Device for growing silicon carbide crystals by using high performance liquid phase method

Abstract

The invention relates to a high performance liquid method silicon carbide crystal growth device, which comprises: a furnace body, a heating member and a crucible assembly, the furnace body is provided with a furnace chamber, the crucible assembly is at least partially arranged in the furnace chamber, the crucible assembly comprises a substrate, more than two graphite crucibles and a driving member, and the driving member is arranged on the substrate. The graphite crucible is arranged on the base plate, the driving part is used for driving the base plate to move so as to switch the position of the graphite crucible, and the heating part is used for heating the graphite crucible. Compared with the condition that the silicon carbide crystals can only grow in one crucible, the device for growing the silicon carbide crystals by the high-performance liquid phase method can realize the growth of the silicon carbide crystals in more than two graphite crucibles, and the growth time of the silicon carbide crystals is prolonged, so that silicon carbide crystal ingots with enough thickness can be obtained.

Description

Technical Field

[0001] The present application relates to the technical field of silicon carbide preparation, and in particular to a device for growing silicon carbide crystals using a high-efficiency liquid phase method. Background Art

[0002] Silicon carbide (SiC), one of the most closely watched third-generation semiconductor materials, boasts excellent properties such as a wide bandgap, high breakdown field strength, high thermal conductivity, high temperature resistance, and a large electron saturation drift rate. It is considered an ideal substrate material for the fabrication of high-voltage, high-frequency, and high-power semiconductor devices, and has been widely used in key fields such as smart grids, new energy vehicles, and aerospace. Currently, while the physical vapor transport method is relatively mature and can supply a large number of silicon carbide single crystal substrates to the market, due to the unstable growth environment, its crystals still suffer from high dislocation density and difficulty in growing highly doped P-type crystals. In contrast, the liquid phase method requires a low growth temperature and a relatively stable growth environment. By introducing metal elements such as aluminum under conditions close to thermodynamic equilibrium, highly doped P-type silicon carbide single crystals with extremely low dislocation density can be produced.

[0003] The current growth apparatus for silicon carbide crystals grown using the liquid-phase method consists of a graphite crucible and an external heating coil that induction heats the graphite crucible. The graphite crucible serves as both a container for the high-temperature solution and a carbon source. During crystal growth, the crucible is first heated by the heating coil until the raw material inside is completely melted. Once a stable temperature field is established and the carbon concentration in the high-temperature solution reaches equilibrium, a seed rod containing a seed crystal is slowly immersed into the high-temperature solution from the top. The axial temperature gradient within the crucible creates a differential carbon solubility, and a silicon carbide single crystal grows on the surface of the seed crystal. During crystal growth, because the graphite crucible acts as a carbon source, the crucible's own carbon is continuously dissolved by the high-temperature solution without being replenished. If liquid-phase growth continues for too long, the crucible can be severely corroded or even eroded through. Therefore, to prevent crucible erosion, the crystal growth time is typically shortened, which directly results in insufficient silicon carbide ingot thickness. Summary of the Invention

[0004] Based on this, it is necessary to provide a high-efficiency liquid phase silicon carbide crystal growth device that can extend the silicon carbide crystal growth time.

[0005] The present application provides a device for growing silicon carbide crystals using a high-efficiency liquid phase method, comprising: a furnace body, a heating element, and a crucible assembly, wherein the furnace body is provided with a furnace chamber, the crucible assembly is at least partially provided in the furnace chamber, the crucible assembly comprises a substrate, a graphite crucible, and a driving element, the graphite crucibles being provided in a number of at least two, the graphite crucibles being provided on the substrate, the driving element being used to drive the substrate to move so as to switch the position of the graphite crucible, and the heating element being used to heat the graphite crucible.

[0006] In one embodiment, two or more graphite crucibles are arranged along the circumference of the substrate, the substrate is fixedly connected to a support rod, and the driving member is configured to drive the support rod to rotate around its own axis, and the driving member is configured to be a motor.

[0007] In one embodiment, any two adjacent graphite crucibles are connected via a graphite pipe, and the graphite pipe is provided on the side wall of the bottom of the graphite crucible.

[0008] In one embodiment, the support rod is perpendicular to the base plate and is tilted relative to the vertical direction.

[0009] In one embodiment, any two graphite crucibles are not connected.

[0010] In one embodiment, a connecting through hole is provided on the substrate, an inner wall of the connecting through hole is provided with an internal thread, an outer wall of the graphite crucible is provided with an external thread adapted to the internal thread, and the graphite crucible is threadedly connected to the connecting through hole.

[0011] In one embodiment, the connecting through hole is arranged to be inclined from bottom to top toward the central axis of the substrate.

[0012] In one embodiment, a pressure sensor is provided on the support rod or the driving member, and the pressure sensor is used to detect pressure changes on the support rod. The pressure sensor is electrically connected to a controller, and the controller is electrically connected to the driving member. The controller is used to control the start and stop of the driving member according to the pressure detected by the pressure sensor.

[0013] In one embodiment, the furnace body includes a quartz cover and a heat-insulating cover arranged in the quartz cover, the heating element is arranged on the outer peripheral side of the quartz cover, the heat-insulating cover includes a cover body and a cover, the cover body and the cover cover enclose the furnace cavity, the substrate and the graphite crucible are arranged in the furnace cavity, the driving element is arranged outside the furnace cavity, and the support rod is passed through the cover body.

[0014] In one embodiment, the heating element is configured as a heating coil, which is annular or spiral and surrounds the outer periphery of the furnace body, and a cooling channel is provided in the heating coil.

[0015] Compared with the prior art, the device for growing silicon carbide crystals using the high-efficiency liquid phase method provided by the present application has a crucible assembly comprising two or more graphite crucibles and is provided with a driving member for driving the movement of the substrate. When the graphite crucible at the target position is corroded and damaged, the driving member can be used to drive the substrate to move, switch the position of the graphite crucible, and transfer the new graphite crucible to the target position, thereby realizing the replacement of the graphite crucible. The device for growing silicon carbide crystals using the high-efficiency liquid phase method does not require opening the furnace chamber when replacing the graphite crucible, thus avoiding the problem of unstable growth of silicon carbide single crystals caused by reopening the furnace and loading the furnace, omitting the step of reopening the furnace and loading the furnace, ensuring the continuity of the production process, saving time, and improving production efficiency. Compared with the situation where growth can only be achieved in one crucible, the device for growing silicon carbide crystals using the high-efficiency liquid phase method of the present application can achieve the growth of silicon carbide crystals in two or more graphite crucibles, extending the growth time of the silicon carbide crystals, thereby obtaining silicon carbide ingots of sufficient thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following is a brief introduction to the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A partially cutaway perspective view of an apparatus for growing silicon carbide crystals using a high performance liquid phase method according to an embodiment of the present application;

[0018] Figure 2 A half-cutaway perspective view of an apparatus for growing silicon carbide crystals using a high-performance liquid phase method according to an embodiment of the present application;

[0019] Figure 3 A half-sectional side view of an apparatus for growing silicon carbide crystals using a high-performance liquid phase method according to an embodiment of the present application;

[0020] Figure 4 A side view of an apparatus for growing silicon carbide crystals using a high performance liquid phase method according to an embodiment of the present application;

[0021] Figure 5 A perspective view of a crucible assembly according to an embodiment of the present application;

[0022] Figure 6 for Figure 5 A schematic diagram of another perspective of the crucible assembly shown;

[0023] Figure 7 for Figure 5 A top view of the crucible assembly is shown.

[0024] Figure numerals: 10, furnace body; 11, furnace chamber; 12, heat preservation cover; 121, cover body; 122, cover; 13, quartz cover; 20, heating element; 21, cooling channel; 30, crucible assembly; 31, substrate; 311, connecting through hole; 32, graphite crucible; 321, mounting through hole; 33, driving part; 34, support rod; 35, connecting part; 36, graphite pipe; 37, pressure sensor; 40, seed crystal rod; 50, seed crystal. DETAILED DESCRIPTION

[0025] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0026] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0028] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more of the relevant listed items.

[0030] See Figures 1 to 7 The present application provides an apparatus for growing silicon carbide crystals using a high-efficiency liquid phase method, comprising: a furnace body 10, a heating element 20, and a crucible assembly 30. The furnace body 10 is provided with a furnace chamber 11, and the crucible assembly 30 is at least partially disposed within the furnace chamber 11. The crucible assembly 30 includes a substrate 31, a graphite crucible 32, and a driving element 33. Two or more graphite crucibles 32 are provided, and the graphite crucibles 32 are disposed on the substrate 31. The driving element 33 is used to drive the substrate 31 to move to switch the position of the graphite crucible 32. The heating element 20 is used to heat the graphite crucible 32. It is understood that the apparatus for growing silicon carbide crystals using a high-efficiency liquid phase method also includes a seed crystal rod 40, which is used to connect to a seed crystal 50 to control the rotation and elevation of the seed crystal 50. The graphite crucible 32 serves as a container for the raw materials required for silicon carbide crystal growth and continuously provides carbon elements during the silicon carbide crystal growth process. During silicon carbide growth, the graphite crucible 32 is filled with the raw materials required for crystal growth, and the graphite crucible 32 and the raw materials within the graphite crucible 32 are heated by the heating element 20. A seed crystal 50 is placed on the seed crystal rod 40 and inserted into the graphite crucible 32 at the target position, thereby achieving silicon carbide growth. Because the crucible assembly 30 includes two or more graphite crucibles 32 and is provided with a driving element 33 for driving the movement of the substrate 31, if the graphite crucible 32 at the target position is corroded and damaged, the driving element 33 can drive the substrate 31 to move, switching the position of the graphite crucible 32 so that a new graphite crucible 32 is transferred to the target position, thereby achieving the replacement of the graphite crucible 32. This high-efficiency liquid phase method for silicon carbide crystal growth does not require opening the furnace chamber 11 when replacing the graphite crucible 32, avoiding the problem of unstable silicon carbide single crystal growth caused by reopening the furnace and reloading the furnace. This eliminates the step of reopening the furnace and reloading the furnace, ensuring the continuity of the production process, saving time, and improving production efficiency. Compared with the situation where silicon carbide can only grow in one crucible, the high-efficiency liquid phase method for growing silicon carbide crystals of the present application can realize the growth of silicon carbide crystals in more than two graphite crucibles 32, thereby extending the growth time of silicon carbide crystals and obtaining silicon carbide ingots of sufficient thickness.

[0031] It is understood that the seed crystal 50 is the seed crystal 50 required for the growth of silicon carbide crystals, which is fixed by the seed crystal rod 40 and extends into the graphite crucible 32 during the growth of silicon carbide, so that the crystal grows on the seed crystal 50. The function of the seed crystal rod 40 is to connect the seed crystal 50, such as Figures 1 to 3As shown, a seed crystal 50 is connected to the lower end of a seed crystal rod 40. By controlling the rotation and elevation of the seed crystal 50, the seed crystal 50 can be inserted into the graphite crucible 32 for silicon carbide growth, and the seed crystal 50 can be removed from the graphite crucible 32 when the graphite crucible 32 is replaced or when silicon carbide growth is completed. The seed crystal rod 40 can be made of graphite.

[0032] Furthermore, two or more graphite crucibles 32 are arranged along the circumference of the base plate 31. The base plate 31 is fixedly connected to a support rod 34, and a driver 33 is used to drive the support rod 34 to rotate about its axis. In this way, the driver 33 can switch the position of the graphite crucible 32 by controlling the rotation of the base plate 31, making the control method very simple and easy to implement. In this embodiment, the driver 33 is equipped with a motor, which can achieve precise control of the rotation of the base plate 31 and is easy to operate.

[0033] The support rod 34 can be connected to the lower side of the base plate 31 via a connector 35. In this embodiment, the connector 35 is provided on the lower surface of the base plate 31. The connector 35 can be an integrally formed structure with the base plate 31, or it can be an independent structure fixed to the lower surface of the base plate 31. This application does not impose any restrictions on this. Furthermore, the connector 35 is provided with a slot, and one end of the support rod 34 is inserted into the slot to achieve connection with the connector 35. The support rod 34 can be connected to the slot by an interference fit or by a threaded connection. This application does not impose any restrictions on this, as long as the support rod 34 can be connected to the base plate 31 via the connector 35.

[0034] See Figure 3 、 Figure 5 and Figure 6 In one embodiment, any two adjacent graphite crucibles 32 are connected by a graphite pipe 36 disposed on the sidewall of the bottom of the graphite crucible 32. This allows the solution in a graphite crucible 32 to flow into an adjacent graphite crucible 32. Therefore, when a new graphite crucible 32 is replaced for silicon carbide growth, the solution in the original graphite crucible 32 can flow into the new one, allowing the remaining solution to be reused, thereby reducing production costs.

[0035] It is understood that a mounting hole 321 may be provided on the sidewall of the graphite crucible 32, into which the end of the graphite pipe 36 is inserted, thereby establishing communication between the graphite pipe 36 and the interior of the graphite crucible 32. In one embodiment, the mounting hole 321 may be internally threaded, and the outer wall of the graphite pipe 36 may be externally threaded. In this manner, the graphite pipe 36 may be connected to the mounting hole 321 via a threaded connection. However, the present invention is not limited thereto. The graphite pipe 36 may also be connected to the mounting hole 321 via an interference fit. In this manner, installation requires only inserting the end of the graphite pipe 36 into the mounting hole 321.

[0036] See Figures 1 to 3 Furthermore, the support rod 34 is perpendicular to the substrate 31 and is tilted relative to the vertical direction. Correspondingly, the substrate 31 is tilted relative to the horizontal direction, so that the graphite crucibles 32 arranged on the substrate 31 are at different heights. In this way, when growing silicon carbide, the graphite crucible 32 at the lower position is used as the target crucible, and the seed crystal 50 is inserted into the target crucible for silicon carbide growth. When the silicon carbide crystal grows to a certain extent and the graphite crucible 32 needs to be replaced, the driving member 33 drives the substrate 31 to rotate, so that the upper graphite crucible 32 is switched to the lower position. Accordingly, the previously used graphite crucible 32 is switched to the upper position, and the residual solution in the previously used graphite crucible 32 is more easily flowed into the new graphite crucible 32 at the lower position, making it convenient to reuse the residual solution in the previously used graphite crucible 32.

[0037] In another embodiment, no two graphite crucibles 32 are connected, that is, no graphite conduit 36 ​​is provided. This allows different graphite crucibles 32 to be filled with different growth materials, thereby growing different types of silicon carbide crystals, making the growth of silicon carbide crystals more flexible and diverse. In this embodiment, since there is no need to transfer the solution in a graphite crucible 32 to a new graphite crucible 32, the substrate 31 can be arranged horizontally, and accordingly, the support rods 34 can be arranged vertically.

[0038] See Figures 5 to 7 In this embodiment, three graphite crucibles 32 are provided. Furthermore, the three graphite crucibles 32 are evenly spaced along the circumference of the substrate 31. This ensures that the force on the substrate 31 is balanced, making the rotation of the substrate 31 controlled by the driving member 33 more stable and preventing the solution in the graphite crucibles 32 from spilling. Of course, in other embodiments, the number of graphite crucibles 32 may be other numbers, such as two, four, five, etc.

[0039] The substrate 31 is made of graphite, which facilitates heat transfer with the graphite crucibles 32, thereby achieving a more uniform temperature across the graphite crucibles 32 on the substrate 31. In this embodiment, the substrate 31 is circular so that it does not occupy much space when rotating. Of course, in other embodiments, the substrate 31 may also have other shapes, such as a square.

[0040] Furthermore, the substrate 31 is provided with a connecting through-hole 311, the inner wall of which is provided with an internal thread. The outer wall of the graphite crucible 32 is provided with an external thread that matches the internal thread. The graphite crucible 32 is threadedly connected to the connecting through-hole 311. In this way, the graphite crucible 32 is connected to the substrate 31 via a threaded connection. This arrangement makes it easy to install the graphite crucible 32 on the substrate 31 and also facilitates removal of the graphite crucible 32 if damaged. The substrate 31 can also be reused.

[0041] It can be understood that the number of the connecting through holes 311 corresponds to the number of the graphite crucibles 32 . In this embodiment, the number of the graphite crucibles 32 is three, and accordingly, the number of the connecting through holes 311 is three.

[0042] Furthermore, the connecting through-hole 311 is tilted upward from bottom to top toward the central axis of the substrate 31. This allows the upper opening of the graphite crucible 32 to be closer to the central axis of the substrate 31. When the driving member 33 rotates the substrate 31, the solution in the graphite crucible 32 is less likely to spill. Furthermore, the graphite conduit 36 ​​facilitates the flow of solution from the upper graphite crucible 32 to the lower graphite crucible 32, making it easier to utilize any remaining solution when replacing a new graphite crucible 32 for silicon carbide growth.

[0043] Of course, the graphite crucible 32 may also be connected to the substrate 31 in other ways.

[0044] Furthermore, a pressure sensor 37 is provided on the support rod 34 or the drive member 33. The pressure sensor 37 is used to detect pressure changes on the support rod 34. The pressure sensor 37 is electrically connected to a controller, which is electrically connected to the drive member 33. The controller is used to control the start and stop of the drive member 33 based on the pressure detected by the pressure sensor 37. During silicon carbide crystal growth, the weight of the graphite crucible 32 connected to the substrate 31 will decrease due to crystal growth and volatilization of the solution, thereby reducing the pressure on the support rod 34. Therefore, the crystal growth status can be determined based on the pressure changes on the support rod 34. By providing the pressure sensor 37, this embodiment can detect the pressure of the support rod 34. Therefore, based on the pressure changes on the support rod 34, the drive member 33 can be controlled when the silicon carbide crystal grows to a certain extent. The drive member 33 can also drive the substrate 31 to rotate, thereby replacing the graphite crucible 32, which is very convenient.

[0045] See Figures 1 to 4 The furnace body 10 includes a quartz cover 13 and a heat-insulating cover 12 arranged in the quartz cover 13, and the heating element 20 is arranged on the outer peripheral side of the quartz cover 13. The heat-insulating cover 12 includes a cover body 121 and a cover 122. The cover body 121 and the cover 122 enclose the furnace chamber 11. The substrate 31 and the graphite crucible 32 are arranged in the furnace chamber 11. The driving element 33 is arranged outside the furnace chamber 11, and the support rod 34 is passed through the cover body 121. In this way, the furnace chamber 11 is enclosed by the heat-insulating cover 12, and the heat-insulating cover 12 plays a role in heat preservation, which can maintain the stability of the temperature in the furnace chamber 11. The quartz cover 13 can isolate the heating element 20 from the temperature field in the furnace chamber 11, prevent the high temperature environment in the furnace chamber 11 from affecting the surrounding equipment, and at the same time reduce the heat loss in the furnace chamber 11 and improve the heat preservation effect. The driving element 33 is arranged outside the furnace chamber 11, which prevents the driving element 33 from being damaged by the high temperature environment in the furnace chamber 11.

[0046] The cover 121 and the cover 122 can be made of graphite insulation cotton, which has a good thermal insulation effect. Furthermore, the cover 121 and the cover 122 can be set to multiple layers. In this embodiment, the cover 121 is set to two layers and the cover 122 is set to four layers. Furthermore, the cover 121 is fixed to the inner side of the quartz cover 13. It is understandable that the cover 121 and the quartz cover 13 can be set on the same machine, so that the positions of the cover 121 and the quartz cover 13 are relatively fixed. The cover 122 is set to a detachable structure, that is, the cover 122 can be removed from the cover 121 or covered on the cover 121. In this embodiment, four layers of cover 122 are stacked on the upper end of the cover 121.

[0047] It is understandable that the seed crystal rod 40 passes through the cover 122 and extends into the furnace chamber 11. The seed crystal rod 40 can be set on a lifting mechanism (not shown in the figure), and the lifting mechanism is used to control the lifting of the seed crystal rod 40, so that the seed crystal 50 can be moved into or out of the graphite crucible 32.

[0048] The driving member 33 can be fixed to the quartz cover 13 through a connecting structure, or fixed to the machine platform. This application does not impose any restrictions on this, as long as the relative positions of the driving member 33 and the quartz cover 13 are fixed.

[0049] The heating element 20 is configured as a heating coil. The heating coil is annular or spiral, surrounding the outer periphery of the furnace body 10, and has a cooling channel 21 within the heating coil. The heating coil heats the graphite crucible 32 within the furnace cavity 11 through electromagnetic induction. The annular or spiral heating coil, surrounding the outer periphery of the furnace body 10, ensures uniform heating of the graphite crucible 32 within the furnace cavity 11. The cooling channel 21 within the heating coil allows for the passage of a coolant (e.g., water) to protect the heating coil during the reaction.

[0050] See Figures 1 to 7 The device for growing silicon carbide crystals by a high-efficiency liquid phase method provided in this embodiment includes three graphite crucibles 32, and a graphite pipe 36 is provided between any two adjacent graphite crucibles 32. Figures 1 to 7 , the method of using the device for high performance liquid phase silicon carbide crystal growth is explained.

[0051] Step 1: Install the graphite crucible 32 and the graphite pipe 36 : Install the three graphite crucibles 32 at the three connecting through holes 311 of the substrate 31 respectively, and connect the graphite pipe 36 to the three graphite crucibles 32 .

[0052] Step 2: Adding materials: Add the raw materials required for growth into one of the graphite crucibles 32, and record the graphite crucible 32 as crucible No. 1, and the others as crucible No. 2 and crucible No. 3.

[0053] Step 3: Install the substrate 31 : Install the substrate 31 on the support rod 34 , and adjust the position of the seed rod 40 so that the seed rod 40 is located above the No. 1 crucible.

[0054] Step 4: Heating and crystal growth: The heating element 20 starts heating, and after the temperature inside the graphite crucible 32 stabilizes, the seed crystal 50 on the seed crystal rod 40 is immersed in the No. 1 graphite crucible 32 to grow silicon carbide crystals.

[0055] Step 5: Replace the graphite crucible 32: After several hours of crystal growth, crucible No. 1 has corroded and is no longer suitable for growth operations. The graphite crucible 32 needs to be rotated. As the solution in the graphite crucible 32 is transferred to the seed crystal 50 fixed by the seed crystal rod 40 in the form of crystal growth, the mass of the graphite crucible 32 will inevitably decrease. At this time, the pressure sensor 37 below the support rod 34 will detect the change in pressure. When a certain set value is reached (this value can be manually set according to the situation), the pressure sensor 37 will send a signal to the controller, and then pull the seed crystal 50 immersed in the solution in crucible No. 1 upward. When pulling the seed crystal 50 upward, the lifting height of the seed crystal 50 must be higher than the substrate 31 to ensure that the substrate 31 and the graphite crucible 32 do not touch the seed crystal 50 during the rotation of the substrate 31. After the seed crystal 50 rises, the support rod 34 and base plate 31, controlled by the driver 33, rotate the graphite crucible 32, transferring the No. 2 crucible to the original position of the No. 1 crucible. The seed crystal 50 now faces the unused No. 2 crucible. Because the base plate 31 is tilted, the remaining solution in the No. 1 crucible after it moves to its new position flows through the lower graphite channel 36 into the No. 2 crucible, allowing the seed crystal 50 to continue growing in the No. 2 crucible, utilizing the remaining solution from the No. 1 crucible. It is important to note that the driver 33 rotates the graphite crucible 32 at a relatively slow speed (e.g., 0.5 rpm). This allows sufficient time for the remaining solution in the No. 1 crucible 32 to flow through the graphite channel 36 below the No. 1 crucible into the No. 2 crucible.

[0056] Step 6: Continue crystal growth: After the solution in crucible No. 1 is transferred, lower the seed crystal rod 40 so that the seed crystal 50 is immersed in the solution in crucible No. 2, and continue growing the seed crystal 50. After crucible No. 2 has grown for a certain period of time, repeat step 5 with crucible No. 2, moving crucible No. 3 to a lower position. After all three graphite crucibles 32 have rotated their positions and grown crystals in their corresponding positions, growth is stopped, the temperature is lowered, and the furnace is opened to retrieve the crystals. In this way, crystal growth can be continued for an extended period of time without opening the furnace chamber 11, and any remaining material can be reused.

[0057] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall be determined by the appended claims.

Claims

1. A device for growing silicon carbide crystals using a high-performance liquid phase method, characterized in that: include: A furnace body, a heating element and a crucible assembly, wherein the furnace body is provided with a furnace cavity, the crucible assembly is at least partially provided in the furnace cavity, the crucible assembly includes a substrate, a graphite crucible and a driving element, the graphite crucibles are provided in two or more forms, the graphite crucibles are provided on the substrate, the driving element is used to drive the substrate to move to switch the position of the graphite crucible, and the heating element is used to heat the graphite crucible.

2. The device for growing silicon carbide crystals using a high-performance liquid phase method according to claim 1, wherein: The two or more graphite crucibles are arranged along the circumference of the substrate. The substrate is fixedly connected to a support rod. The driving member is used to drive the support rod to rotate around its own axis. The driving member is configured as a motor.

3. The device for growing silicon carbide crystals by high performance liquid phase method according to claim 2, characterized in that: Any two adjacent graphite crucibles are connected via a graphite pipe, and the graphite pipe is arranged on the side wall of the bottom of the graphite crucible.

4. The device for growing silicon carbide crystals using a high-performance liquid phase method according to claim 3, wherein: The support rod is perpendicular to the base plate and is tilted relative to the vertical direction.

5. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 2, wherein: Any two graphite crucibles are not connected.

6. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 2, wherein: The substrate is provided with a connecting through hole, the inner wall of the connecting through hole is provided with an internal thread, the outer wall of the graphite crucible is provided with an external thread adapted to the internal thread, and the graphite crucible is threadedly connected to the connecting through hole.

7. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 6, characterized in that: The connecting through hole is arranged obliquely from bottom to top toward the direction close to the central axis of the substrate.

8. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 2, wherein: A pressure sensor is provided on the support rod or the driving member, and the pressure sensor is used to detect pressure changes on the support rod. The pressure sensor is electrically connected to a controller, and the controller is electrically connected to the driving member. The controller is used to control the start and stop of the driving member according to the pressure detected by the pressure sensor.

9. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 2, wherein: The furnace body includes a quartz cover and a heat-insulating cover arranged in the quartz cover. The heating element is arranged on the outer peripheral side of the quartz cover. The heat-insulating cover includes a cover body and a cover. The cover body and the cover cover enclose the furnace cavity. The substrate and the graphite crucible are arranged in the furnace cavity. The driving element is arranged outside the furnace cavity. The support rod is passed through the cover body.

10. The device for growing silicon carbide crystals using a high performance liquid phase method according to claim 1, characterized in that: The heating element is configured as a heating coil. The heating coil is annular or spiral and surrounds the outer periphery of the furnace body. A cooling channel is provided in the heating coil.

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