A large size crystal growth apparatus and method

Abstract

The embodiment of the present application provides a large-size crystal growth device and method, and relates to the technical field of silicon carbide crystal growth. The large-size crystal growth method is used for growing a silicon carbide crystal by using a large-size crystal growth device. The large-size crystal growth device comprises a crucible, a seed crystal, a flow guide member and a heating assembly. The crucible is provided with a porous graphite plate. The porous graphite plate divides the crucible into a first chamber and a second chamber arranged along an axial direction. The first chamber is located on the upper side of the second chamber. The first chamber and the second chamber are both used for containing silicon carbide powder. The flow guide member and the inner wall of the second chamber form a flow guide channel. The flow guide channel has an inlet and an outlet. The inlet is directed towards the porous graphite plate, and the outlet is directed towards the outer side of the seed crystal. According to the special arrangement of the heating member, the crystal growth atmosphere of the sublimated silicon carbide powder in the first chamber can flow from the outlet to the outer side of the seed crystal under the guidance of the flow guide channel, so that the silicon carbide crystal can be expanded and grown on the seed crystal, thereby preparing a large-diameter silicon carbide crystal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon carbide crystal growth, in particular to a large-size crystal growth device and method. BACKGROUND

[0002] The physical vapor transport (PVT) method for growing silicon carbide crystals is a method for growing silicon carbide crystals by transporting the sublimated solid silicon carbide powder to a designated position at high temperature, vacuum or controlled atmosphere, and then growing silicon carbide crystals on a substrate (such as a seed crystal). The inventors have found that in the related art, it is difficult to achieve efficient diameter expansion growth of silicon carbide crystals in the silicon carbide crystal growth device. SUMMARY

[0003] The present application aims to provide a large-size crystal growth device and method, which can achieve diameter expansion growth of silicon carbide crystals, for example, from 6 inches to 8 inches, from 8 inches to 12 inches, to prepare large-diameter silicon carbide crystals.

[0004] Embodiments of the present application can be implemented as follows:

[0005] In a first aspect, the present application provides a large-size crystal growth device, comprising:

[0006] A crucible, a porous graphite plate is arranged in the crucible, the porous graphite plate divides the crucible into a first chamber and a second chamber arranged along an 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 accommodating silicon carbide powder;

[0007] A seed crystal, the seed crystal is located in the second chamber and on the upper side of the silicon carbide powder in the second chamber;

[0008] A flow guide, the flow guide is connected to the side of the porous graphite plate close to 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 guide channel, and the flow guide channel has an inlet and an outlet, the inlet faces the porous graphite plate, and the outlet faces the outer side of the seed crystal;

[0009] A heating assembly, the heating assembly comprises a first heating element and a second heating element, the first heating element is arranged corresponding to the first chamber, and the second heating element is arranged corresponding to the second chamber;

[0010] The sublimated crystal growth atmosphere of the silicon carbide powder in the first chamber can flow from the outlet to the outer side of the seed crystal under the guidance of the flow guide channel.

[0011] In an optional embodiment, the first heating element is arranged above the crucible to heat the first chamber;

[0012] The second heating member is arranged at the lower side of the crucible to heat the second chamber.

[0013] In an optional embodiment, the flow guide member comprises a flow guide cover, the inner wall of the second chamber and the outer wall of the flow guide cover jointly define a first flow channel, the first flow channel has an inlet at one end close to the porous graphite plate, the flow guide cover is arranged at the side of the porous graphite plate in the second chamber, the flow guide cover has a first flow guide wall at the end away from the porous graphite plate, and the radial dimension of the first flow guide wall gradually decreases in the direction close to the porous graphite plate.

[0014] In an optional embodiment, the inner peripheral wall of the crucible is convexly provided with a second flow guide wall opposite to the first flow guide wall, the second flow guide wall is annular, the radial dimension of the second flow guide wall 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 jointly defines a second flow channel, the first flow channel and the second flow channel are in communication and jointly form a flow guide passage, and the second flow channel has an outlet at the end away from the first flow channel.

[0015] In an optional embodiment, the second chamber has a containing groove for containing the silicon carbide powder, the opening end of the containing groove is connected with the opening end of the second flow guide wall, and the containing groove is coaxial with the seed crystal.

[0016] In an optional embodiment, at least one of the first flow guide wall and the second flow guide wall is provided with a tantalum carbide layer.

[0017] The upper end of the outer peripheral wall of the flow guide cover is provided with an external thread, and the porous graphite plate is provided with a threaded hole connected with the flow guide cover.

[0018] In an optional embodiment, the large-size crystal growth device comprises a connecting block, the connecting block is arranged at the side of the porous graphite plate in the second chamber, the connecting block is located inside the flow guide cover, a seed crystal is mounted at the side of the connecting block away from the porous graphite plate, and the outer wall of the connecting block and the inner peripheral wall of the flow guide cover are spaced apart and jointly form a preset chamber.

[0019] In an optional embodiment, the connecting block comprises a first connecting part and a second connecting part, the radial dimension of the first connecting part is greater than the radial dimension of the second connecting part and is relatively close to the porous graphite plate, the outer peripheral wall of the first connecting part abuts against the inner wall of the flow guide cover, and the outer wall of the second connecting part and the inner wall of the flow guide cover have the preset chamber therebetween.

[0020] In an optional embodiment, the crucible comprises a body and a crucible cover, and the large-size crystal growth device further comprises a connecting column, the connecting column is located at the middle part of the first chamber, one end of the connecting column is connected with the connecting block through the porous graphite plate, and the other end of the connecting column is connected with the crucible cover.

[0021] In a second aspect, the present application provides a large-size crystal growth method for growing a silicon carbide crystal by using the large-size crystal growth device according to any one of the foregoing embodiments, and the method comprises:

[0022] Filling silicon carbide powder in the first chamber and the second chamber;

[0023] Controlling the first heating member to heat the first chamber and controlling the second heating member to heat the second chamber, so that the crystal growth atmosphere after sublimation of the silicon carbide powder in the first chamber enters the flow guide channel through the porous graphite plate to flow from the outlet to the outside of the seed crystal, and the crystal growth atmosphere after sublimation of the silicon carbide powder in the second chamber flows to the growth surface of the seed crystal.

[0024] The embodiments of the present application provide a large-size crystal growth device and method. The large-size crystal growth method is applied to the large-size crystal growth device to grow a silicon carbide crystal. The large-size crystal growth device comprises a crucible, a seed crystal, a flow guide member and a heating assembly. The crucible is provided with a porous graphite plate. The porous graphite plate divides the crucible into a first chamber and a second chamber arranged along an axial direction. The first chamber is located on the upper side of the second chamber. The first chamber and the second chamber are both used for containing silicon carbide powder. The flow guide member and the inner wall of the second chamber form a flow guide channel. The flow guide channel 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 comprises a first heating member and a second heating member. The first heating member is arranged corresponding to the first chamber, and the second heating member is arranged corresponding to the second chamber. The crystal growth atmosphere after sublimation of the silicon carbide powder in the first chamber can flow from the outlet to the outside of the seed crystal under the guidance of the flow guide channel, so as to realize the diameter expansion growth of the silicon carbide crystal on the seed crystal, thereby preparing a large-diameter silicon carbide crystal. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0026] Figure 1 The structural schematic diagram of the large-size crystal growth device provided by the present embodiment;

[0027] Figure 2 The schematic diagram of growing a silicon carbide crystal in the large-size crystal growth device provided by the present embodiment;

[0028] Figure 3 The partial enlarged view of Figure 2

[0029] ​Icon: 1-large size crystal growth device; 110-body; 120-crucible cover; 130-connection column; 140-second flow guide wall; 100-crucible; 101-first cavity; 102-second cavity; 1011-first flow channel; 1012-second flow channel; 1014-outlet; 1015-inlet; 1020-pre-set cavity; 103-receiving groove; 200-flow guide; 210-first flow guide wall; 300-connection block; 310-first connection part; 320-second connection 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 DESCRIPTION

[0030] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the drawings in the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0032] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0034] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0036] In the prior art, the process of growing silicon carbide crystals is performed by setting a heating member outside a crucible to provide a thermal field for the growth of silicon carbide crystals in the crucible, so that the crystal growth atmosphere after sublimation of silicon carbide powder in the crucible flows upward to the growth surface of the seed crystal, thereby depositing silicon carbide on the seed crystal, and only a certain size of silicon carbide crystal can be grown, and it is difficult to achieve rapid expansion growth of the silicon carbide crystal.

[0037] To solve the above problems, the embodiment of the present application provides a large-size crystal growth device, which can divide the crucible 100 into a first chamber 101 and a second chamber 102 arranged axially by setting a porous graphite plate 600 in the crucible 100, and form a flow guide channel with the second chamber 102 by a flow guide member 200, the inlet of the flow guide channel is toward the porous graphite plate 600, the outlet 1014 of the flow guide channel is toward the outside of the seed crystal 500, and the first heating member 710 and the second heating member 720 are independently arranged on the upper and lower sides of the crucible 100, respectively, to independently build a thermal field. The first heating member 710 and the second heating member 720 are controlled to make the temperature on the crystal growth surface of the seed crystal 500 be the lowest, so that the crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 can flow downward to the seed crystal 500 after passing through the flow guide member 200, and the crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the second chamber 102 can flow upward to the seed crystal 500, to achieve the expansion growth of the crystal.

[0038] The specific structure of the large-size crystal growth device provided by the embodiment of the present application and the corresponding technical effects brought by it will be described in detail below with reference to the accompanying drawings.

[0039] Please refer to Figures 1-3The large-size crystal growth device 1 provided by the embodiment of the present application comprises a crucible 100, a seed crystal 500, a flow guide 200 and a heating assembly. The crucible 100 is provided with a porous graphite plate 600, which divides the crucible 100 into a first chamber 101 and a second chamber 102 arranged along an axial direction. The first chamber 101 is located on the upper side of the second chamber 102, and both the first chamber 101 and the second chamber 102 are used for containing silicon carbide powder 2. The seed crystal 500 is located in the second chamber 102 and on the upper side of the silicon carbide powder 2 in the second chamber 102. The flow guide 200 is connected to one side of the second chamber 102 and is connected to the porous graphite plate 600. The flow guide 200 is annular and is 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 guide channel. The flow guide channel has an inlet 1015 and an outlet 1014. The inlet 1015 is directed towards the porous graphite plate 600, and the outlet 1014 is directed towards the outer side of the seed crystal 500. The heating assembly comprises a first heating element 710 and a second heating element 720. The first heating element 710 is arranged corresponding to the first chamber 101, and the second heating element 720 is arranged corresponding to the second chamber 102. The crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 can flow from the outlet 1014 to the outer side of the seed crystal 500 under the guidance of the flow guide channel, so as to realize the diameter expansion growth of the silicon carbide crystal 3 on the seed crystal 500, thereby preparing a large-diameter silicon carbide crystal 3.

[0040] It is easy to understand that the first chamber 101 is provided with the first heating element 710, and the second chamber 102 is provided with the second heating element 720. The silicon carbide powder 2 in the first chamber 101 and the second chamber 102 can be heated separately, and a thermal field can be independently constructed. Then, by controlling the first heating element 710, the heating efficiency of the first chamber 101 is lower than that of the second chamber 102, and the temperature on the crystal growth surface of the seed crystal 500 is relatively the lowest. Thus, the crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 can flow to the seed crystal 500 after passing through the flow guide 200 downward, and the crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the second chamber 102 can flow to the seed crystal 500 upward.

[0041] The crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the second chamber 102 mainly provides raw materials for the axial growth of the silicon carbide crystal 3. The crystal growth atmosphere after sublimation in the first chamber 101 flows to the outer side of the seed crystal 500 under the guidance of the flow guide channel, and mainly provides raw materials for the radial growth of the silicon carbide crystal 3 grown on the seed crystal 500. Thus, the diameter expansion growth of the silicon carbide crystal 3 is realized, so as to prepare a large-diameter silicon carbide crystal 3.

[0042] It should be noted that when the silicon carbide crystal 3 is grown, the first heating element 710 and the second heating element 720 can be adjusted so that the growth rate of the crystal in the axial direction is slightly higher than the growth rate in the radial direction. Through the arrangement of the first heating element 710 and the second heating element 720, the thermal field of the first chamber 101 and the second chamber 102 can be independently adjusted, and under the action of the flow guide 200, the diameter expansion growth during the growth of the silicon carbide crystal 3 is realized to prepare a large-diameter silicon carbide crystal 3.

[0043] In the present embodiment, since the first chamber 101 and the second chamber 102 are arranged in the axial direction, when the first chamber 101 and the second chamber 102 are independently heated, the temperature at the seed crystal 500 can be relatively low, thereby facilitating the downward flow of the sublimated crystal growth atmosphere in the first chamber 101 and the flow to the outside of the seed crystal 500 under the guidance of the flow guide 200.

[0044] In detail, the first heating element 710 in the present embodiment is arranged above the crucible 100 for heating the first chamber 101 on the upper side, and the second heating element 720 is arranged below the crucible 100 for heating the second chamber 102 on the lower side.

[0045] Specifically, the first heating element 710 and the second heating element 720 are arranged in the axial direction of the crucible 100 and are respectively located at both ends of the crucible 100 in the axial direction to independently heat the first chamber 101 and the second chamber 102. The heating efficiency of the first heating element 710 and the second heating element 720 can be adjusted to make the temperature at the seed crystal 500 relatively low, thereby ensuring the downward flow of the sublimated crystal growth atmosphere in the first chamber 101 and the flow to the outside of the seed crystal 500 under the guidance of the flow guide 200 to provide a growth basis for the diameter expansion growth of the silicon carbide crystal 3.

[0046] Similarly, the first heating element 710 can also be controlled to have a lower heating efficiency for the first chamber 101 than the second chamber 102, so that the growth rate of the silicon carbide crystal 3 in the radial direction is slightly lower than the growth rate of the silicon carbide crystal 3 in the axial direction, and the axial growth is slightly faster than the radial growth, which helps to maintain the crystal growth interface in a slightly convex shape and also enables the growth of a thicker silicon carbide crystal 3.

[0047] It should be noted that the porous graphite plate 600 in the present embodiment can be understood as a graphite plate made of porous graphite. Since the graphite plate made of porous graphite itself has pores, it can facilitate the growth of the atmosphere, and by independently controlling the first heating element 710 and the second heating element 720, the temperature of the crystal growth surface of the seed crystal 500 can be relatively low, so that the gas sublimated in the first chamber 101 can flow downward through the pores to the flow guide channel.

[0048] In order to ensure that the porous graphite plate 600 is stably installed in the crucible 100, a boss 400 is arranged 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 an annular boss 400.

[0049] In detail, the flow guide 200 includes a flow guide cover, and the inner wall of the second chamber 102 and the outer wall of the flow guide cover jointly define a first flow channel 1011, one end of the first flow channel 1011 close to the porous graphite plate 600 is an inlet 1015, the flow guide cover is arranged on one side of the porous graphite plate 600 in the second chamber 102, and one end of the flow guide cover away from the porous graphite plate 600 has a first flow guide wall 210, and the radial dimension of the first flow guide wall 210 gradually decreases in the direction close to the porous graphite plate 600. That is, the first flow guide wall 210 is arranged in an inclined upward manner in the direction close to the middle of the crucible 100, so as to guide 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.

[0050] In detail, in the embodiment, in order to facilitate the fixation of the flow guide cover in the second chamber 102, the outer circumferential surface of the flow guide cover in the embodiment is in a cylindrical shape, and the outer circumferential wall of the flow guide cover is provided with an external thread at the upper end, and the porous graphite plate 600 is provided with a threaded hole connected with the flow guide cover, so as to realize the assembly of the flow guide cover and the porous graphite plate 600.

[0051] The inner circumferential wall of the crucible 100 is provided with a second flow guide wall 140 opposite to the first flow guide wall 210, the second flow guide wall 140 is in an annular shape, the radial dimension of the second flow guide wall 140 gradually decreases in the direction close to the porous graphite plate 600, the second flow guide wall 140 is opposite to the first flow guide wall 210 and jointly defines a second flow channel 1012, the first flow channel 1011 and the second flow channel 1012 are communicated and jointly form the above-mentioned flow guide passage, and one end of the second flow channel 1012 away from the first flow channel 1011 is an outlet 1014.

[0052] Through the arrangement of the second flow guide wall 140, the guidance to the sublimated crystal growth atmosphere in the first chamber 101 is enhanced, one end of the second flow channel 1012 away from the first flow channel 1011 is the above-mentioned outlet 1014, that is, the second flow channel 1012 is towards the outside of the seed crystal 500, therefore, the sublimated crystal growth atmosphere in the first chamber 101 will sequentially pass through the first flow channel 1011 and the second flow channel 1012, and flow to the outside of the seed crystal 500 under the guidance of the second flow channel 1012, so as to provide raw materials for the radial growth of the silicon carbide crystal 3 grown on the seed crystal 500. Thus, the diameter expansion growth of the silicon carbide crystal 3 is realized, so as to prepare a large-diameter silicon carbide crystal 3.

[0053] And, by the setting of the second flow channel 1012, not only can the growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 be guided to the seed crystal 500, but also the interference between the growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 and the growth atmosphere directly flowing upward in the second chamber 102 can be reduced.

[0054] Optionally, the second chamber 102 in the embodiment has a containing groove 103 for containing the silicon carbide powder 2, the opening end of the containing groove 103 is connected with the opening end of the second flow guide wall 140, and the containing groove 103 is coaxial with the seed crystal 500. The sublimated growth atmosphere in the containing groove 103 mainly provides raw materials for the axial growth of the silicon carbide crystal 3.

[0055] Optionally, in some embodiments, the radial dimension of the containing groove 103 is less than or equal to the radial dimension of the seed crystal 500, so that the interference between the sublimated growth atmosphere in the first chamber 101 flowing out of the outlet 1014 of the second flow channel 1012 and the growth atmosphere directly flowing upward in the second chamber 102 can be reduced. Of course, in the embodiment, the radial dimension of the containing groove 103 is not limited to the radial dimension of the seed crystal 500, and in some other embodiments, the radial dimension of the containing groove 103 can also be greater than the radial dimension of the seed crystal 500.

[0056] In order to avoid the deposition of 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. In detail, both the first flow guide wall 210 and the second flow guide wall 140 in the embodiment are provided with a tantalum carbide layer.

[0057] In detail, the large-size crystal growth device 1 in the embodiment includes a connecting block 300, which is arranged on one side of the porous graphite plate 600 located in the second chamber 102, is located on the inner side of the flow guide cover, and has the seed crystal 500 mounted on the side away from the porous graphite plate 600. The outer wall of the connecting block 300 is arranged in a spaced manner with the inner wall of the flow guide cover and together forms a preset chamber 1020.

[0058] It can be understood that, since the preset chamber 1020 is arranged between the connecting block 300 and the inner wall of the flow guide cover, the 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 sidewall of the grown crystal to the first flow guide wall 210, so as to reduce the edge defects of the silicon carbide crystal 3 grown on the growth surface of the seed crystal 500.

[0059] Specifically, the connecting block 300 comprises a first connecting part 310 and a second connecting part 320, the radial dimension of the first connecting part 310 is greater than that of the second connecting part 320 and the first connecting part 310 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 cover, and the outer wall of the second connecting part 320 has a preset chamber 1020 between the inner wall of the flow guide cover, and the second connecting part 320 is provided with the seed crystal 500 away from the first connecting part 310.

[0060] It can be understood that, since the outer peripheral wall of the first connecting part 310 abuts against the inner wall of the flow guide cover, the upper end surface of the first connecting part 310 can block part of the porous graphite plate 600, and the gas in the first chamber 101 can be prevented from directly entering the preset chamber 1020 downward. The crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 is ensured to flow into the second chamber 102 as much as possible through the first flow channel 1011 and the second flow channel 1012, so as to realize the diameter expansion growth of the silicon carbide crystal 3.

[0061] In detail, the crucible 100 comprises a body 110 and a crucible cover 120, and the large-size crystal growth device 1 further comprises a connecting column 130, the connecting column 130 is located in the middle part of the first chamber 101, one end of the connecting column 130 penetrates through the porous graphite plate 600 and is connected with the connecting block 300, and the other end of the connecting column 130 is connected with the crucible cover 120.

[0062] It can be understood that, in the crucible 100, the silicon carbide crystal growth powder is easy to sinter into a block in the middle part at high temperature, forming a "hard shell" to hinder the sublimation of the internal raw material. The arrangement of the connecting column 130 can avoid the accumulation of the silicon carbide powder 2 in the middle part of the first chamber 101, thereby improving the utilization rate of the silicon carbide powder 2. The connecting block 300 can also be connected through the connecting column 130. The end of the connecting column 130 close to the connecting block 300 can be provided with external threads, and the connecting block 300 is provided with a threaded groove for threadedly connecting with the connecting column 130.

[0063] It can be understood that the connecting column 130 can be in an integral structure with the crucible cover 120. The porous graphite plate 600 has a through hole for the connecting column 130 to penetrate.

[0064] The embodiment of the present application also provides a large-size crystal growth method applied to the large-size crystal growth device, and the method comprises the following steps:

[0065] Filling the silicon carbide powder in the first chamber 101 and the second chamber 102;

[0066] The first heating member 710 is controlled to heat the first chamber 101, and the second heating member 720 is controlled to heat the second chamber 102, so that the crystal growth atmosphere after sublimation of the silicon carbide powder in the first chamber 101 enters the flow guide channel through the porous graphite plate 600 to flow from the outlet 1014 to the outside of the seed crystal 500, and the crystal growth atmosphere after sublimation of the silicon carbide powder in the second chamber 102 flows to the growth surface of the seed crystal 500.

[0067] In summary, the embodiment of the present application provides a large-size crystal growth method and device. The large-size crystal growth is applied to grow a silicon carbide crystal 3 by using a large-size crystal growth device 1. The large-size crystal growth device 1 includes a crucible 100, a seed crystal 500, a flow guide member 200, and a heating assembly. The crucible 100 is provided with a porous graphite plate 600. The porous graphite plate 600 divides the crucible 100 into a first chamber 101 and a second chamber 102 arranged along an axial direction. The first chamber 101 is located on the upper side of the second chamber 102. Both the first chamber 101 and the second chamber 102 are used to accommodate silicon carbide powder 2. The flow guide member 200 and the inner wall of the second chamber 102 form a flow guide channel. The flow guide channel has an inlet 1015 and an outlet 1014. The inlet 1015 is directed to the porous graphite plate 600, and the outlet 1014 is directed to the outside of the seed crystal 500. The heating assembly includes a first heating member 710 and a second heating member 720. The first heating member 710 is arranged corresponding to the first chamber 101, and the second heating member 720 is arranged corresponding to the second chamber 102. The crystal growth atmosphere after sublimation of the silicon carbide powder 2 in the first chamber 101 can flow to the outside of the seed crystal 500 from the outlet 1014 under the guidance of the flow guide channel, so as to realize the diameter expansion growth of the silicon carbide crystal on the seed crystal 500, thereby preparing a large-diameter silicon carbide crystal 3.

[0068] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed by the present application can be easily thought by those skilled in the art, and should be covered within the protection scope of the present application.

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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