A silicon carbide crystal growth device

Abstract

An embodiment of the present invention provides a silicon carbide crystal growth device, which relates to the technical field of silicon carbide crystal growth. The silicon carbide crystal growth device includes a first crucible, a second crucible, an enclosing member, a weighing assembly and a lifting assembly. The weighing assembly is connected to the second crucible, and the lifting assembly is connected to the second crucible through the weighing assembly. The lifting assembly is used to drive the second crucible to move axially relative to the first crucible and the enclosing member, so that there is a preset distance between the second enclosure and the first enclosure axially, and the gas inlet hole can be communicated with the growth chamber through the gas filling chamber. During 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 doping gas introduced by the external doping gas source according to the growth rate of the silicon carbide crystals, so as to ensure a stable doping effect and improve the growth quality of the silicon carbide crystals.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide crystal growth, and more particularly, to a silicon carbide crystal growth apparatus. Background Art

[0002] Doping in the growth of silicon carbide (SiC) crystals is a process of intentionally adding a small amount of impurity atoms during crystal growth, aiming to change the electrical properties of the material. Doping can control the conduction 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 apparatus fills the doping gas, the situation inside the crystal growth apparatus cannot be observed, and the gas filling rate or the doping amount can only be adjusted according to experience, resulting in poor doping effect and affecting the crystal quality. Summary of the Invention

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

[0005] The embodiments of the present invention are implemented as follows:

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

[0007] A first crucible, the first crucible includes a first enclosing plate and a bottom plate connected to each other, and the first enclosing plate and the bottom plate define a receiving cavity for placing silicon carbide powder;

[0008] A second crucible, the second crucible includes a second enclosing plate and a top plate connected to each other, and the second enclosing plate and the top plate jointly define a growth cavity, the growth cavity is communicated with the receiving cavity, and the top plate is opposite to the bottom plate;

[0009] A surrounding member, the surrounding member is used to surround the outer sides of the first enclosing plate and the second enclosing plate, and the surrounding member can define an inflation cavity between the first enclosing plate and the second enclosing plate, and the surrounding member is provided with an inflation hole communicated with the inflation cavity;

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

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

[0012] In an alternative embodiment, the surrounding member includes 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 disposed at both ends of the third surrounding plate. An annular groove is provided on the outer wall of the first surrounding plate, and the first end plate is clamped in the annular groove. The first surrounding plate and the second surrounding plate face the third surrounding plate. The second end plate abuts 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. The first distance is in the range of 0.5 mm to 2 mm.

[0013] In an alternative embodiment, an annular sliding groove is provided on the outer side of the second surrounding plate. The annular sliding 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 surrounding plate. The second end plate is disposed in the annular sliding groove. The dimension of the surrounding wall in the axial direction is greater 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 alternative embodiment, an annular sliding groove is provided on the outer side of the second surrounding plate. The annular sliding 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 surrounding plate. The second end plate is located in the annular sliding groove. The dimension of the surrounding wall in the axial direction is greater 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.

[0015] In an alternative embodiment, the surrounding member includes two surrounding structures. Each surrounding structure includes a first sub-end plate, a second sub-end plate, and a third sub-surrounding plate. When the two surrounding structures are clamped in the annular groove, the two first sub-end plates abut against each other to jointly form the first end plate, the two second sub-end plates abut against each other to jointly form the second end plate, and the two third sub-surrounding plates abut against each other to jointly form the third surrounding plate.

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

[0017] In an alternative embodiment, when the first surrounding plate abuts against the second surrounding plate, the center line of the inflation hole passes through the intersection of the first surrounding plate and the second surrounding plate.

[0018] In an alternative embodiment, a first ventilation portion is provided at one end of the first surrounding plate close to the second surrounding plate. The first ventilation portion is annularly arranged and is detachably connected to the first surrounding plate. The first ventilation portion is made of porous graphite.

[0019] In an alternative embodiment, a second ventilation portion is provided at one end of the second surrounding plate close to the first surrounding plate. The second ventilation portion is annularly arranged and is detachably connected to the second surrounding plate. The second ventilation portion is made of porous graphite.

[0020] In an alternative embodiment, the surrounding member includes a third surrounding plate and a first end plate that are both annular and connected. An annular slot is provided on the outer wall of the first surrounding plate, and the first end plate is clamped in the annular slot. The first surrounding plate and the second surrounding plate are opposite to the third surrounding plate. The third surrounding plate abuts 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. The first distance is in the range of 0.5 mm to 2 mm.

[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 nitrogen doping is carried out during the growth of silicon carbide crystals, external doping gas can enter the inflation cavity through the inflation holes, and then pass between the first crucible and the second crucible and enter the growth cavity, improving the utilization rate of the doping gas. During the process of gradually depositing silicon carbide crystals in the second crucible, operators 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 crystals, so as to ensure a stable doping effect and improve the growth quality of the silicon carbide crystals. Third, introducing nitrogen does not affect the sublimation and transmission of raw materials and reduces the formation of carbon inclusions. Fourth, by adjusting the amount of nitrogen introduced, the convexity of the crystal can be regulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic cross-sectional structure diagram of the silicon carbide crystal growth device provided by the embodiment of the present invention;

[0024] Figure 2 It is a schematic structural diagram of two surrounding structures before being assembled with the first crucible and the second crucible provided by the embodiment of the present invention;

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

[0026] Icons: 1 - Silicon carbide crystal growth device; 100 - First crucible; 110 - First enclosing plate; 120 - Bottom plate; 130 - First ventilation part; 140 - Accommodating cavity; 150 - Annular card slot; 200 - Second crucible; 210 - Second enclosing plate; 220 - Top plate; 230 - Second ventilation part; 240 - Seed crystal; 250 - Growth cavity; 260 - Annular sliding groove; 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 enclosing plate; 340 - Inflation hole; 350 - Inflation cavity; 400 - Weighing assembly; 500 - Lifting assembly. Detailed implementation manners

[0027] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying 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 claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall 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. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0030] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0031] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0032] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", and "coupled" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] The following will introduce in detail the specific structure of a silicon carbide crystal growth device provided by an embodiment of the present invention in conjunction with the patent drawings and the corresponding technical effects brought thereby.

[0034] Please refer to Figures 1 - 3 , a silicon carbide crystal growth device 1 provided by an embodiment of the present invention includes a first crucible 100, a second crucible 200, an enclosing 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. The first surrounding plate 110 and the bottom plate 120 define a receiving cavity 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. The second surrounding plate 210 and the top plate 220 together define a growth cavity 250. The growth cavity 250 is communicated with the receiving cavity 140, and the top plate 220 is opposite to the bottom plate 120. The enclosing member 300 is used to enclose the outside of the first surrounding plate 110 and the second surrounding plate 210. The enclosing member 300 can define an inflation cavity 350 between the first surrounding plate 110 and the second surrounding plate 210. The enclosing member 300 is provided with an inflation hole 340 communicated with the inflation cavity 350. 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 enclosing member 300, so that a preset distance is provided axially between the second surrounding plate 210 and the first surrounding plate 110, and the inflation hole 340 can be communicated with the growth cavity 250 through the inflation cavity 350.

[0036] Optionally, the second surrounding plate 210 and the top plate 220 in the second crucible 200 can be an integral structure or can be detachably connected to each other. It can be understood that when the top plate 220 and the second surrounding plate 210 are detachably connected, it is convenient for the operator 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 a silicon carbide crystal, the second crucible 200 is located above the first crucible 100. The silicon carbide powder in the first crucible 100 sublimes into a growth atmosphere and then deposits on the seed crystal 240 as a silicon carbide crystal. The gas injection hole 340 is used to connect with a doping gas source. For example, when nitrogen doping is carried out during the growth of a silicon carbide crystal and the second crucible 200 is lifted by the lifting assembly 500 so that there is a preset distance between the second shroud 210 and the first shroud 110 in the axial direction, an external doping gas source can pass the doping gas into the doping gas chamber 350 through the gas injection hole 340, and then pass between the first crucible 100 and the second crucible 200 and enter the growth chamber 250 to achieve doping. The doping gas can be nitrogen or other doping gases.

[0038] Moreover, in this embodiment, since the gas injection hole 340 is located outside the outer peripheral walls of the first crucible 100 and the second crucible 200, when passing the doping gas through the gas injection hole 340, it will not impact the raw materials, that is, it will not affect the sublimation and transmission of the raw materials contained in the second crucible 200, and reduce the formation of carbon inclusions.

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

[0040] It can be understood that when the silicon carbide crystal is 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 there is a preset distance between the second shroud 210 and the first shroud 110 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 during the process of gradually depositing the silicon carbide crystal 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 crystal in the second crucible 200 according to the measured weight change of the second crucible 200, and then control the rate of the doping gas passed by the external doping gas source according to the growth rate of the silicon carbide crystal, so as to ensure a stable doping effect and improve the growth quality of the silicon carbide crystal.

[0041] It can be understood 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, therefore, during doping, in some embodiments, the lifting assembly 500 can also be used to drive the second crucible 200 to rise to adjust the size of the preset spacing. Of course, in some other embodiments, during doping, the lifting assembly 500 can be used to lift the second crucible 200, and the spacing between the second crucible 200 and the first crucible 100 can be 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 using 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 at intervals axially and are disposed at both ends of the third surrounding plate 330. An annular slot 150 is provided on the outer wall of the first surrounding plate 110, and the first end plate 310 is clamped in the annular slot 150. The first surrounding plate 110 and the second surrounding plate 210 face 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 spacing 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. The first spacing is in the range of 0.5 mm - 2 mm.

[0043] It should be noted that in this embodiment, the second end plate 320 abuts against the outer wall of the second surrounding plate 210 to reduce the outflow of the growth atmosphere in the first crucible 100 from between the second end plate 320 and the second surrounding plate 210. It can be understood that when the lifting assembly 500 lifts the second crucible 200 again, the friction force between the second end plate 320 and the second surrounding plate 210 needs to be overcome. During the growth of silicon carbide crystals, the weight of the second crucible 200 measured 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 force. Of course, in the natural state, the gravity of the second crucible 200 is greater than the friction force between the second end plate 320 and the second surrounding plate 210, and since the second end plate 320 abuts against the outer wall of the second surrounding plate 210, the amount of the growth atmosphere running out from between the second end plate 320 and the second surrounding plate 210 can be reduced.

[0044] Optionally, in some other embodiments, the second end plate 320 has a first spacing from the outer wall of the second shroud 210, and the first spacing is in the range of 0.5 - 2 mm. That is to say, there is a small gap between the second end plate 320 and the second shroud 210 and they do not contact. That is to say, when the silicon carbide crystal is growing, the weight of the second crucible 200 measured by the weighing assembly 400 is the weight of the second crucible 200, 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 enter the growth chamber 250 through the inflation chamber 350.

[0045] Optionally, in some embodiments, an annular chute 260 is formed on the outer side of the second shroud 210. The annular chute 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 shroud 110. The second end plate 320 is disposed in the annular chute 260. The size of the surrounding wall 263 in the axial direction is greater than the thickness size of the second end plate 320. The second end plate 320 abuts against the surrounding wall 263 or has a first spacing 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 frictional force between the second end plate 320 and the surrounding wall 263. Of course, in the natural state, the gravity of the second crucible 200 is greater than the frictional force between the second end plate 320 and the surrounding wall 263.

[0047] When there is a first spacing between the second surrounding wall 263 and the second end plate 320, during the growth of the silicon carbide crystal, and when the lifting assembly 500 is connected to the second crucible 200 through the weighing assembly 400, the weight of the second crucible 200 measured 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 size of the annular chute 260 in the axial direction is greater than the thickness size of the second end plate 320, when the lifting assembly 500 drives the second crucible 200 to move axially, at this time, the annular chute 260 moves axially relative to the second end plate 320. That is to say, at this time, the second end plate 320 moves axially in the annular chute 260. The first end wall 261 of the annular chute 260 is disposed on the side of the surrounding wall 263 close to the first shroud 110.

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

[0050] Optionally, the annular chute 260 further includes a second end wall 262. The second end wall 262 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 arranged axially opposite to each other. That is to say, the second end plate 320 slides between the first end wall 261 and the second end wall 262 in the annular chute 260.

[0051] Optionally, to facilitate the installation and disassembly of the surrounding member 300 by the operator, the surrounding member 300 includes two surrounding structures 301. The surrounding structure 301 includes a first sub-end plate, a second sub-end plate, and a third sub-end plate. When the two surrounding structures 301 are clamped in the annular slot 150 on the first crucible 100, the two first sub-end plates abut against each other to jointly form the first end plate 310, the two second sub-end plates abut against each other to jointly form the second end plate 320, and the two third sub-surrounding plates abut against each other to jointly form the third surrounding plate 330. For the two surrounding structures 301, an inflation hole 340 can be provided for one of the two surrounding structures 301, or inflation holes 340 can be provided for both of the two surrounding structures 301.

[0052] Optionally, the two inflation holes 340 are arranged at intervals along the radial direction of the surrounding member 300. Therefore, when adjusting the charging amount of the doping gas through the two inflation holes 340, the flow direction of the upward growth atmosphere in the second crucible 200 can be changed. In other words, by adjusting the charging amount of the doping gas through the two inflation holes 340, the convexity of the growth of the silicon carbide crystal can be adjusted.

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

[0054] Optionally, to support the surrounding member 300, the silicon carbide crystal growth device 1 further includes a support member. The support member 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. Specifically, 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 placement table, one end of the support member is used to be placed on the placement table, and the other end is used to abut against the side of the first sub-end plate close to the placement 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 surrounding plate 330. That is to say, when the enclosing member 300 is assembled with the first crucible 100, the two first sub-end plates can be inserted into the annular card slot 150 from the radial direction in advance. At this time, the two ends of the two first sub-end plates abut against each other respectively to form an annular first end plate 310, and then the first sub-end plates are respectively connected to the third surrounding plate 330. Among them, the first sub-end plate can be snap-connected to the third surrounding plate 330, and the first sub-end plate can also be connected to the third surrounding plate 330 through a threaded fastener or a pin.

[0056] It can be understood that when the annular sliding groove 260 in the second surrounding plate 210 only has the surrounding wall 263 and the 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 surrounding plate 330 can be sleeved on the surrounding wall 263. After being connected to the first end plate 310, the second end plate 320 is then sleeved on the outer wall of the second crucible 200 and is detachably connected to the third surrounding plate 330.

[0057] Optionally, when the annular sliding groove 260 has the second end wall 262, the second end plate 320 can also include two second sub-end plates. When connecting to the third surrounding plate 330, the two second sub-end plates can be inserted into the annular sliding groove 260 from the radial direction of the second crucible 200 respectively. 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 surrounding plate 110 abuts against the second surrounding plate 210, the center line of the gas injection hole 340 passes through the intersection of the first surrounding plate 110 and the second surrounding plate 210. To improve the efficiency of the doping gas entering the growth chamber 250 when injected through the gas injection hole 340. Of course, in some other embodiments, the gas injection hole 340 is not limited to the above setting, and the position of the gas injection hole 340 can also be other positions of the enclosing member 300. For example, the gas injection hole 340 can also be provided on the first end plate 310 or the second end plate 320.

[0059] Optionally, a first ventilation part 130 is provided at one end of the first surrounding plate 110 close to the second surrounding plate 210. The first ventilation part 130 is annularly arranged and is detachably connected to the first surrounding plate 110. The first ventilation part 130 is made of porous graphite. It can be understood that since the first ventilation part 130 is made of porous graphite, when the doping gas enters the accommodation cavity 140 through the gas injection hole 340 and then enters the growth chamber 250 through the first ventilation part 130, at this time, the second surrounding plate 210 is opposite to the end of the first ventilation part 130 away from the first surrounding plate 110.

[0060] Optionally, a second ventilation portion 230 is provided at one end of the second enclosure plate 210 close to the first enclosure plate 110. The second ventilation portion 230 is annularly arranged and detachably connected to the second enclosure plate 210. The second ventilation portion 230 is made of porous graphite. Similarly, since the second ventilation portion 230 is made of porous graphite, when the doping gas enters the growth chamber 250 through the inflation hole 340 and into the second ventilation portion 230. In this embodiment, the first ventilation portion 130 faces the second ventilation portion 230. That is to say, when the second crucible 200 is placed on the first crucible 100, the first ventilation portion 130 abuts against the second ventilation portion 230.

[0061] Among them, the first ventilation portion 130 can be connected to the first enclosure plate 110 through a threaded fastener. For example, the first ventilation portion 130 is provided with a through hole, and the first enclosure plate 110 is provided with a threaded hole. By inserting the threaded fastener into the through hole and screwing it into the threaded hole, the second ventilation portion 230 can also be connected to the second enclosure plate 210 through a threaded fastener. Similarly, the second ventilation portion 230 is provided with a through hole, and the second enclosure plate 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 materials such as tungsten and molybdenum.

[0062] Optionally, in some embodiments, the enclosing member 300 includes a third enclosure plate 330 and a first end plate 310 that are annular and connected. An annular card slot 150 is provided on the outer wall of the first enclosure plate 110. The first end plate 310 is clamped in the annular card slot 150. The first enclosure plate 110 and the second enclosure plate 210 face the third enclosure plate 330. The third enclosure plate 330 abuts against the outer wall of the second enclosure plate 210 or has a first distance from the outer wall of the second enclosure plate 210, and the second enclosure plate 210 can axially move relative to the third enclosure plate 330. In this embodiment, the outer diameter dimension of the second enclosure plate 210 is larger than the outer diameter dimension of the first enclosure plate 110.

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

[0064] In summary, the embodiment of the present invention provides a silicon carbide crystal growth device 1, which includes a first crucible 100, a second crucible 200, an enclosure member 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 enclosure member 300, so that there is a preset distance between the second enclosure plate 210 and the first enclosure plate 110 axially, and the gas injection hole 340 can communicate with the growth cavity 250 through the gas injection cavity 350. When nitrogen doping is carried out during the growth of silicon carbide crystals, external doping gas can enter the gas injection cavity 350 through the gas injection hole 340, and then pass between the first crucible 100 and the second crucible 200 and enter the growth cavity 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 according to the measured weight change of the second crucible 200, and then control the rate of the external doping gas source to inject the doping gas according to the growth rate of the silicon carbide crystals, so as to ensure a stable doping effect and improve the growth quality of the silicon carbide crystals.

[0065] The foregoing 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 changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A silicon carbide crystal growth apparatus, characterized in that, Comprising: A first crucible (100), the first crucible (100) includes a connected first enclosing plate (110) and a bottom plate (120), the first enclosing plate (110) and the bottom plate (120) define a receiving cavity (140) for placing silicon carbide powder; A second crucible (200), the second crucible (200) includes a connected second enclosing plate (210) and a top plate (220), the second enclosing plate (210) and the top plate (220) jointly define a growth cavity (250), the growth cavity (250) is communicated with the receiving cavity (140), and the top plate (220) is opposite to the bottom plate (120); A surrounding member (300), the surrounding member (300) is used for surrounding the outside of the first enclosing plate (110) and the second enclosing plate (210), the surrounding member (300) can define an inflation cavity (350) between the first enclosing plate (110) and the second enclosing plate (210), the surrounding member (300) is provided with an inflation hole (340) communicated with the inflation cavity (350), and external doping gas can enter the inflation cavity (350) through the inflation hole (340); A weighing assembly (400), the weighing assembly (400) is connected to the second crucible (200); A lifting assembly (500), 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 member (300), so that the second enclosing plate (210) and the first enclosing plate (110) have a preset distance in the axial direction, and can make the inflation hole (340) communicate with the growth cavity (250) through the inflation cavity (350); The growth rate of the silicon carbide crystal in the second crucible (200) can be calculated according to the measured weight change of the second crucible (200), and then the rate of the external doping gas source introducing the doping gas can be controlled according to the growth rate of the silicon carbide crystal.

2. The silicon carbide crystal growth device according to claim 1, wherein: 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 at intervals in the axial direction and are disposed at both ends of the third surrounding plate (330). An annular slot (150) is provided on the outer wall of the first surrounding plate (110), and the first end plate (310) is clamped in the annular slot (150). The first surrounding plate (110) and the second surrounding plate (210) face 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 relative to the third surrounding plate (330) in the axial direction. The first distance is in the range of 0.5 mm - 2 mm.

3. The silicon carbide crystal growth device according to claim 2, wherein: An annular sliding groove (260) is provided on the outer side of the second surrounding plate (210). The annular sliding 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 surrounding plate (110). The second end plate (320) is disposed in the annular sliding groove (260). The dimension of the surrounding wall (263) in the axial direction 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).

4. The silicon carbide crystal growth device according to claim 2, wherein: An annular sliding groove (260) is provided on the outer side of the second surrounding plate (210). The annular sliding groove (260) includes a surrounding wall (263) and a second end wall (262). The second end wall (262) is located on the side of the surrounding wall (263) away from the first surrounding plate (110). The second end plate (320) is located in the annular sliding groove (260). The dimension of the surrounding wall (263) in the axial direction 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).

5. The silicon carbide crystal growth device according to claim 2, wherein: The surrounding member (300) includes two surrounding structures (301). The surrounding structure (301) includes a first sub-end plate, a second sub-end plate, and a third sub-surrounding plate. When the two surrounding structures (301) are clamped in the annular slot (150), the two first sub-end plates abut against each other to jointly form the first end plate (310), the two second sub-end plates abut against each other to jointly form the second end plate (320), and the two third sub-surrounding plates abut against each other to jointly form the third surrounding plate (330).

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

7. The silicon carbide crystal growth device according to claim 1, wherein: When the first surrounding plate (110) abuts against the second surrounding plate (210), the center line of the gas injection hole (340) passes through the intersection of the first surrounding plate (110) and the second surrounding plate (210).

8. The silicon carbide crystal growth device according to claim 1, wherein: One end of the first surrounding plate (110) close to the second surrounding plate (210) is provided with a first ventilation part (130), the first ventilation part (130) is arranged in a ring shape and is detachably connected to the first surrounding plate (110), and the first ventilation part (130) is made of porous graphite.

9. The silicon carbide crystal growth device according to claim 1, wherein: One end of the second surrounding plate (210) close to the first surrounding plate (110) is provided with a second ventilation part (230), the second ventilation part (230) is arranged in a ring shape and is detachably connected to the second surrounding plate (210), and the second ventilation part (230) is made of porous graphite.

10. The silicon carbide crystal growth device according to claim 1, wherein: The surrounding member (300) includes a third surrounding plate (330) and a first end plate (310) that are both in a ring shape and are connected to each other. An annular slot (150) is provided on the outer wall of the first surrounding plate (110), the first end plate (310) is clamped in the annular slot (150), the first surrounding plate (110) and the second surrounding plate (210) face 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 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 0.5 mm - 2 mm.

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