Silicon carbide growth apparatus and method

Abstract

The present invention provides a silicon carbide growth apparatus and method, which relates to the technical field of silicon carbide crystal growth. The silicon carbide growth apparatus includes a growth crucible, a heating device, a seed crystal positioning cover, a positioning frame, a weighing device, and a load-bearing connecting member. The load-bearing connecting member connects the seed crystal positioning cover to the weighing device, and the seed crystal positioning cover is loosely fitted with the growth crucible, thereby avoiding the need for the seed crystal positioning cover to support the growth crucible. The weighing device can lift the seed crystal positioning cover through the load-bearing connecting member, so that the seed crystal positioning cover, the seed crystal, and the grown silicon carbide crystal only act on the weighing device. The weighing device measures the weights of the seed crystal positioning cover, the seed crystal, and the silicon carbide crystal in real time. Since the weights of the seed crystal positioning cover and the seed crystal are constant, the weight of the silicon carbide crystal can be precisely measured in real time, thereby adjusting the process and improving the growth quality of the silicon carbide crystal.

Description

[Technical Field]

[0001] The present invention relates to the field of silicon carbide crystal growth, and more particularly to an apparatus and method for growing silicon carbide. [Background technology]

[0002] Silicon carbide (SiC) is an emerging third-generation semiconductor core material. It has excellent properties such as a wide band gap, high critical breakdown field strength, high electron mobility, and good radiation resistance and chemical stability, making it an important and widely used substrate wafer material. It shows good prospects for application in fields such as aviation equipment, new energy vehicles, railway transportation, and home appliances.

[0003] Currently, silicon carbide crystals are mainly grown using physical vapor transport (PVT). However, through research by the inventors, they found that in many conventional growth devices, a seed crystal is attached to the crucible lid, and then the crucible lid is fixed to the crucible, forming a sealed "block box" structure, making it difficult to obtain information about the growth status of the internal crystal and to monitor the rate and weight of the crystal growth. Summary of the Invention

[0004] Objects of the present invention include providing a silicon carbide growth apparatus and method that directly measures the weight of the crystal growth, allowing for precise monitoring of the rate and weight of the crystal growth, and thereby adjusting the process to improve the growth quality of the silicon carbide crystal. [Means for solving the problem]

[0005] An embodiment of the present invention can be implemented as follows.

[0006] According to a first aspect, the present invention provides a method for manufacturing a semiconductor device comprising:

[0007] a growth crucible having an opening for containing silicon carbide powder;

[0008] a heating device disposed around the growth crucible for heating the growth crucible;

[0009] a seed crystal positioning cover that is placed on the opening and has a clearance fit with the edge of the opening, and has a seed crystal for growing silicon carbide crystals adhered to its bottom side;

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

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

[0012] a load-bearing connecting member having one end connected to the top side of the seed crystal positioning cover and the other end connected to the weighing device;

[0013] The weighing device is used to lift the seed crystal positioning cover via the load-bearing connecting member and measure the weight of the seed crystal positioning cover, the seed crystal, and the silicon carbide crystal in real time, providing a silicon carbide growth apparatus.

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

[0015] In an alternative embodiment, the edge of the seed crystal positioning cover is further provided with a bending curtain that blocks a gap between the seed crystal positioning cover and the edge of the opening.

[0016] In an alternative embodiment, the edges of the bending curtain sealingly engage the growth crucible and are slidable relative to the growth crucible.

[0017] In an alternative 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 installed above the opening, the edge of the seed crystal positioning cover corresponds to and fits loosely with the edge of the opening, and the bending curtain fits outside the top of the growth crucible and fits loosely with the outer wall of the growth crucible.

[0018] In an alternative 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 installed in the opening, the edge of the seed crystal positioning cover corresponds to the edge of the opening and fits snugly, the bending curtain is installed corresponding to the edge of the opening and blocks the gap between the seed crystal positioning cover and the growth crucible, and the bending curtain fits snugly with the top of the growth crucible.

[0019] In an alternative embodiment, the load-bearing connecting member includes a screw, a threaded sleeve, and a sleeve, the top of the screw is connected to the weighing device, and a male thread is installed on the outer surface of the screw, the threaded sleeve is installed on the screw and threadedly connected to the screw, the sleeve is fitted on the outside of the screw, and one end of the sleeve is connected to the threaded sleeve and the other end is connected to the seed crystal positioning cover, and the threaded 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 alternative embodiment, the load-bearing connecting member includes a first connecting rod, an electric push rod, a second connecting rod, and a guide tube, wherein the top of the first connecting rod is connected to the weighing device, the electric push rod is installed 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 tube is installed on the first connecting rod and fitted on the outside of the electric push rod and the second connecting rod.

[0021] According to a second aspect, the present invention provides a method for growing silicon carbide crystals, which is applied to the silicon carbide growth apparatus according to any one of the preceding embodiments.

[0022] The growth method comprises:

[0023] Loading silicon carbide powder into the growth crucible through an opening;

[0024] placing a seed crystal positioning cover over the opening, the seed crystal being a clearance fit with the edge of the opening;

[0025] Heating the growth crucible using a heating device and setting process parameters;

[0026] measuring the weight of the seed crystal positioning cover, the seed crystal, and the silicon carbide crystal in real time using a weighing device to obtain the weight of the silicon carbide crystal in real time;

[0027] and adjusting the process parameters based on the weight of the silicon carbide crystals.

[0028] According to a third aspect, the present invention provides silicon carbide crystals produced using the silicon carbide growth method described above.

[0029] Beneficial effects of embodiments of the present invention include, for example:

[0030] In the silicon carbide growth apparatus provided by the embodiment of the present invention, the seed crystal positioning cover is connected to the weighing device by a load-bearing connecting member, and the seed crystal positioning cover is loosely fitted with the growth crucible, thereby avoiding the need for the growth crucible to be supported by the seed crystal positioning cover, and the weighing device can lift the seed crystal positioning cover via the load-bearing connecting member, so that the seed crystal positioning cover, the seed crystal, and the grown silicon carbide crystal only act on the weighing device, and the weighing device measures the weight of the seed crystal positioning cover, the seed crystal, and the silicon carbide crystal in real time. Since the weights of the seed crystal positioning cover and the seed crystal are constant, the weight of the silicon carbide crystal can be accurately measured in real time. Compared with the prior art, the silicon carbide growth apparatus provided by the present invention directly measures the weight of the crystal growth, realizing precise monitoring of the crystal growth rate and weight, and thereby adjusting the process and improving the growth quality of the silicon carbide crystal. [Brief explanation of the drawings]

[0031] In order to more clearly explain the technical solutions of the embodiments of the present invention, the drawings that need to be used in the embodiments will be briefly described below. However, the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope. It should be understood that those skilled in the art can obtain other related drawings according to these drawings without requiring creative efforts. [Figure 1] 1 is a diagram showing the overall configuration of a silicon carbide growth apparatus provided according to a first embodiment of the present invention. [Figure 2] 1 is a partial schematic diagram of a silicon carbide growth apparatus provided by a first embodiment of the present invention; [Figure 3] FIG. 1 is a partial structural view of a silicon carbide growth apparatus according to another preferred embodiment of the present invention. [Figure 4] 3 is a diagram showing the connection configuration between the seed crystal positioning cover and the sleeve in FIG. 2. FIG. [Figure 5] FIG. 2 is a block diagram of a silicon carbide growth apparatus provided according to a second embodiment of the present invention. [Figure 6]FIG. 2 is another schematic diagram of a silicon carbide growth apparatus provided according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a block diagram of a silicon carbide growth apparatus provided according to a third embodiment of the present invention. [Figure 8] 10 is a flowchart of a method for growing silicon carbide provided by a fourth embodiment of the present invention.

[0032] Drawing symbols: 100 - silicon carbide growth apparatus, 110 - growth crucible, 111 - opening, 120 - heating device, 130 - seed crystal positioning cover, 131 - seed crystal, 132 - bending curtain, 1321 - flexible resistance element, 133 - boss, 134 - assembly groove, 135 - through groove, 136 - retaining ring groove, 137 - retaining block, 140 - positioning frame, 150 - weighing device, 160 - load-bearing connecting element, 161 - screw, 162 - threaded sleeve, 163 - sleeve, 164 - stop block, 165 - first connecting rod, 166 - electric push rod, 167 - second connecting rod, 168 - guide tube, 169 - damping rod, 1691 - first damping cylinder, 1693 - second damping cylinder, 200 - furnace body. DETAILED DESCRIPTION OF THE INVENTION

[0033] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, and not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings in this specification can be arranged and designed in a variety of different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention, provided by the drawings, is not intended to limit the scope of the claimed invention, but represents only selected embodiments of the present invention. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without requiring creative effort are included in the scope of the claims of the present invention.

[0035] It should be noted that like symbols and letters indicate like items in the following drawings, so that once an item is defined in one drawing, it need not be further defined or explained in subsequent drawings.

[0036] In describing the present invention, it should be explained that terms such as "upper," "lower," "inner," "outer," etc., when the indicated orientation or positional relationship is the orientation or positional relationship shown in the drawings or the orientation or positional relationship in which the product of the invention is customarily disposed when used, are intended to facilitate and simplify the description of the present invention, and are not intended to indicate or imply that the referred device or element must have a particular orientation, be configured, or operate in a particular orientation, and therefore should not be understood as a limitation of the present invention.

[0037] Additionally, when terms such as "first," "second," etc. appear, they are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0038] As disclosed in the background art, in the field of growing silicon carbide crystals using the PVT method, the prior art typically uses a fixed crucible, i.e., the crucible lid is usually closed to the crucible body by screws or engagement, and the seed crystal is adhered to the inside of the crucible lid, and in this case, the crucible body serves as a support for the crucible lid. This method forms a sealed "block box" structure, making it impossible to intuitively monitor the growth status of the internal crystal from the outside.

[0039] Furthermore, there is a method of calculating the amount of crystal growth by weighing the crucible or the powder remaining at the bottom, i.e., the amount of powder remaining. However, since powder is lost during the crystal growth process, the method of calculating the crystal weight based on the powder becomes inaccurate, and the obtained amount of crystal growth also becomes inaccurate, which also makes it difficult to monitor the rate and weight of crystal growth.

[0040] To solve the above problems, the present invention provides a silicon carbide growth apparatus, a silicon carbide crystal growth method, and a silicon carbide crystal. It should be noted that features in the embodiments of the present invention can be combined with each other unless they are inconsistent.

[0041] First Example

[0042] Referring to FIG. 1 , the present embodiment provides a silicon carbide growth apparatus 100 that directly measures the weight of the crystal growth, enabling precise monitoring of the rate and weight of the crystal growth, thereby adjusting the process and improving the growth quality of the silicon carbide crystal.

[0043] The silicon carbide growth apparatus 100 provided by this embodiment includes a growth crucible 110 having an opening 111 for containing silicon carbide powder, a heating device 120 installed around the growth crucible 110 for heating the growth crucible 110, a seed crystal positioning cover 130 installed at the opening 111 and loosely fitting with the edge of the opening 111, with a seed crystal 131 for growing silicon carbide crystals adhered to the bottom side, and a positioning frame 130 at least a portion of which extends above the growth crucible 110. The seed crystal positioning cover 130 includes a frame 140, a weighing device 150 fixedly installed on a portion of the positioning frame 140 extending above the growth crucible 110, and a load-bearing connecting member 160 having one end connected to the top side of the seed crystal positioning cover 130 and the other end connected to the weighing device 150. The weighing device 150 is used to lift the seed crystal positioning cover 130 via the load-bearing connecting 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.

[0044] In this embodiment, the silicon carbide growth apparatus 100 may be a growth furnace, in which the growth crucible 110 is installed inside the furnace body 200, the positioning frame 140 is installed on the top of the furnace body 200 and extends directly above the growth crucible 110, and the weighing device 150 is fixedly installed on the positioning frame 140 so that the components below can be weighed. Other components inside the growth furnace can refer to conventional silicon carbide growth furnaces and will not be described in detail here.

[0045] It should be noted that in this embodiment, the seed crystal positioning cover 130 is connected to the weighing device 150 via the load-bearing connecting member 160, and the seed crystal positioning cover 130 is loosely fitted with the growth crucible 110, thereby avoiding the need for the growth crucible 110 to be supported by the seed crystal positioning cover 130. The weighing device 150 can lift the seed crystal positioning cover 130 via the load-bearing connecting member 160, so that the seed crystal positioning cover 130, the seed crystal 131, and the grown silicon carbide crystal only act on the weighing device 150. The weighing device 150 measures the weights of the seed crystal positioning cover 130, the seed crystal 131, and the silicon carbide crystal in real time. Since the weights of the seed crystal positioning cover 130 and the seed crystal 131 are constant, the weight of the silicon carbide crystal can be precisely measured in real time, thereby realizing precise monitoring of the crystal growth rate and weight, thereby adjusting the process and improving the growth quality of the silicon carbide crystal.

[0046] In this embodiment, the weighing device 150 includes an electronic scale and a display (not shown). The electronic scale is fixedly installed on the positioning frame 140 and connected to the load-bearing connecting member 160, and the display is communicatively connected to the electronic scale. Specifically, the weighing accuracy of the electronic scale may be less than 1 gram, which is high. The display may be installed outside the positioning frame 140 and exposed to the outside of the growth furnace. The weighing data of the electronic scale may be directly displayed on the display so that an operator can easily monitor the readings of the electronic scale in real time.

[0047] The display may also display the growth rate, specifically, by analyzing the readings of the electronic scale and time, the weight growth rate of the silicon carbide crystals can be calculated and displayed on the display, allowing for better adjustment of process parameters. For example, if the display shows that the weight growth rate of the silicon carbide crystals is relatively low, the process parameters conducive to growth can be adjusted, such as increasing the heating temperature or adjusting the temperature gradient, to further improve the crystal growth rate.

[0048] In this embodiment, the gap L1 between the seed crystal positioning cover 130 and the edge of the opening 111 is between 0.1 mm and 10 mm. Preferably, the gap L1 between the seed crystal positioning cover 130 and the edge of the opening 111 is 1 mm. By appropriately controlling the gap L1, a balance can be achieved between the loss of silicon carbide powder and the weighing accuracy. If the gap is too small, for example, less than 0.1 mm, the distance between the seed crystal positioning cover 130 and the growth crucible 110 is too small, resulting in interference, which affects the lifting state of the growth crucible 110 and the seed crystal positioning cover 130 and further affects the weighing accuracy. If the gap is too large, for example, greater than 10 mm, excessive powder loss occurs, affecting the crystallization speed and quality.

[0049] 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, and the seed crystal positioning cover 130 is installed above the opening 111, with the edge of the seed crystal positioning cover 130 corresponding to the edge of the opening 111 and providing a clearance fit. Specifically, the diameter of the seed crystal positioning cover 130 is matched to the outer diameter of the growth crucible 110, so that the seed crystal positioning cover 130 can completely block the opening 111 of the growth crucible 110 in the vertical direction, thereby ensuring that the seed crystal 131 has sufficient adhesion space.

[0050] In this embodiment, the load-bearing connecting member 160 includes a screw 161, a threaded sleeve 162, and a sleeve 163. The top of the screw 161 is connected to the weighing device 150, and a male thread is installed on the outer surface of the screw 161. The threaded sleeve 162 is installed on the screw 161 and is threadedly connected to the screw 161. The sleeve 163 is fitted on the outside of the screw 161, and one end of the sleeve 163 is connected to the threaded sleeve 162 and the other end is connected to the seed crystal positioning cover 130. The threaded sleeve 162 is used to adjust the relative position of the screw 161 and the sleeve 163 so as to adjust the relative position between the seed crystal positioning cover 130 and the growth crucible 110. Specifically, the threaded sleeve 162 is integrally installed on the top of the sleeve 163, and the bottom of the sleeve 163 is fixedly connected to the top side of the seed crystal positioning cover 130. When actually installed, the sleeve 163 and the threaded sleeve 162 can be driven to rotate relative to the screw 161 by rotating the seed crystal positioning cover 130, and the relative position between the seed crystal positioning cover 130 and the growth crucible 110 can be further adjusted to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is between 0.1 mm and 10 mm.

[0051] It should be noted that in this embodiment, the number of rotations can be determined to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is accurately controlled to 1 mm. Specifically, the male thread pitch of the screw 161 may be 0.5 mm, so that one rotation of the seed crystal positioning cover 130 adjusts the distance by 0.5 mm. When actually installing, the seed crystal positioning cover 130 can be first rotated in the forward direction and adjusted downward to the limit position, i.e., the seed crystal positioning cover 130 resists the growth crucible 110. In this case, the seed crystal positioning cover 130 can be rotated in the reverse direction twice more to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is accurately controlled to 1 mm.

[0052] In this embodiment, a stop block 164 is further installed at the bottom of the screw 161, and the size of the stop block 164 is larger than the inner diameter of the threaded sleeve 162, thereby preventing the sleeve 163 and the threaded sleeve 162 from falling off the screw 161.

[0053] In this embodiment, a bending curtain 132 is further installed around the periphery of the seed crystal positioning cover 130. The bending curtain 132 is fitted onto the outside of the top of the growth crucible 110 and has a clearance fit with the outer wall of the growth crucible 110. Specifically, the material of the bending curtain 132 can be the same as that of the seed crystal positioning cover 130. The bending curtain 132 extends outward from the periphery of the seed crystal positioning cover 130 and bends downward. After the seed crystal positioning cover 130 is adjusted to a predetermined position, the bending curtain 132 can accurately block the gap between the seed crystal positioning cover 130 and the growth crucible 110, thereby blocking the overflow of a large amount of gaseous material inside the growth crucible 110 and further reducing the loss of silicon carbide powder.

[0054] It should be noted that in this embodiment, the bending curtain 132 is integrally installed on the periphery of the seed crystal positioning cover 130, and can form a groove around the inside of the seed crystal positioning cover 130, the size of which can be adapted to the size of the growth crucible 110 and can be slightly larger than the outer diameter of the growth crucible 110, and during actual assembly, the bending curtain 132 can be used to orient and align the growth crucible 110, thereby aligning the growth crucible 110 and the seed crystal positioning cover 130 and ensuring assembly accuracy.

[0055] Furthermore, in this embodiment, the gap L2 between the bending curtain 132 and the outer wall of the growth crucible 110 can be set to be between 0.1 mm and 10 mm. On the one hand, it is possible to prevent the growth crucible 110 from interfering with the seed crystal positioning cover 130, and on the other hand, it is possible to prevent a large amount of gaseous substances from overflowing, thereby reducing the loss of silicon carbide powder.

[0056] 3, in another preferred embodiment of the present invention, the edge of the bending curtain 132 is sealed and engaged with the growth crucible 110, and is slidable relative to the growth crucible 110. Specifically, a flexible resistance member 1321 can be installed on the bottom edge of the bending curtain 132. The flexible resistance member 1321 may be graphite paper, and it can resist the outer wall of the growth crucible 110 to further prevent the overflow of gaseous substances. In addition, since the graphite paper is lightweight and soft, it can slide freely between the growth crucible 110 and the graphite paper, and it is considered that the accuracy of the weighing device 150 is not affected.

[0057] In this embodiment, because the seed crystal positioning cover 130 loses support from the growth crucible 110, the weights of the seed crystal positioning cover 130, the seed crystal 131, and the silicon carbide crystal are all concentrated on the load-bearing connecting member 160. Therefore, it is necessary to reinforce the connection between the threaded sleeve 162 and the seed crystal positioning cover 130. Preferably, a boss 133 is formed by locally bulging out from the center of the top of the seed crystal positioning cover 130, and an assembly groove 134 is provided in the boss 133. The sleeve 163 is then assembled to the threaded groove to secure the sleeve 163 to the seed crystal positioning cover 130. Specifically, a through-groove 135 is provided in the side wall of the assembly groove 134, and a retaining ring groove 136 is provided at the bottom of the through-groove 135. A retaining block 137 can be provided around the bottom of the sleeve 163. The retaining block 137 is inserted into the retaining ring groove 136 along the through-groove 135 to secure the sleeve 163 to the assembly groove 134. Also, to avoid the loosening of the holding block 137 in the process of rotating the seed crystal positioning cover 130, an interference fit is ensured between the holding ring groove 136 and the holding block 137 here.

[0058] Furthermore, in order to avoid the boss 133 from affecting the thermal uniformity of the seed crystal positioning cover 130, a heat-insulating layer can be installed around the boss 133, and by adjusting the thickness of the heat-insulating layer, the thermal conductivity performance of each part of the seed crystal positioning cover 130 can be approximated, thereby ensuring thermal uniformity.

[0059] In summary, the silicon carbide growth apparatus 100 provided in this embodiment connects the seed crystal positioning cover 130 to the weighing device 150 via the load-bearing connecting member 160, and the seed crystal positioning cover 130 is loosely fitted with the growth crucible 110, thereby avoiding the need for the growth crucible 110 to be supported by the seed crystal positioning cover 130. The weighing device 150 can lift the seed crystal positioning cover 130 via the load-bearing connecting member 160, so that the seed crystal positioning cover 130, the seed crystal 131, and the grown silicon carbide crystal only act on the weighing device 150. The weighing device 150 measures the weights of the seed crystal positioning cover 130, the seed crystal 131, and the silicon carbide crystal in real time. Since the weights of the seed crystal positioning cover 130 and the seed crystal 131 are constant, the weight of the silicon carbide crystal can be precisely measured in real time, thereby adjusting the process and improving the growth quality of the silicon carbide crystal.

[0060] Second Example

[0061] Referring to FIG. 5, this embodiment provides a silicon carbide growth apparatus 100, the basic structure, principle and technical effects of which are the same as those of the first embodiment. For the sake of brevity, when any part of this embodiment is not mentioned, reference can be made to the corresponding content in the first embodiment.

[0062] In this embodiment, the load-bearing connecting member 160 includes a first connecting rod 165, an electric push rod 166, a second connecting rod 167, and a guide tube 168. The top of the first connecting rod 165 is connected to the weighing device 150, the electric push rod 166 is installed 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 tube 168 is installed on the first connecting rod 165 and fitted on the outside of the electric push rod 166 and the second connecting rod 167. Specifically, the electric push rod 166 can be installed to automatically adjust the vertical position of the second connecting rod 167, thereby adjusting the distance between the seed crystal positioning cover 130 and the growth crucible 110, which is very convenient. In addition, by installing the guide tube 168, the second connecting rod 167 can be attached to the guide tube 168, and the second connecting rod 167 can be guided and restricted, thereby avoiding the horizontal torque generated in the electric push rod 166 from affecting the movement trajectory of the second connecting rod 167, and ensuring the assembly accuracy of the seed crystal positioning cover 130.

[0063] 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 and 10 mm, for example, that the gap is accurately controlled to 1 mm, similarly, the electric push rod 166 is used to first push the second connecting rod 167 downward to the limit position, i.e., to a state where the seed crystal positioning cover 130 resists the growth crucible 110, and then the electric push rod 166 is used to push the second connecting rod 167 upward by 1 mm, and by accurately pushing the electric push rod 166, it is possible to ensure that the gap between the seed crystal positioning cover 130 and the growth crucible 110 is accurately controlled to 1 mm.

[0064] It should be noted that in this embodiment, the basic structure of the electric push rod 166 can refer to the prior art, and after passing through the first connecting rod 165 via a wire, it is connected to an external power source and can be supplied with power. Here, the activation operation of the electric push rod 166 can be calibrated. For example, after the electric push rod 166 is activated, it always advances the second connecting rod 167 to the bottom end and then returns it 1 mm upward to achieve accurate control of the seed crystal positioning cover 130. Of course, here, the value of the gap can be adjusted according to actual conditions, and in this case, the response value of the electric push rod 166 can also be adaptively adjusted.

[0065] Referring to FIG. 6 , furthermore, since the weight of the silicon carbide crystal increases during the growth process, the force received by the load-bearing connecting member 160 is further increased. To avoid excessive tension on the electric push rod 166 and affecting its normal operation, in another preferred embodiment of the present invention, multiple damping rods 169 can be uniformly installed around the load-bearing connecting member 160. The multiple damping rods 169 can provide a certain 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, and can bear a certain acting force for the load-bearing connecting member 160.

[0066] In this embodiment, a load-bearing plate can be installed on the weighing device 150, and connected to the lower load-bearing connecting member 160 by the load-bearing plate. 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 load-bearing plate, and the other end extends downward. One end of the second damping cylinder 1693 is fitted onto the outside of 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 is in direct contact with the inner wall of the second damping cylinder 1693. Microscopic protrusions are installed on both the outside of the first damping cylinder 1691 and the inner wall of the second damping cylinder 1693, which can increase the friction force between the first damping cylinder 1691 and the second damping cylinder 1693 and provide more consistent damping. The first damping cylinder 1691 and the second damping cylinder 1693 can provide a moving connection friction force after the position of the seed crystal positioning cover 130 is fixed, thereby dispersing the tensile stress experienced by the load-bearing connecting member 160. The first damping cylinder 1691 and the second damping cylinder 1693 can also perform a certain guiding function, further preventing the horizontal torque generated in the electric push rod 166 from affecting the movement trajectory of the second connecting rod 167, and ensuring the assembly accuracy of the seed crystal positioning cover 130.

[0067] It should be noted that, since the friction force between the first damping cylinder 1691 and the second damping cylinder 1693 is much smaller than the thrust force provided by the electric push rod 166, when the electric push rod 166 acts, the friction force 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.

[0068] The silicon carbide growth apparatus 100 provided in this embodiment adjusts the position of the seed crystal positioning cover 130 using the structure of the electric push rod 166, which has high precision and accurate adjustment, and can also ensure the assembly precision of the seed crystal positioning cover 130.

[0069] Third Example

[0070] Referring to FIG. 7, this embodiment provides a silicon carbide growth apparatus 100, the basic structure, principle and technical effects of which are the same as those of the first embodiment. For the sake of brevity, when parts of this embodiment are not mentioned, reference can be made to the corresponding content in the first embodiment.

[0071] 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 installed in the opening 111, with the edge of the seed crystal positioning cover 130 corresponding to and gap-fitting with the edge of the opening 111. Specifically, the seed crystal positioning cover 130 can be accurately assembled inside the opening 111 of the growth crucible 110, and the top side of the seed crystal positioning cover 130 can be aligned with the top of the growth crucible 110, with the periphery of the seed crystal positioning cover 130 gap-fitting with the inner wall of the growth crucible 110, thereby avoiding the support restriction of the growth crucible 110 relative to the seed crystal positioning cover 130.

[0072] 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 may be 0.1 mm to 10 mm, preferably 1 mm. In this embodiment, since the sizes of the seed crystal positioning cover 130 and the growth crucible 110 are fixed, during actual assembly, simply ensuring that the seed crystal positioning cover 130 is accurately inserted into the opening 111 ensures that the gap is within a predetermined range. This eliminates the need for complex precision positioning, and improves the assembly accuracy between the seed crystal positioning cover 130 and the growth crucible 110. By rationally controlling the gap, a balance can be achieved between the amount of silicon carbide powder loss and weighing accuracy.

[0073] In this embodiment, a bending curtain 132 is further installed on the uppermost edge of the seed crystal positioning cover 130. The bending curtain 132 is correspondingly installed on the edge of the opening 111, blocking the gap between the seed crystal positioning cover 130 and the growth crucible 110, and the bending curtain 132 is clearance-fitted with the top of the growth crucible 110. Specifically, the bending curtain 132 is integrally installed on the uppermost edge of the seed crystal positioning cover 130 and bent upward and outward. Preferably, the layer of the bending curtain 132 is distributed annularly on the edge of the seed crystal positioning cover 130, and the outer diameter of the bending curtain 132 is the same as the outer diameter of the growth crucible 110, so that the bending curtain 132 can ensure that the gap between the seed crystal positioning cover 130 and the inner wall of the growth crucible 110 is completely blocked. By installing the bending curtain 132, it is possible to block a large amount of gaseous substances from overflowing inside the growth crucible 110, thereby reducing the loss of silicon carbide powder.

[0074] It should be noted that in this embodiment, the gap between the seed crystal positioning cover 130 and the growth crucible 110 is vertically disposed and directly communicates with the interior of the growth crucible 110. Meanwhile, the silicon carbide powder in the growth crucible 110 sublimes under high temperature and then moves vertically upward under the temperature gradient to the seed crystal 131. Therefore, the airflow direction in the growth crucible 110 also rises vertically within the region, directly overflowing from the gap. The overflow speed is relatively high, resulting in a large amount of powder loss. Therefore, in this embodiment, the bending curtain 132 is installed to block the vertically rising airflow and realize a slow flow, preventing a large amount of gas material from suddenly leaking out and effectively reducing powder loss.

[0075] In this embodiment, the gap L2 between the bending curtain 132 and the top of the growth crucible 110 may be between 0.1 mm and 10 mm, preferably 1 mm. Specifically, the method for controlling the gap between the bending curtain 132 and the growth crucible 110 can refer to the inversion method after positioning in the first embodiment, and its description will be omitted here. Relatively speaking, the requirement for accuracy of the gap between the bending curtain 132 and the growth crucible 110 is relatively low, and positioning can also be performed directly by visual inspection.

[0076] The silicon carbide growth apparatus 100 provided by this embodiment is simpler and more convenient by using an embedded seed crystal positioning cover 130, and always ensures an accurate gap between the seed crystal positioning cover 130 and the growth crucible 110 without requiring a complicated positioning method.

[0077] Fourth Example

[0078] 8, this embodiment provides a silicon carbide growth method that is applied to the silicon carbide growth apparatus 100 in the first, second or third embodiment. The growth method includes the following steps.

[0079] S1: Silicon carbide powder is loaded into the growth crucible 110 through the opening 111.

[0080] Specifically, silicon carbide powder can be loaded through the opening 111, and the amount of silicon carbide powder used can be determined by reference to conventional silicon carbide growth methods.

[0081] S2: The seed crystal positioning cover 130 having the seed crystal 131 is placed in the opening 111.

[0082] Specifically, the seed crystal 131 can be pre-attached to the seed crystal positioning cover 130, and the seed crystal positioning cover 130 is then loosely fitted to the edge of the opening 111. During actual assembly, the gap can be set to between 0.1 mm and 10 mm, preferably about 1 mm, using the load-bearing connecting member 160.

[0083] S3: The growth crucible 110 is heated using the heating device 120, and process parameters are set.

[0084] Specifically, the growth crucible 110 is heated by the heating device 120, and process parameters such as temperature and pressure can be set. Here, before heating, the growth furnace and the growth crucible 110 are heated to a temperature of 5×10 -6 After evacuating to a pressure of 100 mbar or less, a process gas can be filled in. The process gas may be one or more selected from argon gas, nitrogen gas, hydrogen gas, helium gas, etc. Furthermore, the pressure inside the growth crucible 110 is maintained at 1 to 800 mbar, and then the growth crucible 110 is heated using the heating device 120. After the temperature reaches 1800 to 2300°C, the silicon carbide powder sublimes into a gas, flows from the high-temperature region to the low-temperature region along the temperature gradient, and deposits on the growth surface of the seed crystal 131 to form a silicon carbide single crystal.

[0085] S4: To obtain the weight of the silicon carbide crystal in real time, the weights of the seed crystal positioning cover 130, the seed crystal 131 and the silicon carbide crystal are measured in real time by the weighing device 150.

[0086] Specifically, by obtaining the weight of the silicon carbide crystal in real time during the growth process using weighing device 150, the growth rate of the silicon carbide crystal can be monitored in real time.

[0087] S5: Adjust the process parameters based on the weight of the silicon carbide crystals.

[0088] Specifically, during the monitoring process, the 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 enabling more stable and efficient growth of the silicon carbide crystal.

[0089] This embodiment further provides silicon carbide crystals that are produced using the silicon carbide crystal growth method, and have high production efficiency and excellent crystal quality.

[0090] In summary, in the silicon carbide growth method provided by this embodiment, the seed crystal positioning cover 130 is loosely fitted with the growth crucible 110, thereby avoiding the need for the growth crucible 110 to be supported by the seed crystal positioning cover 130. Furthermore, the weighing device 150 can lift the seed crystal positioning cover 130 via the load-bearing connecting member 160, so that the seed crystal positioning cover 130, the seed crystal 131, and the grown silicon carbide crystal only act on the weighing device 150. The weighing device 150 measures the weights of the seed crystal positioning cover 130, the seed crystal 131, and the silicon carbide crystal in real time. Since the weights of the seed crystal positioning cover 130 and the seed crystal 131 are constant, the weight of the silicon carbide crystal can be precisely measured in real time, allowing for precise monitoring of the crystal growth rate and weight, thereby adjusting the process and improving the growth quality of the silicon carbide crystal.

[0091] The above are merely specific embodiments of the present invention, but the scope of the claims of the present invention is not limited thereto, and any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention are included in the scope of the claims of the present invention. Therefore, the scope of protection of the present invention shall be in accordance with the scope of protection of the claims described.

Claims

1. 1. An apparatus for growing silicon carbide, comprising: a growth crucible (110) having an opening (111) and for containing silicon carbide powder; a heating device (120) disposed around the growth crucible (110) for heating the growth crucible (110); a seed crystal positioning cover (130) that is placed in the opening (111) and that fits snugly against the edge of the opening (111), and that has a seed crystal (131) attached to its bottom side for growing a silicon carbide crystal; a positioning frame (140) extending at least partially above the growth crucible (110); a weighing device (150) fixedly mounted on a portion of the positioning frame (140) extending above the growth crucible (110); a load-bearing connecting member (160) having one end connected to the top side of the seed crystal positioning cover (130) and the other end connected to the weighing device (150); the weighing device (150) is used to lift the seed crystal positioning cover (130) via the load-bearing connecting member (160) and measure the weight of the seed crystal positioning cover (130), the seed crystal (131), and the silicon carbide crystal in real time; A bending curtain (132) is further installed on the edge of the seed crystal positioning cover (130) to block the gap between the seed crystal positioning cover (130) and the edge of the opening (111).

1. A silicon carbide growth apparatus comprising:

2. The edges of the bending curtain (132) sealingly engage with the growth crucible (110) and are slidable relative to the growth crucible (110).

2. The silicon carbide growth apparatus of claim 1.

3. The diameter of the seed crystal positioning cover (130) is larger than the inner diameter of the opening (111), and the seed crystal positioning cover (130) is installed above the opening (111), and the edge of the seed crystal positioning cover (130) corresponds to and is loosely fitted with the edge of the opening (111), and the bending curtain (132) fits outside the top of the growth crucible (110) and is loosely fitted with the outer wall of the growth crucible (110); 2. The silicon carbide growth apparatus of claim 1.

4. 2. The silicon carbide growth apparatus of claim 1, wherein 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 installed in the opening (111), the edge of the seed crystal positioning cover (130) corresponds to the edge of the opening (111) and fits with it, and the bending curtain (132) is installed 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 bending curtain (132) fits with the top of the growth crucible (110).

5. The load-bearing connecting member (160) includes a screw (161), a threaded sleeve (162), and a sleeve (163). The top of the screw (161) is connected to the weighing device (150), and a male thread is installed on the outer circumferential surface of the screw (161). The threaded sleeve (162) is installed on the screw (161) and is threadedly connected to the screw (161). The sleeve (163) is fitted on the outside of the screw (161). One end of the sleeve (163) is connected to the threaded sleeve (162), and the other end is connected to the seed crystal positioning cover (130). The threaded sleeve (162) is used to adjust the relative position of the screw (161) and the sleeve (163) so as to adjust the relative position between the seed crystal positioning cover (130) and the growth crucible (110).

5. The silicon carbide growth apparatus according to claim 3 or 4.

6. The load-bearing connecting member (160) includes a first connecting rod (165), an electric push rod (166), a second connecting rod (167), and a guide tube (168), the top of the first connecting rod (165) is connected to the weighing device (150), the electric push rod (166) is installed 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), and the guide tube (168) is installed on the first connecting rod (165) and fitted on the outside of the electric push rod (166) and the second connecting rod (167).

5. The silicon carbide growth apparatus according to claim 3 or 4.

7. 1. A method for growing silicon carbide, comprising: Loading silicon carbide powder into the opening (111) of the growth crucible (110); placing a seed crystal positioning cover (130) having a seed crystal (131) in the opening (111); Heating the growth crucible (110) using a heating device (120) and setting process parameters; measuring the weight of the seed crystal positioning cover (130), the seed crystal (131) and the silicon carbide crystal in real time using a weighing device (150) to obtain the weight of the silicon carbide crystal in real time; and adjusting the process parameters based on the weight of the silicon carbide crystals; the seed crystal positioning cover (130) fits snugly against the edge of the opening (111) so that 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); A growth method characterized by:

Images