Silicon carbide growth device and growth method

Abstract

The present invention relates to the technical field of silicon carbide crystal growth. Provided are a silicon carbide growth device and a growth method. The silicon carbide growth device comprises a growth crucible, a heating device, a seed crystal positioning cover, a positioning support, a weighing device and a bearing connection member. The seed crystal positioning cover is connected to the weighing device by means of the bearing connection member, and the seed crystal positioning cover is in clearance fit with the growth crucible, thereby avoiding the growth crucible supporting the seed crystal positioning cover; in addition, the weighing device can hoist the seed crystal positioning cover by means of the bearing connection member, such that the seed crystal positioning cover, a seed crystal and a growing silicon carbide crystal can only act on the weighing device. Thus, the weighing device measures the weight of the seed crystal positioning cover, the seed crystal and the silicon carbide crystal in real time, thereby achieving the real-time accurate measurement on the weight of the silicon carbide crystal since the weights of the seed crystal positioning cover and the seed crystal are constant. In addition, on this basis, process adjustment can be realized, thereby improving the growth quality of silicon carbide crystals.

Description

Silicon carbide growth device and growth method Technical Field

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

[0002] Silicon carbide (SiC), as an emerging third-generation semiconductor core material, has excellent properties such as wide bandgap, high critical breakdown electric field strength, high electron mobility, good radiation resistance and chemical stability. This makes it an important substrate wafer material with wide applications and shows good application prospects in aviation devices, new energy vehicles, rail transportation and household appliances.

[0003] Currently, physical vapor transport (PVT) is the main method used to grow silicon carbide crystals. However, the inventors have found that most growth devices in the existing technology use a crucible lid to bond the seed crystal and then fix the crucible lid to the crucible, thus forming a closed "black box" structure. This makes it difficult to obtain the growth status of the crystal inside and difficult to monitor the growth rate and weight of the crystal. Summary of the Invention

[0004] The objects of the present invention include, for example, providing a silicon carbide growth device and growth method, which can directly measure the weight of the growing crystal, accurately monitor the growth rate and weight of the crystal, and thereby realize process adjustment to improve the growth quality of silicon carbide crystals.

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

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

[0007] a growth crucible having an opening and configured to contain silicon carbide powder;

[0008] a heating device, the heating device being arranged around the growth crucible and being used to heat the growth crucible;

[0009] A seed crystal positioning cover is provided at the opening and is gap-matched with an edge of the opening. A seed crystal is bonded to the bottom side of the seed crystal positioning cover, and the seed crystal is used to grow silicon carbide crystals.

[0010] a positioning frame extending at least partially above the growth crucible;

[0011] a weighing device, the weighing device being fixedly disposed on a portion of the positioning frame extending above the growth crucible;

[0012] a load-bearing connector, one end of which is connected to the top side of the seed crystal positioning cover, and the other end of which is connected to the weighing device;

[0013] The weighing device is used to hoist the seed crystal positioning cover through the load-bearing connector and measure the weight of the seed crystal positioning cover, the seed crystal and the silicon carbide crystal in real time.

[0014] In an optional embodiment, a gap between the seed crystal positioning cover and the edge of the opening is between 0.1 mm and 10 mm.

[0015] In an optional embodiment, a bent curtain is further provided on the edge of the seed crystal positioning cover, and the bent curtain blocks the gap between the seed crystal positioning cover and the edge of the opening.

[0016] In an optional embodiment, an edge of the bent curtain is in sealing engagement with the growth crucible and is slidable relative to the growth crucible.

[0017] In an optional embodiment, the diameter of the seed crystal positioning cover is larger than the inner diameter of the opening, and the seed crystal positioning cover is arranged above the opening, the edge of the seed crystal positioning cover corresponds to the edge of the opening and is gap-fitted, and the bent curtain cover is arranged on the outside of the top end of the growth crucible and is gap-fitted with the outer wall of the growth crucible.

[0018] In an optional embodiment, the diameter of the seed crystal positioning cover is smaller than the inner diameter of the opening, and the seed crystal positioning cover is arranged in the opening, the edge of the seed crystal positioning cover corresponds to the edge of the opening and the gap is matched, the bent curtain is arranged corresponding to the edge of the opening, and blocks the gap between the seed crystal positioning cover and the growth crucible, and the bent curtain is matched with the top gap of the growth crucible.

[0019] In an optional embodiment, the load-bearing connection member includes a screw, a sleeve and a barrel, the top end of the screw is connected to the weighing device, and the outer peripheral surface of the screw is provided with an external thread, the sleeve is provided on the screw and is threadedly connected to the screw, the sleeve is provided outside the screw, and one end of the sleeve is connected to the sleeve, and the other end is connected to the seed crystal positioning cover, the sleeve is used to adjust the relative position of the screw and the sleeve to adjust the relative position between the seed crystal positioning cover and the growth crucible.

[0020] In an optional embodiment, the load-bearing connecting member includes a first connecting rod, an electric push rod, a second connecting rod and a guide cylinder, the top end of the first connecting rod is connected to the weighing device, the electric push rod is arranged at the other end of the first connecting rod, one end of the second connecting rod is connected to the electric push rod, and the other end is connected to the seed crystal positioning cover, and the guide cylinder is arranged on the first connecting rod and is sleeved outside the electric push rod and the second connecting rod.

[0021] In a second aspect, the present invention provides a method for growing a silicon carbide crystal, applicable to the silicon carbide growth apparatus as described in any one of the aforementioned embodiments, the growth method comprising:

[0022] Loading silicon carbide powder into the growth crucible from its opening;

[0023] placing a seed crystal positioning cover with a seed crystal at the opening, wherein the seed crystal positioning cover is in clearance fit with the edge of the opening;

[0024] heating the growth crucible using a heating device and setting process parameters;

[0025] Measuring the weight of the seed crystal positioning cover, the seed crystal, and the silicon carbide crystal in real time by a weighing device to obtain the weight of the silicon carbide crystal in real time;

[0026] The process parameters are adjusted according to the weight of the silicon carbide crystal.

[0027] In a third aspect, the present invention provides a silicon carbide crystal prepared by the aforementioned silicon carbide growth method.

[0028] The beneficial effects of the embodiments of the present invention include, for example:

[0029] The silicon carbide growth device provided by the embodiment of the present invention connects the seed crystal positioning cover to the weighing device through a load-bearing connector, and the seed crystal positioning cover is clearance-matched with the growth crucible, thereby avoiding the support of the growth crucible on the seed crystal positioning cover, and the weighing device can hoist the seed crystal positioning cover through the load-bearing connector, so that the seed crystal positioning cover, seed crystal and growing silicon carbide crystal can only act on the weighing device, and the weight of the seed crystal positioning cover, seed crystal and silicon carbide crystal is measured in real time by the weighing device, while the weight of the seed crystal positioning cover and seed crystal is fixed, thereby achieving real-time and accurate measurement of the weight of the silicon carbide crystal. Compared with the prior art, the silicon carbide growth device provided by the present invention can directly measure the weight of the growing crystal, accurately monitor the growth rate and weight of the crystal, and can thereby achieve process adjustment and improve the growth quality of the silicon carbide crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0031] FIG1 is a schematic diagram of the overall structure of a silicon carbide growth device provided in a first embodiment of the present invention;

[0032] FIG2 is a schematic diagram of a partial structure of a silicon carbide growth device provided in a first embodiment of the present invention;

[0033] FIG3 is a schematic diagram of a partial structure of a silicon carbide growth device in another preferred embodiment of the present invention;

[0034] FIG4 is a schematic diagram of the connection structure between the seed crystal positioning cover and the sleeve in FIG2 ;

[0035] FIG5 is a schematic structural diagram of a silicon carbide growth apparatus provided in a second embodiment of the present invention;

[0036] FIG6 is a schematic diagram of another structure of a silicon carbide growth device provided in a second embodiment of the present invention;

[0037] FIG7 is a schematic structural diagram of a silicon carbide growth apparatus provided in a third embodiment of the present invention;

[0038] FIG8 is a flowchart of a silicon carbide growth method according to a fourth embodiment of the present invention.

[0039] Icons: 100-silicon carbide growth device; 110-growth crucible; 111-opening; 120-heating device; 130-seed crystal positioning cover; 131-seed crystal; 132-bending curtain; 1321-flexible support member; 133-boss; 134-assembly groove; 135-through groove; 136-holding ring groove; 137-holding block; 140-positioning frame; 150-weighing device; 160-bearing connecting member; 161-screw; 162-screw sleeve; 163-sleeve; 164-stop block; 165-first connecting rod; 166-electric push rod; 167-second connecting rod; 168-guide cylinder; 169-damping rod; 1691-first damping cylinder; 1693-second damping cylinder; 200-furnace body. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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 herein can be arranged and designed in various different configurations.

[0041] 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 as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0042] 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, it does not need to be further defined or explained in subsequent drawings.

[0043] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0045] As disclosed in the background, PVT methods for growing silicon carbide crystals typically employ a fixed crucible. Specifically, the crucible lid is typically screwed or snapped onto the crucible body, with a seed crystal bonded to the inside. The crucible body supports the lid, creating a closed "black box" structure that prevents direct external monitoring of the crystal growth process.

[0046] Furthermore, a solution has been proposed to weigh the crucible, or to weigh the remaining powder at the bottom, that is, to calculate the crystal growth amount based on the remaining powder. However, since powder will be lost during the crystal growth process, the method of calculating the crystal weight based on the powder is not accurate, and the obtained crystal growth amount is also not precise. It is also difficult to monitor the crystal growth rate and weight.

[0047] In order to solve the above problems, the present invention provides a silicon carbide growth device, a silicon carbide crystal growth method and a silicon carbide crystal. It should be noted that the features in the embodiments of the present invention can be combined with each other without conflict. First embodiment

[0048] 1 , this embodiment provides a silicon carbide growth apparatus 100 that can directly measure the weight of a growing crystal, accurately monitor the growth rate and weight of the crystal, and thereby implement process adjustments to improve the growth quality of silicon carbide crystals.

[0049] The silicon carbide growth device 100 provided in this embodiment includes a growth crucible 110, a heating device 120, a seed crystal positioning cover 130, a positioning frame 140, a weighing device 150 and a supporting connector 160. The growth crucible 110 has an opening 111 and is used to accommodate silicon carbide powder; the heating device 120 is arranged around the growth crucible 110 and is used to heat the growth crucible 110; the seed crystal positioning cover 130 is arranged at the opening 111 and is in a gap with the edge of the opening 111. The seed crystal positioning cover 130 is bonded to the bottom side of the seed crystal positioning cover 130. 1. The seed crystal 131 is used to grow a silicon carbide crystal; the positioning frame 140 at least partially extends above the growth crucible 110; the weighing device 150 is fixedly arranged on the portion of the positioning frame 140 extending above the growth crucible 110; one end of the supporting connector 160 is connected to the top side of the seed crystal positioning cover 130, and the other end is connected to the weighing device 150; wherein the weighing device 150 is used to lift the seed crystal positioning cover 130 through the supporting connector 160 and measure the weight of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal in real time.

[0050] In this embodiment, the silicon carbide growth apparatus 100 may be a growth furnace. The growth crucible 110 is disposed within the furnace body 200, and a positioning frame 140 is disposed on the top of the furnace body 200 and extends directly above the growth crucible 110. A weighing device 150 is fixed to the positioning frame 140 to weigh the components below. The other internal components of the growth furnace can be referenced to existing silicon carbide growth furnaces and are not described in detail here.

[0051] It should be noted that, in this embodiment, the seed crystal positioning cover 130 is connected to the weighing device 150 through the load-bearing connection 160, and the seed crystal positioning cover 130 is loosely matched with the growth crucible 110, thereby avoiding the support of the seed crystal positioning cover 130 by the growth crucible 110, and the weighing device 150 can lift the seed crystal positioning cover 130 through the load-bearing connection 160, so that the seed crystal positioning cover 130, the seed crystal 131 and the grown silicon carbide crystal can only act on the weighing device 150, and the weight of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal is measured in real time by the weighing device 150, while the weight of the seed crystal positioning cover 130 and the seed crystal 131 is fixed, thereby realizing real-time and accurate measurement of the weight of the silicon carbide crystal, thereby realizing accurate monitoring of the crystal growth rate and weight, and realizing process adjustment to improve the growth quality of the silicon carbide crystal.

[0052] In this embodiment, the weighing device 150 includes an electronic scale and a display screen (not shown). The electronic scale is fixedly mounted on the positioning frame 140 and connected to the supporting connector 160. The display screen is in communication with the electronic scale. Specifically, the electronic scale can achieve a high weighing accuracy of less than 1 gram. The display screen can be mounted outside the positioning frame 140 and exposed to the outside of the growth furnace. The electronic scale's weighing data can be directly displayed on the display screen, allowing personnel to monitor the scale's readings in real time.

[0053] Furthermore, the display can also display the growth rate. Specifically, by analyzing the electronic scale reading and time, the weight growth rate of the silicon carbide crystal can be calculated and displayed on the screen, facilitating better adjustment of process parameters. For example, if the display shows a low weight growth rate of the silicon carbide crystal, process parameters that are conducive to growth can be adjusted, such as increasing the heating temperature or adjusting the temperature gradient, to further increase the crystal growth rate.

[0054] In this embodiment, the gap L1 between the seed crystal positioning cover 130 and the edge of the opening 111 is between 0.1mm and 10mm. Preferably, the gap L1 between the seed crystal positioning cover 130 and the edge of the opening 111 is 1mm. Here, by properly controlling the gap L1, a balance is achieved between the loss of silicon carbide powder and the weighing accuracy. If the gap is too small, for example, less than 0.1mm, the distance between the seed crystal positioning cover 130 and the growth crucible 110 will be too small, resulting in interference. The growth crucible 110 will affect the hanging state of the seed crystal positioning cover 130, thereby affecting the weighing accuracy. If the gap is too large, for example, greater than 10mm, it will cause excessive powder loss, affecting the crystallization speed and quality.

[0055] 2 and 4 , in this embodiment, the diameter of the seed crystal positioning cover 130 is larger than the inner diameter of the opening 111. The seed crystal positioning cover 130 is positioned above the opening 111, and the edge of the seed crystal positioning cover 130 corresponds to and has a clearance fit with the edge of the opening 111. Specifically, the diameter of the seed crystal positioning cover 130 matches the outer diameter of the growth crucible 110, so that the seed crystal positioning cover 130 can completely cover the opening 111 of the growth crucible 110 in the vertical direction, thereby ensuring sufficient bonding space for the seed crystal 131.

[0056] In this embodiment, the load-bearing connecting member 160 includes a screw 161, a sleeve 162 and a sleeve 163. The top end of the screw 161 is connected to the weighing device 150, and the outer peripheral surface of the screw 161 is provided with an external thread. The sleeve 162 is provided on the screw 161 and is threadedly connected to the screw 161. The sleeve 163 is sleeved on the outside of the screw 161, and one end of the sleeve 163 is connected to the sleeve 162, and the other end is connected to the seed crystal positioning cover 130. The sleeve 162 is used to adjust the relative position of the screw 161 and the sleeve 163 to adjust the relative position between the seed crystal positioning cover 130 and the growth crucible 110. Specifically, the screw sleeve 162 is integrally arranged at the top end of the sleeve 163, and the bottom end of the sleeve 163 is fixedly connected to the top side of the seed crystal positioning cover 130. During actual installation, the sleeve 163 and the screw sleeve 162 can be driven to rotate relative to the screw 161 by rotating the seed crystal positioning cover 130, thereby adjusting the relative position between the seed crystal positioning cover 130 and the growth crucible 110 to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is between 0.1mm-10mm.

[0057] It is worth noting that in order to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is accurately controlled at 1mm in this embodiment, it can be determined by the number of rotations. Specifically, the pitch of the external thread on the screw 161 can be 0.5mm, so the distance adjusted by rotating the seed crystal positioning cover 130 one circle is 0.5mm. During actual installation, the seed crystal positioning cover 130 can be rotated forward first, and the seed crystal positioning cover 130 can be adjusted downward to the extreme position, that is, the state where the seed crystal positioning cover 130 and the growth crucible 110 are against each other. At this time, the seed crystal positioning cover 130 is rotated in the opposite direction for two circles to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is accurately controlled at 1mm.

[0058] In this embodiment, a stop block 164 is further provided at the bottom end of the screw rod 161 . The size of the stop block 164 is larger than the inner diameter of the screw sleeve 162 , thereby preventing the sleeve 163 and the screw sleeve 162 from falling off the screw rod 161 .

[0059] In this embodiment, a bent barrier curtain 132 is further provided on the periphery of the seed crystal positioning cover 130. The bent barrier curtain 132 is positioned to cover the outside of the top end of the growth crucible 110 and to fit within the gap of the outer wall of the growth crucible 110. Specifically, the bent barrier curtain 132 can be made of the same material as the seed crystal positioning cover 130, and extends outward from the periphery of the seed crystal positioning cover 130 and bends downward. After the seed crystal positioning cover 130 is adjusted into place, the bent barrier curtain 132 can precisely cover the gap between the seed crystal positioning cover 130 and the growth crucible 110, thereby preventing a large amount of gaseous material from escaping from the growth crucible 110 and further reducing the loss of silicon carbide powder.

[0060] It should be noted that, in this embodiment, the bent curtain 132 is integrally arranged on the periphery of the seed crystal positioning cover 130, and can form a groove on the inner side of the seed crystal positioning cover 130. The size of the groove can be adapted to the size of the growth crucible 110 and is slightly larger than the outer diameter of the growth crucible 110. During actual assembly, the bent curtain 132 can be used to guide and align the growth crucible 110, thereby ensuring that the growth crucible 110 and the seed crystal positioning cover 130 can be aligned, thereby ensuring assembly accuracy.

[0061] Furthermore, in this embodiment, the gap L2 between the bent curtain 132 and the outer wall of the growth crucible 110 can also be between 0.1 mm and 10 mm. On the one hand, it can avoid the interference of the growth crucible 110 on the seed crystal positioning cover 130, and on the other hand, it can avoid a large amount of gaseous material overflowing, thereby reducing the loss of silicon carbide powder.

[0062] In another preferred embodiment of the present invention, as shown in FIG3 , the edge of the curved curtain 132 is sealed against the growth crucible 110 and is capable of sliding relative to the growth crucible 110. Specifically, a flexible abutment 1321, which may be graphite paper, can be provided at the bottom edge of the curved curtain 132. This abutment 1321 abuts against the outer wall of the growth crucible 110, further preventing the escape of gaseous substances. Furthermore, due to the light weight and soft texture of graphite paper, it can be assumed that it can slide freely between the growth crucible 110 and will not affect the accuracy of the weighing device 150.

[0063] In this embodiment, since the seed crystal positioning cover 130 has lost the support of the growth crucible 110, the weight of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal are all concentrated on the bearing connector 160. Therefore, the connection between the threaded sleeve 162 and the seed crystal positioning cover 130 needs to be reinforced. Preferably, a boss 133 can be formed by locally bulging at the center of the top side of the seed crystal positioning cover 130. The boss 133 is provided with an assembly groove 134, and the sleeve 163 is assembled in the threaded groove, thereby achieving fixation between the sleeve 163 and the seed crystal positioning cover 130. Specifically, a through groove 135 can be opened on the side wall of the assembly groove 134, and a retaining ring groove 136 can be provided on the bottom side of the through groove 135. A retaining block 137 is provided on the periphery of the bottom end of the sleeve 163. The retaining block 137 can be inserted into the retaining ring groove 136 along the through groove 135, thereby achieving fixation between the sleeve 163 and the assembly groove 134. Furthermore, in order to prevent the holding block 137 from loosening during the rotation of the seed crystal positioning cover 130 , an interference fit can be ensured between the holding ring groove 136 and the holding block 137 .

[0064] Furthermore, in order to prevent the boss 133 from affecting the thermal uniformity of the seed crystal positioning cover 130, an insulation layer can be provided around the boss 133. By adjusting the thickness of the insulation layer, the thermal conductivity of each part of the seed crystal positioning cover 130 can be made similar, thereby ensuring thermal uniformity.

[0065] In summary, this embodiment provides a silicon carbide growth device 100, in which the seed crystal positioning cover 130 is connected to the weighing device 150 through a load-bearing connection 160, and the seed crystal positioning cover 130 is gap-fitted with the growth crucible 110, thereby avoiding the support of the seed crystal positioning cover 130 by the growth crucible 110, and the weighing device 150 can lift the seed crystal positioning cover 130 through the load-bearing connection 160, so that the seed crystal positioning cover 130, the seed crystal 131 and the grown silicon carbide crystal can only act on the weighing device 150, and the weight of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal is measured in real time by the weighing device 150, while the weight of the seed crystal positioning cover 130 and the seed crystal 131 is fixed, thereby realizing real-time and accurate measurement of the weight of the silicon carbide crystal, and can thereby realize process adjustment and improve the growth quality of the silicon carbide crystal. Second embodiment

[0066] 5 , this embodiment provides a silicon carbide growth device 100 , whose basic structure, principle and technical effects are the same as those of the first embodiment. For the sake of brief description, for parts not mentioned in this embodiment, reference may be made to the corresponding contents in the first embodiment.

[0067] In this embodiment, the load-bearing connector 160 includes a first connecting rod 165, an electric push rod 166, a second connecting rod 167, and a guide cylinder 168. The top end of the first connecting rod 165 is connected to the weighing device 150. The electric push rod 166 is disposed at the other end of the first connecting rod 165. One end of the second connecting rod 167 is connected to the electric push rod 166, and the other end is connected to the seed crystal positioning cover 130. The guide cylinder 168 is disposed on the first connecting rod 165 and is sleeved outside the electric push rod 166 and the second connecting rod 167. Specifically, the provision of the electric push rod 166 allows the second connecting rod 167 to be automatically adjusted up and down, thereby conveniently adjusting the distance between the seed crystal positioning cover 130 and the growth crucible 110. In addition, by setting up the guide cylinder 168, the second connecting rod 167 can be assembled in the guide cylinder 168, and the second connecting rod 167 can be guided and limited, thereby avoiding the horizontal torque generated by the electric push rod 166 from affecting the movement trajectory of the second connecting rod 167, thereby ensuring the assembly accuracy of the seed crystal positioning cover 130.

[0068] In this embodiment, in order to ensure that the gap L1 between the seed crystal positioning cover 130 and the growth crucible 110 is between 0.1-10 mm, for example, the gap is precisely controlled at 1 mm, the electric push rod 166 can also be used to first push the second connecting rod 167 downward to the extreme position, that is, the state where the seed crystal positioning cover 130 and the growth crucible 110 are abutted against each other, and then the electric push rod 166 is used to push the second connecting rod 167 upward by 1 mm. The precise advancement of the electric push rod 166 can ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is precisely controlled at 1 mm.

[0069] It should be noted that the basic structure of the electric push rod 166 in this embodiment can refer to existing technologies, and it can be connected to an external power source via a wire passing through the first connecting rod 165 to achieve power supply. The activation action of the electric push rod 166 can be calibrated here. For example, after the electric push rod 166 is activated, it will always push the second connecting rod 167 to the lowest point and then return it upward by 1 mm, achieving precise control of the seed crystal positioning cover 130. Of course, the gap value here can be adjusted according to actual conditions, and the return value of the electric push rod 166 can also be adaptively adjusted.

[0070] Referring to Figure 6, further, since the weight of the silicon carbide crystal will increase during the growth process, thereby increasing the force on the supporting connection 160, in order to avoid excessive pulling on the electric push rod 166 and affecting the normal operation of the electric push rod 166, in other preferred embodiments of the present invention, multiple damping rods 169 can be evenly arranged around the supporting connection 160. The multiple damping rods 169 can provide a certain amount of damping during the movement of the seed crystal positioning cover 130, and continue to provide damping after the seed crystal positioning cover 130 is fixed, thereby sharing a certain amount of force for the supporting connection 160.

[0071] In this embodiment, the weighing device 150 can be provided with a bearing plate, which is used to connect the bearing connector 160 below. The damping rod 169 includes a first damping cylinder 1691 and a second damping cylinder 1693. One end of the first damping cylinder 1691 is connected to the bearing plate, and the other end extends downward. One end of the second damping cylinder 1693 is sleeved on the first damping cylinder 1691, and the other end is connected to the seed crystal positioning cover 130. The outer wall of the first damping cylinder 1691 and the inner wall of the second damping cylinder 1693 are in direct contact, and small protrusions are provided on the outside of the first damping cylinder 1691 and the inner wall of the second damping cylinder 1693, thereby increasing the friction between the first damping cylinder 1691 and the second damping cylinder 1693, thereby providing a certain amount of damping. By setting the first damping cylinder 1691 and the second damping cylinder 1693, a moving connection friction force can be provided after the seed crystal positioning cover 130 is fixed in position, so that the tensile stress on the bearing connection part 160 can be dispersed. In addition, the first damping cylinder 1691 and the second damping cylinder 1693 can also play a certain guiding role, further avoiding the horizontal torque generated by the electric push rod 166 from affecting the movement trajectory of the second connecting rod 167, thereby ensuring the assembly accuracy of the seed crystal positioning cover 130.

[0072] It should be noted that the friction between the first damping cylinder 1691 and the second damping cylinder 1693 is much smaller than the driving force provided by the electric push rod 166. Therefore, when the electric push rod 166 acts, the friction between the first damping cylinder 1691 and the second damping cylinder 1693 does not affect the electric push rod 166 and the seed crystal positioning cover 130.

[0073] The silicon carbide growth device 100 provided in this embodiment adjusts the position of the seed crystal positioning cover 130 through the structure of the electric push rod 166 , which has high precision and accurate adjustment, and can ensure the assembly accuracy of the seed crystal positioning cover 130 . Third embodiment

[0074] 7 , this embodiment provides a silicon carbide growth device 100 , whose basic structure, principle and technical effects are the same as those of the first embodiment. For the sake of brief description, for parts not mentioned in this embodiment, reference may be made to the corresponding contents in the first embodiment.

[0075] In this embodiment, the diameter of the seed crystal positioning cover 130 is smaller than the inner diameter of the opening 111, and the seed crystal positioning cover 130 is disposed within the opening 111. The edge of the seed crystal positioning cover 130 corresponds to and has a clearance fit with the edge of the opening 111. Specifically, the seed crystal positioning cover 130 can be precisely assembled inside the opening 111 of the growth crucible 110, and the top side of the seed crystal positioning cover 130 can be flush with the top of the growth crucible 110. In this case, the periphery of the seed crystal positioning cover 130 has a clearance fit with the inner wall of the growth crucible 110, which can also prevent the growth crucible 110 from supporting and limiting the seed crystal positioning cover 130.

[0076] In this embodiment, the gap L1 between the periphery of the seed crystal positioning cover 130 and the inner wall of the growth crucible 110 can also be 0.1mm-10mm, preferably 1mm. Since the dimensions of the seed crystal positioning cover 130 and the growth crucible 110 are fixed in this embodiment, during actual assembly, it is only necessary to ensure that the seed crystal positioning cover 130 is accurately installed in the opening 111 to ensure that the gap is within the preset range. Therefore, there is no need for complex precision positioning methods, which makes the assembly accuracy between the seed crystal positioning cover 130 and the growth crucible 110 higher. Here, by properly controlling the gap, a balance is achieved between silicon carbide powder loss and weighing accuracy.

[0077] In this embodiment, a bent curtain 132 is further provided on the top edge of the seed crystal positioning cover 130. The bent curtain 132 is arranged corresponding to the edge of the opening 111 and blocks the gap between the seed crystal positioning cover 130 and the growth crucible 110. The bent curtain 132 cooperates with the top gap of the growth crucible 110. Specifically, the bent curtain 132 is integrally provided on the top edge of the seed crystal positioning cover 130 and is bent upward and outward. Preferably, the bent curtain 132 is annularly distributed around the edge of the seed crystal positioning cover 130, and the outer diameter of the bent curtain 132 is the same as the outer diameter of the growth crucible 110, thereby ensuring that the bent curtain 132 can completely block the gap between the seed crystal positioning cover 130 and the inner wall of the growth crucible 110. By providing the bent curtain 132, a large amount of gaseous material inside the growth crucible 110 can be prevented from overflowing, further reducing the loss of silicon carbide powder.

[0078] It should be noted that in this embodiment, the gap between the seed crystal positioning cover 130 and the growth crucible 110 is vertically arranged and directly connected to the interior of the growth crucible 110. After the silicon carbide powder inside the growth crucible 110 sublimates under the action of high temperature, it moves vertically upward to the seed crystal 131 under the action of the temperature gradient. Therefore, the airflow direction within the growth crucible 110 is also vertically upward, directly overflowing from the gap at a high overflow rate, resulting in a large amount of powder loss. Therefore, in this embodiment, by providing a curved barrier curtain 132, the vertically upward airflow can be blocked, achieving a slow flow, preventing the rapid outflow of large amounts of gaseous material, and effectively reducing powder loss.

[0079] In this embodiment, the gap L2 between the bent curtain 132 and the top of the growth crucible 110 can also be between 0.1 mm and 10 mm, preferably 1 mm. Specifically, the method for controlling the gap between the bent curtain 132 and the growth crucible 110 can refer to the positioning and then reversing method described in the first embodiment and will not be further described here. In contrast, the gap between the bent curtain 132 and the growth crucible 110 requires less precision and can be positioned directly by visual inspection.

[0080] The silicon carbide growth device 100 provided in this embodiment uses an embedded seed crystal positioning cover 130 to ensure that there is always a precise gap between the seed crystal positioning cover 130 and the growth crucible 110, eliminating the need for a complex positioning solution and making it simpler and more convenient. Fourth embodiment

[0081] 8 , this embodiment provides a silicon carbide growth method, which is applicable to the silicon carbide growth apparatus 100 in the first embodiment, the second embodiment, or the third embodiment. The growth method includes the following steps:

[0082] S1: Silicon carbide powder is loaded into the growth crucible 110 through the opening 111 .

[0083] Specifically, silicon carbide powder can be loaded through the opening 111 , and the amount of silicon carbide powder used can refer to conventional silicon carbide growth solutions.

[0084] S2 : placing the seed crystal positioning cover 130 with the seed crystal 131 at the opening 111 .

[0085] Specifically, the seed crystal 131 can be bonded to the seed crystal positioning cover 130 in advance, wherein the seed crystal positioning cover 130 is gap-matched with the edge of the opening 111. During actual assembly, the gap can be adjusted by the bearing connector 160 so that the gap is set between 0.1 mm and 10 mm, preferably around 1 mm.

[0086] S3: heating the growth crucible 110 using the heating device 120 and setting process parameters.

[0087] Specifically, the growth crucible 110 can be heated by the heating device 120, and process parameters such as temperature and pressure can be set. Before heating, the growth furnace and the growth crucible 110 can be evacuated to a vacuum of 5×10-6

[0088] The crucible 110 is heated to a temperature of 1800-2300°C. The crucible 110 is then filled with a process gas, which can be one or more of argon, nitrogen, hydrogen, and helium. The crucible 110 is then heated to a temperature of 1800-2300°C by a heating device 120. The silicon carbide powder sublimates into a gas, flowing along the temperature gradient from the high-temperature region to the low-temperature region, where it is deposited on the growth surface of the seed crystal 131 to form a silicon carbide single crystal.

[0089] S4: The weight of the seed crystal positioning cover 130 , the seed crystal 131 and the silicon carbide crystal is measured in real time by the weighing device 150 to obtain the weight of the silicon carbide crystal in real time.

[0090] Specifically, during the growth process, the weight of the silicon carbide crystal can be obtained in real time by the weighing device 150 , thereby monitoring the growth rate of the silicon carbide crystal in real time.

[0091] S5: Adjusting process parameters according to the weight of the silicon carbide crystal.

[0092] Specifically, during the monitoring process, corresponding process parameters, such as temperature or pressure, can be feedback-adjusted based on the weight change and growth rate of the silicon carbide crystal, thereby making the growth of the silicon carbide crystal more stable and efficient.

[0093] This embodiment also provides a silicon carbide crystal, which is prepared using the aforementioned silicon carbide crystal growth method, with high preparation efficiency and good crystal quality.

[0094] In summary, the silicon carbide growth method provided in this embodiment matches the seed crystal positioning cover 130 with the growth crucible 110 in a clearance manner, thereby avoiding the support of the seed crystal positioning cover 130 by the growth crucible 110, and the weighing device 150 can lift the seed crystal positioning cover 130 through the load-bearing connector 160, so that the seed crystal positioning cover 130, the seed crystal 131 and the grown silicon carbide crystal can only act on the weighing device 150, and the weight of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal is measured in real time by the weighing device 150, while the weight of the seed crystal positioning cover 130 and the seed crystal 131 is fixed, thereby realizing real-time and accurate measurement of the weight of the silicon carbide crystal, and realizing accurate monitoring of the crystal growth rate and weight, so as to realize process adjustment and improve the growth quality of the silicon carbide crystal.

[0095] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A silicon carbide growth device, characterized in that: include: A growth crucible (110), wherein the growth crucible (110) has an opening (111) and is used to contain silicon carbide powder; a heating device (120), the heating device (120) being arranged around the growth crucible (110) and used for heating the growth crucible (110); A seed crystal positioning cover (130), the seed crystal positioning cover (130) being arranged at the opening (111) and being gap-matched with an edge of the opening (111), a seed crystal (131) being bonded to the bottom side of the seed crystal positioning cover (130), the seed crystal (131) being used to grow silicon carbide crystals; A positioning frame (140), the positioning frame (140) at least partially extending above the growth crucible (110); a weighing device (150), the weighing device (150) being fixedly arranged on a portion of the positioning frame (140) extending above the growth crucible (110); A load-bearing connection member (160), one end of the load-bearing connection member (160) being connected to the top side of the seed crystal positioning cover (130), and the other end of the load-bearing connection member (160) being connected to the weighing device (150); The weighing device (150) is used to hoist the seed crystal positioning cover (130) via the load-bearing connection member (160), and to measure the weight of the seed crystal positioning cover (130), the seed crystal (131), and the silicon carbide crystal in real time; The edge of the seed crystal positioning cover (130) is also provided with a bent curtain (132), and the bent curtain (132) covers the gap between the seed crystal positioning cover (130) and the edge of the opening (111).

2. The silicon carbide growth device according to claim 1, characterized in that: The edge of the bent curtain (132) is sealed and engaged with the growth crucible (110), and is able to slide relative to the growth crucible (110).

3. The silicon carbide growth device according to claim 1, characterized in that: The diameter of the seed crystal positioning cover (130) is greater than the inner diameter of the opening (111), and the seed crystal positioning cover (130) is arranged above the opening (111), the edge of the seed crystal positioning cover (130) corresponds to the edge of the opening (111) and is gap-matched, and the bent curtain (132) is arranged on the outside of the top end of the growth crucible (110) and is gap-matched with the outer wall of the growth crucible (110).

4. The silicon carbide growth device according to claim 1, characterized in that: The diameter of the seed crystal positioning cover (130) is smaller than the inner diameter of the opening (111), and the seed crystal positioning cover (130) is arranged in the opening (111), the edge of the seed crystal positioning cover (130) corresponds to the edge of the opening (111) and is gap-matched, the bent curtain (132) is arranged corresponding to the edge of the opening (111) and blocks the gap between the seed crystal positioning cover (130) and the growth crucible (110), and the bent curtain (132) is gap-matched with the top end of the growth crucible (110).

5. The silicon carbide growth device according to claim 3 or 4, characterized in that: The load-bearing connecting member (160) comprises a screw rod (161), a screw sleeve (162) and a sleeve (163); the top end of the screw rod (161) is connected to the weighing device (150), and the outer peripheral surface of the screw rod (161) is provided with an external thread; the screw sleeve (162) is provided on the screw rod (161) and is threadedly connected to the screw rod (161); the sleeve (163) is sleeved outside the screw rod (161), and one end of the sleeve (163) is connected to the screw sleeve (162), and the other end is connected to the seed crystal positioning cover (130); the screw sleeve (162) is used to adjust the relative position of the screw rod (161) and the sleeve (163), so as to adjust the relative position between the seed crystal positioning cover (130) and the growth crucible (110).

6. The silicon carbide growth device according to claim 3 or 4, characterized in that: The load-bearing connecting member (160) comprises a first connecting rod (165), an electric push rod (166), a second connecting rod (167) and a guide cylinder (168); the top end of the first connecting rod (165) is connected to the weighing device (150); the electric push rod (166) is arranged at the other end of the first connecting rod (165); one end of the second connecting rod (167) is connected to the electric push rod (166), and the other end is connected to the seed crystal positioning cover (130); the guide cylinder (168) is arranged on the first connecting rod (165) and is sleeved outside the electric push rod (166) and the second connecting rod (167).

7. A method for growing silicon carbide, characterized in that: The growing method comprises: Filling silicon carbide powder into the growth crucible (110) through an opening (111); A seed crystal positioning cover (130) with a seed crystal (131) is arranged at the opening (111), wherein the seed crystal positioning cover (130) is matched with the edge gap of the opening (111), and a bent curtain (132) at the edge of the seed crystal positioning cover (130) blocks the gap between the seed crystal positioning cover (130) and the edge of the opening (111); Using a heating device (120) to heat the growth crucible (110), and setting process parameters; The weight of the seed crystal positioning cover (130), the seed crystal (131) and the silicon carbide crystal is measured in real time by a weighing device (150) to obtain the weight of the silicon carbide crystal in real time; The process parameters are adjusted according to the weight of the silicon carbide crystal.

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