 500, thereby preparing a large-diameter silicon carbide crystal 3.

[0039] In detail, in this embodiment, in order to facilitate the fixing of the flow guide in the second chamber 102, the outer peripheral surface of the flow guide in this embodiment is cylindrical, and the upper end of the outer peripheral wall of the flow guide is provided with external threads. The porous graphite plate 600 is provided with threaded holes that connect with the flow guide, so as to realize the assembly of the flow guide and the porous graphite plate 600.

[0040] The inner peripheral wall of the crucible 100 is provided with a second flow guide wall 140 that is opposite to the first flow guide wall 210. The second flow guide wall 140 is annular. In the direction close to the porous graphite plate 600, the radial dimension of the second flow guide wall 140 gradually decreases. The second flow guide wall 140 and the first flow guide wall 210 are opposite to each other and together define the second flow channel 1012. The first flow channel 1011 and the second flow channel 1012 are connected and together form the above-mentioned flow guide channel. The end of the second flow channel 1012 away from the first flow channel 1011 is the outlet 1014.

[0041] The second guide wall 140 enhances the guidance of the sublimated crystal growth atmosphere within the first chamber 101. The end of the second flow channel 1012 furthest from the first flow channel 1011 is the aforementioned outlet 1014. In other words, the second flow channel 1012 faces the outer side of the seed crystal 500. Therefore, the sublimated crystal growth atmosphere within the first chamber 101 passes sequentially through the first flow channel 1011 and the second flow channel 1012, and flows towards the outer side of the seed crystal 500 under the guidance of the second flow channel 1012, providing raw materials for the radial growth of the silicon carbide crystal 3 grown on the seed crystal 500. This achieves diameter expansion growth of the silicon carbide crystal 3, enabling the preparation of a large-diameter silicon carbide crystal 3.

[0042] Furthermore, by setting the second flow channel 1012, not only can the growth atmosphere after the silicon carbide powder 2 in the first chamber 101 be guided to flow to the seed crystal 500, but the interference between the growth atmosphere after the silicon carbide powder 2 in the first chamber 101 and the growth atmosphere flowing directly upward in the second chamber 102 can also be reduced.

[0043] Optionally, in this embodiment, the second chamber 102 has a receiving tank 103 for containing silicon carbide powder 2. The opening end of the receiving tank 103 is connected to the opening end of the second guide wall 140, and the receiving tank 103 is coaxial with the seed crystal 500. The sublimated crystal growth atmosphere in the receiving tank 103 mainly provides raw materials for the axial growth of silicon carbide crystal 3.

[0044] Optionally, in some embodiments, the radial dimension of the receiving groove 103 is less than or equal to the radial dimension of the seed crystal 500. This configuration can reduce the interference between the sublimated crystal growth atmosphere in the first chamber 101 flowing out of the outlet 1014 of the second flow channel 1012 and the crystal growth atmosphere flowing directly upward in the second chamber 102. Of course, in this embodiment, the radial dimensions of the receiving groove 103 and the seed crystal 500 are not limited. In some other embodiments, the radial dimension of the receiving groove 103 may be greater than the radial dimension of the seed crystal 500.

[0045] To avoid depositing silicon carbide on the first flow guide wall 210 or the second flow guide wall 140, at least one of the first flow guide wall 210 and the second flow guide wall 140 is provided with a tantalum carbide layer. Specifically, in this embodiment, both the first flow guide wall 210 and the second flow guide wall 140 are provided with a tantalum carbide layer.

[0046] In detail, in this embodiment, the large-size crystal growth apparatus 1 includes a connecting block 300. The connecting block 300 is disposed on one side of the porous graphite plate 600 located in the second chamber 102. The connecting block 300 is located inside the flow guide shroud. A seed crystal 500 is installed on the side of the connecting block 300 away from the porous graphite plate 600. The outer wall of the connecting block 300 and the inner wall of the flow guide shroud are spaced apart and together form a preset chamber 1020.

[0047] Understandably, since there is a preset chamber 1020 between the connecting block 300 and the inner wall of the flow guide, the crystal growth atmosphere can flow into the preset chamber 1020, further avoiding the deposition of silicon carbide between the first flow guide wall 210 and the second flow guide wall 140, and also avoiding the adhesion of the grown crystal sidewall to the first flow guide wall 210, thereby reducing the edge defects of the silicon carbide crystal 3 grown on the growth surface of the seed crystal 500.

[0048] Specifically, the connecting block 300 includes a first connecting portion 310 and a second connecting portion 320. The radial dimension of the first connecting portion 310 is larger than that of the second connecting portion 320 and is relatively close to the porous graphite plate 600. The outer peripheral wall of the first connecting portion 310 abuts against the inner wall of the flow guide. A preset chamber 1020 is provided between the outer wall of the second connecting portion 320 and the inner wall of the flow guide. A seed crystal 500 is provided on the side of the second connecting portion 320 away from the first connecting portion 310.

[0049] Understandably, since the outer peripheral wall of the first connecting part 310 abuts against the inner wall of the guide shroud, the upper end face of the first connecting part 310 can block part of the porous graphite plate 600, preventing the gas in the first chamber 101 from directly entering the preset chamber 1020 downwards. This ensures that the crystal growth atmosphere after the silicon carbide powder 2 sublimates in the first chamber 101 flows into the second chamber 102 as much as possible through the first flow channel 1011 and the second flow channel 1012, thereby achieving the diameter expansion growth of the silicon carbide crystal 3.

[0050] In detail, the crucible 100 includes a body 110 and a crucible cover 120. The large-size crystal growth apparatus 1 also includes a connecting column 130, which is located in the middle of the first chamber 101. One end of the connecting column 130 passes through the porous graphite plate 600 and is connected to the connecting block 300, and the other end of the connecting column 130 is connected to the crucible cover 120.

[0051] Understandably, in crucible 100, silicon carbide powder tends to sinter into a block in the middle at high temperatures, forming a "hard shell" that hinders the sublimation of the internal raw materials. The connecting post 130 prevents the silicon carbide powder 2 in the first chamber 101 from accumulating in the middle, thereby improving the utilization rate of the silicon carbide powder 2. The connecting post 130 can also connect the connecting block 300. The end of the connecting post 130 near the connecting block 300 can be provided with an external thread, and the connecting block 300 is provided with a threaded groove that connects with the threaded connection of the connecting post 130.

[0052] Understandably, the connecting post 130 can be an integral part of the crucible lid 120. The porous graphite plate 600 has through holes for the connecting post 130 to pass through.

[0053] This invention also provides a method for growing large-size crystals, applied to the aforementioned large-size crystal growth apparatus, the method comprising: Silicon carbide powder is filled into the first chamber 101 and the second chamber 102. The first heating element 710 is controlled to heat the first chamber 101, and the second heating element 720 is controlled to heat the second chamber 102, so that the crystal growth atmosphere after the silicon carbide powder sublimation in the first chamber 101 enters the guide channel through the porous graphite plate 600 and flows from the outlet 1014 to the outside of the seed crystal 500, and the crystal growth atmosphere after the silicon carbide powder sublimation in the second chamber 102 flows to the growth surface of the seed crystal 500.

[0054] In summary, this invention provides a method and apparatus for growing large-size crystals. The large-size crystal growth apparatus 1 is used to grow silicon carbide crystals 3. The large-size crystal growth apparatus 1 includes a crucible 100, a seed crystal 500, a flow guide 200, and a heating assembly. A porous graphite plate 600 is disposed inside the crucible 100, dividing the crucible 100 into a first chamber 101 and a second chamber 102 arranged axially. The first chamber 101 is located above the second chamber 102. Both the first chamber 101 and the second chamber 102 are used to contain silicon carbide powder 2. The flow guide 200 and the inner wall of the second chamber 102 form a flow channel. The flow channel has an inlet 1015 and an outlet 1014. The inlet 1015 faces the porous graphite plate 600, and the outlet 1014 faces the outside of the seed crystal 500. The heating assembly includes a first heating element 710 and a second heating element 720. The first heating element 710 is disposed in the first chamber 101, and the second heating element 720 is disposed in the second chamber 102. The crystal growth atmosphere after the silicon carbide powder 2 in the first chamber 101 is guided by the flow channel to flow from the outlet 1014 to the outside of the seed crystal 500, so as to realize the diameter expansion growth of silicon carbide crystal on the seed crystal 500, thereby preparing a large-diameter silicon carbide crystal 3.

[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A large-size crystal growth apparatus, characterized in that, include: A crucible (100) is provided with a porous graphite plate (600) inside the crucible (100). The porous graphite plate (600) divides the crucible (100) into a first chamber (101) and a second chamber (102) arranged at intervals along the axial direction. The first chamber (101) is located above the second chamber (102). Both the first chamber (101) and the second chamber (102) are used to contain silicon carbide powder (2). Seed crystal (500), the seed crystal (500) is located in the second chamber (102) and above the silicon carbide powder (2) in the second chamber (102); A flow guide (200) is connected to the side of the porous graphite plate (600) near the second chamber (102). The flow guide (200) is annular and located between the seed crystal (500) and the inner wall of the second chamber (102). The flow guide (200) and the inner wall of the second chamber (102) form a flow channel, and the flow channel has an inlet (1015) and an outlet (1014). The inlet (1015) faces the porous graphite plate (600), and the outlet (1014) faces the outside of the seed crystal (500). The heating assembly includes a first heating element (710) and a second heating element (720), wherein the first heating element (710) is disposed corresponding to the first chamber (101) and the second heating element (720) is disposed corresponding to the second chamber (102); The crystal growth atmosphere of the silicon carbide powder (2) in the first chamber (101) after sublimation can flow from the outlet (1014) to the outside of the seed crystal (500) under the guidance of the flow channel.

2. The large-size crystal growth apparatus according to claim 1, characterized in that: The first heating element (710) is disposed above the crucible (100) for heating the first chamber (101); The second heating element (720) is disposed on the lower side of the crucible (100) for heating the second chamber (102).

3. The large-size crystal growth apparatus according to claim 1, characterized in that: The flow guide (200) includes a flow guide shroud. The inner wall of the second chamber (102) and the outer wall of the flow guide shroud together define a first flow channel (1011). The first flow channel (1011) is located at one end near the porous graphite plate (600) as the inlet (1015). The flow guide shroud is disposed on one side of the porous graphite plate (600) located in the second chamber (102). The flow guide shroud has a first flow guide wall (210) at the end away from the porous graphite plate (600). The radial dimension of the first flow guide wall (210) gradually decreases in the direction near the porous graphite plate (600).

4. The large-size crystal growth apparatus according to claim 3, characterized in that: The crucible (100) has a second guide wall (140) protruding from its inner peripheral wall, which is opposite to the first guide wall (210). The second guide wall (140) is annular, and its radial dimension gradually decreases in the direction close to the porous graphite plate (600). The second guide wall (140) is opposite to the first guide wall (210) and together defines a second flow channel (1012). The first flow channel (1011) and the second flow channel (1012) are connected and together form the guide channel. The end of the second flow channel (1012) away from the first flow channel (1011) is the outlet (1014).

5. The large-size crystal growth apparatus according to claim 4, characterized in that: At least one of the first guide wall (210) and the second guide wall (140) is provided with a tantalum carbide layer.

6. The large-size crystal growth apparatus according to claim 3, characterized in that: The upper end of the outer peripheral wall of the flow guide is provided with external threads, and the porous graphite plate (600) is provided with threaded holes that connect with the flow guide.

7. The large-size crystal growth apparatus according to claim 3, characterized in that: The large-size crystal growth apparatus includes a connecting block (300), which is disposed on one side of the porous graphite plate (600) located in the second chamber (102). The connecting block (300) is located inside the flow guide shroud. The seed crystal (500) is installed on the side of the connecting block (300) away from the porous graphite plate (600). The outer wall of the connecting block (300) and the inner peripheral wall of the flow guide shroud are spaced apart and together form a preset chamber (1020).

8. The large-size crystal growth apparatus according to claim 7, characterized in that: The connecting block (300) includes a first connecting part (310) and a second connecting part (320). The radial dimension of the first connecting part (310) is larger than that of the second connecting part (320) and is relatively close to the porous graphite plate (600). The outer peripheral wall of the first connecting part (310) abuts against the inner wall of the flow guide. A preset chamber (1020) is provided between the outer wall of the second connecting part (320) and the inner wall of the flow guide. The seed crystal (500) is provided on the side of the second connecting part (320) away from the first connecting part (310).

9. The large-size crystal growth apparatus according to claim 7, characterized in that: The crucible (100) includes a body (110) and a crucible cover (120). The large-size crystal growth device also includes a connecting column (130). The connecting column (130) is located in the middle of the first chamber (101). One end of the connecting column (130) passes through the porous graphite plate (600) and is connected to the connecting block (300). The other end of the connecting column (130) is connected to the crucible cover (120).

10. A method for growing large-size crystals, applied to the large-size crystal growth apparatus according to any one of claims 1-9, characterized in that, The method includes: Silicon carbide powder (2) is filled in the first chamber (101) and the second chamber (102); The first heating element (710) is controlled to heat the first chamber (101), and the second heating element (720) is controlled to heat the second chamber (102), so that the crystal growth atmosphere after the silicon carbide powder (2) in the first chamber (101) is sublimated enters the flow channel through the porous graphite plate (600) and flows from the outlet (1014) to the outside of the seed crystal (500), and the crystal growth atmosphere after the silicon carbide powder (2) in the second chamber (102) is sublimated flows to the growth surface of the seed crystal (500).

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