A mold for growing gallium oxide crystals and a method for growing gallium oxide crystals

Abstract

The present application discloses a mold for growing gallium oxide crystals and a method for growing gallium oxide crystals. A mold for growing gallium oxide crystals includes two mold plates, which are spaced apart to form a gap between the two mold plates, and the cross-section of the upper end of each mold plate is a non-right-angled parallelogram structure. The parallelogram structure designed in the mold fully matches the morphology of crystal growth, reducing the generation of stress, thereby ensuring the stable growth of (001)-face gallium oxide crystals, effectively avoiding gallium oxide crystal growth failure, and improving the quality of the grown (001)-face gallium oxide crystals. Furthermore, the designed outwardly protruding arc-shaped structure achieves a large radial temperature gradient, effectively controlling the crystal shouldering speed and allowing sufficient time for the atoms inside the crystal to arrange themselves regularly, thereby solving the problem of polycrystalline growth in (001)-face gallium oxide crystals.

Description

Technical Field

[0001] The present application relates to the technical field of crystal growth, and in particular to a mold for growing gallium oxide crystals and a method for growing gallium oxide crystals. Background Art

[0002] Existing growth devices for growing (001)-surface gallium oxide crystals using guided mode methods include Figure 1A and Figure 1B As shown, a mold 2 with a slit is placed into a crucible 3 containing gallium oxide raw material. The upper end of the mold 2 has a rectangular cross-section, and the crucible 3 is equipped with an induction coil and insulation material. During crystal growth, the crucible 3 is first heated by the induction coil. The gallium oxide raw material inside the crucible 3 is heated to a melt, which rises through the slit to the upper surface of the mold 2 through capillary action. A gallium oxide seed crystal with a vertical orientation of

[010] and a frontal orientation of

[001] is then lowered onto the upper surface of the mold 2, allowing the gallium oxide seed crystal to contact the melt on the upper surface of the mold 2. After sufficient fusion, the gallium oxide seed crystal is slowly pulled upward. Then, through processes such as necking, seeding, shouldering (slowly cooling the crystal to gradually increase to the specified size), and sizing, the desired gallium oxide crystal 4 is finally grown. However, when actually using the above-mentioned growth device to grow gallium oxide crystals, the inventors found that cracks appeared on the crystal edges in the late stage of shouldering, and the crystal could not grow stably, which easily led to the problem of gallium oxide crystal growth failure or poor gallium oxide crystallization quality.

[0003] With respect to the above-mentioned prior art problems that gallium oxide crystal growth failure or poor gallium oxide crystal quality may occur when gallium oxide crystals are grown using existing growth devices, no effective solution has been proposed so far. Summary of the Invention

[0004] The present disclosure provides a mold for growing gallium oxide crystals and a method for growing gallium oxide crystals, to at least solve the technical problem in the prior art that when using existing growth devices to grow gallium oxide crystals, gallium oxide crystal growth failure or poor gallium oxide crystallization quality may occur.

[0005] According to a first aspect of the present application, a mold for growing gallium oxide crystals is provided, comprising: two mold plates, the two mold plates being spaced apart to form a gap between the two mold plates, and the cross-section at the upper end of each mold plate being a non-right-angled parallelogram structure.

[0006] Optionally, an inner angle of a cross section at the upper end of the mold plate is 100° to 105°.

[0007] Optionally, an inner angle of a cross section of the upper end of the mold plate is 103.8°.

[0008] Optionally, the upper end surface of each mold plate is a planar structure.

[0009] Optionally, the upper end surface of each mold plate is an outwardly protruding arc-shaped structure.

[0010] Optionally, a height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2 mm to 3 mm.

[0011] Optionally, the height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2.5 mm.

[0012] Optionally, the opposite surfaces of the two mold plates are connected by a fixing member.

[0013] Optionally, each mold plate is made of iridium or platinum-rhodium.

[0014] According to a second aspect of the present application, a method for growing gallium oxide crystals is provided, comprising: placing the mold described in the first aspect of the present application in a crucible containing gallium oxide raw material; heating the gallium oxide raw material in the crucible to melt it; allowing the molten gallium oxide melt to rise to the upper surfaces of two mold plates through a gap under capillary action; lowering a gallium oxide seed crystal to the upper surfaces of the two mold plates; observing the morphology of the gallium oxide seed crystal and controlling the temperature to melt the lower end of the gallium oxide seed crystal; pulling the gallium oxide seed crystal when the height of the meniscus between the melted gallium oxide seed crystal and the upper surfaces of the two mold plates is 1 mm; as the gallium oxide seed crystal rises, the gallium oxide melt attached to the gallium oxide seed crystal crystallizes due to temperature changes, thereby generating a gallium oxide crystal with a diameter of 1 mm. Gallium oxide crystal; increasing the pulling speed and temperature at a certain rate so that the diameter of the grown gallium oxide crystal gradually decreases to 0.5 mm; adjusting the pulling speed and temperature according to the morphological characteristics of the gallium oxide crystal fed back by the CCD camera so that the gallium oxide crystal grows to 10 mm in diameter; reducing the pulling speed and temperature at a certain rate so that the gallium oxide crystal gradually enlarges until the gallium oxide crystal covers the entire upper surface of the mold; adjusting the pulling speed and temperature according to the morphological characteristics of the gallium oxide crystal fed back by the CCD camera so that the gallium oxide crystal grows in a constant diameter until the gallium oxide raw material in the crucible is exhausted and the gallium oxide crystal automatically detaches from the upper surfaces of the two mold plates; and stopping pulling and slowly reducing the temperature so that the temperature field drops to room temperature, and removing the gallium oxide crystal.

[0015] Based on the growth characteristics of the (001) face gallium oxide crystal itself, this application designs a mold with a cross-section of the upper end having an inner angle of 100°~105° (preferably 103.8°), and an outwardly protruding arc-shaped structure on the upper end. This mold combines the morphological characteristics of shouldering during the growth of the (001) face gallium oxide crystal and the problem that the (001) crystal is prone to shouldering too quickly. The designed parallelogram structure is completely consistent with the morphology of crystal growth, reducing the generation of stress, thereby ensuring the stable growth of the (001) face gallium oxide crystal, effectively avoiding the failure of gallium oxide crystal growth and improving the quality of the grown (001) face gallium oxide crystal. In addition, the outwardly protruding arc-shaped structure realizes a large radial temperature gradient, so that the crystal shouldering speed is effectively controlled, so that the atoms inside the crystal have sufficient time to arrange regularly, thereby solving the problem that the (001) face gallium oxide crystal is prone to polycrystalline growth.

[0016] Based on the detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings below, those skilled in the art will become more aware of the above and other objects, advantages and features of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Hereinafter, some specific embodiments of the present application will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0018] Figure 1A is a schematic diagram of an existing growth device;

[0019] Figure 1B yes Figure 1A A top view of the growth apparatus in FIG.

[0020] Figure 2A This is a schematic diagram of the lattice structure of a gallium oxide crystal;

[0021] Figure 2B is another schematic diagram of the lattice structure of a gallium oxide crystal;

[0022] Figure 3 This is a schematic diagram of the existing gallium oxide crystals covering the upper surface of the mold at the late stage of shoulder placement;

[0023] Figure 4 1 is a structural schematic diagram of the mold described in this embodiment;

[0024] Figure 5 yes Figure 4 A top view of the mold is shown;

[0025] Figure 6is another structural schematic diagram of the mold described in this embodiment;

[0026] Figure 7 2 is another structural schematic diagram of the mold described in this embodiment;

[0027] Figure 8 Schematic diagram of the structure of the mold plate described in this embodiment;

[0028] Figure 9 is another structural schematic diagram of the mold plate described in this embodiment;

[0029] Figure 10 yes Figure 4 The temperature field distribution diagram of the upper end surface of the mold shown;

[0030] Figure 11 is another structural schematic diagram of the mold described in this embodiment; and

[0031] Figure 12 yes Figure 11 The temperature field distribution diagram of the upper end surface of the mold is shown. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure can be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] In order to enable those skilled in the art to better understand the solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present disclosure.

[0034] To address the issues of gallium oxide crystal growth failure or poor quality, the inventors conducted extensive research on gallium oxide crystal growth equipment and processes. Through extensive research and practice, the inventors discovered that the growth morphology of gallium oxide crystals is potentially influenced by the shape of their lattice. Specifically, as gallium oxide crystals grow, their macroscopic appearance tends to match the shape of their microscopic lattice. Figure 2A and Figure 2B The lattice structure of gallium oxide crystals is shown in Figures 2A and 2B. Figure 2BAs shown in Figure 1, the lattice constants of gallium oxide crystals are 90° for α and 90° for γ, and 103.8° for β (often omitted as 104°). Therefore, when growing a gallium oxide seed crystal with a

[010] orientation, the gallium oxide crystal will gradually expand into a parallelogram with a growth interface at 103.8° during the shouldering stage.

[0035] However, referring to Figure 1B As shown, since the cross section of the upper end of the mold 2 in the existing growth device is rectangular, and the growth interface of the crystal is a parallelogram with an angle of 103.8°, the degree of coverage of the crystal on the upper surface of the mold 2 will be inconsistent in the later stage of shouldering. Specifically, as Figure 3 As shown, when part of crystal A has grown to the edge of the upper surface of mold 2, another part of crystal B has not yet completely covered the mold 2. In order for the crystal to cover the entire mold 2, the temperature must be further lowered to allow part of crystal B to continue to grow. At this time, the part of crystal A that has grown to the edge of mold 2 will also be affected by the cooling and tend to continue to grow. However, it is constrained by the edge of mold 2 and cannot continue to grow, resulting in stress. The accumulated stress at this stage can cause defects such as surface slip, twinning, and even polycrystalline defects in the crystal, which can cause gallium oxide crystal growth failure or seriously affect the quality of the grown crystal.

[0036] In view of this, the first aspect of this embodiment proposes a mold 2 for growing (001)-plane gallium oxide crystals. Figures 4 to 6 As shown, in the first aspect of this embodiment, a mold 2 for growing (001) gallium oxide crystals is designed based on the growth characteristics of the (001) face gallium oxide crystals themselves. The mold 2 includes two mold plates 10, which are spaced apart and form a gap 20 between the two mold plates 10, and the cross-section of the upper end of each mold plate 10 is a non-right-angled parallelogram structure. The mold 2 provided in this embodiment combines the morphological characteristics of the shoulder during the growth of the (001) face gallium oxide crystals, and designs the cross-section of the upper end of each mold plate 10 to be a non-right-angled parallelogram structure, so that the shape of the upper surface of the mold 2 fits the morphology of the growth of the (001) face gallium oxide crystals. In the later stage of shouldering, all the crystals grow to the edge of the mold 2 at the same time, and there will be no inconsistent degree of coverage of the crystals on the upper surface of the mold 2. Therefore, during the process of spreading the (001) face gallium oxide crystals over the entire mold designed in this embodiment, the crystals will not generate additional stress due to the mold shape restriction, thereby ensuring the stable growth of the (001) face gallium oxide crystals, effectively avoiding gallium oxide crystal growth failure, and improving the quality of the grown (001) face gallium oxide crystals.

[0037] Optionally, in this embodiment, an internal angle of the cross-section of the upper end of the mold plate 10 is between 100° and 105°. By employing this technical solution, an internal angle of the mold plate 10 is substantially identical to an internal angle of the gallium oxide crystal lattice, so that the shape of the upper surface of the mold 2 conforms to the growth habits of the gallium oxide crystals, ensuring that the gallium oxide crystals are not restricted by the mold shape and generate additional stress during the later stages of shouldering.

[0038] Preferably, in this embodiment, an internal angle of the parallelogram structure is 103.8°. By employing the above technical solution, an internal angle of the mold plate 10 is aligned with an internal angle of the gallium oxide crystal lattice, so that the shape of the upper surface of the mold 2 conforms to the growth habits of the gallium oxide crystal, effectively ensuring that the gallium oxide crystal will not be restricted by the mold shape and generate additional stress during the later stage of shouldering.

[0039] Optionally, refer to Figure 4 and Figure 6 As shown, in this embodiment, the upper end surface (i.e., top surface) of each mold plate 10 is a planar structure. By adopting the above technical solution, the temperature distribution of the gallium oxide melt covering the entire upper surface of the mold plate 10 is more uniform, and the thermal stress generated during the growth of the gallium oxide crystals is reduced.

[0040] Optionally, refer to Figure 7 As shown, in this embodiment, the opposite surfaces of the two mold plates 10 are connected by a fixing member 30. The fixing member 30 can be a gasket or a connecting piece, and the fixing member 30 is fixedly connected to the two mold plates 10 by rivets.

[0041] Optionally, refer to Figure 6 As shown, in this embodiment, the value range of the gap 20 is 0.1 mm to 0.6 mm. Preferably, the value of the gap 20 is 0.3 mm.

[0042] In addition, refer to Figure 8 As shown, three round rods 50 are disposed between the two mold plates 10. The three round rods 50 are arranged horizontally and side by side, and the round rods 50 are fixedly connected to the two mold plates 10. The ends of the round rods 50 away from the channels 40 extend into the two mold plates 10, forming a spacing of 3 mm between the top edges of the mold plates 10 where the channels 40 are not provided. This spacing reduces the effect of the round rods 50 on the growth of gallium oxide crystals on the upper surfaces of the mold plates 10. The round rods 50 extend into the two mold plates 10, increasing the contact area between them and the two mold plates 10. Consequently, after long-term use of the mold 2, the gap 20 between the two mold plates 10 does not change due to the support provided by the round rods 50, thereby increasing the service life of the mold 2.

[0043] Optionally, in this embodiment, the two mold plates 10 and the fixing member 30 are integrally formed. Specifically, the mold 2 is cut inwardly at the center position, so that the mold 2 is divided into two mold plates 10, and the position between the two mold plates 2 near the bottom of the crucible is not completely cut. Figure 9 As shown, three connecting blocks 60 are positioned between the two mold plates 10. These connecting blocks 60 are arranged horizontally and side by side. These connecting blocks 60 leave a gap 20 of 0.3 mm between the two mold plates 10. This creates an integrated structure for the two mold plates 10 and the three connecting blocks 60, reducing the risk of the mold plates 10 falling apart and ensuring proper operation of the mold 2.

[0044] Optionally, in this embodiment, the two mold plates 10 and the fixing member 30 are formed separately.

[0045] Optionally, in this embodiment, each mold plate 10 is made of iridium or platinum-rhodium.

[0046] In addition, refer to Figures 6 to 9 As shown, two channels 40 are provided at the bottom of each mold plate 10. The mold 2 is placed in a crucible 3 filled with gallium oxide raw material, and after heating, the gallium oxide melt enters the gap 20 through the channels 40.

[0047] Furthermore, the inventors have found through research that when growing (001) face gallium oxide crystals, in order for the crystals to properly shoulder, the required cooling range is much higher than that of growing (100) face crystals. However, due to the influence of control accuracy under ultra-high temperature, the cooling process is often excessive and the means of achieving cooling is to reduce the power of the heating coil to cool the crucible and mold as a whole, and it is impossible to adjust the local temperature of the mold. Figure 10As shown, during the initial growth phase, the mold center temperature is 1840°C, while the temperatures on the sides are only 1870°C. This temperature gradient is too small, and the gallium oxide crystal grows at 1840°C. During shouldering, to expand the crystal and lower the mold temperature, the mold center temperature drops to 1810°C due to precision constraints. At this point, the temperatures on the sides also drop from 1870°C to 1840°C. Because the temperatures on the sides are also sufficiently low, the crystal rapidly expands and fills the entire mold. However, shouldering must be a slow process. Only when shouldering is slow enough to achieve a regular arrangement of atoms within the crystal can a single crystal be grown. Furthermore, when the crystal reaches the uniform diameter stage, the center temperature of the crystal becomes higher than the sides because the heat dissipation capacity of the center is lower than that of the sides. The low radial temperature gradient in existing molds cannot compensate for the heat dissipation difference. Consequently, the center of the crystal becomes disconnected from the mold during uniform diameter growth, interrupting crystal growth. Upon removal, the crystal is found to be polycrystalline. Therefore, the mold design with a planar top surface proposed in Example 1 cannot meet the requirements for growing (001)-plane gallium oxide crystals. It should be noted that the mold radial direction is the mold width direction, which is perpendicular to the crystal growth direction, and the mold thickness direction is parallel to the crystal thickness direction.

[0048] In view of this, the inventors have made further improvements to the mold 2 on the basis of the above. Specifically, referring to Figure 11 As shown, in this embodiment, the upper end surface of each mold plate 10 is designed to be an outward-protruding arc-shaped structure. Because the heating source of the entire mold 2 is the crucible 3, and the crucible 3 is located below the periphery of the mold 2, the temperature of the mold 2 is higher the farther away from the crucible. The design of the upper end surface as an outward-protruding arc-shaped structure makes the center of the mold 2 farther away from the crucible and the temperature lower, and the closer the mold is to the two sides, the closer the mold is to the crucible and the higher the temperature. Figure 12 As shown in the figure, during the initial growth phase, the temperature at the mold center is 1840°C, while the temperature on both sides is 1920°C. This temperature gradient is too small, and the gallium oxide crystal grows at 1840°C. During shoulder release, to enlarge the crystal and lower the mold temperature, the mold center temperature is reduced to 1810°C due to precision. At this time, the temperature on both sides of the mold also drops from 1920°C to 1890°C. At this point, because the temperature on both sides of the mold is still higher than the gallium oxide crystal growth temperature, a larger temperature gradient is achieved. During cooling, the gallium oxide crystal is affected by the large temperature gradient between the mold's sides and the mold's center. The shoulder release process does not result in the rapid enlargement seen in molds with a planar top surface. Instead, a slow shoulder release is achieved, allowing sufficient time for the atoms within the crystal to arrange themselves in a regular pattern, thus resolving the problem of polycrystalline growth in gallium oxide crystals with (001) faces.

[0049] Optionally, in this embodiment, the height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2mm to 3mm. Specifically, the outwardly protruding arc-shaped structure is determined by the following method: Note that the two ends of the mold are points a and b, and points a and b are connected to form a straight line. The center of the line is point c. The position 2mm to 3mm vertically upward from point c is point d. Using the three-point arc method, points a, b, and d are connected to form an arc, and the mold is processed as the desired shape. Preferably, the height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2.5mm.

[0050] In addition, a second aspect of this embodiment provides a method for growing gallium oxide crystals, comprising the following steps:

[0051] Step 1: placing the mold 2 described in the first aspect of this embodiment into a crucible filled with gallium oxide raw material;

[0052] Step 2: heating the gallium oxide raw material in the crucible to melt;

[0053] Step 3: The molten gallium oxide melt rises to the upper surfaces of the two mold plates 10 through the gap 20 under the action of capillary action;

[0054] Step 4: Lower the gallium oxide seed crystal to the upper surface of the two mold plates 10;

[0055] Step 5: Observe the morphology of the gallium oxide seed crystal and control the temperature to melt the lower end of the gallium oxide seed crystal;

[0056] Step 6: When the height of the meniscus between the melted gallium oxide seed crystal and the upper surfaces of the two mold plates 10 is 1 mm, pull the gallium oxide seed crystal;

[0057] Step 7: As the gallium oxide seed crystal rises, the gallium oxide melt attached to the gallium oxide seed crystal crystallizes due to temperature changes, thereby generating a gallium oxide crystal with a diameter of 1 mm;

[0058] Step 8: increasing the pulling speed and temperature at a certain rate so that the diameter of the grown gallium oxide crystal gradually decreases to 0.5 mm;

[0059] Step 9: According to the morphological characteristics of the gallium oxide crystal fed back by the CCD camera, the pulling speed and temperature are adjusted to make the gallium oxide crystal grow with a constant diameter of 10 mm;

[0060] Step 10: reducing the pulling speed and temperature at a certain rate, so that the gallium oxide crystals gradually expand until the gallium oxide crystals cover the entire upper surface of the mold 2;

[0061] Step 11: Adjust the pulling speed and temperature according to the morphological characteristics of the gallium oxide crystals fed back by the CCD camera to make the gallium oxide crystals grow in equal diameters until the gallium oxide raw material in the crucible is exhausted and the gallium oxide crystals automatically separate from the upper surfaces of the two mold plates 10; and

[0062] Step 12: Stop pulling and slowly lower the temperature to room temperature, and take out the gallium oxide crystal.

[0063] Therefore, the gallium oxide crystal growth method proposed in the second aspect of this embodiment has the following beneficial effects:

[0064] 1. In the later stage of shoulder placement, when the (001)-plane gallium oxide crystals are spread over the entire mold designed in this embodiment, no additional stress will be generated in the crystals due to the limitation of the mold shape, thereby ensuring the stable growth of the (001)-plane gallium oxide crystals, effectively avoiding the growth failure of the gallium oxide crystals and improving the quality of the grown (001)-plane gallium oxide crystals.

[0065] 2. When cooling, the gallium oxide crystal is affected by the large temperature gradient between the two sides and the center of the mold. The shoulder release process does not show the rapid enlargement similar to the mold with a flat upper end face. Slow shoulder release is achieved, so that the atoms inside the crystal have sufficient time to arrange regularly, thus solving the problem of polycrystalline growth of (001) face gallium oxide crystal.

[0066] In addition, the present invention is further described below through specific examples.

[0067] Comparative Example 1:

[0068] A 4-inch gallium oxide single crystal was grown using the guided mold method: an iridium heater, crucible, and mold were placed in a strictly concentric furnace. The furnace was evacuated and filled with 50% CO2 and 50% Ar as protective gas. The upper end of the mold had a rectangular cross-section and a mold width of 110 mm. The target growth width was a 110 mm (001) gallium oxide single crystal. After heating to completely melt the gallium oxide raw material in the crucible, the gallium oxide seed crystal was placed in contact with the upper surface of the mold at a suitable temperature. The crystal was then pulled and cooled to release the shoulder. In the later stages of the shoulder release, cracks appeared at the edge of the crystal, and the crystal could not grow stably.

[0069] Example 1:

[0070] The furnace was loaded using a structure essentially identical to that of Comparative Example 1, except that a mold with a parallelogram-shaped cross-section at the top, with an internal angle of 100° to 105° (preferably 103.8°), was used. The shouldering process was relatively smooth. After the crystals filled the mold, the center of the top remained in a stable crystalline state. Subsequently, a complete 110 mm wide gallium oxide single crystal was grown. The grown 110 mm wide gallium oxide single crystal was processed to obtain a 4-inch (001) gallium oxide single crystal.

[0071] Comparative Example 2:

[0072] A 4-inch gallium oxide single crystal was grown using the guided mold method: an iridium heater, crucible, and mold were installed in a strictly concentric furnace. The furnace was evacuated and filled with 50% CO2 and 50% Ar as protective gas. The upper end surface of the mold was a flat structure with a mold width of 110 mm. The target growth width was a 110 mm (001) face gallium oxide single crystal. After heating to completely melt the gallium oxide raw material, the seed crystal was placed in contact with the upper surface of the mold at a suitable temperature. The crystal was pulled and cooled while the shoulder was released. During the shoulder release process, the shoulder release process accelerated significantly. At the end of the equal diameter stage, a depression first appeared inside the crystal and it separated from the mold prematurely. After the crystal was removed, it was found to be polycrystalline.

[0073] Example 2:

[0074] The furnace was loaded using a structure essentially identical to that used in Comparative Example 2, except that a mold with an outwardly protruding arc-shaped upper surface was used, with the height difference between the highest and lowest points of the mold being 2 mm to 3 mm (preferably 2.5 mm). The shouldering process was performed at a constant and slow speed. After the crystals covered the entire upper surface of the mold, the center of the mold top remained in a stable crystalline state. Subsequently, a complete 110 mm wide gallium oxide single crystal was grown. The grown 110 mm wide gallium oxide single crystal was processed to obtain a 4-inch (001) face gallium oxide single crystal.

[0075] In summary, the present disclosure and this embodiment are designed based on the growth characteristics of the (001) face gallium oxide crystal itself, with a parallelogram structure having a cross-section of 100° to 105° (preferably 103.8°) at the upper end, and a mold having an outwardly protruding arc-shaped structure at the upper end. The parallelogram structure designed in the mold is completely consistent with the morphology of crystal growth, reducing the generation of stress, thereby ensuring the stable growth of the (001) face gallium oxide crystal, effectively avoiding the failure of gallium oxide crystal growth, and improving the quality of the grown (001) face gallium oxide crystal. In addition, the outwardly protruding arc-shaped structure realizes a large radial temperature gradient, so that the crystal shoulder speed is effectively controlled, so that the atoms inside the crystal have sufficient time to arrange regularly, thereby solving the problem that the growth of the (001) face gallium oxide crystal is prone to polycrystalline.

[0076] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which this application belongs.

[0077] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0078] In addition, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of this application, "plurality" means more than two, unless otherwise specifically defined.

[0079] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0080] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0081] The above description is merely a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A mold for growing gallium oxide crystals, characterized in that: include: Two mold plates (10), the two mold plates (10) are spaced apart and a gap (20) is formed between the two mold plates (10), and the cross-section of the upper end of each mold plate (10) is a non-right-angled parallelogram structure; An inner angle of a cross section of the upper end of the mold plate (10) is 100° to 105°, and the gap (20) is 0.3 mm.

2. The mold according to claim 1, characterized in that An internal angle of the cross section of the upper end of the mold plate (10) is 103.8°.

3. The mold according to claim 1, characterized in that The upper end surface of each mold plate (10) is a planar structure.

4. The mold according to claim 1, characterized in that The upper end surface of each mold plate (10) is an outwardly protruding arc-shaped structure.

5. The mold according to claim 4, characterized in that The height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2 mm to 3 mm.

6. The mold according to claim 5, characterized in that The height difference between the highest point and the lowest point of the outwardly protruding arc-shaped structure is 2.5 mm.

7. The mold according to claim 1, characterized in that The opposing surfaces of the two mold plates (10) are connected via a fixing member (3).

8. The mold according to claim 1, characterized in that The material of each mold plate (10) is iridium or platinum rhodium.

9. A method for growing gallium oxide crystals, characterized in that: include: Placing the mold according to any one of claims 1 to 8 into a crucible filled with gallium oxide raw material; heating to melt the gallium oxide raw material in the crucible; The molten gallium oxide melt rises to the upper surfaces of the two mold plates (10) through the gap (20) under capillary action; Lowering gallium oxide seed crystals onto the upper surfaces of the two mold plates (10); observing the morphology of the gallium oxide seed crystal and controlling the temperature to melt the lower end of the gallium oxide seed crystal; When the height of the meniscus between the melted gallium oxide seed crystal and the upper surfaces of the two mold plates (10) is 1 mm, pulling the gallium oxide seed crystal; As the gallium oxide seed crystal rises, the gallium oxide melt attached to the gallium oxide seed crystal crystallizes due to temperature changes, thereby generating a gallium oxide crystal with a diameter of 1 mm; The pulling speed and temperature were increased at a certain rate, so that the diameter of the grown gallium oxide crystals gradually decreased to 0.5 mm; According to the morphological characteristics of the gallium oxide crystal fed back by the CCD camera, the pulling speed and temperature were adjusted to make the gallium oxide crystal grow with a constant diameter of 10mm; reducing the pulling speed and temperature at a certain rate so that the gallium oxide crystals gradually enlarge until the gallium oxide crystals cover the entire upper surface of the mold; According to the morphological characteristics of the gallium oxide crystals fed back by the CCD camera, the pulling speed and temperature are adjusted to make the gallium oxide crystals grow in equal diameters until the gallium oxide raw material in the crucible is exhausted and the gallium oxide crystals are automatically separated from the upper surfaces of the two mold plates (10); and Stop pulling and slowly lower the temperature to room temperature, and take out the gallium oxide crystal.

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