Necking process for growing gallium oxide single crystal by vertical Bridgman method and crucible

Abstract

The invention discloses a necking process and a crucible for growing a gallium oxide single crystal through a vertical Bridgman method, the crucible is used for growing the gallium oxide single crystal through the vertical Bridgman method in a necking mode, the crucible comprises a crucible lower bottom, a seed crystal space, a necking area, a shouldering area and an equal-diameter growth area, and the seed crystal space, the necking area, the shouldering area and the equal-diameter growth area are communicated. And the seed crystal is put into the seed crystal space from the lower bottom of the crucible. During use, the crucible is inverted, the seed crystal space faces upwards, seed crystals are placed in the seed crystal space, the lower bottom of the crucible is covered, the inverted placement is kept, the crucible and the lower bottom of the crucible are placed in an electric arc melting furnace, the edge area, making contact with the crucible, of the lower bottom of the crucible is melted, bottom sealing of the lower bottom of the crucible is achieved, a gallium oxide raw material can be loaded after cooling, and normal crystal growth is conducted. Based on the growth process of the existing vertical Bridgman method, an electric arc melting technology is introduced, the appearance of the crucible is redesigned, and a key necking process is completed before shouldering and equal-diameter growth, so that dislocation extension is further reduced, and the crystal quality is improved.

Description

Technical Field

[0001] The present application relates to a method for preparing an ultra-wide bandgap semiconductor gallium oxide single crystal, which is applicable to preparing high-quality semiconductor single crystals by a vertical Bridgman method, and in particular to a necking process and a crucible for growing gallium oxide single crystals by a vertical Bridgman method. Background Art

[0002] Gallium oxide is an important strategic material, belonging to the field of fourth-generation semiconductor materials. Gallium oxide has gained wide attention and favor in the power device, RF device, optoelectronic device and other markets due to its high bandgap width of 4.9eV, good Baliga figure of merit, and ultra-high stability in extreme environments. The preparation of gallium oxide materials and devices has become the key to competition in the semiconductor field. The quality of the material is the key to determining the performance of the device, and the single crystal substrate is the basis for epitaxy and device preparation. Therefore, the development of high-quality gallium oxide single crystals is an important link in the future competition for the epitaxy and device markets.

[0003] The existing methods for preparing gallium oxide single crystals mainly include the following two categories: 1. Guided mold method and Czochralski method The guided mold method and the Czochralski method are the most widely used methods for growing gallium oxide single crystals. The growth process is to plant seeds, neck down, shoulder release, equal diameter growth, and then lift off to produce a complete crystal. The guided mold method can grow plate-like crystals due to the presence of the mold, which limits the growth shape. It has been developed to a 6-inch substrate and has great commercial value. The Czochralski method can grow columnar ingots and can currently produce 3-inch substrates.

[0004] Disadvantages: From a cost perspective, the crucible used in the first technique is an iridium crucible. Metal iridium reacts with the gallium oxide melt at high temperatures and reacts with trace amounts of oxygen in the growth atmosphere, causing loss of precious metals. In addition, the cost of the iridium crucible is extremely high. The cost of maintenance and renovation is huge, which is not conducive to experimental exploration and future industrial mass production.

[0005] From the product perspective, the single crystal substrates grown by the guided mode method in Technology 1 are mostly (100) and (001) oriented according to the Miller index representation method, but the guided mode method cannot grow the substrate with the (010) orientation, which has the best heat dissipation performance. The Czochralski method in Technology 1 makes up for the lack of (010) substrates, but is limited by the spiral growth factor and cannot produce large-sized single crystals. The current size limit is 3 inches, which is not conducive to future industrialization layout.

[0006] 2. Traditional Vertical Bridgman Method The vertical Bridgman method has obvious cost advantages, high repeatability, can grow gallium oxide single crystals in air, and can prepare gallium oxide single crystal substrates with various crystal orientations. Its development potential and attention in recent years have gradually surpassed the traditional guided mold method and Czochralski method. The vertical Bridgman method does not require expensive iridium crucibles to grow gallium oxide single crystal substrates, which conforms to the development direction of gallium oxide iridium-free methods.

[0007] The traditional vertical Bridgman method can already grow large-sized gallium oxide ingots. Recently, Japan has announced the successful growth of a 6-inch gallium oxide ingot, solving the current problem of gallium oxide lacking large-sized (010) substrates. The traditional vertical Bridgman method uses seed crystal growth, which melts the gallium oxide raw material by high-temperature heating. Under the guidance of the seed crystal, it begins to release shoulders and grow in equal diameters, and gradually grows into a columnar ingot with the same orientation as the seed crystal.

[0008] Disadvantages: Although the second technology solution can grow ingots like the Czochralski method, its growth process is limited by process requirements and crucible design. Compared with the Czochralski method and the guided mold method, it lacks the key necking step that can significantly improve the crystal quality. The reason is that the growth process of the vertical Bridgman method is carried out in the crucible, unlike the Czochralski method and the guided mold method, which is carried out outside the crucible. The vertical Bridgman method takes into account that the seed crystal can be smoothly placed at the bottom of the crucible, so the necking area cannot be set in the crucible design. As a result, in the process of growing gallium oxide single crystals by the vertical Bridgman method, dislocations from the seed crystal, dislocations caused by thermal shock of the seed crystal, and dislocations caused when the seed crystal contacts the new crystal will all extend into the new crystal. This deteriorates the quality of the new crystal and affects the performance and yield of downstream epitaxy and devices.

[0009] The present invention is aimed at the growth of gallium oxide single crystal substrates. Based on the vertical Bridgman technology, it focuses on solving the problem of lack of necking process in traditional vertical Bridgman technology. Through a new crucible design and processing scheme, it guides the interception and discharge of dislocations in the early stage of crystal growth, further improving the crystal quality. Summary of the invention

[0010] Based on the above description, the present invention provides a necking process and crucible for growing gallium oxide single crystals by a vertical Bridgman method, so as to solve the problem that in the process of growing gallium oxide single crystals, due to the lack of a necking process, dislocations in the seed crystal, dislocations caused by thermal shock of the seed crystal, and dislocations generated when the seed crystal contacts the new crystal all extend into the new crystal, thereby deteriorating the quality of the new crystal and affecting the performance and yield of downstream epitaxy and devices.

[0011] The technical solution of the present invention to solve the above technical problems is as follows: A crucible with a necking function is used for vertical Bridgman method necking growth of gallium oxide single crystals, comprising a crucible bottom and connected seed crystal space, a necking area, a shoulder area, and an equal diameter growth area. The crucible bottom can be opened to allow seed crystals to be placed into the seed crystal space from the crucible bottom.

[0012] Based on the above technical solution, the present invention can also be improved as follows.

[0013] Furthermore, in the above-mentioned crucible with a necking function, the lower bottom of the crucible can be opened, which means that the lower bottom of the crucible is spatially separated from the seed crystal, threadedly connected, plugged or snap-connected.

[0014] Furthermore, the above-mentioned crucible with necking function has a crucible thickness between 0.5mm-1.5mm; a seed crystal diameter between 10mm-20mm, and a height between 30mm-50mm; a seed crystal space has a diameter 1-3mm larger than the seed crystal, and a height 2-5mm larger than the seed crystal; an inner diameter in the necking area is 3-8mm, and a height of 5-15mm; an inner diameter of the crucible in the equal-diameter growth area is 55-160mm, and a height of 75-85mm; a diameter of the bottom of the crucible is 1-2mm larger than the outer diameter of the seed crystal space, and a thickness of 0.5-1.5mm.

[0015] Furthermore, in the above-mentioned crucible with necking function, the shoulder angle of the shoulder area is 60°-80°.

[0016] Furthermore, in the above-mentioned crucible with necking function, the inner diameter of the equal-diameter growth zone is 55-160 mm.

[0017] Furthermore, the above-mentioned crucible with necking function is made of platinum-rhodium alloy, in which metal platinum accounts for 70%-80% and metal rhodium accounts for 30%-20%.

[0018] Furthermore, in the above-mentioned crucible with necking function, the gallium oxide single crystal can be replaced by a gallium arsenide or indium phosphide single crystal.

[0019] The present invention also provides a necking process for growing gallium oxide single crystals by a vertical Bridgman method, using any of the above-mentioned crucibles, inverting the bottomless crucible with the seed crystal space facing upward, placing the seed crystal in the crucible, and clamping it in the seed crystal space above the necking area after inversion, covering the lower bottom of the crucible and keeping it upside down, placing the crucible together with the lower bottom of the crucible in an arc melting furnace, increasing the arc energy by adjusting the current, achieving local heating of the contact area between the arc and the platinum-rhodium alloy crucible, and then melting the edge area where the lower bottom of the crucible contacts the crucible, achieving the bottom sealing of the lower bottom of the crucible, and after cooling, the gallium oxide raw material can be loaded to carry out normal crystal growth.

[0020] Furthermore, in the above-mentioned necking process for growing gallium oxide single crystals by the vertical Bridgman method, after the crucible is completely cooled in the arc melting area, the crucible is taken out, and at this time, the seed crystal is fixed below the necking area and cannot be taken out; high-purity gallium oxide powder is loaded into the crucible from the top of the crucible, and the powder is melted in the crucible, and as the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes; during the crystallization process, the crystallization direction is from bottom to top, and the necking area solidifies preferentially. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction are discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: The present invention is based on the existing vertical Bridgman growth process, introduces arc melting technology, redesigns the crucible shape, completes the key necking process before shoulder placement and equal diameter growth, further reduces dislocation extension, and improves crystal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the main structure of a crucible with a necking function provided by an embodiment of the present invention; Figure 2 A schematic diagram of a three-dimensional structure of a crucible with a necking function provided in an embodiment of the present invention; Figure 3 Schematic diagram of the steps for placing a seed crystal in a crucible. In the figure, (A) the bottom of the crucible is opened, (B) the seed crystal is placed, and (C) the bottom is sealed by arc melting.

[0023] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Bottom of crucible; 2. Space for seed crystal; 3. Neck shrinkage area; 4. Shoulder area; 5. Equal diameter growth area; 6. Seed crystal. DETAILED DESCRIPTION

[0024] In order to facilitate understanding of the present application, the present application will be described more comprehensively below. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0026] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0027] The present invention relates to a crucible design for growing gallium oxide single crystals by the vertical Bridgman method, aiming to solve the problems of defect extension and crystal quality degradation caused by the lack of necking process during the growth process. The present invention can effectively stop dislocation transmission before shouldering, thereby greatly improving the yield and crystal quality of gallium oxide single crystals.

[0028] A crucible with a necking function is used for vertical Bridgman method necking growth of gallium oxide single crystals, comprising a crucible bottom 1 and a connected seed crystal space 2, a necking area 3, a shoulder area 4, and an equal diameter growth area 5. The crucible bottom 1 can be opened to allow a seed crystal 6 to be placed from the crucible bottom 1 into the seed crystal space 2.

[0029] Based on the above technical solution, the present invention can also be improved as follows.

[0030] Furthermore, in the above-mentioned crucible with a necking function, the lower bottom 1 of the crucible can be opened, which means that the lower bottom 1 of the crucible and the seed crystal space 2 are separated, threaded, plugged or snap-connected.

[0031] Furthermore, the above-mentioned crucible with necking function has a crucible thickness between 0.5mm-1.5mm; the diameter of the seed crystal 6 is between 10mm-20mm, and the height is between 30mm-50mm; the diameter of the seed crystal space 2 is 1-3mm larger than the seed crystal 6, and the height is 2-5mm larger than the seed crystal 6; the inner diameter of the necking area 3 is 3-8mm, and the height is 5-15mm; the inner diameter of the crucible in the equal-diameter growth area is 55-160mm, and the height is 75-85mm; the diameter of the bottom 1 of the crucible is 1-2mm larger than the outer diameter of the seed crystal space 2, and the thickness is 0.5-1.5mm.

[0032] Furthermore, in the above-mentioned crucible with necking function, the shoulder angle of the shoulder area 4 is 60°-80°.

[0033] Furthermore, in the above-mentioned crucible with necking function, the inner diameter of the equal-diameter growth region 5 is 55-160 mm.

[0034] Furthermore, the above-mentioned crucible with necking function is made of platinum-rhodium alloy, in which metal platinum accounts for 70%-80% and metal rhodium accounts for 30%-20%.

[0035] Furthermore, in the above-mentioned crucible with necking function, the gallium oxide single crystal can be replaced by a gallium arsenide or indium phosphide single crystal.

[0036] The present invention also provides a necking process for growing gallium oxide single crystals by a vertical Bridgman method, using any of the above-mentioned crucibles, inverting the bottomless crucible with the seed crystal space 2 facing upward, placing a seed crystal 6 in the crucible, and clamping it in the seed crystal space 2 located above the necking area 3 after inversion, covering the lower bottom 1 of the crucible, and keeping it upside down, placing the crucible together with the lower bottom of the crucible in an arc melting furnace, increasing the arc energy by adjusting the current, achieving local heating of the contact area between the arc and the platinum-rhodium alloy crucible, and then melting the edge area of ​​the lower bottom 1 of the crucible in contact with the crucible, achieving the bottom sealing of the lower bottom 1 of the crucible, and after cooling, the gallium oxide raw material can be loaded to carry out normal crystal growth.

[0037] Furthermore, in the above-mentioned necking process for growing gallium oxide single crystals by the vertical Bridgman method, after the crucible is completely cooled in the arc melting area, the crucible is taken out, and at this time, the seed crystal 6 is fixed below the necking area 3 and cannot be taken out; high-purity gallium oxide powder is loaded into the crucible from the top of the crucible, and the powder is melted in the crucible, and as the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes; during the crystallization process, the crystallization direction is from bottom to top, and the necking area 3 solidifies preferentially. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction can be discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals.

[0038] Furthermore, the present invention includes: a crucible with a necking function, specifically: like Figure 1 and Figure 2 As shown, the crucible specifically includes a crucible bottom 1, a seed crystal space 2, a necking region 3, a shoulder region 4, and an equal diameter growth region 5. The crucible thickness can be set between 0.5 mm and 1.5 mm. For growing 2-inch crystals, the seed crystal 6 has a diameter between 10 mm and 20 mm and a length between 30 mm and 50 mm. The seed crystal space 2 has a diameter 1-3 mm larger than the seed crystal 6 and a height 2-5 mm larger than the seed crystal. The inner diameter of the necking region 3 is designed to be 3-8 mm and the length is designed to be 5-15 mm. The shoulder region 4 has a shoulder angle designed to be between 60 and 80 degrees. The inner diameter of the equal diameter growth region 5 can be designed to be between 55 and 160 mm according to the specific crystal size requirements.

[0039] The present invention also provides a necking process for growing gallium oxide single crystals by the vertical Bridgman method, which mainly uses the above crucible with a necking function. Due to the existence of the necking stage, the seed crystal 6 cannot be directly placed in the crucible like the conventional solution, so the present invention relates to a new method for installing the seed crystal 6, specifically, the bottomless crucible is inverted, the seed crystal space 2 is facing upward, the seed crystal 6 is placed in the crucible, stuck above the necking area 3 in the seed crystal space 2, the crucible bottom 1 is covered, the crucible and the crucible bottom are placed in an arc melting furnace, the crucible is sealed by arc melting, and the gallium oxide raw material can be loaded after cooling to carry out normal crystal growth.

[0040] Embodiment 1: In this embodiment, a crystal ingot with a diameter of 10 mm and a height of 30 mm is used as the seed crystal 6. The materials used for the crucible are all platinum-rhodium alloys, of which metal platinum accounts for 80% and metal rhodium accounts for 20%, and it can withstand a high temperature of 1830°C. The bottom 1 of the crucible is a disc with a diameter of 16 mm and a thickness of 1 mm, which is independent of the crucible. The crucible is designed as a hollow structure without an upper and lower bottom, and the thickness of the crucible is 1 mm. The seed crystal space 2 for placing the seed crystal 6 is designed as a cylindrical space with an inner diameter of 12 mm, an outer diameter of 14 mm, and a height of 32 mm. The size of the necking area 3 is designed as a hollow cylindrical channel with an inner diameter of 5 mm and a height of 10 mm. The necking area 3 is designed as a "V"-shaped shoulder area 4 at 65° to the horizontal direction. The inner diameter of the equal-diameter growth area 5 is 55 mm and the length is 80 mm.

[0041] Limited by the existence of the necking stage, the seed crystal 6 cannot be directly placed into the bottom of the crucible from the equal-diameter growth area 5. Therefore, the present invention adopts a crucible without a bottom, and the seed crystal 6 is placed in the platinum-rhodium crucible from the bottom of the crucible without a bottom surface. Then the crucible and the seed crystal 6 are inverted, and the crucible bottom 1 is installed and placed coaxially with the crucible. The placed crucible and the crucible bottom 1 are kept upside down and transferred to the water-cooled table for arc melting. By adjusting the current to increase the arc energy to irradiate the edge of the crucible bottom 1, local heating of the contact area between the arc and the platinum-rhodium alloy crucible is achieved, and then the edge area of ​​the crucible bottom 1 in contact with the crucible is melted, and the bottom of the crucible bottom 1 is sealed.

[0042] After the crucible is completely cooled in the arc melting area, the platinum-rhodium alloy crucible is taken out. At this time, the seed crystal 6 is fixed below the necking area 3 and cannot be taken out. High-purity gallium oxide powder (5N) is loaded from the top of the crucible into the platinum-rhodium crucible placed in the insulation layer. The powder melts in the crucible. As the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes. The temperature gradient is formed by the silicon-molybdenum heating element and the insulation material. During the crystallization process, the crystallization direction is from bottom to top, and the necking area 3 solidifies first. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction can be discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals. The diameter of the generated gallium oxide single crystal is 55 mm. The gallium oxide powder here can also be replaced by gallium arsenide powder or indium phosphide powder.

[0043] Embodiment 2: In this embodiment, a crystal ingot with a diameter of 15 mm and a height of 30 mm is used as the seed crystal 6. The materials used for the crucible are all platinum-rhodium alloys, of which metal platinum accounts for 80% and metal rhodium accounts for 20%. The crucible is designed as a hollow structure without an upper and lower bottom, and the thickness of the crucible is 1 mm. The seed crystal space 2 for placing the seed crystal 6 is designed as a hollow cylindrical space with an inner diameter of 17 mm, an outer diameter of 18 mm, and a height of 32 mm. The size of the necking area 3 is designed as a hollow cylindrical channel with an inner diameter of 5 mm and a height of 10 mm, and the shoulder area 4 above the necking area 3 is designed to be 65° to the horizontal direction. The inner diameter of the crucible in the equal-diameter growth area 5 is 110 mm and the height is 80 mm. The bottom 1 of the crucible is a disc with a diameter of 20 mm and a thickness of 1 mm, which is independent of the crucible.

[0044] Limited by the existence of the necking stage, the seed crystal 6 cannot be directly placed into the bottom of the crucible from the equal-diameter growth area 5. Therefore, the present invention adopts a crucible without a bottom, and the seed crystal 6 is placed in the platinum-rhodium crucible from the bottom of the crucible without a bottom surface. Then the crucible and the seed crystal 6 are inverted, and the crucible bottom 1 is installed and placed coaxially with the crucible. The placed crucible and the crucible bottom 1 are transferred to the water-cooled table for arc melting, and the arc energy is increased by adjusting the current to irradiate the edge of the crucible bottom 1, so as to achieve local heating of the contact area between the arc and the platinum-rhodium alloy crucible, and then the crucible bottom 1 and the edge area in contact with the crucible are melted, so as to achieve the bottom sealing of the crucible bottom 1.

[0045] After the crucible is completely cooled in the arc melting area, the platinum-rhodium alloy crucible is taken out. At this time, the seed crystal 6 is fixed below the necking area 3 and cannot be taken out. High-purity gallium oxide powder (5N) is loaded from the top of the crucible into the platinum-rhodium crucible placed in the insulation layer. The powder melts in the crucible, and as the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes. During the crystallization process, the crystallization direction is from bottom to top, and the necking area 3 solidifies first. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction can be discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals. The diameter of the generated gallium oxide single crystal is 110mm.

[0046] Embodiment 3: In this embodiment, a crystal ingot with a diameter of 10 mm and a height of 30 mm is used as the seed crystal 6. The materials used for the crucible are all platinum-rhodium alloys, of which metal platinum accounts for 70% and metal rhodium accounts for 30%. The crucible is designed as a hollow structure without an upper and lower bottom, and the thickness of the crucible is 1 mm. The seed crystal space 2 for placing the seed crystal 6 is designed as a hollow cylindrical space with an inner diameter of 12 mm, an outer diameter of 14 mm, and a height of 32 mm. The size of the necking area 3 is designed as a hollow cylindrical channel with an inner diameter of 5 mm and a height of 10 mm, and the shoulder area 4 above the necking area 3 is designed to be 75° to the horizontal direction. The inner diameter of the crucible in the equal-diameter growth area 5 is 160 mm and the height is 80 mm. The bottom 1 of the crucible is a disc with a diameter of 15 mm and a thickness of 1 mm, which is independent of the crucible.

[0047] Limited by the existence of the necking stage, the seed crystal 6 cannot be directly placed into the bottom of the crucible from the equal-diameter growth area 5. Therefore, the present invention adopts a crucible without a bottom, and the seed crystal 6 is placed in the platinum-rhodium crucible from the bottom of the crucible without a bottom surface. Then the crucible and the seed crystal 6 are inverted, and the crucible bottom 1 is installed and placed coaxially with the crucible. The placed crucible and the crucible bottom 1 are transferred to the water-cooled table for arc melting, and the arc energy is increased by adjusting the current to irradiate the edge of the crucible bottom 1, so as to achieve local heating of the contact area between the arc and the platinum-rhodium alloy crucible, and then the crucible bottom 1 and the edge area in contact with the crucible are melted, so as to achieve the bottom sealing of the crucible bottom 1.

[0048] After the crucible is completely cooled in the arc melting area, the platinum-rhodium alloy crucible is taken out. At this time, the seed crystal 6 is fixed below the necking area 3 and cannot be taken out. High-purity gallium oxide powder (5N) is loaded from the top of the crucible into the platinum-rhodium crucible placed in the insulation layer. The powder melts in the crucible, and as the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes. During the crystallization process, the crystallization direction is from bottom to top, and the necking area 3 solidifies first. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction can be discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals. The size of the generated gallium oxide single crystal is 160mm.

[0049] In the above-mentioned embodiments 1-3, compared with the existing solutions, the addition of the necking region 3 can effectively reduce the extension of dislocations, providing a new optimization direction for the traditional vertical Bridgman method for growing crystals, and making up for the defect that the vertical Bridgman method cannot neck like the guided mold method and the Czochralski method. The crucible design and processing scheme of the present invention has the universality of materials. In addition to being applicable to the field of gallium oxide single crystal growth, it can also be used for the vertical Bridgman method growth of other materials, such as InP (indium phosphide), GaAs (gallium arsenide), etc. The proposal of the present invention provides a new direction and technical route for the development of the vertical Bridgman method in the growth of large-size low-defect crystals.

[0050] It will be appreciated that spatial relationship terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0051] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A crucible with a necking function, characterized in that: The invention is used for the vertical Bridgman method of necking and growing gallium oxide single crystals, and comprises a crucible bottom and connected seed crystal space, a necking area, a shoulder area, and an equal diameter growth area. The crucible bottom can be opened to allow seed crystals to be placed into the seed crystal space from the crucible bottom.

2. A crucible with necking function according to claim 1, characterized in that: The lower bottom of the crucible being openable means that the lower bottom of the crucible is spatially separated from the seed crystal, threadedly connected, plugged in, or snap-connected.

3. The crucible with necking function according to claim 1, characterized in that: The thickness of the crucible is between 0.5mm and 1.5mm; the diameter of the seed crystal is between 10mm and 20mm, and the height is between 30mm and 50mm; the diameter of the seed crystal space is 1-3mm larger than the seed crystal, and the height is 2-5mm larger than the seed crystal; the inner diameter of the necking area is 3-8mm, and the height is 5-15mm; the inner diameter of the crucible in the equal-diameter growth area is 55-160mm, and the height is 75-85mm; the diameter of the bottom of the crucible is 1-2mm larger than the outer diameter of the seed crystal space, and the thickness is 0.5-1.5mm.

4. The crucible with necking function according to claim 1, characterized in that: The shoulder release angle of the shoulder release area is 60°-80°.

5. The crucible with necking function according to claim 1, characterized in that: The inner diameter of the equal-diameter growth zone is 55-160 mm.

6. The crucible with necking function according to claim 1, characterized in that: The material of the crucible is platinum-rhodium alloy, in which metal platinum accounts for 70%-80% and metal rhodium accounts for 30%-20%.

7. The crucible with necking function according to claim 1, characterized in that: The gallium oxide single crystal may be replaced by a gallium arsenide or indium phosphide single crystal.

8. A necking process for growing gallium oxide single crystals by vertical Bridgman method, characterized in that: Using the crucible described in any one of claims 1 to 7, the bottomless crucible is inverted with the seed crystal space facing upward, the seed crystal is placed in the crucible, stuck in the seed crystal space above the necking area after inversion, the lower bottom of the crucible is covered, and the crucible is kept upside down, and the crucible and the lower bottom of the crucible are placed in an arc melting furnace, and the arc energy is increased by adjusting the current to achieve local heating of the contact area between the arc and the platinum-rhodium alloy crucible, and then the edge area where the lower bottom of the crucible contacts the crucible is melted, and the lower bottom of the crucible is sealed, and after cooling, the gallium oxide raw material can be loaded to carry out normal crystal growth.

9. The necking process for growing gallium oxide single crystals by vertical Bridgman method according to claim 8, characterized in that: After the crucible is completely cooled in the arc melting area, the crucible is taken out. At this time, the seed crystal is fixed below the necking area and cannot be taken out. High-purity gallium oxide powder is loaded into the crucible from the top of the crucible. The powder melts in the crucible. As the crucible moves, it passes through a certain temperature gradient and gradually cools and crystallizes. During the crystallization process, the crystallization direction is from bottom to top, and the necking area solidifies first. During the formation of the narrow neck, the dislocation extension can be cut off, and most of the dislocations that are different from the growth direction can be discharged from the new crystal, thereby greatly improving the crystal quality and realizing the preparation of low-defect gallium oxide single crystals.

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