Silicon carbide crystal growth device

Abstract

The embodiment of the invention provides a silicon carbide crystal growth device, and relates to the technical field of silicon carbide crystal growth. The silicon carbide crystal growth device comprises a first crucible, a second crucible, a surrounding piece, a weighing assembly and a lifting assembly. The weighing assembly is connected with the second crucible, the lifting assembly is connected with the second crucible through the weighing assembly, and the lifting assembly is used for driving the second crucible to move in the axial direction relative to the first crucible and the surrounding piece so that a preset distance can be formed between the second surrounding plate and the first surrounding plate in the axial direction, and the inflation hole can communicate with the growth cavity through the inflation cavity. In the process of gradually depositing the silicon carbide crystals in the second crucible, an operator can calculate the growth rate of the silicon carbide crystals in the second crucible according to the measured weight change of the second crucible, and further control the doping gas introduction rate of an external doping gas source according to the growth rate of the silicon carbide crystals; therefore, a stable doping effect is ensured, and the growth quality of silicon carbide crystals is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide crystal growth, and in particular to a silicon carbide crystal growth device. Background Art

[0002] Doping of silicon carbide (SiC) crystal growth is the process of intentionally adding a small amount of impurity atoms during the crystal growth process in order to change the electrical properties of the material. Doping can control the conductivity type (n-type or p-type) of silicon carbide, which is crucial for manufacturing semiconductor devices.

[0003] The inventors have found that when the existing silicon carbide crystal growth device is filled with doping gas, the situation inside the crystal growth device cannot be observed, and the gas filling rate or doping amount can only be adjusted based on experience, resulting in poor doping effect and affecting the crystal quality. Summary of the invention

[0004] The object of the present invention is to provide a silicon carbide crystal growth device, which can improve the doping effect and thus improve the quality of the crystal.

[0005] The embodiment of the present invention is achieved as follows:

[0006] In a first aspect, the present invention provides a silicon carbide crystal growth device, comprising:

[0007] A first crucible, the first crucible comprising a first surrounding plate and a bottom plate connected to each other, the first surrounding plate and the bottom plate defining a containing cavity for placing silicon carbide powder;

[0008] A second crucible, the second crucible comprises a second surrounding plate and a top plate connected to each other, the second surrounding plate and the top plate jointly define a growth chamber, the growth chamber is communicated with the accommodating chamber, and the top plate is opposite to the bottom plate;

[0009] The surrounding piece is used to surround the outside of the first enclosure and the second enclosure, and the surrounding piece can define an inflation cavity between the first enclosure and the second enclosure, and the surrounding piece is provided with an inflation hole connected with the inflation cavity;

[0010] A weighing assembly connected to the second crucible;

[0011] A lifting assembly is connected to the second crucible through a weighing assembly, and is used to drive the second crucible to move axially relative to the first crucible and the surrounding member, so that the second surrounding plate and the first surrounding plate have a preset spacing in the axial direction, and the inflation hole can be connected to the growth chamber through the inflation cavity.

[0012] In an optional embodiment, the surrounding parts include a third surrounding plate, a first end plate and a second end plate, all of which are annular. The first end plate and the second end plate are arranged at intervals in the axial direction and are arranged at both ends of the third surrounding plate. The outer wall of the first surrounding plate is provided with an annular groove, and the first end plate is clamped in the annular groove. The first surrounding plate and the second surrounding plate are opposite to the third surrounding plate, and the second end plate is abutted against the outer wall of the second surrounding plate or has a first distance from the outer wall of the second surrounding plate, and the second surrounding plate can move axially relative to the third surrounding plate, and the first distance is in the range of 0.5mm-2mm.

[0013] In an optional embodiment, an annular groove is opened on the outer side of the second enclosure plate, and the annular groove includes a surrounding wall and a first end wall. The first end wall is located on the side of the surrounding wall close to the first enclosure plate. The second end plate is arranged in the annular groove. The axial dimension of the surrounding wall is larger than the thickness dimension of the second end plate. The second end plate abuts against the surrounding wall or has a first distance from the surrounding wall.

[0014] In an optional embodiment, an annular slide groove is opened on the outer side of the second enclosure plate, and the annular slide groove includes a surrounding wall and a second end wall. The second end wall is located on the side of the surrounding wall away from the first enclosure plate, and the second end plate is located in the annular slide groove. The axial dimension of the surrounding wall is larger than the thickness dimension of the second end plate, and the second end plate abuts against the surrounding wall or has a first distance from the surrounding wall.

[0015] In an optional embodiment, the enclosure includes two enclosure structures, which include a first sub-end plate, a second sub-end plate and a third sub-enclosure plate. When the two enclosure structures are clamped in the annular groove, the two first sub-end plates abut to jointly form a first end plate, the two second sub-end plates abut to jointly form a second end plate, and the two third sub-enclosure plates abut to jointly form a third enclosure.

[0016] In an optional embodiment, the first end plate includes two first sub-end plates, the first sub-end plates are detachably connected to the third surrounding plate, and the second end plate is detachably connected to the third surrounding plate.

[0017] In an optional embodiment, when the first enclosure panel abuts against the second enclosure panel, the center line of the inflation hole passes through the intersection of the first enclosure panel and the second enclosure panel.

[0018] In an optional embodiment, a first ventilation portion is provided at one end of the first enclosure plate close to the second enclosure plate, the first ventilation portion is arranged in an annular shape and is detachably connected to the first enclosure plate, and the first ventilation portion is made of porous graphite.

[0019] In an optional embodiment, a second ventilation portion is provided at one end of the second enclosure close to the first enclosure, the second ventilation portion is arranged in an annular shape and is detachably connected to the second enclosure, and the second ventilation portion is made of porous graphite.

[0020] In an optional embodiment, the surrounding parts include a third enclosure plate and a first end plate, both of which are annular and connected. The outer wall of the first enclosure plate is provided with an annular groove, and the first end plate is clamped in the annular groove. The first enclosure plate and the second enclosure plate are opposite to the third enclosure plate, and the third enclosure plate abuts against the outer wall of the second enclosure plate or has a first distance from the outer wall of the second enclosure plate, and the second enclosure plate can move axially relative to the third enclosure plate, and the first distance is in the range of 0.5mm-2mm.

[0021] The beneficial effects of the embodiments of the present invention are as follows: the embodiments of the present invention provide a silicon carbide crystal growth device. When the silicon carbide crystal is grown and nitrogen is doped, the external doping gas can enter the filling chamber through the filling hole, and then pass through the first crucible and the second crucible and enter the growth chamber, thereby improving the utilization rate of the doping gas. In the process of gradually depositing silicon carbide crystals in the second crucible, the operator can calculate the growth rate of the silicon carbide crystals in the second crucible according to the measured weight change of the second crucible, and then control the rate of the external doping gas source to introduce the doping gas according to the growth rate of the silicon carbide crystal, thereby ensuring a stable doping effect and improving the growth quality of the silicon carbide crystal. Third, the introduction of nitrogen does not affect the sublimation and transmission of the raw materials, and reduces the formation of carbon inclusions. Fourth, by adjusting the amount of nitrogen charged, the convexity of the crystal can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic cross-sectional view of the structure of a silicon carbide crystal growth device provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of two surrounding structures provided in an embodiment of the present invention before being assembled with a first crucible and a second crucible;

[0025] Figure 3 A schematic structural diagram of two surrounding structures provided in an embodiment of the present invention after being assembled with a first crucible and a second crucible.

[0026] Icons: 1-silicon carbide crystal growth device; 100-first crucible; 110-first enclosure; 120-bottom plate; 130-first ventilation portion; 140-accommodating chamber; 150-annular slot; 200-second crucible; 210-second enclosure; 220-top plate; 230-second ventilation portion; 240-seed crystal; 250-growth chamber; 260-annular slide; 261-first end wall; 262-second end wall; 263-enclosing wall; 300-enclosing member; 301-enclosing structure; 310-first end plate; 320-second end plate; 330-third enclosure; 340-inflating hole; 350-inflating chamber; 400-weighing assembly; 500-lifting assembly. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The specific structure of a silicon carbide crystal growth device provided by an embodiment of the present invention and the corresponding technical effects it brings are described in detail below in conjunction with the patent drawings.

[0034] Please refer to Figure 1-Figure 3 A silicon carbide crystal growth device 1 provided in an embodiment of the present invention includes a first crucible 100 , a second crucible 200 , a surrounding member 300 , a weighing assembly 400 and a lifting assembly 500 .

[0035] The first crucible 100 includes a first surrounding plate 110 and a bottom plate 120 connected to each other, and the first surrounding plate 110 and the bottom plate 120 define a receiving chamber 140 for placing silicon carbide powder. The second crucible 200 includes a second surrounding plate 210 and a top plate 220 connected to each other, and the second surrounding plate 210 and the top plate 220 jointly define a growth chamber 250, and the growth chamber 250 is connected to the receiving chamber 140, and the top plate 220 is opposite to the bottom plate 120. The enclosure 300 is used to be arranged on the outside of the first enclosure 110 and the second enclosure 210. The enclosure 300 can define an inflation cavity 350 between the first enclosure 110 and the second enclosure 210. The enclosure 300 is provided with an inflation hole 340 connected to the inflation cavity 350. The weighing component 400 is connected to the second crucible 200. The lifting component 500 is connected to the second crucible 200 through the weighing component 400. The lifting component 500 is used to drive the second crucible 200 to move axially relative to the first crucible 100 and the enclosure 300, so that the second enclosure 210 and the first enclosure 110 have a preset spacing in the axial direction, and the inflation hole 340 can be connected to the growth cavity 250 through the inflation cavity 350.

[0036] Optionally, the second enclosure 210 and the top plate 220 in the second crucible 200 may be an integral structure or may be detachably connected to each other. It is understandable that when the top plate 220 and the second enclosure 210 are detachably connected, it is convenient for operators to assemble the seed crystal 240 .

[0037] It should be noted that a seed crystal 240 is provided on the top plate 220 of the second crucible 200. When growing silicon carbide crystals, the second crucible 200 is located above the first crucible 100, and the silicon carbide powder in the first crucible 100 is sublimated into a growth atmosphere, and then deposited on the seed crystal 240 as silicon carbide crystals. The gas filling hole 340 is used to connect with a doping gas source. For example, when the silicon carbide crystals are grown and nitrogen is doped, and after the second crucible 200 is lifted by the lifting assembly 500, so that the second enclosure 210 and the first enclosure 110 have a preset spacing in the axial direction, an external doping gas source can pass the doping gas through the gas filling hole 340 into the gas filling cavity 350, and then pass between the first crucible 100 and the second crucible 200 and enter the growth cavity 250 to achieve doping. The doping gas can be nitrogen or other doping gases.

[0038] Moreover, in this embodiment, since the filling hole 340 is located on the outside of the outer wall of the first crucible 100 and the second crucible 200, when the doping gas is introduced through the filling hole 340, it will not form an impact on the raw material, that is, it will not affect the sublimation and transmission of the raw material contained in the second crucible 200, thereby reducing the formation of carbon inclusions.

[0039] When the growth of silicon carbide crystal is not being performed, the second crucible 200 can be placed on the first crucible 100 .

[0040] It can be understood that when the silicon carbide crystals are growing, the lifting assembly 500 can drive the second crucible 200 to move axially relative to the first crucible 100 and the surrounding member 300, so that the second enclosure 210 and the first enclosure 110 have a preset distance in the axial direction. At this time, since the lifting assembly 500 is connected to the second crucible 200 through the weighing assembly 400, the weighing assembly 400 can obtain the weight of the second crucible 200 to weigh the second crucible 200. It can be understood that in the process of gradually depositing silicon carbide crystals in the second crucible 200, the weight of the second crucible 200 gradually changes. At this time, the operator can calculate the growth rate of the silicon carbide crystals in the second crucible 200 based on the measured weight change of the second crucible 200, and then control the rate at which the external doping gas source introduces the doping gas according to the growth rate of the silicon carbide crystals, thereby ensuring a stable doping effect to improve the growth quality of the silicon carbide crystals.

[0041] It is understandable that, since the lifting assembly 500 can drive the second crucible 200 to move axially relative to the first crucible 100 and the surrounding member 300, when doping is performed, in some embodiments, the second crucible 200 can also be driven to rise by the lifting assembly 500 to adjust the size of the preset spacing. Of course, in some other embodiments, when doping, the second crucible 200 can be lifted by the lifting assembly 500, and the spacing between the second crucible 200 and the first crucible 100 is ensured, that is, when growing silicon carbide crystals, the size of the preset spacing between the first crucible 100 and the second crucible 200 can be adjusted without the lifting assembly 500.

[0042] Optionally, the surrounding member 300 includes a third surrounding plate 330, a first end plate 310 and a second end plate 320, all of which are annular. The first end plate 310 and the second end plate 320 are arranged axially at intervals and are arranged at both ends of the third surrounding plate 330. The outer wall of the first surrounding plate 110 is provided with an annular groove 150. The first end plate 310 is clamped in the annular groove 150. The first surrounding plate 110 and the second surrounding plate 210 are opposite to the third surrounding plate 330. The second end plate 320 abuts against the outer wall of the second surrounding plate 210 or has a first distance from the outer wall of the second surrounding plate 210, and the second surrounding plate 210 can move axially relative to the third surrounding plate 330, and the first distance is in the range of 0.5mm-2mm.

[0043] It should be noted that, in the present embodiment, the second end plate 320 abuts against the outer wall of the second enclosure 210 to reduce the outflow of the growth atmosphere in the first crucible 100 from between the second end plate 320 and the second enclosure 210. It can be understood that when the lifting assembly 500 lifts the second crucible 200 again, it is necessary to overcome the friction between the second end plate 320 and the second enclosure 210. When the silicon carbide crystal grows, the weight of the second crucible 200 weighed by the weighing assembly 400 is the weight of the second crucible 200, the internal seed crystal 240 and the silicon carbide crystal minus the friction. Of course, under natural conditions, the gravity of the second crucible 200 is greater than the friction between the second end plate 320 and the second enclosure 210, and because the second end plate 320 abuts against the outer wall of the second enclosure 210, the amount of growth atmosphere escaping from between the second end plate 320 and the second enclosure 210 can be reduced.

[0044] Optionally, in some other embodiments, the second end plate 320 and the outer wall of the second enclosure 210 have a first spacing, and the first spacing is in the range of 0.5-2 mm, that is, the second end plate 320 and the second enclosure 210 have a small gap and will not contact, that is, when the silicon carbide crystal grows, the weight of the second crucible 200 weighed by the weighing assembly 400 is the weight of the second crucible 200 and the internal seed crystal 240 and the silicon carbide crystal. It should be noted that the size of the first spacing is smaller than the size of the preset spacing to ensure that the doping gas can smoothly pass through the gas filling cavity 350 into the growth cavity 250.

[0045] Optionally, in some embodiments, an annular groove 260 is opened on the outer side of the second enclosure 210, and the annular groove 260 includes a surrounding wall 263 and a first end wall 261. The first end wall 261 is located on the side of the surrounding wall 263 close to the first enclosure 110. The second end plate 320 is arranged in the annular groove 260. The axial dimension of the surrounding wall 263 is greater than the thickness dimension of the second end plate 320. The second end plate 320 abuts against the surrounding wall 263 or has a first distance from the surrounding wall 263.

[0046] When the surrounding wall 263 abuts against the second end plate 320, when the second end plate 320 abuts against the surrounding wall 263 and the lifting assembly 500 drives the second crucible 200 to move axially relative to the first crucible 100, it is necessary to overcome the friction between the second end plate 320 and the surrounding wall 263. Of course, in a natural state, the gravity of the second crucible 200 is greater than the friction between the second end plate 320 and the surrounding wall 263.

[0047] When there is a first distance between the second surrounding wall 263 and the second end plate 320, when the silicon carbide crystal grows and the lifting assembly 500 is connected to the second crucible 200 through the weighing assembly 400, the weight of the second crucible 200 weighed by the weighing assembly 400 is the weight of the second crucible 200, the internal seed crystal 240 and the silicon carbide crystal.

[0048] It can be understood that since the axial dimension of the annular groove 260 is greater than the thickness dimension of the second end plate 320, when the lifting assembly 500 drives the second crucible 200 to move axially, the annular groove 260 moves axially relative to the second end plate 320, that is, the second end plate 320 moves axially in the annular groove 260 at this time. The first end wall 261 of the annular groove 260 is arranged on the side of the surrounding wall 263 close to the first surrounding plate 110.

[0049] The first end wall 261 can be understood as a limiting wall. When the first end wall 261 abuts against the second end plate 320 during the movement of the second crucible 200 away from the first crucible 100 in the axial direction, it is the maximum position of the second crucible 200 away from the first crucible 100 in the axial direction. At this time, the preset axial distance between the second crucible 200 and the first crucible 100 is the maximum.

[0050] Optionally, the annular groove 260 also includes a second end wall 262, which is located on the side of the surrounding wall 263 away from the first surrounding plate 110, and the first end wall 261 and the second end wall 262 are axially arranged opposite to each other, that is, the second end plate 320 slides between the first end wall 261 and the second end wall 262 in the annular groove 260.

[0051] Optionally, in order to facilitate operators to install and disassemble the enclosure 300, the enclosure 300 includes two enclosure structures 301, and the enclosure structure 301 includes a first sub-end plate, a second sub-end plate and a third sub-end plate. When the two enclosure structures 301 are clamped in the annular groove 150 on the first crucible 100, the two first sub-end plates are abutted to jointly form a first end plate 310, the two second sub-end plates are abutted to jointly form a second end plate 320, and the two third sub-enclosure plates are abutted to jointly form a third enclosure 330. For the two enclosure structures 301, one of the two enclosure structures 301 can be provided with an inflation hole 340, or both of the enclosure structures 301 can be provided with an inflation hole 340.

[0052] Optionally, the number of the two filling holes 340 is spaced apart along the radial direction of the surrounding member 300. Therefore, when the filling amount of the doping gas is adjusted through the two filling holes 340, the flow direction of the upward growing atmosphere in the second crucible 200 can be changed. In other words, by adjusting the filling amount of the doping gas through the two filling holes 340, the convexity of the growing silicon carbide crystal can be adjusted.

[0053] Therefore, when disassembling and assembling the enclosure 300, the two enclosure structures 301 can be respectively inserted into the annular groove 150 from the radial direction of the second crucible 200 to form the enclosure 300, wherein the first sub-end plate, the second sub-end plate and the third sub-enclosure plate in each enclosure structure 301 are three parts of an integrated enclosure mechanism.

[0054] Optionally, in order to support the surrounding member 300, the silicon carbide crystal growth device 1 also includes a support member, which is located on the side of the surrounding member 300 close to the first crucible 100, and the support member is used to support the first end plate 310. In detail, there are two support members, and the two support members are respectively used to support the two first sub-end plates. It can be understood that when the first crucible 100 is placed on the placing table, one end of the support member is used to be placed on the placing table, and the other end is used to abut against the side of the first sub-end plate close to the placing table.

[0055] Optionally, in some other embodiments, the first end plate 310 includes two first sub-end plates, and the first sub-end plates are detachably connected to the third enclosure 330, that is, when the enclosure 300 and the first crucible 100 are assembled, the two first sub-end plates can be pre-inserted into the annular grooves 150 from the radial direction. At this time, the two ends of the two first sub-end plates are respectively abutted against each other to form an annular first end plate 310, and then the first sub-end plates are respectively connected to the third enclosure 330, wherein the first sub-end plates can be clamped with the third enclosure 330, and the first sub-end plates can also be connected to the third enclosure 330 through threaded fasteners or latches.

[0056] It can be understood that when the annular groove 260 in the second enclosure 210 only has a surrounding wall 263 and a first end wall 261, the surrounding wall 263 extends to the end of the second crucible 200 away from the first crucible 100. At this time, the third enclosure 330 can be sleeved on the surrounding wall 263, and after being connected to the first end plate 310, the second end plate 320 can be sleeved on the outer wall of the second crucible 200 and detachably connected to the third enclosure 330.

[0057] Optionally, when the annular groove 260 has a second end wall 262, the second end plate 320 may also include two second sub-end plates. When connected to the third enclosure plate 330, the two second sub-end plates may be respectively inserted into the annular groove 260 in the radial direction of the second crucible 200. After the two second sub-end plates are inserted, the two ends of the two second sub-end plates in the circumferential direction abut against each other to form the second end plate 320.

[0058] Optionally, in some embodiments, when the first enclosure 110 and the second enclosure 210 are in contact, the center line of the gas-filling hole 340 passes through the intersection of the first enclosure 110 and the second enclosure 210. This is to improve the efficiency of the doping gas entering the growth chamber 250 when it is filled through the gas-filling hole 340. Of course, in some other embodiments, the gas-filling hole 340 is not limited to the above-mentioned setting, and the position of the gas-filling hole 340 can also be other positions of the surrounding member 300, for example, the gas-filling hole 340 can also be set on the first end plate 310 or the second end plate 320.

[0059] Optionally, a first ventilation portion 130 is provided at one end of the first enclosure 110 close to the second enclosure 210. The first ventilation portion 130 is arranged in a ring shape and is detachably connected to the first enclosure 110. The first ventilation portion 130 is made of porous graphite. It can be understood that since the first ventilation portion 130 is made of porous graphite, when the doping gas enters the first ventilation portion 130 through the inflation hole 340, enters the accommodating chamber 140 and then enters the growth chamber 250, at this time, the second enclosure 210 is opposite to the end of the first ventilation portion 130 away from the first enclosure 110.

[0060] Optionally, a second vent 230 is provided at one end of the second enclosure 210 close to the first enclosure 110. The second vent 230 is annularly arranged and detachably connected to the second enclosure 210. The second vent 230 is made of porous graphite. Similarly, since the second vent 230 is made of porous graphite, when the doping gas enters the second vent 230 through the gas filling hole 340 and enters the growth chamber 250, in this embodiment, the first vent 130 is opposite to the second vent 230, that is, when the second crucible 200 is placed on the first crucible 100, the first vent 130 is in contact with the second vent 230.

[0061] The first vent 130 can be connected to the first enclosure 110 by a threaded fastener. For example, the first vent 130 is provided with a through hole, and the first enclosure 110 is provided with a threaded hole. The threaded fastener is inserted into the through hole and screwed into the threaded hole. The second vent 230 can also be connected to the second enclosure 210 by a threaded fastener. Similarly, the second vent 230 is provided with a through hole, and the second enclosure is provided with a threaded hole. It should be noted that the threaded fastener is made of a high temperature resistant material, which can be made of tungsten, molybdenum and other materials.

[0062] Optionally, in some embodiments, the surrounding member 300 includes a third enclosure 330 and a first end plate 310 that are ring-shaped and connected to each other. The outer wall of the first enclosure 110 is provided with an annular groove 150, and the first end plate 310 is clamped in the annular groove 150. The first enclosure 110 and the second enclosure 210 are opposite to the third enclosure 330. The third enclosure 330 abuts against the outer wall of the second enclosure 210 or has a first distance from the outer wall of the second enclosure 210, and the second enclosure 210 can move axially relative to the third enclosure 330. In this embodiment, the outer diameter of the second enclosure 210 is larger than the outer diameter of the first enclosure 110.

[0063] It should be noted that in this embodiment, the inner diameter of the first enclosure 110 is the same as the inner diameter of the second enclosure 210 , and the inner diameter of the third enclosure 330 is larger than the outer diameters of the first enclosure 110 and the second enclosure 210 .

[0064] In summary, the embodiment of the present invention provides a silicon carbide crystal growth device 1 including a first crucible 100, a second crucible 200, a surrounding piece 300, a weighing assembly 400 and a lifting assembly 500. The weighing assembly 400 is connected to the second crucible 200, and the lifting assembly 500 is connected to the second crucible 200 through the weighing assembly 400. The lifting assembly 500 is used to drive the second crucible 200 to move axially relative to the first crucible 100 and the surrounding piece 300, so that the second enclosure 210 and the first enclosure 110 have a preset spacing in the axial direction, and the inflation hole 340 can be connected to the growth chamber 250 through the inflation cavity 350. When nitrogen is doped during the growth of silicon carbide crystals, the external doping gas can enter the filling chamber 350 through the filling hole 340, and then pass through the first crucible 100 and the second crucible 200 and enter the growth chamber 250. During the process of gradually depositing silicon carbide crystals in the second crucible 200, the weight of the second crucible 200 gradually changes. At this time, the operator can calculate the growth rate of the silicon carbide crystals in the second crucible 200 based on the measured weight change of the second crucible 200, and then control the rate at which the doping gas is introduced from the external doping gas source based on the growth rate of the silicon carbide crystals, thereby ensuring a stable doping effect and improving the growth quality of the silicon carbide crystals.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A silicon carbide crystal growth device, characterized in that: include: A first crucible (100), the first crucible (100) comprising a first surrounding plate (110) and a bottom plate (120) connected to each other, the first surrounding plate (110) and the bottom plate (120) defining a containing cavity (140) for placing silicon carbide powder; a second crucible (200), the second crucible (200) comprising a second surrounding plate (210) and a top plate (220) connected to each other, the second surrounding plate (210) and the top plate (220) jointly defining a growth chamber (250), the growth chamber (250) being in communication with the accommodating chamber (140), and the top plate (220) being opposite to the bottom plate (120); A surrounding piece (300), the surrounding piece (300) is used to surround the outside of the first enclosure (110) and the second enclosure (210), the surrounding piece (300) can define an inflation cavity (350) between the first enclosure (110) and the second enclosure (210), and the surrounding piece (300) is provided with an inflation hole (340) connected to the inflation cavity (350); A weighing assembly (400), the weighing assembly (400) being connected to the second crucible (200); A lifting assembly (500), wherein the lifting assembly (500) is connected to the second crucible (200) via the weighing assembly (400), and the lifting assembly (500) is used to drive the second crucible (200) to move axially relative to the first crucible (100) and the surrounding member (300), so that the second surrounding plate (210) and the first surrounding plate (110) have a preset spacing in the axial direction, and the inflation hole (340) can be connected to the growth chamber (250) through the inflation chamber (350).

2. The silicon carbide crystal growth device according to claim 1, characterized in that: The surrounding component (300) includes a third surrounding plate (330), a first end plate (310) and a second end plate (320), all of which are annular. The first end plate (310) and the second end plate (320) are arranged in an axial direction at intervals and are arranged at both ends of the third surrounding plate (330). The outer wall of the first surrounding plate (110) is provided with an annular groove (150). The first end plate (310) is clamped in the annular groove (150). The first surrounding plate (110) and the second surrounding plate (210) are opposite to the third surrounding plate (330). The second end plate (320) is in contact with the outer wall of the second surrounding plate (210) or has a first distance with the outer wall of the second surrounding plate (210), and the second surrounding plate (210) can move in the axial direction relative to the third surrounding plate (330). The first distance is in the range of 0.5mm-2mm.

3. The silicon carbide crystal growth device according to claim 2, characterized in that: An annular groove (260) is provided on the outer side of the second enclosure (210), and the annular groove (260) includes a surrounding wall (263) and a first end wall (261), wherein the first end wall (261) is located on the side of the surrounding wall (263) close to the first enclosure (110), and the second end plate (320) is arranged in the annular groove (260), and the axial dimension of the surrounding wall (263) is greater than the thickness dimension of the second end plate (320), and the second end plate (320) is in contact with the surrounding wall (263) or has a first spacing with the surrounding wall (263).

4. The silicon carbide crystal growth device according to claim 2, characterized in that: An annular groove (260) is provided on the outer side of the second enclosure (210), and the annular groove (260) includes a surrounding wall (263) and a second end wall (262), and the second end wall (262) is located on the side of the surrounding wall (263) away from the first enclosure (110), and the second end plate (320) is located in the annular groove (260), and the axial dimension of the surrounding wall (263) is greater than the thickness dimension of the second end plate (320), and the second end plate (320) is in contact with the surrounding wall (263) or has a first distance with the surrounding wall (263).

5. The silicon carbide crystal growth device according to claim 2, characterized in that: The enclosure (300) includes two enclosure structures (301), and the enclosure structure (301) includes a first sub-end plate, a second sub-end plate and a third sub-enclosure plate. When the two enclosure structures (301) are clamped in the annular groove (150), the two first sub-end plates abut to form a first end plate (310), the two second sub-end plates abut to form a second end plate (320), and the two third sub-enclosure plates abut to form a third enclosure (330).

6. The silicon carbide crystal growth device according to claim 2, characterized in that: The first end plate (310) includes two first sub-end plates, the first sub-end plates are detachably connected to the third enclosure plate (330), and the second end plate (320) is detachably connected to the third enclosure plate (330).

7. The silicon carbide crystal growth device according to claim 1, characterized in that: When the first enclosure plate (110) is in contact with the second enclosure plate (210), the center line of the inflation hole (340) passes through the intersection of the first enclosure plate (110) and the second enclosure plate (210).

8. The silicon carbide crystal growth device according to claim 1, characterized in that: A first ventilation portion (130) is provided at one end of the first enclosure (110) close to the second enclosure (210); the first ventilation portion (130) is arranged in an annular shape and is detachably connected to the first enclosure (110); the first ventilation portion (130) is made of porous graphite.

9. The silicon carbide crystal growth device according to claim 1, characterized in that: A second ventilation portion (230) is provided at one end of the second enclosure (210) close to the first enclosure (110); the second ventilation portion (230) is arranged in an annular shape and is detachably connected to the second enclosure (210); the second ventilation portion (230) is made of porous graphite.

10. The silicon carbide crystal growth device according to claim 1, characterized in that: The surrounding component (300) includes a third surrounding plate (330) and a first end plate (310) which are both annular and connected to each other. The outer wall of the first surrounding plate (110) is provided with an annular groove (150), and the first end plate (310) is clamped in the annular groove (150). The first surrounding plate (110) and the second surrounding plate (210) are opposite to the third surrounding plate (330). The third surrounding plate (330) abuts against the outer wall of the second surrounding plate (210) or has a first distance with the outer wall of the second surrounding plate (210), and the second surrounding plate (210) can move in the axial direction relative to the third surrounding plate (330), and the first distance is in the range of 0.5mm-2mm.

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