A double-crucible silicon carbide crystal growth device and method based on a liquid-phase method

Abstract

The present application provides a double-crucible silicon carbide crystal growth device and method based on a liquid phase method, belonging to the technical field of semiconductor material preparation, including: a furnace body; a first crucible disposed inside the furnace body, and a plurality of first flow channels are provided along the circumferential direction of the first crucible on the inner side wall of the first crucible; a second crucible is embedded in the first crucible, and the second crucible can move along the height direction of the furnace body. A plurality of second flow channels are provided on the inner side wall of the second crucible, and the second flow channels correspond to and communicate with the first flow channels one by one. A first chamber is formed between the bottom wall of the second crucible and the first crucible; a lifting device is connected to the second crucible, and the lifting device is used to drive the second crucible to move along the height direction of the furnace body; a heating component is used to heat the first crucible and the second crucible. By using the double-crucible silicon carbide crystal growth device based on the liquid phase method provided by the present application, the evaporation effect of the solution can be inhibited, and the stability of long-term crystal growth can be improved; at the same time, by providing a raw material supply pipe, the consumed solute can be timely supplemented during the growth process, so that the mixed solution for growing silicon carbide crystals in the first crucible maintains the optimal ratio state.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor material preparation. Specifically, it relates to a double-crucible silicon carbide crystal growth device and method based on the liquid phase method. Background Art

[0002] As a representative third-generation wide-bandgap semiconductor material, silicon carbide has broad application prospects in fields such as new energy vehicles and energy storage due to its excellent properties such as high breakdown field strength, high thermal conductivity, high saturated electron mobility, high chemical stability, and radiation resistance. TSSG (TOP Seed Solution Growth) is a common method for growing SiC crystals. The TSSG method generally uses a graphite crucible to hold the Si raw material and the solvent Cr. The Si raw material and the solvent Cr melt to form a solution at high temperature. The carbon element in the graphite crucible containing the growth solution gradually dissolves in the solution and forms a nearly saturated solution at the high-temperature part. Since the temperature at the seed crystal is low and the solution is in a solute supersaturated state, SiC gradually precipitates and grows on the seed crystal.

[0003] The growth furnace of the TSSG method is a closed system, which is inherently unstable. The physical and chemical reactions proceed unidirectionally, and the growth conditions evolve irreversibly. Among various unstable factors, the evaporation of the solution and the evolution of the crucible configuration directly affect the stability of the growth conditions, causing them to deviate from the good initial design conditions. The growth of SiC crystals by the TSSG method is carried out in a high-temperature environment. Si and the solvent Cr in the solution are volatile. As the growth time extends, the volatilization of the solvent Cr leads to a decrease in the dissolution rate of carbon in the solution, thereby reducing the growth rate of SiC crystals. The volatilization and insufficient supply of Si will change the Si / C ratio in the solution, causing it to deviate from the optimal growth state (stoichiometric ratio of 1:1), affecting the long-term growth stability of SiC crystals.

[0004] Therefore, effectively suppressing the evaporation effect of the solution is of great significance for the long-term growth of crystals. Summary of the Invention

[0005] This application aims to provide a double-crucible silicon carbide crystal growth device and method based on the liquid phase method, aiming to suppress the evaporation effect of the solution and improve the long-term growth stability of the crystal.

[0006] The first aspect of the embodiment of this application provides a double-crucible silicon carbide crystal growth device based on the liquid phase method, including:

[0007] A furnace body;

[0008] A first crucible, arranged inside the furnace body. A plurality of first flow channels are evenly opened along the circumferential direction of the inner side wall of the first crucible, and the first flow channels are opened along the height direction of the furnace body;

[0009] A second crucible is embedded in the first crucible, and the second crucible can move along the height direction of the furnace body. A plurality of second flow channels are evenly formed on the inner side wall of the second crucible. The second flow channels penetrate through the side wall of the second crucible. The second flow channels correspond to and communicate with the first flow channels one by one. A first chamber is formed between the bottom wall of the second crucible and the first crucible;

[0010] A lifting device is arranged on the top wall of the furnace body. The lifting device is connected to the second crucible and is used to drive the second crucible to move along the height direction of the furnace body;

[0011] A seed crystal rod is rotatably arranged in the furnace body along the height direction of the furnace body. One end of the seed crystal rod passes through the second crucible into the first crucible, and a seed crystal holder is arranged at the end of the seed crystal rod located in the first crucible;

[0012] A heating assembly is arranged in the furnace body. The heating assembly surrounds the first crucible and the second crucible and is used to heat the first crucible and the second crucible;

[0013] A raw material supply pipe is arranged on the furnace body. One end of the raw material supply pipe is located outside the furnace body, and the other end extends into the second crucible.

[0014] Optionally, a boss structure is arranged at the central position of the bottom of the second crucible. The boss structure extends in a direction away from the first crucible, and the inside of the boss structure is hollow. A second chamber is formed between the boss structure and the side wall of the second crucible.

[0015] Optionally, the growth device further includes:

[0016] A plurality of flow control parts are respectively arranged at the communication positions of the corresponding first flow channels and the second flow channels. The flow control parts can move along the height direction of the furnace body to change the communication area at the communication positions of the first flow channels and the second flow channels.

[0017] Optionally, a stirring device is arranged on the seed crystal rod. The stirring device is located in the second crucible, and the stirring paddle of the stirring device extends into the second chamber.

[0018] Optionally, a limiting part is arranged at the position where the second crucible communicates with the first flow channel. The position where the limiting part is located is flush with the bottom wall of the second chamber.

[0019] Optionally, the material of the first crucible includes boron nitride, corundum, sapphire and tantalum carbide;

[0020] The material of the second crucible includes graphite.

[0021] In the second aspect of the embodiments of the present application, a double-crucible silicon carbide crystal growth device based on the liquid phase method is provided, including:

[0022] A furnace body;

[0023] A first crucible disposed in the furnace body, a circular ring portion is provided in the first crucible, an annular first flow channel is formed between the circular ring portion and the inner side wall of the first crucible, and there is a gap between the circular ring portion and the bottom wall of the first crucible. The circular ring portion and the inner side wall of the first crucible are connected by a plurality of first connecting plates;

[0024] A second crucible embedded in the first crucible, the outer wall of the second crucible is in contact with the inner wall of the circular ring portion, and the second crucible can move along the height direction of the furnace body. An annular second flow channel is opened at the bottom of the inner side wall of the second crucible. The second flow channel is communicated with the first flow channel, and a plurality of second connecting plates are arranged in the second flow channel. A first chamber is formed between the bottom wall of the second crucible and the first crucible;

[0025] A lifting device disposed on the top wall of the furnace body, the lifting device is connected to the second crucible, and the lifting device is used to drive the second crucible to move along the height direction of the furnace body;

[0026] A seed crystal rod rotatably disposed in the furnace body along the height direction of the furnace body. One end of the seed crystal rod passes through the second crucible into the first crucible, and a seed crystal holder is disposed at the end of the seed crystal rod located in the first crucible;

[0027] A heating assembly disposed in the furnace body, the heating assembly surrounds the first crucible and the second crucible, and the heating assembly is used to heat the first crucible and the second crucible.

[0028] Optionally, the plurality of first connecting plates are connected to each other, and a plurality of through holes are opened on the first connecting plates.

[0029] The plurality of second connecting plates are connected to each other, and a plurality of through holes are opened on the second connecting plates.

[0030] Optionally, the material of the first connecting plate includes boron nitride, corundum, sapphire and tantalum carbide;

[0031] The material of the second connecting plate includes boron nitride, corundum, sapphire and tantalum carbide.

[0032] In the third aspect of the embodiments of the present application, a double-crucible silicon carbide crystal growth method based on the liquid phase method is provided. The growth method includes:

[0033] Raw materials are added into the second crucible through a raw material supply pipe, and a heating component is used to heat the first crucible and the second crucible in the furnace body, and the first flow channel and the second flow channel in the double-crucible silicon carbide crystal growth device are in a closed state;

[0034] The lifting device is used to drive the second crucible to move away from the first crucible;

[0035] After heating to the target temperature, the first flow channel and the second flow channel are communicated, so that the second melt in the second crucible flows into the first crucible to form a first melt;

[0036] The seed crystal rod is used to drive the seed crystal holder to rotate above the first melt, so that silicon carbide crystals grow on the seed crystal of the seed crystal holder, and the raw materials in the second crucible are replenished in real time through the raw material supply pipe.

[0037] Beneficial effects:

[0038] The present application provides a double-crucible silicon carbide crystal growth device and method based on the liquid phase method. By setting a furnace body, a first crucible and a second crucible, wherein a plurality of first flow channels are opened on the inner side wall of the first crucible, the second crucible is embedded in the first crucible, and a second flow channel communicating with each first flow channel is opened on the bottom wall of the second crucible. A first chamber is formed between the bottom wall of the second crucible and the first crucible. The growth device further includes a lifting device, and the lifting device can drive the second crucible to move along the height direction of the furnace body, so that the air pressure in the first chamber can be changed during the crystal growth process, thereby effectively suppressing the evaporation effect of silicon and chromium during the growth process of silicon carbide crystals, reducing the consumption of silicon and chromium, and improving the stability of silicon carbide crystal growth; at the same time, by setting a raw material supply pipe, the consumed solute can be replenished in a timely manner during the growth process, so that the mixed solution for growing silicon carbide crystals in the first crucible maintains the best ratio state. Description of the drawings

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 is a schematic structural diagram of a double-crucible silicon carbide crystal growth device based on the liquid phase method proposed in an embodiment of the present application;

[0041] Figure 2 is Figure 1 the schematic structural diagram of the A-A cross section in

[0042] Figure 3 It is a schematic structural diagram of a first crucible and a second crucible in another liquid-phase-based double-crucible silicon carbide crystal growth device proposed in an embodiment of the present application;

[0043] Figure 4 is Figure 3 a schematic structural diagram of the B-B cross-section in;

[0044] Figure 5 is Figure 3 a schematic structural diagram of the C-C cross-section in.

[0045] Explanation of reference numerals: 1, furnace body; 2, heat insulation layer; 3, side heater; 4, first crucible; 5, first flow channel; 501, first connecting plate; 6, limiting part; 7, second flow channel; 701, second connecting plate; 8, flow control part; 9, second crucible; 10, raw material supply pipe; 11, lifting device; 1101, connecting rod; 1102, fixing nut; 12, crucible cover; 13, second chamber; 14, stirring device; 15, second melt; 16, seed crystal rod; 17, seed crystal holder; 18, first chamber; 19, seed crystal; 20, first melt; 21, bottom heater; 22, circular ring part. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0047] Embodiment 1

[0048] Referring to Figure 1 shown, a liquid-phase-based double-crucible silicon carbide crystal growth device disclosed in an embodiment of the present application, the growth device includes a furnace body 1, a first crucible 4, a second crucible 9, a lifting device 11, a seed crystal rod 16, and a heating assembly.

[0049] Specifically, the furnace body 1 can provide a stable environment for the growth of silicon carbide crystals.

[0050] Referring to Figure 1 and Figure 2As shown, the first crucible 4 is fixedly arranged in the furnace body 1. A plurality of first flow channels 5 are evenly arranged on the inner side wall of the first crucible 4 along the circumferential direction of the first crucible 4. The first flow channels 5 are arranged along the height direction of the furnace body 1 and extend to the bottom wall position of the first crucible 4. In the embodiment of the present application, a total of four first flow channels 5 are arranged on the inner side wall of the first crucible 4. At the same time, in the embodiment of the present application, the first crucible 4 is mainly used to contain the first melt 20, and the first melt 20 can be a mixed solution composed of Si, C and the solvent Cr.

[0051] Referring to Figure 1 As shown, the second crucible 9 is embedded in the first crucible 4, that is to say, the outer side wall of the second crucible 9 is in contact with the inner side wall of the first crucible 4. From the perspective of the dimensional relationship, the outer diameter of the second crucible 9 is approximately equal to the inner diameter of the first crucible 4 (the shapes of the first crucible 4 and the second crucible 9 are both circular). The second crucible 9 is mainly used to contain the second melt 15. At the same time, the second crucible 9 can move in the first crucible 4 along the height direction of the furnace body 1. A first chamber 18 is formed between the bottom wall of the second crucible 9 and the first crucible 4, and the first melt 20 is located in the first chamber 18.

[0052] Referring to Figure 1 and Figure 2 As shown, a plurality of second flow channels 7 are evenly arranged on the inner side wall of the second crucible 9 along the circumferential direction. The second flow channels 7 penetrate the side wall of the second crucible 9, and the second flow channels 7 correspond to and communicate with the first flow channels 5 one by one. In the embodiment of the present application, the second flow channels 7 are arranged at a position close to the bottom wall of the second crucible 9. In this way, the second melt 15 located in the second crucible 9 can flow into the first flow channels 5 through the second flow channels 7 and finally flow into the first crucible 4.

[0053] Referring to Figure 1 As shown, in order to control the flow of the first melt 20, in the embodiment of the present application, the growth device further includes a plurality of flow control parts 8.

[0054] Specifically, the flow control parts 8 correspond to each of the second flow channels 7 and the first flow channels 5 one by one, and the flow control parts 8 are arranged at the communication positions of the corresponding first flow channels 5 and the second flow channels 7. The flow control parts 8 can move along the height direction of the furnace body 1 to change the communication area at the communication positions of the first flow channels 5 and the second flow channels 7. That is to say, when the flow control parts 8 completely block the communication positions of the first flow channels 5 and the second flow channels 7, the first flow channels 5 and the second flow channels 7 are separated at this time; when the flow control parts 8 do not occupy the communication positions of the first flow channels 5 and the second flow channels 7 at all, the communication area between the first flow channels 5 and the second flow channels 7 is the largest. Therefore, by adjusting the positions of the flow control parts 8, the flow rate of the second melt 15 flowing into the first crucible 4 can be changed.

[0055] Meanwhile, in order to better seal the connection position between the first flow channel 5 and the second flow channel 7, in the embodiment of the present application, the flow control part 8 is set to be arc-shaped.

[0056] Referring to Figure 1 As shown, the lifting device 11 is arranged on the top wall of the furnace body 1, and the lifting device 11 is connected to the second crucible 9. The lifting device 11 can drive the second crucible 9 to move along the height direction of the furnace body 1.

[0057] Specifically, a crucible cover 12 is arranged on the top of the second crucible 9, and the crucible cover 12 is fixedly connected to the second crucible 9. At the same time, the lifting device 11 includes at least two connecting rods 1101 and a driving member connected to the connecting rods 1101. One end of the connecting rod 1101 away from the driving member penetrates through the crucible cover 12, and fixing nuts 1102 are arranged on both sides of the crucible cover 12 on the connecting rod 1101. By making the fixing nuts 1102 abut against the crucible cover 12, the fixed connection between the connecting rod 1101 and the crucible cover 12 can be realized. Then, by using the driving member, the connecting rod 1101 can be driven to move, and the crucible cover 12 and the second crucible 9 can be driven to move. The driving member can include a cylinder and the like.

[0058] Referring to Figure 1 As shown, in the embodiment of the present application, a boss structure is arranged at the central position of the bottom of the second crucible 9. The boss structure extends in a direction away from the first crucible 4, and the inside of the boss structure is hollow. A second chamber 13 is formed between the boss structure and the side wall of the second crucible 9. The boss structure can prevent the high-temperature melt in the second crucible 9 from penetrating into the first crucible 4 through fine gaps.

[0059] Referring to Figure 1 As shown, in order to better control the moving position of the second crucible 9, in the embodiment of the present application, a limiting part 6 is arranged at the position where the second flow channel 7 communicates with the first flow channel 5 on the second crucible 9. The limiting part 6 protrudes from the outer side wall of the second crucible 9, and the position where the limiting part 6 is located is flush with the bottom wall of the second chamber 13. When the lifting device 11 drives the second crucible 9 to move, the limiting part 6 will enable the second crucible 9 to move only within a certain range, that is, the second crucible 9 has a highest moving point and a lowest moving point.

[0060] In addition, referring to Figure 1 As shown, a raw material supplement pipe 10 is further arranged on the furnace body 1. One end of the raw material supplement pipe 10 is located outside the furnace body 1, and the other end extends into the second crucible 9. The raw material supplement pipe 10 can be used to supplement raw materials into the second crucible 9.

[0061] Referring to Figure 1As shown, the seed crystal rod 16 is rotatably arranged in the furnace body 1 along the height direction of the furnace body 1, and one end of the seed crystal rod 16 passes through the second crucible 9 into the first crucible 4. A seed crystal holder 17 is arranged at the end of the seed crystal rod 16 located in the first crucible 4, and a seed crystal 19 is arranged on the seed crystal holder 17. The crystallization growth of silicon carbide can be realized by using the seed crystal 19. At the same time, the seed crystal rod 16 can move along the height direction of the furnace body 1 to change the position of the seed crystal holder 17. In the embodiment of the present application, a stirring device 14 is arranged on the part of the seed crystal rod 16 located in the second crucible 9, and the stirring paddle of the stirring device 14 extends into the second chamber 13. The furnace body 1 further includes a driving unit that can drive the seed crystal rod 16 to rotate and move up and down.

[0062] Referring to Figure 1 As shown, the heating assembly is arranged in the furnace body 1, and the heating assembly is arranged around the first crucible 4 and the second crucible 9. The heating assembly is used to heat the first crucible 4 and the second crucible 9. In the embodiment of the present application, the heating assembly may include a side heater 3 and a bottom heater 21. The side wall heater surrounds the first crucible 4 and the second crucible 9, and the bottom heater 21 is located at the bottom of the first crucible 4. At the same time, a protective layer is arranged around the first crucible 4 and the second crucible 9. The heating of the first crucible 4 and the second crucible 9 can be realized by using these heaters.

[0063] The growth process of the silicon carbide crystal is as follows:

[0064] During the preparation period of crystal growth, the flow between the first flow channel 5 and the second flow channel 7 is maintained. First, the furnace body 1 is evacuated. When the pressure inside the furnace body 1 is maintained below 1×10-4 Pa, the side heater 3 and the bottom heater 21 are started. In the first step, the temperature is first raised to 700 °C, and it is kept at 700 °C for half an hour and filled with the protective gas Ar so that the pressure is 0.5 atm - 1.3 atm. At this time, the flow control part 8 is controlled to completely cover the second flow channel 7 to block the flow of the second melt 15 between the first flow channel 5 and the second flow channel 7. The connecting rod 1101 is controlled to move upward, and when the limiting part 6 reaches the highest point, the movement stops. At this time, the first chamber 18 has the maximum working volume.

[0065] In the second step, the side heater 3 near the second crucible 9 is controlled to raise the temperature of the second crucible 9 to 1700 - 1900 °C, so that the polycrystalline Si and Cr particles in the second crucible 9 are melted, and heat preservation is carried out for a period of time to saturate the melt with carbon.

[0066] After the preparation is completed, the lifting device 11 is controlled to lower the second crucible 9 along the axis, reduce the working volume of the first chamber 18, increase the total gas pressure above the first melt 20, and effectively inhibit the evaporation effect of Si and Cr in the first melt 20.

[0067] Control the side heater 3 and the bottom heater 21 near the first crucible 4 to heat the first crucible 4 to 1700 - 1900 °C. At this time, move the flow control unit 8 upward to connect the first flow channel 5 and the second flow channel 7, so that the second melt 15 flows towards the bottom of the first crucible 4 under the action of gravity and the pressure above the second melt 15, so as to form the first melt 20 for SiC crystal growth.

[0068] After controlling the seed crystal rod 16 to lower the seed crystal holder 17 to the liquid level position of the first melt 20, control the seed crystal holder 17 to rotate at a certain speed, and at the same time drive the stirring device 14 fixed to the seed crystal rod 16 to rotate to enhance the uniformity in the second melt 15.

[0069] During the long-term growth process of SiC, the consumption of Si and the change in the crucible shape caused by the dissolution of the graphite crucible will significantly affect the stability of the growth environment, deviating from the good initial growth conditions. For this reason, the second melt 15 that fully dissolves silicon and carbon elements continuously flows towards the first crucible 4 at a certain flow rate to supplement the solute consumed by the first crucible 4 during the growth process.

[0070] The second crucible 9 is connected to the raw material supply pipe 10 to replenish solutes such as Si and carbon in real time, so that the Si / C ratio in the second melt 15 always remains in the optimal growth state. To inhibit the evaporation effect of the second melt 15, gas is filled into the second chamber 13 to control the pressure above the second melt 15. The increase in its pressure helps to maintain the stable flow of the second melt 15 in the flow channel and prevent the interruption of flow caused by excessive pressure in the first chamber 18.

[0071] In the related art, due to the unsaturated conditions, the dissolved carbon element is continuously transported to the surface of the seed crystal 19 and the bottom of the crucible through convection and diffusion effects. Single crystals grow on the seed crystal 19, and polycrystals precipitate freely at the bottom of the crucible through spontaneous nucleation, resulting in additional Si consumption and C consumption. As the growth time extends, the shape of the crucible will change significantly, thus affecting the solution flow, temperature and growth rate during the growth process, and may lead to low crystal quality. In addition to quality problems, the excessive dissolution of the crucible wall may increase the risk of cracking of the crucible under high-speed rotation, leading to serious safety problems.

[0072] For this reason, in order to prevent the influence of the change in the crucible shape in the crystal growth region on the stability of the crystal growth environment, in the embodiment of the present application, a first crucible 4 made of a non-carbon material is selected. Exemplarily, the material of the first crucible 4 may include one of boron nitride, corundum, sapphire or tantalum carbide. The second crucible 9 is made of graphite material, and the thickness of the second crucible 9 is relatively thick, which can prevent the cracking phenomenon caused by the too thin crucible wall during the long-term growth process. At the same time, the real-time replenishment of carbon elements in the second crucible 9 helps to inhibit the dissolution of the second crucible 9 and maintain the stability of the crucible shape.

[0073] With the silicon carbide crystal growth device provided by the embodiments of the present application, an axial double crucible fitting structure is adopted to achieve real-time replenishment of solutes such as Si and carbon. On the one hand, it provides a solution with the optimal Si / C ratio for the long-term growth of SiC crystals, and on the other hand, it inhibits the dissolution of the graphite crucible used for preparing the growth solution. Moreover, by compressing the working volume and filling Ar gas to control the pressure of the first crucible 4 and the second crucible 9, the evaporation effect of the melt is effectively inhibited, and the consumption of Si and Cr is reduced.

[0074] In addition, the first crucible 4 for crystal growth is made of non-carbon material, which prevents the dissolution of the crucible in a high-temperature environment and maintains the stability of the crucible shape and the optimal growth environment during the long-term growth of SiC. The stirring device 14 can strengthen the transport of solutes such as carbon in the second melt 15 and prevent the deposition of solutes at the bottom of the second crucible 9. Adjusting the bottom heater 21 helps to form an axial temperature gradient with a lower temperature at the top and a higher temperature at the bottom in the crystal growth crucible, strengthens the transport of solutes towards the direction of the seed crystal 19, and inhibits the growth of SiC crystals at the bottom of the first crucible 4.

[0075] Embodiment 2

[0076] Based on the same inventive concept, referring to Figure 3 as shown, the embodiments of the present application also disclose a double-crucible silicon carbide crystal growth device based on the liquid phase method. This growth device also includes a furnace body 1 (not shown in the figure), a first crucible 4, a second crucible 9, a lifting device 11 (not shown in the figure), a seed crystal rod 16 (not shown in the figure), and a heating assembly (not shown in the figure).

[0077] Referring to Figure 3 and Figure 4 as shown, different from Embodiment 1, in the embodiments of the present application, a circular ring portion is provided inside the first crucible 4. An annular first flow channel 5 is formed between the circular ring portion and the inner side wall of the first crucible 4, and there is a gap between the circular ring portion and the bottom wall of the first crucible 4. The circular ring portion and the inner side wall of the first crucible 4 are connected by a plurality of first connecting plates 501.

[0078] Meanwhile, referring to Figure 3 and Figure 5 as shown, the outer wall of the second crucible 9 contacts the inner wall of the circular ring portion. An annular second flow channel 7 is formed on the inner side wall of the second crucible 9. The second flow channel 7 is communicated with the first flow channel 5, and a plurality of second connecting plates 701 are provided in the second flow channel 7.

[0079] That is to say, in the embodiments of the present application, both the first flow channel 5 and the second flow channel 7 are annular flow channels, which can better achieve the uniform inflow of the second melt 15, reduce the influence of liquid inflow on the volatility of the first melt 20, and maintain the stability of the melt environment.

[0080] In addition, referring to Figure 3As shown, in the embodiment of the present application, multiple first connecting plates 501 can be connected to each other, and multiple through holes are provided on the first connecting plate 501 ( Figure 3 as shown within the dashed box in Figure 3 ); multiple second connecting plates 701 can also be connected to each other, and multiple through holes are provided on the second connecting plate 701 (

[0081] as shown within the dashed box in

[0082] ). The inflow of the melt can be achieved through the through holes, and the first connecting plate 501 and the second connecting plate 701 connected to each other to form a ring can be more conducive to the uniform inflow of the melt.

[0081] Meanwhile, the material of the first connecting plate 501 includes one of boron nitride, corundum, sapphire, or tantalum carbide; the material of the second connecting plate 701 includes one of boron nitride, corundum, sapphire, or tantalum carbide to prevent the high-temperature solution from corroding the first connecting plate 501 and the second connecting plate 701.

[0082] Embodiment Three

[0083] The embodiment of the present application also discloses a method for growing a double-crucible silicon carbide crystal based on the liquid phase method, which is applied to the double-crucible silicon carbide crystal growth device provided in Embodiment One or Embodiment Two of the present application. The growth method includes:

[0084] Step 101: Add raw materials into the second crucible through the raw material supply pipe, and use the heating component to heat the first crucible and the second crucible in the furnace body, and the first flow channel and the second flow channel in the double-crucible silicon carbide crystal growth device are in a closed state.

[0085] Step 102: Use the lifting device to drive the second crucible to move away from the first crucible.

[0086] Step 103: After heating to the target temperature, connect the first flow channel and the second flow channel to enable the second melt in the second crucible to flow into the first crucible to form the first melt.

[0087] Step 104: Use the seed crystal rod to drive the seed crystal holder to rotate above the first melt so that silicon carbide crystals grow on the seed crystal of the seed crystal holder, and replenish the raw materials in the second crucible in real time through the raw material supply pipe.

[0088] It should be noted that the various embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0089] It should also be noted that in this text, terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to this application. In addition, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor can they be construed as indicating or implying relative importance. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or terminal device comprising the element.

[0090] The technical solutions provided by this application have been introduced in detail above. Specific examples are used in this text to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only for helping to understand this application, and the content of this specification should not be construed as a limitation to this application. At the same time, for those of ordinary skill in the art, based on this application, there will be various forms of changes in the specific implementation manners and application scopes. It is not necessary and impossible to enumerate all the implementation manners here, and the obvious changes or variations derived therefrom are still within the protection scope of this application.

Claims

1. A double crucible silicon carbide crystal growth device based on a liquid phase method, characterized in that Comprising: Furnace body; A first crucible, disposed within the furnace body, on the inner sidewall of the first crucible, a plurality of first flow channels are uniformly opened along the circumferential direction of the first crucible, and the first flow channels are opened along the height direction of the furnace body; the first crucible is made of non-carbon material; A second crucible, embedded within the first crucible, and the second crucible can move along the height direction of the furnace body. A plurality of second flow channels are uniformly opened on the inner sidewall of the second crucible, the second flow channels penetrate through the sidewall of the second crucible, the second flow channels correspond to and communicate with the first flow channels one by one, and a first chamber is formed between the bottom wall of the second crucible and the first crucible; the material of the second crucible includes graphite; A lifting device, disposed on the top wall of the furnace body, the lifting device is connected to the second crucible, and the lifting device is used to drive the second crucible to move along the height direction of the furnace body; A seed crystal rod, rotatably disposed within the furnace body along the height direction of the furnace body, one end of the seed crystal rod passes through the second crucible into the first crucible, and a seed crystal holder is disposed on the end of the seed crystal rod within the first crucible; A heating assembly, disposed within the furnace body, the heating assembly surrounds the first crucible and the second crucible, and the heating assembly is used to heat the first crucible and the second crucible; the heating assembly includes a bottom heater, and the bottom heater is located at the bottom of the first crucible; A raw material supply pipe, disposed on the furnace body, one end of the raw material supply pipe is outside the furnace body, and the other end extends into the second crucible.

2. The dual-crucible silicon carbide crystal growth device based on the liquid phase method according to claim 1, wherein: A boss structure is provided at the central position of the bottom of the second crucible, the boss structure extends in a direction away from the first crucible, and the inside of the boss structure is hollow, and a second chamber is formed between the boss structure and the sidewall of the second crucible.

3. The double-crucible silicon carbide crystal growth device based on the liquid phase method according to claim 1, wherein, The growth device further includes: A plurality of flow control parts, respectively disposed at the communication positions of the corresponding first flow channels and the second flow channels, and the flow control parts can move along the height direction of the furnace body to change the communication area at the communication positions of the first flow channels and the second flow channels.

4. The dual-crucible silicon carbide crystal growth device based on the liquid phase method according to claim 2, wherein: A stirring device is provided on the seed crystal rod, the stirring device is located within the second crucible, and the stirring paddle of the stirring device extends into the second chamber.

5. The dual-crucible silicon carbide crystal growth device based on the liquid phase method according to claim 4, wherein: A limiting part is provided at the position where the second crucible communicates with the first flow channel, and the position where the limiting part is located is flush with the bottom wall of the second chamber.

6. The dual-crucible silicon carbide crystal growth device based on the liquid phase method according to claim 1, wherein: The material of the first crucible includes one of boron nitride, corundum, sapphire and tantalum carbide.

7. A double crucible silicon carbide crystal growth device based on a liquid phase method, characterized in that, Comprising: Furnace body; The first crucible is arranged inside the furnace body. A ring part is arranged inside the first crucible. An annular first flow channel is formed between the ring part and the inner side wall of the first crucible. Moreover, there is a gap between the ring part and the bottom wall of the first crucible. The ring part and the inner side wall of the first crucible are connected by a plurality of first connecting plates. The first crucible is made of non-carbon material. The second crucible is embedded inside the first crucible. The outer wall of the second crucible contacts the inner wall of the ring part. Moreover, the second crucible can move along the height direction of the furnace body. An annular second flow channel is opened at the bottom of the inner side wall of the second crucible. The second flow channel is communicated with the first flow channel. Moreover, a plurality of second connecting plates are arranged inside the second flow channel. A first chamber is formed between the bottom wall of the second crucible and the first crucible. The material of the second crucible includes graphite. The lifting device is arranged on the top wall of the furnace body. The lifting device is connected with the second crucible. The lifting device is used for driving the second crucible to move along the height direction of the furnace body. The seed crystal rod is rotatably arranged inside the furnace body along the height direction of the furnace body. One end of the seed crystal rod passes through the second crucible to the inside of the first crucible. Moreover, a seed crystal holder is arranged at the end of the seed crystal rod located inside the first crucible. The heating component is arranged inside the furnace body. The heating component is arranged around the first crucible and the second crucible. The heating component is used for heating the first crucible and the second crucible. The heating component includes a bottom heater which is located at the bottom of the first crucible. The raw material supply pipe is arranged on the furnace body. One end of the raw material supply pipe is located outside the furnace body, and the other end extends to the inside of the second crucible.

8. The liquid-phase-based double-crucible silicon carbide crystal growth device according to claim 7, wherein: A plurality of the first connecting plates are connected to each other, and a plurality of through holes are opened on the first connecting plates. A plurality of the second connecting plates are connected to each other, and a plurality of through holes are opened on the second connecting plates.

9. The liquid-phase-based double-crucible silicon carbide crystal growth device according to claim 7, wherein: The material of the first connecting plate includes one of boron nitride, corundum, sapphire and tantalum carbide. The material of the second connecting plate includes one of boron nitride, corundum, sapphire and tantalum carbide.

10. A method for growing silicon carbide crystals with a double crucible based on the liquid phase method, which is applied to the double crucible silicon carbide crystal growth device described in any one of claims 1-6 or the double crucible silicon carbide crystal growth device described in any one of claims 7-9, characterized in that, The growth method includes: Adding raw materials into the second crucible through the raw material supply pipe, heating the first crucible and the second crucible inside the furnace body by using the heating component, and the first flow channel and the second flow channel in the double-crucible silicon carbide crystal growth device are in a closed state. Driving the second crucible to move away from the first crucible by using the lifting device. After heating to the target temperature, connecting the first flow channel and the second flow channel, so that the second melt in the second crucible flows into the first crucible to form a first melt. Driving the seed crystal holder to rotate above the first melt by using the seed crystal rod, so that silicon carbide crystals grow on the seed crystal of the seed crystal holder, and replenishing the raw materials inside the second crucible in real time through the raw material supply pipe.

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