Ir crucible heating device for a single crystal furnace and method of single crystal growth

Abstract

The application discloses an iridium crucible heating device of a single crystal furnace and a single crystal growth method, and relates to the technical field of single crystal pulling equipment, wherein the iridium crucible heating device of the single crystal furnace comprises: a heat preservation device, the heat preservation device has a cavity, and the cavity is used for placing a crucible; a first induction coil, the first induction coil is used for heating the crucible; and a heating assembly, the heating assembly comprises a second induction coil and a heating sheet, the heating sheet is arranged in the second induction coil, the second induction coil is sleeved on the outer wall of the heat preservation device, and the heating sheet is arranged at the bottom of the crucible. The crucible heating device can effectively solve the influence of floating objects on single crystal growth caused by the reaction between raw materials and the crucible and the like, and effectively improve the single crystal growth efficiency; compared with the traditional method of removing floating objects by using a mechanical transmission device, the crucible heating device effectively avoids the influence of the mechanical transmission device on the temperature distribution of the melt during slag removal, so that the hot field does not need to be adjusted again, the operation steps are simplified, and the single crystal growth efficiency is further improved.

Description

Technical Field

[0001] This invention relates to the field of Czochralski single crystal equipment technology, specifically to an iridium crucible heating device for a single crystal furnace and a method for single crystal growth. Background Technology

[0002] The Czochralski method is a traditional single crystal growth method for preparing large-size, high-quality single crystals from melt. Common crystals such as silicon, germanium, sapphire, and YAG (yttrium aluminum garnet) are typically grown using this method. In Czochralski growth, the crystal material is heated and melted in a crucible, with precise control of the temperature distribution within the furnace. A seed crystal is immersed in the melt to create a suitable temperature gradient between the seed crystal and the melt. The crystal is then pulled and rotated at a specific rate, causing the melt to continuously crystallize at the solid-liquid interface. The Czochralski method offers advantages such as large single crystal growth size, visible growth process, and fewer single crystal defects. Furthermore, the method is simple, easy to implement, and readily suitable for industrial production.

[0003] When growing some oxide single crystals using the Czochralski method, iridium crucibles are often used as the melt container. However, after the crystal raw material is heated and melted in the crucible, floating matter often forms on the surface of the melt, affecting crystal growth. The cause of floating matter is usually due to impurities in the raw material itself, or the raw material reacting with the crucible to introduce impurities into the melt. For example, when growing gallium oxide (β-Ga₂O₃) single crystals using the Czochralski method, a noble metal iridium crucible is usually used. Because gallium oxide melt decomposes into Ga at high temperatures, it corrodes the iridium crucible, reacts with the iridium in the crucible, and enters the melt, forming floating matter on the free surface of the melt. The floating matter on the melt surface can hinder the fusion of the seed crystal and the melt during the crystal pulling process, and may even adhere to the bottom of the seed crystal, leading to polycrystalline formation and having a significant adverse effect on single crystal growth.

[0004] Currently, the common method for removing floating matter is to use a mechanical transmission device to lift the slag and remove the floating matter from the furnace body. However, this method is only suitable for situations where floating matter is generated due to impurities in the raw materials themselves, and not for situations where floating matter is generated by the reaction between the raw materials and the crucible. Since the reaction between the raw materials and the crucible is continuous, floating matter will continue to be generated even after it is removed, making it impossible to completely eliminate the floating matter, thus affecting the growth efficiency and quality of single crystals. At the same time, the temperature distribution inside the furnace is easily affected by the floating matter removal process, so that each time floating matter is removed, it is necessary to readjust it time-consumingly, thus affecting the overall efficiency. Summary of the Invention

[0005] 1. The technical problem that the invention aims to solve

[0006] To address the technical problem that floating matter on the melt surface is difficult to remove during the Czochralski method of single crystal growth, which affects single crystal growth, this invention provides an iridium crucible heating device for a single crystal furnace and a method for single crystal growth. This method can effectively avoid the influence of floating matter on single crystal growth and improve single crystal growth efficiency.

[0007] 2. Technical Solution

[0008] To solve the above problems, the technical solution provided by the present invention is as follows:

[0009] An iridium crucible heating device for a single crystal furnace, comprising:

[0010] A heat preservation device having a cavity for placing a crucible;

[0011] A first induction coil is used for heating the crucible;

[0012] The heating assembly includes a second induction coil and a heating element. The heating element is disposed inside the second induction coil, which is sleeved on the outer wall of the heat preservation device. The heating element is placed at the bottom of the crucible.

[0013] In this application, a first induction coil is activated to heat the raw material inside the crucible. When all the raw material for single crystal growth has melted and floating objects appear at the center of the free surface of the melt, a second induction coil is activated. The second induction coil uses the principle of electromagnetic induction to heat the heating element, making the temperature of the heating element higher than that of the crucible sidewall. Since the heating element is placed at the bottom of the crucible, it heats the bottom of the crucible, making the temperature of the bottom of the crucible higher than that of the sidewall, thus creating a certain temperature difference between the bottom and the sidewall. This changes the convection mode of the melt inside the crucible, changing the convection direction of the free surface of the melt from the original "edge → center" to "center → edge". At this time, the floating objects, affected by convection, will drift from the center of the melt to the crucible sidewall at the edge, while the clean melt exposed at the center of the free surface will undergo single crystal growth. At the same time, during the single crystal growth process, since the floating objects continue to move towards the crucible wall due to the convection on the melt surface, the presence of the floating objects will not affect the single crystal growth at the center of the crucible. Therefore, the iridium crucible heating device for the single crystal furnace of this application can effectively solve the problem of floating matter caused by the reaction between raw materials and crucible affecting single crystal growth, thus effectively improving single crystal growth efficiency. At the same time, compared with the traditional method of removing floating matter using a mechanical transmission device, the iridium crucible heating device for the single crystal furnace of this application effectively avoids the influence of mechanical transmission device on the melt temperature distribution during slag removal, thus eliminating the need for further adjustment of the thermal field, simplifying the operation steps, and further improving single crystal growth efficiency.

[0014] Optionally, the heat preservation device includes a heat preservation sleeve and a heat preservation base. The heat preservation sleeve is disposed on the heat preservation base. The first induction coil is sleeved on the outer wall of the heat preservation sleeve, the second induction coil is sleeved on the outer wall of the heat preservation base, and the heating element is disposed on the heat preservation base.

[0015] Optionally, the heat-insulating base includes a base and a cover plate, wherein the base and the cover plate are detachably connected.

[0016] Optionally, the cover plate has a through hole.

[0017] Optionally, the heating element includes a body with a central boss on its surface, the central boss being used to contact the center of the bottom of the crucible.

[0018] Optionally, the size of the body is larger than the outer diameter of the crucible bottom.

[0019] Optionally, the heating element body is circular, and the diameter of the body is greater than 10% of the outer diameter of the crucible.

[0020] Optionally, a heat insulation layer is also included, which is disposed between the heating element and the second induction coil.

[0021] Optionally, the heating element can be made of a conductive material that is resistant to high-temperature oxidation.

[0022] This application also provides a method for single crystal growth, comprising the following steps:

[0023] (1) Assemble the iridium crucible heating device of the single crystal furnace described above onto the crucible;

[0024] (2) Place the raw materials into a crucible and heat them to melt;

[0025] (3) After the raw materials in step (2) have been completely melted into a melt, when floating objects appear in the center of the free surface of the melt, start the crucible heating device and observe the state of the floating objects.

[0026] (4) When the floating objects on the free surface of the melt have completely moved from the center to the side wall of the crucible and exposed the clean melt in the center, the melt temperature is reduced to the crystal-initiating temperature and the single crystal growth continues.

[0027] (5) After the single crystal growth is completed, turn off the crucible heating device during the cooling stage.

[0028] 3. Beneficial effects

[0029] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0030] (1) The iridium crucible heating device for a single crystal furnace proposed in this application has a simple structure and can effectively solve the problem of the influence of floating matter generated by the reaction between raw materials and crucible on single crystal growth, thereby effectively improving the single crystal growth efficiency. At the same time, compared with the traditional method of removing floating matter by using a mechanical transmission device, the iridium crucible heating device for a single crystal furnace in this application effectively avoids the influence of mechanical transmission device on the melt temperature distribution during slag removal, so there is no need to adjust the heat field again, simplifying the operation steps and further improving the single crystal growth efficiency.

[0031] (2) The iridium crucible heating device for a single crystal furnace proposed in this application has a heat preservation device structure that facilitates disassembly and assembly, and also facilitates adjustment of the contact position between the heating element and the crucible.

[0032] (3) The iridium crucible heating device for a single crystal furnace proposed in this application includes a heating plate with a body. The body has a central boss on its surface. The central boss is used to contact the center of the bottom of the crucible. This arrangement can fully ensure the uniformity of heating at the bottom of the crucible.

[0033] (4) The iridium crucible heating device for a single crystal furnace proposed in this application sets the size of the main body to be larger than the outer diameter of the bottom of the crucible, so that the heating element is closer to the second induction coil than the crucible, generating a larger induced current, ensuring that the temperature of the heating element is higher than that of the crucible, thereby ensuring that the temperature of the bottom of the crucible is higher than that of the side wall of the crucible, and realizing the control of the convection of the melt inside the crucible.

[0034] (5) The iridium crucible heating device for a single crystal furnace proposed in this application provides that the heating element is made of a conductive material that is resistant to high temperature oxidation, so that the heating component can heat the bottom of the crucible in a high temperature and oxygen atmosphere. Thus, the entire iridium crucible heating device and the single crystal growth method using this iridium crucible heating device can be used for single crystal growth in an oxygen atmosphere.

[0035] (6) The single crystal growth method proposed in this application can effectively solve the influence of floating matter caused by the reaction between raw materials and crucible on single crystal growth, and effectively improve the single crystal growth efficiency. At the same time, it can effectively avoid the influence of mechanical transmission device on the melt temperature distribution during slag removal, so there is no need to adjust the thermal field again. This not only simplifies the operation steps, but also further improves the single crystal growth efficiency and overall efficiency. Attached Figure Description

[0036] Figure 1 This is an internal cross-sectional view of an iridium crucible heating device for a single crystal furnace according to an embodiment of the present invention.

[0037] Figure 2This is an exploded view of the structure of an iridium crucible heating device for a single crystal furnace according to an embodiment of the present invention.

[0038] Figure 3 This is an exploded front view of the structure of an iridium crucible heating device for a single crystal furnace according to an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of the structure of the heat-insulating base in an iridium crucible heating device for a single crystal furnace according to an embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the heating element in an iridium crucible heating device for a single crystal furnace according to an embodiment of the present invention. Detailed Implementation

[0041] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0042] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Example 1

[0044] Combined with appendix Figure 1-5This embodiment provides an iridium crucible heating device for a single crystal furnace, comprising: a heat preservation device 1 having a cavity for placing a crucible 2; a first induction coil 9 for heating the crucible 2; and a heating assembly including a second induction coil 3 and a heating element 4, wherein the heating element 4 is disposed inside the second induction coil 3, the second induction coil 3 is sleeved on the outer wall of the heat preservation device 1, and the heating element 4 is placed at the bottom of the crucible 2.

[0045] The first induction coil 9 is turned on to heat the raw material in crucible 2. When all the raw material for single crystal growth has melted and floating objects appear at the center of the free surface of the melt, the second induction coil 3 is turned on. The second induction coil 3 uses the principle of electromagnetic induction to heat the heating element 4, making the temperature of the heating element 4 higher than that of the side wall of crucible 2. Since the heating element 4 is placed at the bottom of crucible 2, it heats the bottom of crucible 2, making the temperature of the bottom of crucible 2 higher than that of the side wall of crucible 2. This creates a certain temperature difference between the bottom and the side wall of crucible 2, thereby changing the convection mode of the melt in crucible 2. The convection direction of the free surface of the melt changes from the original "edge → center" to "center → edge". At this time, the floating objects will drift from the center of the melt to the side wall of crucible 2 at the edge due to the convection, while the clean melt exposed at the center of the free surface will undergo single crystal growth. At the same time, during the single crystal growth process, since the floating objects remain at the wall of crucible 2 due to the melt convection, the presence of the floating objects will not affect the single crystal growth at the center of crucible 2. Therefore, the iridium crucible heating device for the single crystal furnace of this application can effectively solve the problem of floating matter caused by the reaction between the raw materials and crucible 2 affecting single crystal growth, and effectively improve the single crystal growth efficiency. At the same time, compared with the traditional method of removing floating matter by using a mechanical transmission device, the iridium crucible heating device for the single crystal furnace of this application effectively avoids the influence of the mechanical transmission device on the melt temperature distribution during slag removal, so there is no need to adjust the thermal field again, simplifying the operation steps and further improving the single crystal growth efficiency.

[0046] In practical applications, a control system (not shown in the figure) is also included, which is connected to both the first induction coil 9 and the second induction coil 3. The control system is used to control the power of the first induction coil 9 and the second induction coil 3, and both are individually controlled by the control system. In practical applications, if the atmosphere inside the single crystal furnace is oxygen-free or vacuum, the heating element can be a resistance heater.

[0047] Example 2

[0048] Combined with appendix Figure 1-3In this embodiment, an iridium crucible heating device for a single crystal furnace, compared with the technical solution of embodiment 1, includes an insulation sleeve 5 and an insulation base 6. The insulation sleeve 5 is disposed on the insulation base 6, the first induction coil 9 is sleeved on the outer wall of the insulation sleeve 5, the second induction coil 3 is sleeved on the outer wall of the insulation base 6, and the heating element 4 is disposed on the insulation base 6.

[0049] In practical applications, the insulation sleeve 5 and the insulation base 6 are detachably connected. The insulation sleeve 5 is used to fit the crucible 2. The first induction coil 9 is sleeved on the outer wall of the insulation sleeve 5, which heats the side wall of the crucible 2 while ensuring better temperature stability inside the crucible 2. Since the heating element 4 is located on the insulation base 6 and the second induction coil 3 is sleeved on the outer wall of the insulation base 6, when the second induction coil 3 is activated, it heats the heating element 4. Because the heating element 4 is in contact with the bottom of the crucible 2, the bottom of the crucible 2 can be heated. This arrangement facilitates disassembly and assembly, and also makes it easy to adjust the contact position between the heating element 4 and the crucible 2.

[0050] Example 3

[0051] Combined with appendix Figure 4 This embodiment of an iridium crucible heating device for a single crystal furnace differs from the technical solution of embodiment 2 in that the heat-insulating base 6 includes a base 7 and a cover plate 8, which are detachably connected. This design facilitates disassembly and assembly. In practical application, the cover plate 8 has a groove (not shown in the figure) and a through hole 10 located at the center of the groove. This design allows the base 7 and the cover plate 8 to form a cavity after assembly, which is used to place the heating element 4.

[0052] Example 4

[0053] Combined with appendix Figure 4 In this embodiment, an iridium crucible heating device for a single crystal furnace, compared with the technical solution of embodiment 3, has a through hole 10 provided on the cover plate 8. The through hole 10 is located at the center of the cover plate 8. The through hole 10 can effectively ensure that, except for the surface of the heating element 4 that is in contact with the bottom of the crucible 2, the other heating elements 4 are all located in the heat insulation layer, further ensuring the temperature stability of the bottom heating of the crucible 2.

[0054] Example 5

[0055] Combined with appendix Figure 5This embodiment of an iridium crucible heating device for a single crystal furnace, compared with any of the technical solutions in embodiments 1-4, includes a heating element 4 comprising a body 11, the surface of which is provided with a central protrusion 12, the central protrusion 12 being used to contact the center position of the bottom of the crucible 2. In practical application, the body 11 is embedded in a groove in the cover plate 8, and the central protrusion 12 protrudes through the through hole 10 of the cover plate 8 and contacts the center position of the bottom of the crucible 2. Considering that the crucible 2 is cylindrical, and the central protrusion 12 is cylindrical, this setting can not only fully ensure the uniformity of heating at the bottom of the crucible 2, but also facilitate processing and production; at the same time, the diameter A of the central protrusion 12 is less than or equal to the expected diameter B of the single crystal growth constant diameter stage, wherein the size range of B is 15-300mm.

[0056] Example 6

[0057] In this embodiment, an iridium crucible heating device for a single crystal furnace, compared to the technical solution of embodiment 5, has a body 11 whose size is larger than the bottom outer diameter of the crucible 2. In practical applications, the body 11 of the heating element 4 is in a circular, square, or other geometric shape, and its size is larger than the bottom outer diameter of the crucible 2. This arrangement allows the heating element 4 to be closer to the second induction coil 3 than the crucible 2, generating a larger induced current and ensuring that the temperature of the heating element 4 is higher than that of the crucible 2. This, in turn, ensures that the temperature of the bottom of the crucible 2 is higher than that of the sidewall of the crucible 2, thereby achieving the control of melt convection within the crucible 2.

[0058] Example 7

[0059] Combined with appendix Figure 5 In this embodiment, an iridium crucible heating device for a single-crystal furnace, compared to the technical solution of embodiment 6, has a circular heating element 4 body 11, the diameter of which is greater than 10% of the outer diameter of the crucible 2. Generally, the larger the size of the heating element 4 body 11, the higher the temperature, and the greater the control over melt convection within the crucible 2. By setting the diameter of the body 11 to be 10% larger than the outer diameter of the crucible 2, a larger induced current can be generated between the second induction coil 3 and the heating element 4, resulting in a higher temperature generated by the heating element 4 than that of the crucible 2, thus better controlling the melt convection within the crucible 2.

[0060] Example 8

[0061] This embodiment of the iridium crucible heating device for a single crystal furnace, compared to the technical solution of Embodiment 1, further includes a heat insulation layer, which is disposed between the heating element 4 and the second induction coil 3. In practical applications, the heat insulation layer (not shown in the figure) is disposed between the outer wall of the heat-insulating base 6 and the second induction coil 3. This arrangement can effectively prevent the second induction coil 3 from being damaged due to high temperature.

[0062] Example 9

[0063] This embodiment of the iridium crucible heating device for a single crystal furnace differs from the technical solution of Embodiment 1 in that the heating element 4 is made of a high-temperature oxidation-resistant conductive material. In practical applications, the high-temperature oxidation-resistant conductive material can be iridium metal, platinum-rhodium alloy, etc. This configuration allows the heating assembly to heat the bottom of the crucible 2 under high temperature and oxygen-containing atmosphere.

[0064] Example 10

[0065] This embodiment provides a method for single crystal growth, including the following steps:

[0066] (1) Assemble the iridium crucible heating device of the single crystal furnace described in any one of the technical solutions of Examples 1-9 onto the crucible;

[0067] (2) Place the raw materials into a crucible and heat them to melt;

[0068] (3) After the raw materials in step (2) have been completely melted into a melt, when floating objects appear in the center of the free surface of the melt, start the crucible heating device and observe the state of the floating objects.

[0069] (4) When the floating objects on the free surface of the melt have completely moved from the center to the side wall of the crucible and exposed the clean melt in the center, the melt temperature is reduced to the crystal-initiating temperature and the single crystal growth continues.

[0070] (5) After the single crystal growth is completed, turn off the crucible heating device during the cooling stage.

[0071] In this application, the growth method can effectively solve the problem of floating matter caused by the reaction between raw materials and crucible on the growth of single crystals, and effectively improve the growth efficiency of single crystals. At the same time, it can effectively avoid the influence of mechanical transmission device on the temperature distribution of melt during slag removal, so there is no need to adjust the thermal field again. This not only simplifies the operation steps, but also further improves the growth efficiency of single crystals and the overall efficiency.

[0072] In practical applications, the second induction coil 3 is made of copper tubes, and cooling water flows inside the copper tubes, with the water temperature being less than 80°C.

[0073] In practical applications, during step (3), when the floating object at the center of the free surface of the melt moves towards the side wall of crucible 2, the radial convection velocity of the free surface of the melt is 1×10⁻⁶. -4 -1×10 -1 m / s. This setting allows floating matter on the free surface of the melt to move rapidly and completely from the center to the sidewall of crucible 2, improving the efficiency of single crystal growth.

[0074] In practical application, the circular body 11 of the heating element 4 with a diameter of 60mm is placed inside the base 7 of the heat insulation base 6, and the cover plate 8 of the heat insulation base 6 is covered. The end face of the cylindrical central boss 12 with a diameter of 15mm on the heating element 4 is exposed through the through hole 10 of the cover plate 8 of the heat insulation base 6. Next, the second induction coil 3 is sleeved on the outer wall of the heat insulation base 6, ensuring that the heating element 4 is located inside the second induction coil 3. Then, the crucible 2 is placed on the heat insulation base 6, ensuring that the center position of the bottom of the crucible 2 is in contact with the exposed end face of the central boss 12, so that the second induction coil 3, the heating element 4 and the crucible 2 are coaxially arranged. Next, the heat insulation sleeve 5 is sleeved on the outer wall of the crucible 2 and connected to the heat insulation base 6. Finally, the first induction coil 9 is sleeved on the outer wall of the heat insulation sleeve 5. At this time, the iridium crucible heating device of the single crystal furnace is successfully assembled on the crucible 2. Raw materials are placed into the assembled crucible 2. The raw materials are then subjected to vacuuming, leak detection, and material preparation according to the conventional Czochralski single crystal growth process. When the raw materials are completely melted into a molten body, and floating objects appear at the center of the free surface of the molten body, the second induction coil 3 in the crucible heating device is activated. The power is gradually increased in 5W increments to move the floating objects at the center of the free surface of the molten body towards the side wall of crucible 2, while simultaneously observing the state of the floating objects. When the floating objects on the free surface of the molten body have completely moved from the center to the side wall of crucible 2, exposing the clean molten body at the center, the radial convection velocity of the free surface of the molten body is kept constant. The power of the first induction coil 9 and the second induction coil 3 is gradually decreased in 5W increments to gradually lower the molten body temperature to the crystal-leading temperature. Then, the conventional Czochralski single crystal growth processes, including crystal lead-in, necking, shoulder formation, shoulder rotation, constant diameter growth, and tailing, continue. After the single crystal growth is completed, the power of the second induction coil 3 and the first induction coil 9 is gradually reduced during cooling. Finally, the furnace is shut down according to the conventional Czochralski single crystal growth process.

[0075] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for single crystal growth, implemented using an iridium crucible heating device in a single crystal furnace, wherein the iridium crucible heating device of the single crystal furnace comprises: A heat preservation device having a cavity for placing a crucible, wherein the crucible is an iridium crucible and the raw material placed inside the iridium crucible is gallium oxide; The heat preservation device includes a heat preservation sleeve and a heat preservation base, the heat preservation sleeve being disposed on the heat preservation base; the heat preservation base includes a base body and a cover plate, the base body and the cover plate being detachably connected; a first induction coil, the first induction coil being used for heating the crucible; the first induction coil being sleeved on the outer wall of the heat preservation sleeve; a heating assembly, the heating assembly including a second induction coil and a heating element, the heating element being disposed inside the second induction coil, the second induction coil being sleeved on the outer wall of the heat preservation device, the heating element being placed on the heat preservation base; the heating element includes a body, the surface of the body... The crucible has a central protrusion for contacting the center of the crucible bottom. The heating element is circular, with a diameter greater than 10% of the crucible's outer diameter. When the heating element heats the bottom of the crucible, the temperature at the bottom is higher than that of the sidewalls, creating a temperature difference between the bottom and sidewalls. This alters the convection pattern of the gallium oxide melt within the crucible, changing the convection direction of the melt's free surface to "center → edge." Floating debris, influenced by convection, drifts from the melt's center to the crucible sidewalls at the edge. The single crystal growth method comprises the following steps: (1) Assemble the iridium crucible heating device of the single crystal furnace onto the crucible, wherein the crucible is an iridium crucible; (2) Place the gallium oxide raw material into a crucible and heat it to melt it; (3) After the gallium oxide raw material in step (2) has been completely melted into a melt, when floating objects appear in the center of the free surface of the melt, start the crucible heating device and observe the state of the floating objects. (4) When the floating objects on the free surface of the melt have completely moved from the center to the side wall of the crucible and exposed the clean melt in the center, the melt temperature is reduced to the crystal-initiating temperature and the single crystal growth continues. (5) After the single crystal growth is completed, turn off the crucible heating device during the cooling stage.

2. The method for single crystal growth according to claim 1, characterized in that, The cover plate has a through hole.

3. The method for single crystal growth according to claim 1, characterized in that, The dimensions of the body are larger than the outer diameter of the crucible bottom.

4. The method for single crystal growth according to claim 1, characterized in that, It also includes a heat insulation layer, which is disposed between the heating element and the second induction coil.

5. The method for single crystal growth according to claim 1, characterized in that, The heating element is made of a conductive material that is resistant to high-temperature oxidation.

Images