Single crystal furnace and its heating and heat preservation system, and method for growing gallium oxide crystals

Abstract

The embodiment of the present application provides a single crystal furnace and its heating and heat preservation system, and a method for growing gallium oxide crystals, including a heating element, an induction coil, and a heat preservation assembly, wherein the heating element is used to heat raw materials; the heating element is configured to be electromagnetically coupled with the induction coil to generate heat; the heat preservation assembly includes a first heat preservation sleeve, a second heat preservation sleeve, and heat preservation particles arranged at intervals, and the heat preservation particles are filled between the heating element and the first heat preservation sleeve, and between the first heat preservation sleeve and the second heat preservation sleeve, and are in contact with the heating element, the first heat preservation sleeve, and the second heat preservation sleeve. The heat preservation assembly can reduce the thermal delay of the heating and heat preservation system of the single crystal furnace in the necking and shouldering stages, improve the stability of the temperature field, and thus improve the quality of the grown crystal.

Description

Technical Field

[0001] The present application relates to the technical field of crystal preparation, and in particular to a single crystal furnace and a heating and heat preservation system thereof, and a method for growing gallium oxide crystals. Background Art

[0002] During the process of crystal growth in a single crystal furnace, the necking and shouldering of the crystal are achieved by changing the power of the induction coil to adjust the temperature gradient change of the temperature field. During the above adjustment process, the heating and insulation system of the single crystal furnace has a large thermal delay in the change of the temperature gradient. The thermal delay causes the necking and shouldering operations in the crystal growth process to respond slowly and easily introduce new crystal nuclei. The thermal delay also causes the temperature field to be unstable in the equal diameter stage, which affects the quality of crystal growth and makes it difficult to grow high-quality crystals. Summary of the invention

[0003] The purpose of the embodiment of the present application is to provide a single crystal furnace and its heating and heat preservation system, and a method for growing gallium oxide crystals, which can reduce the thermal delay of the heating and heat preservation system of the single crystal furnace in the necking and shouldering stages, improve the stability of the temperature field, and thus improve the quality of the grown crystals. The specific technical solution is as follows:

[0004] In a first aspect, an embodiment of the present application provides a heating and heat preservation system for a single crystal furnace, comprising:

[0005] Heating element, used for heating raw materials;

[0006] an induction coil, the heating element being configured to be electromagnetically coupled to the induction coil to generate heat;

[0007] The thermal insulation component includes a first thermal insulation sleeve, a second thermal insulation sleeve and thermal insulation particles which are arranged at intervals. The thermal insulation particles are filled between the heat generating element and the first thermal insulation sleeve, and between the first thermal insulation sleeve and the second thermal insulation sleeve, and are in contact with the heat generating element, the first thermal insulation sleeve and the second thermal insulation sleeve.

[0008] According to some embodiments of the present application, the heat generating element is a crucible, and the crucible is used to hold raw materials.

[0009] According to some embodiments of the present application, the crucible is an iridium crucible or an iridium alloy crucible.

[0010] According to some embodiments of the present application, the first thermal insulation sleeve is a zirconium dioxide sleeve or a quartz glass sleeve.

[0011] According to some embodiments of the present application, the second thermal insulation sleeve is a zirconium dioxide sleeve or a quartz glass sleeve.

[0012] According to some embodiments of the present application, the thermal insulation particles are zirconium dioxide particles or zirconium sand.

[0013] According to some embodiments of the present application, the distance between the first thermal insulation sleeve and the heat-generating element is greater than the distance between the second thermal insulation sleeve and the first thermal insulation sleeve.

[0014] In a second aspect, an embodiment of the present application provides a single crystal furnace, comprising a guide mold and the above-mentioned heating and heat preservation system of the single crystal furnace, wherein the guide mold is located inside the heat-generating element.

[0015] According to some embodiments of the present application, the guide mold includes a slit, the top of the slit has a "V"-shaped notch, and the included angle of the "V"-shaped notch is 140°-160°.

[0016] In a third aspect, an embodiment of the present application provides a method for growing gallium oxide crystals using the above-mentioned single crystal furnace guided mold method, wherein the single crystal furnace comprises a guided mold mold and a heating and heat preservation system of the single crystal furnace, wherein the guided mold mold comprises a slit, and the top of the slit has a "V"-shaped notch, and the heating and heat preservation system comprises a heating element, wherein the heating element is a crucible, and the steps are as follows:

[0017] Furnace loading: placing the raw materials in the crucible of the single crystal furnace, installing the guide mold, and aligning the seed crystal with the "V"-shaped notch on the upper surface of the guide mold;

[0018] Melt: Heating with a certain heating power until the power reaches 8500W, all the raw materials in the crucible are melted to form a melt, and the heating power is small at first and then large;

[0019] Lowering the seed crystal: slowly shaking the seed crystal down to become one with the liquid surface of the melt in the guide mold, staying there for 3 to 5 minutes, and then starting to pull the seed crystal upward;

[0020] Neck closing: manually adjust the heating power, increase by 30W-50W each time, maintain for 10min-20min, and then increase by 30W-50W again until the power reaches 8800W without adjusting the heating power. During the power adjustment process, neck closing is performed at a pulling speed of 5mm / h-20mm / h until the seed crystal is thinned;

[0021] Shoulder release: Manually adjust the heating power, reduce it by 50W-80W each time, keep it for 10min-20min, then reduce it by 30W-50W again, keep the pulling speed in the necking process unchanged, and release the shoulder until the crystal fills the slit on the upper surface of the guide mold, and no longer adjust the heating power;

[0022] Equal diameter growth: keeping the final heating power in the shouldering process and the pulling speed in the necking process unchanged, and growing the crystal until the melt in the crucible is completely grown;

[0023] Cooling: After the crystal growth is completed, the temperature is lowered with a heating power of 1000W / h-1500W / h;

[0024] Out of the oven: After cooling to room temperature, the crystal is out of the oven;

[0025] Heat treatment: Place the crystals out of the furnace in a vacuum annealing furnace, and heat them to 1700°C at a heating rate of 300°C / h in a carbon dioxide atmosphere, keep them at that temperature for 4 hours, and cool them to room temperature at a cooling rate of 100°C / h before taking them out of the furnace.

[0026] According to some embodiments of the present application, the steps of melting the material are: first heating the temperature with a heating power of 500W / h, maintaining for 12 hours, and then continuing to heat the temperature with a heating power of 1000W / h until the raw materials are completely melted to form the melt.

[0027] By adopting the above technical solution, the beneficial effects of the embodiments of the present application are:

[0028] The insulation particles are in close contact with the heating element, and most of the heat of the heating element can be stored in the insulation particles between the heating element and the first insulation sleeve, and a small part of the heat can pass through the first insulation sleeve and be conducted to the insulation particles between the first insulation sleeve and the second insulation sleeve. When the power of the induction coil increases, the temperature of the heating element rises rapidly, and the excess heat generated will be stored in the insulation particles, the first insulation sleeve and the second insulation sleeve, reducing thermal delay, improving response efficiency, and the temperature field quickly reaches a stable state; when the power of the induction coil decreases, the temperature of the heating element decreases rapidly, and the temperature changes of the insulation particles, the first insulation sleeve and the second insulation sleeve are small, and the temperature field will also quickly reach stability. Therefore, the insulation component can reduce the thermal delay phenomenon generated by the heating and insulation system of the single crystal furnace when the power changes, thereby improving the response efficiency during the necking and shouldering operations during the crystal growth process, and improving the growth quality of the crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0030] Figure 1 A cross-sectional schematic diagram of a heating and heat preservation system of a single crystal furnace provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of a guide mold provided in an embodiment of the present application;

[0032] Figure 3 for Figure 2 Schematic diagram of another perspective of the center-guided mold. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0034] It should be understood that the terms used in the text are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used in the text may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described in the text are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0035] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0036] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, the element described as "below other elements or features" or "below other elements or features" will then be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise, such as rotated 90 degrees or in other directions, and the spatial relative descriptors used in the text are interpreted accordingly.

[0037] In view of the fact that when the heating and insulation system of the single crystal furnace in the prior art adjusts the temperature gradient change of the temperature field by changing the power, there is a large thermal delay in the change of the temperature gradient in the furnace, which leads to slow response efficiency of the necking and shouldering operations in the crystal growth process, easy introduction of new crystal nuclei, and instability of the temperature field in the equal diameter stage. The embodiment of the present application proposes a heating and insulation system for a single crystal furnace, which can reduce the thermal delay of the heating and insulation system of the single crystal furnace in the necking and shouldering stages, improve the stability of the temperature field, and thus improve the quality of the grown crystal.

[0038] like Figure 1 As shown, the heating and insulation system of the single crystal furnace includes: a heating element 1, an induction coil 5 and an insulation component, the heating element 1 is used to heat the raw material; the heating element 1 is configured to be electromagnetically coupled with the induction coil 5 to generate heat; the insulation component includes a first insulation sleeve 2, a second insulation sleeve 3 and insulation particles 4 arranged at intervals, the insulation particles 4 are filled between the heating element 1 and the first insulation sleeve 2, and between the first insulation sleeve 2 and the second insulation sleeve 3, and are in contact with the heating element 1, the first insulation sleeve 2 and the second insulation sleeve 3.

[0039] In the present embodiment, the heating element 1 is electromagnetically coupled with the induction coil 5. When the induction coil 5 is energized, the induction coil 5 can generate a constantly changing alternating magnetic field. The heating element 1 generates eddy currents in the conductor of the alternating magnetic field. The Joule effect of the eddy currents increases the temperature of the heating element 1, thereby causing the heating element 1 to generate heat. Moreover, the temperature of the heating element 1 can be controlled by changing the power of the induction coil 5. Electromagnetic coupling heating has the advantages of fast heating speed and energy saving. The heat-insulating particles 4 are filled between the heating element 1 and the first heat-insulating sleeve 2, and between the first heat-insulating sleeve 2 and the second heat-insulating sleeve 3. The heat-insulating particles 4 are in close contact with the heating element 1, the first heat-insulating sleeve 2 and the second heat-insulating sleeve 3. In order to increase the filling density, the particle size of the heat-insulating particles 4 is as small as possible.

[0040] The heat-insulating particles 4 are in close contact with the heating element 1, and most of the heat of the heating element 1 can be stored in the heat-insulating particles 4 between the heating element 1 and the first heat-insulating sleeve 2, and a small part of the heat can pass through the first heat-insulating sleeve 2 and be conducted to the heat-insulating particles 4 between the first heat-insulating sleeve 2 and the second heat-insulating sleeve 3. When the power of the induction coil 5 increases, the temperature of the heating element 1 rises rapidly, and the excess heat generated will be stored in the heat-insulating particles 4, the first heat-insulating sleeve 2 and the second heat-insulating sleeve 3, reducing thermal delay, improving response efficiency, and the temperature field quickly reaches a stable state; when the power of the induction coil 5 decreases, the temperature of the heating element 1 decreases rapidly, and the temperature changes of the heat-insulating particles 4, the first heat-insulating sleeve 2 and the second heat-insulating sleeve 3 are small, and the temperature field will also quickly reach stability. Therefore, the heat-insulating component can reduce the heat-increasing delay phenomenon generated by the heating and heat-insulating system of the single crystal furnace when the power changes, thereby improving the response efficiency during the necking and shouldering operations during the crystal growth process, and improving the growth quality of the crystal.

[0041] Among them, necking is to increase the temperature to make the diameter of the seed crystal thinner, and shouldering is to reduce the temperature to make the end of the seed crystal extend outward at a certain angle to grow crystals. The necking and shouldering processes of the seed crystal during crystal growth are particularly important, which directly affects the quality of the grown crystal. Necking and shouldering are achieved by repeatedly regulating the power of the induction coil 5. The thermal delay during the power change process directly affects the effect of necking and shouldering. Necking can greatly reduce the new crystal nuclei introduced by various reasons during the seed crystal elongation process. The seed crystal is thinned and then shouldered. The effective control of the entire necking and shouldering process can avoid impurities, twins and cracking of the crystal. The reduction of thermal delay can improve the response efficiency, better complete the necking and shouldering processes of the seed crystal, and grow high-quality crystals.

[0042] According to some embodiments of the present application, Figure 1 As shown, the heating element 1 is a crucible, and the crucible is used to hold raw materials.

[0043] In some embodiments of the present application, the heating element 1 is a crucible, so that the crucible can be used to hold raw materials and heat the raw materials. Compared with the design in which the crucible and the heating element 1 are separated in the traditional single crystal furnace, the process of transferring heat from the heating element 1 to the crucible is omitted, which can reduce the thermal delay, make the temperature field quickly reach a stable state, and improve the thermal response efficiency of necking and shouldering during crystal growth. The heating element 1 is used for both heating and holding raw materials, and can also reduce heat loss and improve thermal energy utilization.

[0044] At the same time, the temperature field in the single crystal furnace is stable, so that after the crystal completes the necking and shouldering process and enters the equal diameter stage, the crystal growth can be isotropic and the grown crystals are more uniform.

[0045] In some embodiments of the present application, the crucible is an iridium crucible or an iridium alloy crucible, and the iridium alloy can be an iridium-platinum alloy or an iridium-rhodium alloy. The melting point of iridium and iridium alloy is as high as 2000° C. and can be used to grow crystals with higher melting points, such as gallium oxide crystals.

[0046] According to some embodiments of the present application, the first thermal insulation sleeve 2 is a zirconium dioxide sleeve.

[0047] In this embodiment, the chemical formula of zirconium dioxide is ZrO2, which is the main oxide of zirconium, is chemically inactive, has a low thermal conductivity and is resistant to high temperatures. The thermal conductivity is 2.5 W / m·K at room temperature, and is a high-quality thermal insulation and energy-saving material. Therefore, the zirconium dioxide sleeve as the first thermal insulation sleeve 2 has a good thermal insulation effect and is resistant to high temperatures.

[0048] According to some embodiments of the present application, the first heat-insulating sleeve 2 may also be a quartz glass sleeve. Quartz glass is a glass with a single component of silicon dioxide. Quartz glass material has excellent thermal shock resistance and high temperature resistance, and has a small thermal expansion coefficient. The thermal expansion coefficient at room temperature is 5.5×10 -7 / ℃, and the thermal conductivity is 1.46W / m·K at room temperature. Therefore, quartz glass is also a good thermal insulation material. The softening point of quartz glass is about 1730℃, and it can be used for a long time at 1100℃, and the maximum short-term use temperature can reach 1450℃. Therefore, if the temperature allows, the first thermal insulation sleeve 2 can also be a quartz glass sleeve.

[0049] According to some embodiments of the present application, the second heat-insulating sleeve 3 is a zirconium dioxide sleeve or a quartz glass sleeve. Zirconium dioxide or quartz glass can be used as high-temperature heat-insulating materials due to their high heat-resistant temperature and low thermal conductivity.

[0050] Since the second insulation sleeve 3 is located outside the first insulation sleeve 2, the operating temperature of the second insulation sleeve 3 is lower than that of the first insulation sleeve 2. Therefore, from the perspective of cost saving, the first insulation sleeve 2 can be made of zirconium dioxide insulation sleeve, which can withstand higher temperatures, and the second insulation sleeve 3 can be made of quartz glass sleeve.

[0051] The first thermal insulation sleeve 2 and the second thermal insulation sleeve 3 can absorb the excess heat generated by the heating element 1, and because the first thermal insulation sleeve 2 and the second thermal insulation sleeve 3 both have a low thermal conductivity, they have good thermal insulation performance, so that the temperature field between the heating element 1 and the first thermal insulation sleeve 2, and the temperature field between the first sleeve and the second sleeve remain stable. When the power changes, the first thermal insulation sleeve 2 and the second thermal insulation sleeve 3 can reduce the loss of heat to the outside, can quickly respond to temperature changes, and shorten the delay time.

[0052] According to some embodiments of the present application, the thermal insulation particles 4 are zirconium dioxide particles or zirconium sand.

[0053] In some embodiments of the present application, the thermal insulation particles 4 filled between the first thermal insulation sleeve 2 and the heating element 1 are zirconium dioxide particles or zircon sand, and the thermal insulation particles 4 filled between the first thermal insulation sleeve 2 and the second thermal insulation sleeve 3 are zirconium dioxide particles or zircon sand. The zirconium dioxide particles or zircon sand also have a thermal insulation effect. When the temperature of the heating element 1 increases or decreases, due to the thermal insulation effect of the zirconium dioxide particles or zircon sand, the heating element 1 can quickly reach a predetermined temperature and shorten the delay time.

[0054] The main components of zircon sand are ZrO2 particles and SiO2 particles. Specifically, the weight percentage of ZrO2 particles is 65%, the weight percentage of SiO2 particles is 34%, and the melting point of zircon sand is about 2400°C.

[0055] In addition, the use of granular thermal insulation material can effectively fill the gap between the heating element 1 and the first thermal insulation sleeve 2, and the gap between the first sleeve and the second sleeve, and the filling process is simple and easy to operate.

[0056] According to some embodiments of the present application, the distance between the first thermal insulation sleeve 2 and the heating element 1 is greater than the distance between the second thermal insulation sleeve 3 and the first thermal insulation sleeve 2 .

[0057] In some embodiments of the present application, the distance between the first thermal insulation sleeve 2 and the heating element 1 is greater, which means that the thickness of the thermal insulation particles 4 filled between the heating element 1 and the first thermal insulation sleeve 2 is greater, which can increase the thermal insulation effect of the heating element 1 and the raw materials inside it, and keep the temperature field of the heating element 1 and the raw materials inside it stable. During the crystal growth process, as the seed crystal is pulled to complete the necking and shouldering, the crystal spreads over the entire upper surface of the guide mold 6 and enters the equal diameter stage. The stable temperature field at this stage can ensure that the grown crystals are of higher quality.

[0058] In a specific embodiment, the outer diameter of the guide mold 6 is 70-80mm, the thickness of the guide mold 6 is about 3mm, the outer diameter of the first insulation sleeve 2 is 144-164mm, the thickness of the first insulation sleeve 2 is about 14mmm, the outer diameter of the second insulation sleeve 3 is 170-185mm, and the thickness of the second insulation sleeve 3 is about 4mm.

[0059] The embodiment of the present application also provides a single crystal furnace, which includes: a guide mold 6 and the above-mentioned heating and heat preservation system of the single crystal furnace, and the guide mold 6 is located in the heating element 1. The single crystal furnace adopts the above-mentioned heating and heat preservation system to reduce the thermal delay in the heating element 1 and improve the temperature field stability in the heating element 1, thereby improving the quality of the grown crystal.

[0060] According to some embodiments of the present application, Figure 2As shown, the guide mold 6 includes a slit 62, and the top of the slit 62 has a "V"-shaped notch 63, as shown in FIG. Figure 3 In the portion framed by the dotted line, the included angle 64 of the “V”-shaped notch 63 is 140°-160°.

[0061] In some embodiments of the present application, Figure 2 , Figure 3 As shown, the guide mold 6 includes two mirror-symmetrical clamping plates 61, the two clamping plates 61 are connected by pins 65 or screws 65, and there is a slit 62 between the two clamping plates 61. The two ends of the slit 62 along the length direction L of the guide mold 6 can be welded and fixed, and the weld 66 starts from 3 mm at the bottom end, as shown in FIG. Figure 3 As shown. The guide mold 6 is placed in the heating element 1. When the raw material is heated and melted into a melt, the melt in the heating element 1 can be sucked to the top of the guide mold 6 through the siphon effect of the slit 62 along the height direction H, and then the seed crystal is lowered to contact the liquid surface at the top of the guide mold 6. After the end of the seed crystal is melted, it is fused with the melt at the top of the guide mold 6, and then the seed crystal is slowly pulled upward, followed by processes such as retracting and releasing shoulders, and finally the desired crystal is grown with equal diameter. Among them, the width of the slit 62 can be 0.4mm-0.6mm, and the top of the slit 62 has a "V"-shaped notch 63, and the angle 64 of the "V"-shaped notch 63 is 140°-160°. When the angle 64 is 140°-160°, the grown crystal is wider and the grains are more uniform.

[0062] The present application also provides a method for growing gallium oxide crystals using the above-mentioned single crystal furnace, comprising the following steps:

[0063] Furnace loading: placing the raw materials in the crucible of the single crystal furnace, installing the guide mold 6, and aligning the seed crystal with the guide mold 6;

[0064] Melt: Heating with a certain heating power until the power reaches 8500W, all the raw materials in the heating element 1 are melted to form a melt, and the heating power is small at first and then large;

[0065] Lowering the seed crystal: Slowly shake the seed crystal down to become one with the liquid surface of the melt in the guide mold 6, stay there for 3 to 5 minutes, and then start to pull the seed crystal upward;

[0066] Neck closing: Manually adjust the heating power, increase by 30W-50W each time, maintain for 10min-20min, and then increase by 30W-50W again until the power reaches 8800W and the heating power is no longer adjusted. During the power adjustment process, neck closing is performed at a pulling speed of 5mm / h-20mm / h until the seed crystal is thinned;

[0067] Shoulder release: Manually adjust the heating power, reduce it by 50W-80W each time, keep it for 10min-20min, then reduce it by 30W-50W again, keep the pulling speed unchanged during the necking process, and release the shoulder until the crystal fills the slit 62 on the upper surface of the guide mold 6, and no longer adjust the heating power;

[0068] Equal diameter growth: Keep the final heating power during shoulder release and the pulling speed during necking unchanged to grow crystals;

[0069] Cooling: After the crystal growth is completed, the temperature is lowered with a heating power of 1000W / h-1500W / h;

[0070] Out of the oven: After cooling to room temperature, the crystal is out of the oven;

[0071] Heat treatment: Place the crystals out of the furnace in a vacuum annealing furnace, and heat them to 1700°C at a heating rate of 300°C / h in a carbon dioxide atmosphere, keep them at that temperature for 4 hours, and cool them to room temperature at a cooling rate of 100°C / h before taking them out of the furnace.

[0072] The method adopts the above-mentioned single crystal furnace to grow gallium oxide crystals by the guided mold method. The insulation component of the single crystal furnace can reduce the thermal delay phenomenon caused by the heating and insulation system of the single crystal furnace when the power changes, thereby improving the response efficiency during the necking and shouldering operations during the crystal growth process, and improving the temperature field stability of the heating and insulation system, thereby improving the crystal growth quality.

[0073] In addition, during the melting process, the heating power is first small and then large, which can reduce the temperature difference between the first thermal insulation sleeve 2 and the second thermal insulation sleeve 3 and reduce the risk of cracking of the first thermal insulation sleeve 2 and the second thermal insulation sleeve 3.

[0074] Specifically, during the melting process, the temperature is first increased at a heating power of 500 W / h and maintained for 12 hours, and then the temperature is continued to be increased at a heating power of 1000 W / h. When the power reaches 8500 W, the power is no longer changed until all the raw materials are melted to form a melt.

[0075] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0076] The various embodiments of the present application are described in a related manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0077] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A heating and heat preservation system for a single crystal furnace, used for growing gallium oxide crystals by a guided mode method, characterized in that: include: Heating element, used for heating raw materials; an induction coil, the heating element being configured to be electromagnetically coupled to the induction coil to generate heat; A heat-insulating assembly, the heat-insulating assembly comprising a first heat-insulating sleeve, a second heat-insulating sleeve and heat-insulating particles which are arranged at intervals, the heat-insulating particles being filled between the heat-generating element and the first heat-insulating sleeve, and between the first heat-insulating sleeve and the second heat-insulating sleeve, and being in contact with the heat-generating element, the first heat-insulating sleeve and the second heat-insulating sleeve; The distance between the first heat-insulating sleeve and the heat-generating element is greater than the distance between the second heat-insulating sleeve and the first heat-insulating sleeve.

2. The heating and heat preservation system of the single crystal furnace according to claim 1, characterized in that: The heating element is a crucible, and the crucible is used to hold raw materials.

3. The heating and heat preservation system of the single crystal furnace according to claim 2, characterized in that: The crucible is an iridium crucible or an iridium alloy crucible.

4. The heating and heat preservation system of a single crystal furnace according to claim 1, characterized in that: The first heat-insulating sleeve is a zirconium dioxide sleeve or a quartz glass sleeve.

5. The heating and heat preservation system of a single crystal furnace according to claim 1, characterized in that: The second heat-insulating sleeve is a zirconium dioxide sleeve or a quartz glass sleeve.

6. The heating and heat preservation system of a single crystal furnace according to any one of claims 1 to 5, characterized in that: The thermal insulation particles are zirconium dioxide particles or zirconium sand.

7. A single crystal furnace, characterized in that: include: Guide mold; A heating and heat preservation system for a single crystal furnace, wherein the heating and heat preservation system for a single crystal furnace is the heating and heat preservation system for a single crystal furnace according to any one of claims 1 to 6, and the guide mold is located in the heating element.

8. The single crystal furnace according to claim 7, characterized in that: The guide mold comprises a slit, the top of the slit has a "V"-shaped notch, and the angle of the "V"-shaped notch is 140°-160°.

9. A method for growing gallium oxide crystals, using the single crystal furnace according to any one of claims 7-8, wherein the single crystal furnace comprises a guide mold and a heating and heat preservation system of the single crystal furnace, wherein the guide mold comprises a slit, wherein the top of the slit has a "V"-shaped notch, and the heating and heat preservation system comprises a heating element, wherein the heating element is a crucible, wherein: The following steps are involved: Furnace loading: placing the raw materials in the crucible of the single crystal furnace, installing the guide mold, and aligning the seed crystal with the "V"-shaped notch on the upper surface of the guide mold; Melt: Heating with a certain heating power until the power reaches 8500W, all the raw materials in the crucible are melted to form a melt, and the heating power is small at first and then large; Lowering the seed crystal: slowly shaking the seed crystal down to become one with the liquid surface of the melt in the guide mold, staying there for 3 to 5 minutes, and then starting to pull the seed crystal upward; Neck closing: manually adjust the heating power, increase by 30W-50W each time, maintain for 10min-20min, and then increase by 30W-50W again until the power reaches 8800W without adjusting the heating power. During the power adjustment process, neck closing is performed at a pulling speed of 5mm / h-20mm / h until the seed crystal is thinned; Shoulder release: Manually adjust the heating power, reduce it by 50W-80W each time, keep it for 10min-20min, then reduce it by 30W-50W again, keep the pulling speed in the necking process unchanged, and release the shoulder until the crystal fills the slit on the upper surface of the guide mold, and no longer adjust the heating power; Equal diameter growth: keeping the final heating power in the shouldering process and the pulling speed in the necking process unchanged, and growing the crystal until the melt in the crucible is completely grown; Cooling: After the crystal growth is completed, the temperature is lowered with a heating power of 1000W / h-1500W / h; Out of the oven: After cooling to room temperature, the crystal is out of the oven; Heat treatment: Place the crystals out of the furnace in a vacuum annealing furnace, and heat them to 1700°C at a heating rate of 300°C / h in a carbon dioxide atmosphere, keep them at that temperature for 4 hours, and cool them to room temperature at a cooling rate of 100°C / h before taking them out of the furnace.

10. The method for growing gallium oxide crystals according to claim 9, characterized in that: The steps of melting the material are: firstly heating the material with a heating power of 500W / h, maintaining the temperature for 12 hours, and then continuing to heat the material with a heating power of 1000W / h until all the raw materials are melted to form the melt.

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