Crystal growing device

Abstract

The embodiment of the specification provides a crystal growth device, comprising: a crucible for accommodating a raw material for crystal growth; the heating assembly is used for forming a melting zone in the crucible and heating the solid raw material in the melting zone to form a molten raw material; and the cooling assembly is arranged outside the crucible and used for cooling the part, close to the inner wall of the crucible, of the solid raw material to form a skull, and the molten raw material is contained in the skull.

Description

TECHNICAL FIELD

[0001] The present specification relates to the technical field of crystal growth, in particular to a crystal growth device. BACKGROUND

[0002] In the field of single crystal growth technology, there are various mature crystal growth methods, including vapor phase growth, solution growth, melt growth, solid phase growth, etc. For some conductive crystal materials with high melting point, such as GAGG (gadolinium aluminum gallium garnet), YAG (yttrium aluminum garnet), Ga2O3 (gallium oxide), LYSO (lanthanate), YSO (yttrium silicate), etc., the dependence on crucible materials during crystal growth is extremely strong. In general, these high-melting-point crystals are grown using noble metals such as iridium, molybdenum, platinum, etc. as crucible materials, which undoubtedly increases the cost of crystal production. The cold crucible method is a technique for growing crystals from a melt, but the crystal size produced by the cold crucible method is small and cannot meet the production requirements, and the cold crucible method usually heats the reaction raw materials based on the principle of electromagnetic induction, but this heating method only works on conductive bodies and has certain limitations. The Czochralski method, as another technique for melt growth, can generate larger-sized crystals, but the cost is also relatively high.

[0003] Therefore, it is desirable to propose a crystal growth device that can increase the size of finished crystals while reducing the cost of crystal production. CONTENT OF THE INVENTION

[0004] Some embodiments of the present specification provide a crystal growth device, comprising: a crucible for containing raw materials for crystal growth; a heating assembly for forming a melting zone in the crucible and heating solid raw materials in the melting zone to form molten raw materials; a cooling assembly arranged outside the crucible, the cooling assembly being configured to cool a portion of the solid raw materials close to the inner wall of the crucible to form a solidified shell, and the molten raw materials being contained in the solidified shell.

[0005] In some embodiments, the cooling assembly comprises a sealed shell, at least a portion of the crucible is embedded in the sealed shell, the sealed shell is filled with a cooling liquid, the sealed shell is provided with a liquid inlet and a liquid outlet, and the heating assembly is arranged in the sealed shell.

[0006] In some embodiments, the sealed shell is provided with an embedding groove, the embedding groove is adapted to the crucible, and the crucible is detachably arranged in the embedding groove.

[0007] In some embodiments, the crystal growth device further comprises a first temperature detection assembly, the first temperature detection assembly is in communication connection with the cooling assembly, the first temperature detection assembly is configured to detect the temperature of the crucible, and the cooling assembly is configured to perform corresponding operations based on the temperature of the crucible.

[0008] In some embodiments, the first temperature detecting component comprises a temperature measuring gun and an infrared temperature measuring instrument.

[0009] In some embodiments, the heating component comprises an electromagnetic coil, which is arranged in the sealed shell and surrounds the outer wall of the crucible.

[0010] In some embodiments, the crystal growth device further comprises a seed crystal clamp arranged in the crucible, the seed crystal clamp being provided with a seed crystal clamping groove; and a pulling rod connected with the seed crystal clamp, the pulling rod being movable relative to the crucible along the height direction of the crucible to adjust the position of the seed crystal relative to the molten raw material.

[0011] In some embodiments, the crystal growth device further comprises a heat preservation component, the heat preservation component comprising a heat preservation cover, which encloses the opening of the crucible, and an access passage formed at the end of the heat preservation cover away from the opening of the crucible, the access passage being for the passing of the pulling rod.

[0012] In some embodiments, the heat preservation cover comprises a first heat preservation cover, a second heat preservation cover and a third heat preservation cover connected in sequence along the height direction of the crucible, the first heat preservation cover enclosing the opening of the crucible, and the third heat preservation cover being a cover body provided with the access passage.

[0013] In some embodiments, the heat preservation component further comprises a temperature detecting device configured to detect the temperature of the enclosed area of the heat preservation cover, and a post-heating device configured to heat the enclosed area of the heat preservation cover. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present specification will be further illustrated in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same reference numbers represent the same structures, wherein:

[0015] Figure 1 is a simple module schematic diagram of a crystal growth device according to some embodiments of the present specification;

[0016] Figure 2 is a structural schematic diagram of a crystal growth device according to some embodiments of the present specification;

[0017] Figure 3 is a structural schematic diagram of a sealed shell and an electromagnetic coil when assembled according to some embodiments of the present specification;

[0018] Figure 4 is Figure 2A top view of the crystal growth apparatus shown;

[0019] Figure 5 An exemplary flow chart of a crystal production method according to some embodiments of the present specification.

[0020] The crystal growth apparatus provided by some embodiments of the present specification can combine the advantages of the cold crucible method that does not rely on the crucible of precious metal materials and the characteristics of the Czochralski method that can quickly and simply grow crystals, greatly reducing the cost of crystal production, and in the case of sufficient power supply, large-diameter crucibles can be used for material melting and crystal growth, and large-size Czochralski crystal growth can be performed. Moreover, after reducing the cost of the crucible, the production value can be quickly expanded, the fixed asset cost is reduced, and it has high economic value.

[0021] Reference signs: crystal growth apparatus 100; crucible 10; heating assembly 20; electromagnetic coil 21; cooling assembly 30; sealed shell 31; embedded groove 311; cooling liquid 32; liquid inlet 33; liquid outlet 34; seed crystal clamp 40; pulling rod 50; heat preservation assembly 60; first heat preservation cover 61; second heat preservation cover 62; third heat preservation cover 63; access passage 64; molten raw material 200. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings described below are only some examples or embodiments of the present specification, and those skilled in the art can also apply the present specification to other similar scenarios without creative labor. Unless the context clearly indicates otherwise or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0023] As shown in the specification and claims, unless the context clearly indicates otherwise or otherwise stated, "one", "a", "an", and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The term "based on" is "at least partially based on". The term "some embodiments" means "at least one embodiment"; the term "other embodiments" means "at least one other embodiment", and the related definitions of other terms will be given in the following description.

[0024] In some embodiments, the cold crucible method is a melt growth technique that does not require the use of a noble metal crucible. The cold crucible method directly uses the reaction raw material itself as the crucible. Specifically, the inside of the reaction raw material is melted by a heating device, and the outside of the reaction raw material is provided with a cooling device, so that the outside of the reaction raw material forms a solid shell, which can act as a crucible to isolate the internal melt from the outside world. The advantage of the cold crucible method is that the process is simple and easy to control. Since the reaction raw material itself can form a solid shell as a crucible, the dependence on noble metal materials such as platinum, iridium, and molybdenum can be eliminated, and the cost of crystal production can be reduced. However, it is difficult to grow large-size single crystals by the cold crucible method. In addition, the cold crucible method usually heats the reaction raw material by an electromagnetic coil. This heating method only works on objects with strong electrical conductivity. For example, when the reaction raw material is a non-metallic material (such as metal oxide MgO (magnesium oxide), CaO (calcium oxide), etc.), the non-metallic material itself has a high resistivity and weak electrical conductivity, so it is difficult to heat it by electromagnetic induction, resulting in a slow melting rate and reducing the efficiency of crystal production. For another example, zirconium oxide has almost no electrical conductivity below 100°C, but has good electrical conductivity above 1200°C, so it cannot be directly heated by an electromagnetic coil. In some embodiments, the Czochralski method, as another technique for melt growth, can relatively easily grow large-size single crystals with a fast growth rate. However, the cost of producing crystals by the Czochralski method is high, and the profit is low. Both of the above-mentioned crystal growth methods and the corresponding crystal growth devices have certain limitations and cannot simultaneously achieve large-size and low-cost crystal production.

[0025] To solve the above problems, the present specification provides a crystal growth device that can combine the advantages of the cold crucible method, which does not depend on the noble metal material crucible, and the characteristics of the Czochralski method, which can quickly and simply grow crystals, greatly reducing the cost of crystal production. In addition, under the condition that the power of the power supply is sufficient, a large-diameter crucible can be used for material melting and crystal growth, and large-size Czochralski crystal growth can be performed. Moreover, after reducing the cost of the crucible, the production value can be quickly expanded, the fixed asset cost can be reduced, and the economic value is high.

[0026] Figure 1 is a simple module schematic diagram of a crystal growth device according to some embodiments of the present specification;

[0027] Figure 2 is a structural schematic diagram of a crystal growth device according to some embodiments of the present specification. In some embodiments, the crystal growth device 100 can include a crucible 10, a heating assembly 20, and a cooling assembly 30. Figures 1-2

[0028] ​The crucible 10 can be used as a container to hold raw materials for crystal growth. In some embodiments, the crucible 10 can be used to hold solid raw materials. The solid raw materials can be cylindrical blocks made from compacted raw material powders. For example, in the production of β-Ga2O3(β-gallium oxide) crystals, Ga2O3(gallium oxide) powders can be used as raw materials, and the gallium oxide powders can be compacted into cylindrical blocks. In some embodiments, the crucible 10 can be cylindrical, square, or other feasible shapes. In some embodiments, the crucible 10 can be made of materials with good thermal conductivity, low electrical conductivity, and high thermal shock resistance. More details about the materials used to make the crucible 10 can be found in the description of other embodiments of the present disclosure.

[0029] The heating assembly 20 is used to form a melting zone in the crucible 10 and heat the solid raw materials in the melting zone to form molten raw materials 200. The melting zone refers to a region where the temperature reaches the melting point of the solid raw materials. That is, the solid raw materials located in the melting zone can be heated to form molten raw materials 200. The molten raw materials 200 refer to a melt formed by heating the raw materials to a specific temperature until they completely melt. In some embodiments, during the heating process of the heating assembly 20, the solid raw materials located in the melting zone will first be heated and melted. As more solid raw materials melt, the melting zone will continue to expand, and thus more solid raw materials will be melted to form molten raw materials 200. When the solid raw materials completely melt into molten raw materials 200, the molten raw materials 200 will be in direct contact with the inner wall of the crucible 10.

[0030] The cooling assembly 30 is arranged outside the crucible 10, and the cooling assembly 30 is used to cool the portion of the solid raw materials close to the inner wall of the crucible 10 to form a solidified shell, and the molten raw materials 200 are contained in the solidified shell. It can be understood that, during the melting process of the solid raw materials, if the solid raw materials continue to be heated, when the solid raw materials completely melt into molten raw materials 200, the molten raw materials 200 will be in direct contact with the inner wall of the crucible 10, which may contaminate or react with the molten raw materials 200, affecting the quality of the crystal product. By arranging the cooling assembly 30 outside the crucible 10 to cool the crucible 10, the portion of the solid raw materials close to the inner wall of the crucible 10 can be cooled before melting, which can avoid this portion of the solid raw materials from melting to form molten raw materials 200. Under the action of the cooling assembly 30, the un-melted solid raw materials can form a solidified shell (not shown in the figure) as a container (which can be referred to as a cold crucible) to contain the molten raw materials 200, which can isolate the molten raw materials 200 from the inner wall of the crucible 10, avoiding contamination or reaction of the molten raw materials 200 with the crucible 10.

[0031] In some embodiments, based on different heating principles, the heating component 20 can be divided into a resistance heating component based on the principle of resistance heating or an electromagnetic heating component based on the principle of electromagnetic induction. The electromagnetic heating component based on the principle of electromagnetic induction will be described in detail below with reference to specific embodiments.

[0032] Figure 4 yes Figure 2 A top view of the crystal growth apparatus shown. (For illustrative purposes only, combined with...) Figures 1-4 As shown, the heating assembly 20 may include an electromagnetic coil 21, a power source (not shown), and wires (not shown). The power source is connected to the electromagnetic coil 21 via the wires and provides current. When current flows through the electromagnetic coil 21, it can heat the conductive solid material based on the principle of electromagnetic induction. Specifically, when current flows through the electromagnetic coil 21, a magnetic field is generated, and eddy currents are generated inside the solid material. Since the solid material has a certain resistance, heat is generated when the current passes through the solid material, causing the temperature of the solid material to rise. When the temperature of the solid material rises to its melting point, it can melt to form molten material 200.

[0033] In some embodiments, the parameters of each component of the heating assembly 20 can be determined according to the crystal being produced. For example, when producing β-Ga₂O₃ (β-type gallium oxide) crystals, a power supply with an operating frequency of 400 kHz can be used. When producing GAGG (cerium-doped gadolinium aluminum gallium garnet) crystals, a power supply with an operating frequency of 500 kHz can be used.

[0034] In some embodiments, the cooling assembly 30 may include a liquid cooling heat dissipation assembly and an air cooling heat dissipation assembly. In some specific embodiments, the cooling assembly 30 may be a liquid cooling heat dissipation assembly. In some embodiments, the cooling assembly 30 includes a sealed shell 31, at least a portion of the crucible 10 is embedded in the sealed shell 31, the sealed shell 31 is filled with a cooling liquid 32, and the sealed shell 31 is provided with a liquid inlet 33 and a liquid outlet 34. On the one hand, the cooling liquid 32 can cool the crucible 10 through direct or indirect contact, so that the temperature of the portion of the solid material near the inner wall of the crucible 10 (i.e., the portion of the solid material in contact with the inner wall of the crucible 10) is much lower than its melting point, thereby enabling the portion of the solid material near the inner wall of the crucible 10 to form a solidified shell. On the other hand, the cooling liquid 32 can also cool the heating assembly 20 (e.g., the electromagnetic coil 21) through direct or indirect contact, ensuring the normal operation of the heating assembly 20.

[0035] In some embodiments, the crucible 10 and the sealed shell 31 can be independent structures, and the crucible 10 and the sealed shell 31 can be detachably connected. For example, the sealed shell 31 can be provided with an embedding groove 311, and the embedding groove 311 is adapted to the crucible 10. Before the crystal is produced, the crucible 10 can be placed in the embedding groove 311. After the crystal production is completed, the crucible 10 can be taken out of the embedding groove 311. The detachable connection of the crucible 10 and the sealed shell 31 can facilitate the cleaning and replacement of the crucible 10 and the sealed shell 31. In addition, the crucible 10 in the embodiment does not have direct contact with the cooling liquid 32 in the sealed shell 31, which can avoid the mutual contamination of the cooling liquid 32 and the crucible 10, thereby realizing the reuse of the crucible 10 and the cooling liquid 32 and reducing the cost of crystal production.

[0036] In some embodiments, the crucible 10 and the sealed shell 31 can be fixedly connected. For example, the crucible 10 and the sealed shell 31 can be manufactured by an integral molding method. For another example, the crucible 10 and the sealed shell 31 can be assembled by welding, riveting or the like. For example, the sealed shell 31 can be provided with an embedding groove 311, and the crucible 10 can be fixedly arranged in the embedding groove 311 of the sealed shell 31. In another example, the sealed shell 31 is provided with an insertion hole (not shown in the figure), and a part of the crucible 10 extends into the sealed shell 31 through the insertion hole and is fixedly welded to the inner edge of the insertion hole. The part of the crucible 10 extending into the sealed shell 31 can be in direct contact with the cooling liquid 32 in the sealed shell 31, which can effectively improve the cooling efficiency.

[0037] In some embodiments, the electromagnetic coil 21 can be arranged in the sealed shell 31, so that the electromagnetic coil 21 is in direct contact with the cooling liquid 32, thereby effectively improving the cooling efficiency. For example, the sealed shell 31 is provided with an insertion hole, and a part of the crucible 10 extends into the sealed shell 31 through the insertion hole and is fixedly welded to the inner edge of the insertion hole. The electromagnetic coil 21 is arranged on the outer wall of the part of the crucible 10 extending into the sealed shell 31. In another example, the sealed shell 31 can be provided with an embedding groove 311, and the electromagnetic coil 21 can be arranged in the sealed shell 31 and arranged on the side wall of the embedding groove 311.

[0038] In some embodiments, the electromagnetic coil 21 can be arranged outside the sealed shell 31, so that the electromagnetic coil 21 is not in direct contact with the cooling liquid 32. For example, the sealed shell 31 is provided with an embedding groove 311, and the electromagnetic coil 21 is arranged on the side wall of the embedding groove 311. Figure 3As shown, the sealing shell 31 is provided with an embedding groove 311 for placing the crucible 10, the electromagnetic coil 21 can be prearranged in the embedding groove 311 and arranged around the side wall of the embedding groove 311, when the crucible 10 is placed in the embedding groove 311, the electromagnetic coil 21 can be located outside the crucible 10. The electromagnetic coil 21 is arranged outside the sealing shell 31, on the one hand, the electromagnetic coil 21 can be more convenient to maintain and replace, on the other hand, the electromagnetic coil 21 can avoid direct contact with the cooling liquid 32 and be corroded, prolong the service life of the electromagnetic coil 21.

[0039] In some embodiments, the cooling assembly 30 can include a cooling liquid pump (not shown in the figure), the outlet end of the cooling liquid pump is in communication with the liquid inlet 33 of the sealing shell 31, the inlet end of the cooling liquid pump is in communication with the liquid outlet 34 of the sealing shell 31, the cooling liquid pump can pump the cooling liquid 32 with lower temperature into the sealing shell 31 through the liquid inlet 33 to cool the crucible 10 and the electromagnetic coil 21. The cooling liquid pump can pump out the cooling liquid 32 in the sealing shell 31, and cool the cooling liquid 32 after heating by an external cooling device, so as to maintain the temperature of the cooling liquid 32 in the normal operating temperature range.

[0040] In some embodiments, the cooling liquid 32 can include cooling oil, ultrapure water or purified water, etc., the above-mentioned liquid has less corrosive to the electromagnetic coil 21, therefore, the electromagnetic coil 21 can be arranged in the sealing shell 31, so that the electromagnetic coil 21 is directly contacted with the cooling liquid 32, which can improve the cooling efficiency without affecting the working performance of the electromagnetic coil 21.

[0041] It should be noted that the above embodiments are merely used to illustrate the cooling assembly, and cannot cause limitation to the specific structure of the cooling assembly. In other embodiments, the cooling assembly 30 can include a cooling liquid pump and a heat dissipation pipeline, and when the sealing shell 31 is provided with the embedding groove 311, the heat dissipation pipeline can be arranged in the sealing shell 31 and arranged around the side wall of the embedding groove 311. The cooling liquid pump is used to pump the cooling liquid 32 to the heat dissipation pipeline, and the cooling liquid 32 can take away part of the heat of the crucible 10 when passing through the position of the heat dissipation pipeline corresponding to the crucible 10, so as to cool the crucible 10 and the solid raw material close to the inner wall of the crucible 10. Since the cooling liquid 32 only flows in the heat dissipation pipeline, the cooling liquid 32 does not directly contact the crucible 10 and the electromagnetic coil 21, which can on the one hand more conveniently update and maintain the crucible 10, the electromagnetic coil 21 and the heat dissipation pipeline, and on the other hand can avoid corrosion of the cooling liquid 32 to the electromagnetic coil 21, and prolong the service life of the heating assembly 20. In some embodiments, the heat dissipation pipeline can include a metal pipe (for example, a copper pipe, a steel pipe, etc.), a plastic pipe (for example, a polyvinyl chloride pipe, a polyethylene pipe, etc.), a composite pipe (for example, a pipe structure composed of copper, steel, plastic and the like).

[0042] In some embodiments, the crystal growth device 100 can further include a first temperature detection assembly (not shown in the figure), which is in communication connection with the cooling assembly 30. The first temperature detection assembly can be used to detect the temperature of the crucible 10, and the cooling assembly 30 is configured to perform corresponding operations based on the temperature of the crucible 10. In some embodiments, the first temperature detection assembly can include a temperature measuring gun, an infrared temperature measuring instrument, etc.

[0043] For example only, when the first temperature detection component detects that the temperature of the crucible 10 exceeds a first temperature threshold, the first temperature detection component can generate a first temperature detection signal and send the first temperature detection signal to a processor of the cooling component 30 (e.g., a processor of the cooling liquid pump), and the processor of the cooling component 30 can pump the cooling liquid 32 to the sealed enclosure 31 based on the received first temperature detection signal, and take away the heat generated by the crucible 10 through direct or indirect contact between the cooling liquid 32 and the crucible 10, so as to cool the crucible 10 and ensure that the solid raw material near the crucible 10 can form a solid shell smoothly. When the first temperature detection component detects that the temperature of the crucible 10 is lower than a second temperature threshold, the first temperature detection component can generate a second temperature detection signal and send the second temperature detection signal to the processor of the cooling component 30 (e.g., a processor of the cooling liquid pump), and the processor of the cooling component 30 can control the cooling liquid pump to stop pumping the cooling liquid 32 to the sealed enclosure 31 based on the received second temperature detection signal, and further control the cooling liquid pump to suck the cooling liquid 32 in the sealed enclosure 31 based on the received second temperature detection signal. The first temperature threshold refers to the melting point of the solid raw material, and when the temperature of the crucible 10 reaches the first temperature threshold, it indicates that the temperature of the solid raw material is too high and may be melted to affect the formation of the solid shell. The second temperature threshold refers to a temperature much lower than the melting point of the solid raw material, for example, the difference between the second temperature threshold and the melting point of the solid raw material is greater than 500°C. When the temperature of the crucible 10 reaches the second temperature threshold, it indicates that the cooling effect is good and is conducive to the formation of the solid shell.

[0044] In some embodiments, the crystal growth device 100 can further include a second temperature detection component (not shown in the figure), which can be in communication connection with the cooling component 30. The second temperature detection component can be used to detect the temperature of the heating component 20, and the cooling component 30 is configured to perform corresponding operations based on the temperature of the heating component 20. In some embodiments, when the heating component 20 includes the electromagnetic coil 21, the second temperature detection component can be used to detect the temperature of the electromagnetic coil 21. The cooling component 30 can pump the cooling liquid 32 to the sealed enclosure 31 based on the detection result of the second temperature detection component, cool the electromagnetic coil 21, or stop pumping the cooling liquid 32 to the sealed enclosure 31. The structure and working process of the second temperature detection component can be the same as or similar to those of the first temperature detection component, which will not be described here. In some embodiments, the first temperature detection component and the second temperature detection component can be different components and detect the temperatures of the crucible 10 and the electromagnetic coil 21, respectively. In some embodiments, the first temperature detection component and the second temperature detection component can be integrated into one component capable of detecting the temperatures of the crucible 10 and the electromagnetic coil 21.

[0045] In some embodiments, the material used to make the sealing shell 31 may be the same as or similar to the material used to make the crucible 10. In some embodiments, the material used to make the sealing shell 31 may be different from the material used to make the crucible 10. In some embodiments, the sealing shell 31 may be made of a thermal insulation material, thereby giving the sealing shell 31 a certain thermal insulation performance and effectively reducing the influence of the external environment on the temperature of the cooling liquid 32 inside the sealing shell 31. Exemplary thermal insulation materials may include rock wool, glass wool, foamed quartz, expanded perlite, etc. In some specific embodiments, the sealing shell 31 may be made of quartz material. Quartz material has a high melting point and low manufacturing cost, which can effectively reduce the crystal production cost.

[0046] In some embodiments, the crucible 10 can be made of a material with high thermal conductivity and low electrical conductivity, including quartz, silicon carbide, alumina, or magnesium oxide. A material with high thermal conductivity is defined as one with a thermal conductivity exceeding 10 W / (m·K). The crucible 10 made of a material with high thermal conductivity can rapidly transfer heat, allowing for rapid heat exchange between the cooling liquid 32 and the solid raw material. This accelerates the cooling efficiency of the solid raw material near the inner wall of the crucible 10, shortens the shell formation time, and improves crystal production efficiency. Furthermore, accelerating heat transfer efficiency also makes the temperature more uniform across different parts of the crucible 10, resulting in a more uniform thickness of the solidified shell. Using a material with low electrical conductivity to make the crucible 10 prevents it from heating up under the influence of the electromagnetic coil 21, which could prevent the solid raw material near the crucible 10 from forming a solidified shell.

[0047] In some embodiments, such as Figure 2 As shown, the crystal growth apparatus 100 may further include a seed crystal clamp 40, which may be disposed within the crucible 10 and has a seed crystal slot. In some embodiments, the seed crystal slot can fix a strip-shaped seed crystal. The material of the seed crystal slot may be graphite, corundum, platinum, iridium, etc. The seed crystal can be fixed at the lower end of the seed crystal clamp 40 under certain conditions (e.g., vacuum, heating, etc.). During crystal growth, the seed crystal on the seed crystal clamp 40 can come into contact with the molten material 200 in the crucible 10. When the seed crystal comes into contact with the melt, it will first partially melt, and then begin crystal growth steps such as lifting, necking, shoulder formation, equal diameter formation, and tailing. In some embodiments, the seed crystal clamp 40 may be configured as a columnar shape with a hole in the middle or other feasible shapes.

[0048] In some embodiments, the crystal growth apparatus 100 can further include a pulling rod 50 connected with the seed holder 40, the pulling rod 50 being movable along the height direction of the crucible 10 and rotatable along its own axis, so as to adjust the position of the seed attached to the seed holder 40 relative to the molten raw material 200, so as to grow a cylindrical crystal by pulling and / or rotating the seed holder 40. The position relative to the molten raw material 200 refers to the position of the seed holder 40 relative to the liquid surface of the molten raw material 200 in the crucible 10. Specifically, when the seed contacts the surface of the molten raw material 200 and the surface of the seed is slightly melted, the molten raw material 200 attached to the surface of the seed can be crystallized on the seed in a supercooled state by pulling and rotating the pulling rod 50, and then a cylindrical crystal can be grown by continuously pulling and / or rotating the seed. By adjusting the position of the seed holder 40 relative to the molten raw material 200, the contact state of the seed on the seed holder 40 with the liquid surface of the melt can be controlled, so as to ensure the normal operation of the crystal growth. For example, the seed is controlled to contact the liquid surface of the melt by the pulling rod 50 to start the crystal growth. For another example, the crystal after the growth is controlled to leave the melt by the pulling rod 50. In addition, the impurities and temperature distribution in the molten raw material 200 in the crucible 10 can be non-uniform, and the rotation of the seed relative to the crucible 10 driven by the seed holder 40 can reduce defects such as screw dislocations and twins caused by local overheating or condensation, so as to ensure the uniformity of the temperature and composition of the contact surface between the molten raw material 200 and the seed. At the same time, the rotation can also promote the more effective diffusion of atoms or molecules in the molten raw material 200 along the surface of the seed, avoid the formation of a stable contact layer between the seed and the crucible 10, and improve the quality of the finished crystal.

[0049] In some embodiments, the operator can manually operate the pulling rod 50 to pull and / or rotate, so as to grow a crystal on the seed holder 40.

[0050] In some embodiments, the crystal growth apparatus 100 can further include a pulling driving mechanism (not shown in the figure) for controlling the movement of the pulling rod 50 along its own axis. For example, the pulling driving mechanism can include a linear motor for driving the pulling rod 50 to move along its own axis.

[0051] In some embodiments, the crystal growth apparatus 100 can further include a rotating driving mechanism (not shown in the figure). In some embodiments, the rotating driving mechanism can be connected with the pulling rod 50 and drive the pulling rod 50 to rotate. For example, the rotating driving mechanism can include a stepping motor, and the pulling rod 50 can be connected with the stepping motor, and the stepping motor can drive the pulling rod 50 to rotate along its own axis.

[0052] In some embodiments, the rotary drive mechanism and the lifting drive mechanism can be two independent components, which respectively control the lifting rod 50 to rotate along its own axis and along its own axis (parallel to the height direction of the crucible 10). Figure 2 (The direction indicated by arrow Y in the diagram) moves. In some embodiments, the rotary drive mechanism and the lifting drive mechanism can also be integrated into a single drive mechanism that can simultaneously control the lifting rod 50 to move along its own axis and rotate about its own axis. For example, the drive mechanism can integrate a linear motor and a servo motor so that it can both drive the lifting rod 50 to move along its own axis and drive it to rotate about its own axis.

[0053] In the process of producing crystals using the Czochralski method, the ambient temperature of the crystal affects the quality of the finished crystal. For example, if the temperature difference between the ambient temperature of the crystal and the molten material 200 is too large after the crystal detaches from the surface of the molten material 200, the crystal may crack due to excessive heat dissipation. To improve the quality of the finished crystal, it is necessary to control the ambient temperature of the crystal.

[0054] In some embodiments, combined with Figure 1 and Figure 2 As shown, the crystal growth apparatus 100 may further include a heat preservation component 60, which includes a heat preservation cover surrounding the opening of the crucible 10. An inlet / outlet channel 64 is provided at the end of the heat preservation cover away from the opening of the crucible 10, allowing the lifting rod 50 to pass through. In this embodiment, by providing a heat preservation cover at the opening of the crucible 10, the crystal after detaching from the molten material 200 is placed within the area enclosed by the heat preservation cover. The temperature difference between this area and the molten material 200 is smaller, resulting in a smaller temperature gradient and effectively preventing crystal cracking. To facilitate the movement of the lifting rod 50, an inlet / outlet channel 64 is provided at the end of the heat preservation cover away from the opening of the crucible 10, allowing the lifting rod 50 to move and / or rotate along its own axial direction, thus achieving crystal growth and improving the quality of the finished crystal without affecting crystal growth.

[0055] In some embodiments, the heat insulation cover may include a first heat insulation cover 61, a second heat insulation cover 62 and a third heat insulation cover 63 connected sequentially along the height direction of the crucible 10. The first heat insulation cover 61 surrounds the opening of the crucible 10, and the third heat insulation cover 63 is a cover with an access channel 64.

[0056] It should be noted that the first heat preservation cover 61, the second heat preservation cover 62 and the third heat preservation cover 63 in the foregoing embodiments are only for the purpose of illustrating an exemplary heat preservation cover, and cannot cause limitation to the composition and structure of the heat preservation cover. Those skilled in the art can change the heat preservation cover according to actual needs. For example, if the length of the crystal to be produced is longer, the height of the heat preservation cover needs to be lengthened. In this case, a fourth heat preservation cover, a fifth heat preservation cover, etc. can be added between the first heat preservation cover 61 and the second heat preservation cover 62 or between the second heat preservation cover 62 and the third heat preservation cover 63. For another example, if the length of the crystal to be produced is shorter, the height of the heat preservation cover can be shortened to save cost. In this case, the first heat preservation cover 61 or the second heat preservation cover 62 can be removed.

[0057] In some embodiments, the material for making the heat preservation cover can include a metal material (for example, iridium, molybdenum, etc.) and a high-temperature-resistant material (silicon carbide, magnesium oxide, etc.).

[0058] In some embodiments, the heat preservation assembly 60 can further include a rear heating device (not shown in the figure), which is configured to heat the enclosed area of the heat preservation cover, so as to ensure that the crystal is always at a suitable growth temperature and improve the quality of the finished crystal. In some embodiments, the rear heating device can be divided into a resistance heating device and an electromagnetic heating device based on different heating modes. For the convenience of description, the present specification takes resistance heating as an example for description. By way of example only, the rear heating device can include a resistance sheet, a wire and a power supply. The resistance sheet is arranged in the heat preservation cover and connected to the power supply through the wire. When the power supply is turned on, the resistance sheet generates Joule heat by passing current to heat the enclosed area of the heat preservation cover.

[0059] In some embodiments, the heat preservation assembly 60 can further include a heat preservation detection device (not shown in the figure), which is configured to detect the temperature of the enclosed area of the heat preservation cover.

[0060] In some embodiments, the heat preservation detection device can perform corresponding operations based on the temperature of the enclosed area of the heat preservation cover. For example, when the temperature of the enclosed area of the heat preservation cover is too low, the heat preservation detection device can issue a warning to the operator (for example, issue a voice warning through a loudspeaker in communication connection with the temperature detection device, issue a text warning through a display device in communication connection with the heat preservation detection device) to remind the operator to heat the area to avoid the temperature of the enclosed area of the heat preservation cover being too low to cause the crystal to break.

[0061] In some embodiments, the temperature detection device can be communicatively connected with the post-heating device, and the post-heating device can perform corresponding operations based on the temperature of the enclosed area of the temperature-maintaining cover. For example only, when the temperature detection device detects that the temperature in the enclosed area of the temperature-maintaining cover is lower than a third temperature threshold, a third temperature detection signal can be generated and sent to a processor of the post-heating device (e.g., the processor of the post-heating device is used to control the power supply of the post-heating device to turn on and off), and the processor of the post-heating device can control the power supply of the post-heating device to turn on based on the received third temperature detection signal, so as to heat the enclosed area of the temperature-maintaining cover, thereby avoiding that the temperature of the enclosed area of the temperature-maintaining cover is too low. When the temperature detection device detects that the temperature in the enclosed area of the temperature-maintaining cover exceeds a fourth temperature threshold, the temperature detection device can generate a fourth temperature detection signal and send the fourth temperature detection signal to the processor of the post-heating device, and the processor of the post-heating device can control the power supply of the post-heating device to turn off based on the received fourth temperature detection signal, so as to stop heating the enclosed area of the temperature-maintaining cover. The third temperature threshold is the minimum temperature to ensure that the crystal does not crack after being separated from the molten raw material 200. The fourth temperature threshold is the maximum temperature to ensure that the molten raw material 200 can crystallize on the surface of the seed crystal.

[0062] In some embodiments, the crystal growth device 100 can further include a furnace body (not shown in the figure), and the crucible 10 and the sealed shell 31 can be arranged in the furnace chamber of the furnace body. In some embodiments, the furnace chamber can be a sealed environment, which means that the inside of the furnace chamber is not in gas exchange with the atmosphere environment except for necessary contact. The method for achieving sealing can be to use a sealing ring, vacuum grease, or other sealing materials at the joints between the various components of the crystal growth device 100.

[0063] The present specification also provides a method for producing a crystal using the crystal growth device in the foregoing embodiments. Figure 5 is an exemplary flowchart of a method for producing a crystal according to some embodiments of the present specification. As shown in Figure 5 the flowchart 300 includes the following steps:

[0064] After the solid raw material is placed in the crucible in step 310, a melting zone is formed in the crucible by the heating assembly, and the solid raw material in the melting zone is melted to form a molten raw material.

[0065] In some embodiments, the solid-state raw material can be an article obtained by pre-treating a reaction raw material corresponding to the crystal to be produced. For example, in the production of β-Ga2O3(β-gallium oxide) crystals, Ga2O3(gallium oxide) powder can be selected as the reaction raw material. Before the gallium oxide powder is added to the crucible (e.g., the crucible 10), the gallium oxide powder can be pressed into a columnar raw material block, i.e., the solid-state raw material. The pressed gallium oxide columnar raw material block has strong electrical conductivity and fast heat transfer efficiency, which is more conducive to the melting of the reaction raw material. In addition, the reaction raw material is pressed, so that the same size of the crucible 10 can accommodate more reaction raw material, and the addition of the reaction raw material can be avoided.

[0066] In some embodiments, before the production of the crystal, a flux adapted to the reaction raw material can be placed in the crucible 10 to "ignite" the solid-state raw material by the flux, thereby accelerating the melting speed of the reaction raw material.

[0067] For example only, in the production of β-Ga2O3(β-gallium oxide) crystals, the pressed gallium oxide can be used as the reaction raw material. Accordingly, metallic gallium (e.g., metallic gallium sheet) can be selected as the flux. The metallic gallium has strong electrical conductivity and can be heated to a high temperature under the action of the electromagnetic coil 21, thereby forming a melting zone. Through the ignition of the metallic gallium, a portion of the gallium oxide is gradually heated, and the electrical conductivity of the gallium oxide also increases with the increase of the temperature until the melting point is reached to form the molten raw material 200.

[0068] In another example, in the production of a synthetic cubic zirconia crystal, the reaction raw material is a columnar block of ZrO2(zirconia) powder. The zirconia columnar block has no electrical conductivity at room temperature (e.g., below 100°C), but has good electrical conductivity at 1200°C or higher. In order to melt the zirconia columnar block, a metallic zirconium sheet can be placed in the crucible 10 as the flux, and heated by the electromagnetic coil 21. The metallic zirconium sheet has good electrical conductivity and is melted to form a high-temperature molten pool (i.e., a melting zone) under the action of the electromagnetic coil 21. Under the action of the high-temperature molten pool, the zirconia columnar block is continuously melted, and the melting zone is continuously expanded until the zirconia columnar block is completely melted except for the solidified shell.

[0069] In some embodiments, the fluxing agent can include graphite or a metal corresponding to the raw material for crystal growth. For example only, when producing a β-Ga2O3(β-gallium oxide) crystal, a metal gallium can be selected as the fluxing agent because the Ga2O3(gallium oxide) generated by oxidation of the metal gallium can be used as a raw material and will not contaminate the molten raw material 200. In another example, the raw material for producing a GAGG (cerium-doped gadolinium gallium garnet) crystal is a mixture of Gd2O3(gadolinium oxide), α-Al2O3(α-aluminum oxide), β-Ga2O3(β-gallium oxide), and CeO2(cerium oxide) powders. Graphite can be selected as the fluxing agent because the crystal production is performed in an oxygen environment, and the graphite will be converted into carbon monoxide or carbon dioxide and then volatilized, which will not affect the proportion of the various metal components in the molten raw material 200 and ensure the quality of the finished crystal.

[0070] In some embodiments, the solid raw material can be pretreated, and the fluxing agent can be directly placed on the solid raw material. For example, a groove can be formed on the top of the solid raw material, and the fluxing agent can be placed in the groove. The solid raw material is in direct contact with the fluxing agent, and the ignition effect is better and the heating efficiency is higher.

[0071] In some embodiments, the fluxing agent can be suspended on the top of the solid raw material, and the fluxing agent can be spaced apart from the top of the solid raw material by a certain distance. That is, the fluxing agent is not in direct contact with the solid raw material. For example only, when the fluxing agent is a graphite block, the graphite block can be suspended on the top of the solid raw material, and the graphite block can be heated and warmed to form a molten zone under the action of the electromagnetic coil 21.

[0072] In some embodiments, after the fluxing agent is placed in the groove on the top of the solid raw material or suspended on the top of the solid raw material, the heating assembly 20 can be controlled to work at a specific power, so as to heat the fluxing agent to form a molten zone. In some embodiments, after the molten zone is formed, it indicates that at least a portion of the solid raw material can be heated to melt, and the solid raw material can continue to be heated after forming the molten raw material 200.

[0073] Step 320, cooling the solid raw material close to the inner wall of the crucible by the cooling assembly to form a solidified crust.

[0074] In some embodiments, in order to avoid the molten material 200 formed by melting the solid material directly contacting the inner wall of the crucible 10 during the melting of the solid material, the solid material close to the inner wall of the crucible 10 needs to be cooled by a cooling assembly (for example, the cooling assembly 30) to form a solidified shell, so as to isolate the molten material 200 from the crucible 10. For example only, the cooling assembly 30 can include a sealed shell (for example, the sealed shell 31), at least a portion of the crucible 10 is embedded in the sealed shell 31, the sealed shell 31 is filled with a cooling liquid (for example, the cooling liquid 32), the sealed shell 31 is provided with a liquid inlet (for example, the liquid inlet 33) and a liquid outlet (for example, the liquid outlet 34), the liquid inlet 33 and the liquid outlet 34 are connected to the outlet end and the inlet end of a cooling liquid pump respectively, and the cooling liquid 32 at a constant temperature (for example, 5°C) is pumped into the sealed shell 31 by the cooling liquid pump to cool the crucible 10, the solid material close to the inner wall of the crucible 10 is in contact with the crucible 10 and can be kept at a temperature range much lower than the melting point of the solid material, so that the solid material close to the inner wall of the crucible 10 can form a solidified shell, the molten zone is prevented from expanding to the inner wall of the crucible 10, and the molten material 200 is isolated from the crucible 10.

[0075] In some embodiments, the temperature of the crucible 10 can be detected by the first temperature detection assembly, so that the cooling assembly 30 can be controlled in time to perform corresponding operations, so as to ensure that the crucible 10 and the solid material close to the inner wall of the crucible 10 are at a lower temperature, and ensure that the solid material close to the inner wall of the crucible 10 can form a solidified shell smoothly.

[0076] Step 330: After the molten material reaches a stable state, the growth of the crystal is performed.

[0077] The molten material 200 reaching a stable state means that the volume of the solid material melted into the molten material 200 no longer continues to increase. For example, the part of the solid material close to the inner wall of the crucible 10 has formed a solidified shell, and due to the effect of the cooling assembly 30, even if the heating assembly 20 continues to work, the volume of the solidified shell melted is small or can be ignored, so at this time the molten material 200 can be regarded as reaching a stable state.

[0078] In some embodiments, after the molten material 200 reaches a stable state, the Czochralski method can be used to produce the crystal. For example only, a pulling rod (for example, the pulling rod 50) connected with a seed crystal holder (for example, the seed crystal holder 40) can be inserted into the crucible 10, so that the seed crystal on the seed crystal holder 40 is in contact with the surface of the molten material 200, after the surface of the seed crystal is slightly melted, the pulling rod 50 is pulled and rotated, so that the melt is crystallized on the seed crystal, and then a cylindrical crystal is grown on the seed crystal holder 40 by continuously pulling and / or rotating the pulling rod 50.

[0079] In some embodiments, since the temperature of the molten raw material 200 is usually much higher than room temperature (for example, 100°C), in order to keep the molten raw material 200 at a proper temperature, it is necessary to control the heating assembly 20 to continue heating the molten raw material 200 after the molten raw material 200 reaches a steady state.

[0080] In some embodiments, during the crystal growth process, the temperature in the enclosure area of the heat preservation cover can be detected by the heat preservation detection device, so that the post-heating device can be timely controlled to perform corresponding operations, ensuring that the crystal is in a suitable temperature environment after being separated from the molten raw material 200, avoiding cracking of the crystal, and improving the quality of the finished crystal.

[0081] In order to more clearly illustrate the crystal production method based on the crystal growth device of the present disclosure, the following will illustrate the growth process embodiments of two kinds of crystals, β-Ga2O3 (β-gallium oxide) and GAGG (cerium-doped gadolinium gallium garnet).

[0082] Example One: Production of 4-inch β-Ga2O3 (β-gallium oxide) crystal

[0083] Step a, select 6000g Ga2O3 (gallium oxide) powder with a purity of 99.999% as a reaction raw material, press the reaction raw material into a cylindrical raw material block (i.e. solid raw material) with a diameter of 190mm, open a groove with a diameter of 80mm and a depth of 10mm at the top of the cylindrical raw material block, put 200g of metallic gallium powder as a flux into the groove, and put the cylindrical raw material block into a silicon carbide crucible (for example, crucible 10) with a diameter of 200mm and a height of 300mm.

[0084] Step b, start the vacuum pump to perform vacuumization treatment on the inside of the hearth of the furnace body, and then introduce argon into the inside of the furnace body until the pressure inside the hearth of the furnace body reaches 0.5atm.

[0085] Step c, after the aeration is completed, control the power supply with a working frequency of 400kHz to work at a power increasing rate of 2000W / h, and at the same time control the cooling liquid pump to work and pump the cooling liquid (for example, cooling liquid 32) into the sealed shell (for example, sealed shell 31), the temperature of the cooling liquid 32 pumped by the cooling liquid pump is controlled to be 5°C, the pumping flow rate is 200L / min, when the molten zone approaches the inner wall of the crucible 10, introduce oxygen into the hearth of the furnace body at a rate of 100sccm (standard cubic centimeter per minute), and preserve for 5 hours, until the metallic gallium is completely melted, continue to introduce oxygen into the furnace body at a rate of 1000sccm to maintain the pressure in the furnace body at 1atm.

[0086] Step d, adjust the output power of the power supply according to the state of the solidified shell to stabilize the melting of the cylindrical raw material block, and the part of the cylindrical raw material block close to the inner wall of the crucible 10 forms a solidified shell.

[0087] Step e, the pulling rod 50 connected with the seed crystal clamp 40 is extended into the crucible 10, so that the seed crystal on the seed crystal clamp 40 is in contact with the surface of the molten raw material 200. After the surface of the seed crystal is slightly melted, the pulling rod 50 is pulled and rotated, so that the melt is crystallized on the seed crystal. Then the pulling rod 50 is pulled and / or rotated, so that the crystal is grown on the seed crystal clamp 40.

[0088] Example two: production of 4-inch GAGG (cerium-doped gadolinium aluminum gallium garnet) crystal

[0089] Step a, 6000g of Gd2O3 (gadolinium oxide) powder, α-Al2O3 (α-type aluminum oxide) powder, β-Ga2O3 (β-type gallium oxide) powder and CeO2 (cerium oxide) powder with a purity of 99.999% are selected and mixed (the mixing ratio of Gd2O3, α-Al2O3, β-Ga2O3 and CeO2 powder is 3:2:3:0.02) as the reaction raw material. The reaction raw material is pressed into a cylindrical raw material block (i.e. solid raw material) with a diameter of 190mm. A groove with a diameter of 80mm and a depth of 10mm is formed at the top of the cylindrical raw material block. A graphite block with a diameter of 70mm and a height of 5mm is placed in the groove as a flux. The cylindrical raw material block is placed in the crucible 10 made of silicon carbide with a diameter of 200mm and a height of 300mm.

[0090] Step b, the vacuum pump is started to perform vacuumizing treatment on the inside of the hearth of the furnace body. Then argon gas is introduced into the inside of the hearth of the furnace body until the pressure in the inside of the hearth of the furnace body reaches 0.5atm.

[0091] Step c, after the aeration is completed, the power supply with a working frequency of 500kHz is controlled to work at a power increasing rate of 2000W / h, and the cooling liquid pump is controlled to work to pump the cooling liquid 32 into the sealed shell 31. The temperature of the cooling liquid 32 pumped by the cooling liquid pump is 5°C, and the pumping flow rate of the cooling liquid 32 is 200L / min. When the melt zone approaches the inner wall of the crucible 10, oxygen gas is introduced into the hearth of the furnace body at a rate of 100sccm. After 5 hours of heat preservation, the graphite block is completely melted. Then oxygen gas is continuously introduced into the furnace body at a rate of 1000sccm to maintain the pressure in the hearth of the furnace body at 1atm.

[0092] Step d, after the power supply is controlled to work at a power increasing rate of 2000W / h for 10 hours, the cylindrical raw material block is stable, and the part of the cylindrical raw material block close to the inner wall of the crucible 10 forms a solid shell.

[0093] Step e, extending the pulling rod (e.g., pulling rod 50) connected with the seed crystal clamp (e.g., seed crystal clamp 40) into the crucible 10, so that the seed crystal on the seed crystal clamp 40 is in contact with the surface of the molten raw material (e.g., molten raw material 200), after the surface of the seed crystal is slightly melted, the pulling rod 50 is pulled and rotated, so that the melt is crystallized on the seed crystal, and then the pulling rod 50 is pulled and / or rotated, so that the crystal is grown on the seed crystal clamp 40.

[0094] The crystal growth device and the crystal production method provided by the present specification have the following beneficial effects, including but not limited to: (1) the crystal growth device of the present specification can combine the advantages of the cold crucible method which does not rely on the crucible of precious metal material and the characteristics of the pulling method which can quickly and simply grow crystals, greatly reducing the cost of crystal production, and under the condition that the power of the power supply is sufficient, a large-diameter crucible can be used for material melting and crystal growth, large-size pulling method crystal growth can be carried out, and after reducing the cost of the crucible, the production value can be quickly expanded, the fixed asset cost is reduced, and the economic value is high; (2) the electromagnetic coil can be arranged in the sealed shell, so that the electromagnetic coil is in direct contact with the cooling liquid, thereby effectively improving the cooling efficiency; (3) the part of the crucible extending into the sealed shell can be in direct contact with the cooling liquid in the sealed shell, which can effectively improve the cooling efficiency; (4) the crucible made of high thermal conductivity material can quickly transfer heat, so that the cooling liquid and the solid raw material can quickly exchange heat, the cooling efficiency of the solid raw material close to the inner wall of the crucible is accelerated, the solidification crust forming time is shortened, and the crystal production efficiency is improved; (5) by arranging the heat preservation cover at the opening of the crucible, the crystal separated from the molten raw material can be in the area enclosed by the heat preservation cover, the temperature difference between the area and the molten raw material is small, and the temperature gradient is small, which can effectively prevent the crystal from cracking.

[0095] The above has described the basic concept, and it is obvious that the above detailed disclosure is only an example for the person skilled in the art, and does not constitute a limitation on the present specification. Although it is not explicitly stated here, the person skilled in the art can make various modifications, improvements and corrections to the present specification. Such modifications, improvements and corrections are suggested in the present specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present specification.

Claims

1. A crystal growing apparatus, characterized by comprising: The crystal growth device comprises: a crucible for containing raw materials for crystal growth; a heating assembly for forming a melting zone in the crucible and heating solid raw materials in the melting zone to form molten raw materials; a cooling assembly arranged outside the crucible, for cooling a portion of the solid raw materials close to the inner wall of the crucible to form a solidified shell, and the molten raw materials are contained in the solidified shell.

2. The crystal growing apparatus of claim 1, wherein The cooling assembly comprises a sealed shell, at least a portion of the crucible is embedded in the sealed shell, the sealed shell is filled with a cooling liquid, the sealed shell is provided with a liquid inlet and a liquid outlet, and the heating assembly is arranged in the sealed shell.

3. The crystal growing apparatus of claim 2, wherein The sealed shell is provided with an embedding groove which is matched with the crucible, and the crucible is detachably arranged in the embedding groove.

4. The crystal growing apparatus of claim 1, wherein The crystal growth device further comprises a first temperature detection assembly which is communicatively connected with the cooling assembly, and the first temperature detection assembly is used for detecting the temperature of the crucible.

5. The crystal growing apparatus of claim 4, wherein The first temperature detection assembly comprises a temperature measuring gun and an infrared temperature measuring instrument.

6. The crystal growing apparatus of claim 2, wherein The heating assembly comprises an electromagnetic coil which is arranged in the sealed shell and surrounds the outer wall of the crucible.

7. The crystal growing apparatus of claim 1, wherein The crystal growth device further comprises: a seed crystal clamp which is arranged in the crucible and is provided with a seed crystal clamping groove; a pulling rod which is connected with the seed crystal clamp and can move relative to the crucible along the height direction of the crucible to adjust the position of the seed crystal hung on the seed crystal clamp relative to the molten raw materials.

8. The crystal growing apparatus of claim 7, wherein The crystal growth device further comprises a heat preservation assembly which comprises a heat preservation cover that encloses the opening of the crucible, and an end of the heat preservation cover away from the opening of the crucible is provided with an access passage through which the pulling rod passes.

9. The crystal growing apparatus of claim 8, wherein The heat preservation cover comprises a first heat preservation cover, a second heat preservation cover and a third heat preservation cover which are connected in sequence along the height direction of the crucible, the first heat preservation cover encloses the opening of the crucible, and the third heat preservation cover is a cover body provided with the access passage.

10. The crystal growing apparatus of claim 8, wherein The heat preservation assembly further comprises a temperature detection device configured to detect the temperature of the enclosed area of the heat preservation cover, and a post-heating device configured to heat the enclosed area of the heat preservation cover.

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