Growth apparatus and method suitable for batch production of crystals by liquid phase method

Abstract

This invention discloses a growth apparatus and method suitable for mass production of crystals using liquid-phase methods. The growth method includes: placing a seed crystal and liquid-phase growth material in a first growth container; placing the seed crystal in a second growth container; maintaining the temperature of a first temperature zone at a first temperature T1, the temperature of a second temperature zone at a second temperature T2, and the temperature of a third temperature zone at a third temperature T3, where T1 < T2 > T3; and providing other growth conditions required for crystal growth within the growth chamber; rotating a rotating lifting frame to drive the second growth container and its carried seed crystal along a selected rotation trajectory, so that the second growth container and its carried seed crystal are repeatedly transferred between the first and second temperature zones and repeatedly immersed in the liquid-phase growth material in the first growth container. This invention enables industrial-scale, mass production of high-quality gallium nitride and other single crystals of different sizes, improving production efficiency and quality.

Description

Technical Field

[0001] This invention relates in particular to a growth apparatus and method suitable for mass production of crystals using liquid phase methods, belonging to the field of semiconductor crystal growth technology. Background Technology

[0002] Gallium nitride (GaN) materials, with their excellent properties such as wide bandgap, high electron mobility, and high breakdown electric field, have extremely broad application prospects in optoelectronics and power devices. The flux method has shown significant advantages in the preparation of large-size, extremely low dislocation density GaN single crystals.

[0003] However, current methods for growing gallium nitride using flux methods all involve monolithic growth. A single crucible is placed within a growth apparatus, containing a gallium nitride seed crystal, for a closed growth experiment. This method results in a low growth rate, leading to high time costs and low yield. For example, CN118109897A discloses a crystal growth apparatus for growing nitride single crystals using the flux method, which incorporates a lifting device at the top of the apparatus to vertically lift the crucible for growth. CN116536758A discloses an apparatus and method for high-pressure flux epitaxial growth of gallium nitride crystals. Its heater employs upper and lower temperature zones, with a crucible containing a gallium-sodium mixed metal placed between the two heater zones. The temperature gradient between the two zones promotes convection of the solution, facilitating the dissolution and transport of nitrogen atoms to the substrate at the bottom of the crucible, thereby epitaxially growing a single crystal. CN119041003A discloses a stirring device, growth equipment, and growth method for growing GaN single crystals using a flux method. The device designs a stirring apparatus for growing crystals using a flux method, in which the support frame at the bottom of the crucible swings along the vertical axis. This solves the technical problem that existing stirring devices for growing GaN single crystals have poor stirring effect, resulting in a low dissociation rate of N ions and an inability to effectively distribute N ions uniformly in the melt. Summary of the Invention

[0004] The main objective of this invention is to provide a growth apparatus and method suitable for mass production of crystals using liquid phase methods. This method enables the industrial-scale and mass production of high-quality gallium nitride and other single crystals of different sizes, thereby improving production efficiency and quality and overcoming the shortcomings of existing technologies.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] A first aspect of the present invention provides a growth apparatus suitable for mass production of crystals using a liquid-phase method, comprising:

[0007] The growth chamber has a first temperature zone, a second temperature zone, and a third temperature zone arranged sequentially from top to bottom along its own axis. The first temperature zone has a first temperature T1, the second temperature zone has a second temperature T2, and the third temperature zone has a third temperature T3, where T1 < T2 > T3.

[0008] A first growth container with an open top is disposed in the growth chamber. The first growth container is used to contain seed crystals and liquid growth raw materials. The bottom region of the first growth container is located in the third temperature zone, and the top region is located in the second temperature zone. The temperature difference between the second temperature zone and the third temperature zone can cause the liquid growth raw materials in the first growth container to convect in the depth direction.

[0009] A rotating lifting frame and multiple top-open second growth containers are disposed within the growth chamber. The multiple second growth containers are mounted on the rotating lifting frame. Each second growth container holds a seed crystal and liquid-phase growth material. The rotating lifting frame drives the second growth containers to rotate around their own rotation center. The second growth containers maintain a fixed posture during rotation. The rotation trajectory of the second growth containers lies between the first and second temperature zones. The size of the second growth containers is smaller than that of the first growth containers. The first growth containers are located on the rotation trajectory of the second growth containers. During rotation, the second growth containers can repeatedly immerse themselves in the liquid-phase growth material of the first growth containers. Simultaneously, the liquid-phase growth material in the first growth containers is disturbed while entering the second growth containers. The first growth containers, along with the seed crystal and liquid-phase growth material within them, and the second growth containers, along with the seed crystal and liquid-phase growth material within them, each form an independent crystal growth system.

[0010] A second aspect of this invention provides a method for mass production of crystals using a liquid-phase method, comprising:

[0011] Provides the aforementioned growth apparatus suitable for mass production of crystals using liquid phase method;

[0012] Seed crystals and liquid phase growth materials are placed in the first growth container, and seed crystals are placed in the second growth container. The temperature of the first temperature zone is maintained at a first temperature T1, the temperature of the second temperature zone is maintained at a second temperature T2, and the temperature of the third temperature zone is maintained at a third temperature T3, where T1 < T2 > T3. Other growth conditions required for crystal growth are provided in the growth chamber.

[0013] The rotating lifting frame is rotated to drive the second growth container and the seed crystal it carries to rotate along a selected rotation trajectory, so that the second growth container and the seed crystal it carries are repeatedly transferred between the first temperature zone and the second temperature zone, and repeatedly immersed in the liquid phase growth material in the first growth container. At the same time, the liquid phase growth material in the first growth container is disturbed by the repeatedly immersed second growth container, and crystals are grown on the surface of the seed crystal in the first growth container and the second growth container by liquid phase method to form crystals.

[0014] Compared with the prior art, the advantages of the present invention include:

[0015] The present invention provides a growth apparatus suitable for mass production of crystals using liquid phase method. By rotating and lifting the structure, multiple second growth containers are repeatedly immersed in molten metal and repeatedly transferred between the first and second temperature zones. This allows for the simultaneous growth of multiple crystals of different sizes in the same growth chamber, which is conducive to high-efficiency industrial production.

[0016] The present invention provides a growth apparatus suitable for mass production of crystals using liquid phase method. By rotating and lifting the structure, multiple second growth containers are repeatedly immersed in molten metal. While growing crystals, the apparatus also disturbs the molten metal to enhance the efficiency of nitrogen source transfer from the upper surface to the lower surface of the molten metal.

[0017] This invention uses a pulling method to grow small-sized crystals multiple times. During the growth of small-sized crystals, the crystals are repeatedly transferred between the first temperature zone and the second temperature zone, which improves the flatness of the crystal surface, reduces crystal warping and cracking, and improves crystal growth efficiency and quality.

[0018] In the crystal growth process of this invention, the seed crystal is separated from the molten metal during the heating stage to prevent the seed crystal from dissolving back; during the cooling stage, the seed crystal is separated from the molten metal to prevent polycrystalline formation on the crystal surface. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a growth apparatus suitable for mass production of crystals using a liquid phase method, provided in a typical embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a growth system constructed from a second growth container in a growth apparatus suitable for mass production of crystals using a liquid phase method, provided in a typical embodiment of the present invention.

[0021] Figure 3 This is a partial structural schematic diagram of a growth apparatus suitable for mass production of crystals using a liquid phase method, provided in a typical embodiment of the present invention. Figure 4 This is a schematic diagram of the crystal growth process in a typical embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of a growth apparatus suitable for mass production of crystals using a liquid phase method, provided in another typical embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the crystal growth surface morphology before and after the adjustment of growth parameters in a typical embodiment of the present invention. Detailed Implementation

[0024] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0025] A first aspect of the present invention provides a growth apparatus suitable for mass production of crystals using a liquid-phase method, comprising:

[0026] The growth chamber has a first temperature zone, a second temperature zone, and a third temperature zone arranged sequentially from top to bottom along its own axis. The first temperature zone has a first temperature T1, the second temperature zone has a second temperature T2, and the third temperature zone has a third temperature T3, where T1 < T2 > T3.

[0027] A first growth container with an open top is disposed in the growth chamber. The first growth container is used to contain seed crystals and liquid growth raw materials. The bottom region of the first growth container is located in the third temperature zone, and the top region is located in the second temperature zone. The temperature difference between the second temperature zone and the third temperature zone can cause the liquid growth raw materials in the first growth container to convect in the depth direction.

[0028] A rotating lifting frame and multiple top-open second growth containers are disposed within the growth chamber. The multiple second growth containers are mounted on the rotating lifting frame. Each second growth container holds a seed crystal and liquid-phase growth material. The rotating lifting frame drives the second growth containers to rotate around their own rotation center. The second growth containers maintain a fixed posture during rotation. The rotation trajectory of the second growth containers lies between the first and second temperature zones. The size of the second growth containers is smaller than that of the first growth containers. The first growth containers are located on the rotation trajectory of the second growth containers. During rotation, the second growth containers can repeatedly immerse themselves in the liquid-phase growth material of the first growth containers. Simultaneously, the liquid-phase growth material in the first growth containers is disturbed while entering the second growth containers. The first growth containers, along with the seed crystal and liquid-phase growth material within them, and the second growth containers, along with the seed crystal and liquid-phase growth material within them, each form an independent crystal growth system.

[0029] In a more specific implementation, the growth apparatus suitable for mass production of crystals using the liquid phase method includes: a growth furnace, a first heat source, a second heat source, a third heat source, and a heat insulation mechanism. The growth furnace has a closed growth chamber inside. The first heat source, the second heat source, and the third heat source are sequentially and spaced apart from top to bottom along the axial direction of the growth chamber on the inner wall of the growth chamber. The heat insulation mechanism is disposed between the second heat source and the first heat source and the third heat source, and separates the second heat source from the first heat source and the third heat source. The spaces corresponding to the growth chamber and the first heat source, the second heat source, and the third heat source respectively form the first temperature zone, the second temperature zone, and the third temperature zone.

[0030] Furthermore, the growth apparatus suitable for mass production of crystals using the liquid phase method also includes a growth raw material supply mechanism, which is used to supply liquid phase growth raw materials to the first growth container and gas phase growth raw materials to the growth chamber.

[0031] Furthermore, the first heat source, the second heat source, the third heat source, and the heat insulation mechanism are all annular structures arranged circumferentially along the growth chamber.

[0032] Furthermore, the inner wall surface of the growth chamber is an insulated structure.

[0033] Furthermore, the rotating lifting frame includes a rotating shaft and multiple rotating arms, the rotating arms being fixedly connected to the rotating shaft, the multiple rotating arms being radially distributed around the rotating shaft, the second growth container being rotatably connected to the rotating arms, and the rotating lifting frame being able to rotate around the rotating shaft.

[0034] Furthermore, the second growth container is connected to the spiral arm via a hinge or pivot connector.

[0035] Furthermore, the axial direction of the rotating shaft is parallel to the radial direction of the growth chamber.

[0036] Furthermore, the plurality of second growth containers may be the same or different in size, the size including volume.

[0037] In a typical implementation, the growth apparatus suitable for mass production of crystals using liquid phase further includes: an in-situ monitoring mechanism and a control mechanism. The in-situ monitoring mechanism is located outside the growth chamber and is used to obtain the growth thickness distribution and surface defect distribution of the crystal surface grown in the second growth container. The control mechanism is connected to the in-situ monitoring mechanism, the rotating lifting frame, the first heat source, the second heat source, the third heat source, and the growth raw material supply mechanism, and is used to adjust at least one of the rotation speed of the rotating lifting frame, the temperature field distribution in the growth chamber, and the concentration of the gas-phase growth raw material in the growth chamber.

[0038] Furthermore, the growth furnace is provided with a high-temperature resistant optical window, and the in-situ monitoring mechanism includes a structured light full-field scanner. The structured light full-field scanner scans the crystal growing in the second growth container through the high-temperature resistant optical window and obtains the growth thickness distribution, surface uniformity, and surface defect distribution of the crystal surface.

[0039] A second aspect of this invention provides a method for mass production of crystals using a liquid-phase method, comprising:

[0040] Provides the aforementioned growth apparatus suitable for mass production of crystals using liquid phase method;

[0041] Seed crystals and liquid phase growth materials are placed in the first growth container, and seed crystals are placed in the second growth container. The temperature of the first temperature zone is maintained at a first temperature T1, the temperature of the second temperature zone is maintained at a second temperature T2, and the temperature of the third temperature zone is maintained at a third temperature T3, where T1 < T2 > T3. Other growth conditions required for crystal growth are provided in the growth chamber.

[0042] The rotating lifting frame is rotated to drive the second growth container and the seed crystal it carries to rotate along a selected rotation trajectory, so that the second growth container and the seed crystal it carries are repeatedly transferred between the first temperature zone and the second temperature zone, and repeatedly immersed in the liquid phase growth material in the first growth container. At the same time, the liquid phase growth material in the first growth container is disturbed by the repeatedly immersed second growth container, and crystals are grown on the surface of the seed crystal in the first growth container and the second growth container by liquid phase method to form crystals.

[0043] Furthermore, the first temperature T1, the second temperature T2, and the third temperature T3 are all within the range of 700℃ to 1000℃.

[0044] Furthermore, the liquid-phase mass production method for crystal growth also includes: changing the crystal growth rate by altering the rotational speed of the rotating lifting frame and / or the residence time of the second growth container and the seed crystal it carries in the liquid-phase growth raw material within the first growth container.

[0045] Furthermore, the liquid-phase mass production method for crystal growth includes: adjusting the growth conditions in the growth chamber to change at least one of the crystal growth thickness distribution and surface defects, so as to grow a crystal with uniform thickness distribution and no defects. The growth conditions include the temperature field distribution in the growth chamber, the pressure in the growth chamber, the concentration of the gas-phase growth material in the growth chamber, and the residence time of the second growth container and the seed crystal it carries in the liquid-phase growth material in the first growth container.

[0046] Furthermore, the liquid phase method for mass production of crystal growth specifically includes: measuring and obtaining a growth thickness distribution cloud map of the crystal, and adjusting the growth conditions in the growth chamber according to the growth thickness distribution cloud map, so as to grow a crystal with uniform thickness distribution and no defects.

[0047] Furthermore, the growth method specifically includes: constructing a growth database that corresponds to the crystal growth conditions, crystal growth rate, morphology, and quality; and adjusting the growth conditions based on the growth thickness distribution data of the crystal obtained from actual measurements.

[0048] Furthermore, the size of the seed crystal in the first growth container is larger than the size of the seed crystal in the second growth container.

[0049] Furthermore, the seed crystals within the multiple second growth containers may be of the same or different sizes.

[0050] The following will provide a further explanation of the technical solution, its implementation process, and its principles, in conjunction with the accompanying drawings and specific implementation examples.

[0051] Example 1

[0052] Please see Figures 1-3 A growth apparatus suitable for mass production of crystals using liquid phase method includes: a growth furnace 100, a first heat source 210, a second heat source 220, a third heat source 230, a heat insulation mechanism 300, a rotary lifting frame 400, a first growth container 510 with an open top, multiple second growth containers 520 with open tops, and a growth raw material supply mechanism.

[0053] The growth furnace 100 has a sealed growth chamber 110 inside. A first heat source 210, a second heat source 220, and a third heat source 230 are arranged sequentially from top to bottom on the inner wall of the growth chamber 110 along the axial direction (the axial direction of the growth furnace 100 in the working state is approximately parallel to the direction of gravity). A heat insulation mechanism 300 is arranged between the second heat source 220 and the first heat source 210 and the third heat source 230, and separates the second heat source 220 from the first heat source 210 and the third heat source 230. The spaces corresponding to the growth chamber 110 and the first heat source 210, the second heat source 220, and the third heat source 230 respectively form a first temperature zone 111, a second temperature zone 112, and a third temperature zone 113. The first temperature zone 111 has a first temperature T1, the second temperature zone 112 has a second temperature T2, and the third temperature zone 113 has a third temperature T3, where T1 < T2 > T3.

[0054] The rotary lifting frame 400, the first growth container 510, and multiple second growth containers 520 are all disposed within the growth chamber 110. A growth material supply mechanism is connected to the growth furnace 100 and is used to input growth materials into the growth chamber 110. These growth materials include liquid-phase growth materials and gas-phase growth materials. The first growth container 510 is used to hold the seed crystal A and the liquid-phase growth materials. The second growth containers 520 are used to hold the seed crystal A and can accommodate a small amount of liquid-phase growth materials. The bottom region of the first growth container 510 is located in the third temperature zone 113, and the top region is located in the second temperature zone 112. The temperature difference between the second temperature zone 112 and the third temperature zone 113 can cause convection of the liquid-phase growth materials within the first growth container 510 in the depth direction. The rotary lifting frame 400 is located within the first... Temperature zone 111 and temperature zone 112, and multiple second growth containers 520 are arranged on the rotary lifting frame 400. The second growth containers 520 can rotate around the rotation center of the rotary lifting frame 400 under the drive of the rotary lifting frame 400, and repeatedly transfer between the first temperature zone 111 and the second temperature zone 112, and repeatedly immerse themselves in the liquid phase growth material in the first growth container 510. The second growth container 520 always maintains a fixed posture during the rotation process. This fixed posture means that the opening at the top always faces upward along the direction of gravity. The first growth container 510 and the seed crystal A and liquid phase growth material located in the first growth container 510, and the second growth container 520 and the seed crystal A and liquid phase growth material located in the second growth container 520 respectively form independent crystal growth systems.

[0055] It should be noted that the liquid-phase growth material is in a molten state. The liquid-phase growth material includes molten metal, a nitrogen source, additives, etc. As is known to those skilled in the art, the liquid-phase growth material required for flux-driven liquid-phase epitaxial growth of gallium nitride single crystals includes fluxes such as metallic gallium and metallic sodium, and optional additives such as carbon. The specific composition of this liquid-phase growth material is not the focus of this invention and therefore will not be specifically described. It can adopt proportions and compositions known in the art. The gas-phase growth material can be nitrogen or ammonia, etc. Furthermore, it should be emphasized that the improvement direction of this invention is mainly suitable for the main growth-generating part of gallium nitride crystals produced in batches using the flux method.

[0056] Of course, the growth apparatus also includes other functional mechanisms, both necessary and unnecessary, for supporting the flux-assisted liquid phase epitaxial growth of gallium nitride single crystals. For example, functional mechanisms for maintaining high temperature and high pressure within the growth chamber 110. These are known to those skilled in the art and are not considered as directions for improvement of the present invention. Therefore, they are not specifically limited or described.

[0057] Specifically, the growth furnace 100 can adopt a structure known in the art. To improve the stability of the temperature environment required for growth within the growth chamber 110, an insulation structure can be provided on the inner wall surface of the growth chamber 110. The specific structure and equipment model of the growth furnace 100 are not limited here. The aforementioned closed structure of the growth chamber 110 means that the growth chamber 110 can maintain a closed state during operation. The growth furnace 100 is naturally equipped with furnace doors for the seed crystal A and growth containers to be moved in and out; these are common knowledge to those skilled in the art and will not be elaborated upon here.

[0058] Specifically, the first heat source 210, the second heat source 220, the third heat source 230, and the heat insulation mechanism 300 are all annular structures arranged circumferentially along the growth chamber 110. The first heat source 210, the second heat source 220, and the third heat source 230 can be conventional electrothermal heating mechanisms or other heating mechanisms, etc. The material of the heat insulation mechanism 300 can be organic or inorganic heat insulation materials known in the art, such as ceramic fiber materials. The radial widths of the first heat source 210, the second heat source 220, the third heat source 230, and the heat insulation mechanism 300 can be the same. It should be noted that the first temperature zone 111, the second temperature zone 112, and the third temperature zone 113 can be spaces formed by the first heat source 210, the second heat source 220, and the third heat source 230, respectively. The axial height of the heat insulation mechanism 300 is less than the axial height of the first growth container 510, and the specific height is not specifically limited. The axial height of the first temperature zone 111, the second temperature zone 112, and the third temperature zone 113 only needs to be sufficient to fully accommodate the first growth container 510, and the second temperature zone 112 and the first temperature zone 111 need to accommodate the rotating lifting frame 400, the multiple second growth containers 520, and the rotation of the multiple second growth containers 520. No specific volume value is limited here.

[0059] Specifically, the volume of the first growth container 510 is larger than that of the second growth container 520. Specifically, the diameter and height of the first growth container 510 are larger than those of the second growth container 520, respectively. Similarly, the area of ​​the seed crystal A carried within the first growth container 510 is larger than the area of ​​the seed crystal A carried within the second growth container 520. That is, the size of the gallium nitride single crystal grown based on the growth system of the first growth container 510 is larger than the size of the gallium nitride single crystal grown based on the growth system of the second growth container 520. For example, the first growth container 510 and the second growth container 520 can be crucibles, etc. The volumes of the multiple second growth containers 520 can be the same or different. When using second growth containers 520 of different sizes and multiple seed crystals A of different sizes, gallium nitride single crystals of more sizes can be grown in batches.

[0060] Specifically, the rotary lifting frame 400 includes a rotating shaft 410 and multiple rotating arms 420. The rotating arms 420 are fixedly connected to the rotating shaft 410, and the multiple rotating arms 420 are radially distributed around the rotating shaft 410. The axial direction of the rotating shaft 410 is parallel to the radial direction of the growth chamber 110, and the rotating shaft 410 is rotatably engaged with the growth furnace 100. The second growth container 520 is rotatably connected to the rotating arms 420, specifically through a hinge 430. The rotary lifting frame 400 can rotate around the rotating shaft 410. It is understood that the rotation of the rotary lifting frame 400 can be driven by an external power source such as a drive motor through a transmission structure, such as a gear transmission structure. The specific structure of the transmission structure is not limited here. Specifically, the second growth container 520 and the rotating arms 420 can be connected through a hinge or pivot connector. As a typical implementation scheme, the rotating lifting frame 400 is driven by gears, which facilitates the provision of stable power from an external power source for rotation and also makes it easy to control the rotation speed. The rotating lifting frame 400 rotates clockwise or counterclockwise around the central support position via gear meshing. The second growth container 520 also rotates clockwise with the rotating lifting frame 400. The rotating lifting frame 400 and the second growth container 520 are connected by a hinge, so that during the rotation, the second growth container 520 always keeps its opening vertically upward, allowing small-sized crystals to grow stably.

[0061] In a more specific implementation, the process of performing flux-based liquid-phase epitaxial growth of single crystals using this growth apparatus suitable for mass production of crystals in the liquid phase specifically includes:

[0062] A large-sized seed crystal A is placed in the first growth container 510, and small-sized seed crystals A are placed in multiple second growth containers 520 respectively (the size of the multiple small-sized seed crystals A can be the same or different, and the number and arrangement of seed crystals A in the first growth container 510 and the second growth container 520 are not limited). The size of the seed crystal A is 2-8 inches. Molten gallium-sodium metal is placed in the first growth container 510.

[0063] The growth chamber 110 is sealed, and the temperature of the first temperature zone 111 is maintained at the first temperature T1, the temperature of the second temperature zone 112 is maintained at the second temperature T2, and the temperature of the third temperature zone 113 is maintained at the third temperature T3, where T1 < T2 > T3, the first temperature T1, the second temperature T2, and the third temperature T3 ∈ (700℃~1000℃), and / or, the first temperature T1, the second temperature T2, and the third temperature T3 ∈ (700℃~850℃). The pressure inside the growth chamber 110 is adjusted to the pressure required for growing gallium nitride single crystals, and a nitrogen source is introduced into the growth chamber 110.

[0064] The rotating lifting frame 400 is driven to rotate. Taking one of the second growth containers 520 as an example, ... Figure 4 As shown, a second growth container 520 containing a small seed crystal A enters the second temperature zone 112 from the first temperature zone 111 and is immersed in the molten metal in the first growth container 510 to grow gallium nitride single crystals. After a certain period of time, as the rotating lifting frame 400 rotates, the second growth container (along with the molten metal contained inside, the seed crystal A, and the grown crystal) is lifted out of the molten metal, and then enters the first temperature zone 111 from the second temperature zone 112. After that, it is immersed in the molten metal in the first growth container 510 again. This cycle is repeated multiple times until the growth of the gallium nitride crystal is completed.

[0065] Specifically, by setting three different heat sources within the growth chamber 110, separated by a heat insulation mechanism 300, three different temperature zones are formed, thereby achieving a large temperature gradient within the chamber to promote crystal growth. Specifically, the upper surface temperature of the molten metal in the first growth container 510 is higher (second temperature T2), which facilitates the dissolution of the nitrogen source. After leaving the molten metal, the second growth container 520 enters the relatively lower first temperature zone 111 (first temperature T1), which can increase the supersaturation of nitrogen in the molten metal within the second growth container 520, thereby increasing the crystal growth rate. The bottom of the first growth container 510 is located in the third temperature zone 113, which has a relatively lower third temperature T3. The temperature gradient between the upper and lower sides of the molten metal within the first growth container 510 becomes the driving force for nitrogen source transport, thereby promoting the growth of large-sized crystals within the first growth container 510.

[0066] Specifically, the second growth container 520 is first immersed in the molten metal in the first growth container 510 as the rotating lifting frame 400 rotates. After growing for a period of time, it is then pulled out of the molten metal. The optimal rotation speed and corresponding growth time need to be determined by testing growth devices of different sizes. At this time, there may be defects such as unmerged areas or pits caused by crystal back dissolution during the growth process. Therefore, after the second growth container 520 is pulled out of the molten metal, there will be residual molten metal in the pit, which allows the crystal to continue to grow. This allows the defective growth interface to grow into a smoother surface. With the repeated immersion and extraction of the second growth container 520 into the molten metal, the growth quality of the crystal can be effectively improved. Meanwhile, since the nitrogen source dissolves on the upper surface of the molten metal, in order to effectively transfer it to the bottom of the molten metal, the second growth container 520 rotates under the drive of the rotating lifting frame 400, so that the second growth container 520 can be repeatedly immersed in the molten metal and generate disturbance to the molten metal, thereby accelerating the transfer rate of the nitrogen source from the surface of the molten metal to the surface of the seed crystal A, and thus improving the crystal growth rate.

[0067] It should be noted that during the heating phase of the growth chamber 110, all the second growth containers 520 and the seed crystals A inside them do not come into contact with the molten metal to avoid the seed crystals A from melting back. When the temperature reaches the set value and stabilizes, the second growth containers 520 are rotated and immersed in the molten metal for crystal growth. The process of repeatedly entering and exiting the molten metal is repeated to improve the growth quality. After the growth is completed, all the small-sized second growth containers 520 are removed from the molten metal and the crystals are allowed to stop growing. At this time, the surface will not have many poor-quality polycrystalline materials due to the cooling, thereby improving the raw material utilization rate and crystal quality.

[0068] Current flux-based growth methods only allow for single-crystal growth through a pulling and lifting operation. This invention enables the simultaneous growth of multiple crystals while ensuring uniform growth. Furthermore, this invention allows for the simultaneous growth of multiple crystals of different sizes using a single apparatus. By agitating the molten metal during the rotation of the growth container, the nitrogen source on the upper surface of the molten metal is effectively transferred to the seed crystal A at the bottom of the molten metal, improving the growth rate and quality of large-size crystals, increasing crystal yield and efficiency, and facilitating industrialization.

[0069] Example 2

[0070] Please see Figure 5 The structure of the growth apparatus suitable for mass production of crystals using liquid phase method in this embodiment is basically the same as that in Embodiment 1. The parts that are the same will not be described here. The difference is that the growth apparatus in this embodiment also includes an in-situ monitoring mechanism (also called an in-situ monitoring system, the same below) 600 and a control mechanism. The in-situ monitoring mechanism 600 is set outside the growth chamber 110 and is used to obtain the growth thickness distribution and surface defect distribution of the crystal surface grown in the second growth container 520. The control mechanism is connected to the in-situ monitoring mechanism, the rotating lifting frame 400, the first heat source 210, the second heat source 220, the third heat source 230, and the growth raw material supply mechanism, and is used to adjust at least one of the rotation speed of the rotating lifting frame 400, the temperature field distribution in the growth chamber 110, and the concentration of the gas phase growth raw material in the growth chamber 110. Specifically, the in-situ monitoring mechanism 600 and the control mechanism can be integrated.

[0071] Specifically, a high-temperature resistant optical window is provided on the side of the growth furnace 100. The in-situ monitoring mechanism monitors the crystal in the second growth container 520 located in the growth chamber 110 through the high-temperature resistant optical window. Specifically, the in-situ monitoring mechanism 600 is a structured light full-field scanner. When the second growth container 520 and the crystal growth system it constitutes move to the designated position corresponding to the high-temperature resistant optical window, a specific geometric pattern (such as sine fringes or Gray code) is projected onto the crystal surface using structured light projection technology. The specific geometric pattern deforms due to the change in crystal surface height. The deformed pattern is captured by a binocular camera or a monocular camera combined with multi-angle shooting. Based on the principle of triangulation, the three-dimensional coordinates (X / Y / Z) of each pixel are calculated. Finally, the thickness of the crystal is calculated by the height difference between the upper and lower surfaces, generating a full-field thickness distribution cloud map. Because the liquid-phase growth of gallium nitride crystals occurs in a high-temperature, high-pressure environment, and the molten metal is highly corrosive, the cleanliness of the internal growth environment is critical. Therefore, the in-situ monitoring and control mechanisms are configured as an automated detection system, coupled with high-speed scanning, to track the thickness changes during crystal growth in real time, obtaining the growth thickness distribution, surface uniformity, and surface defect distribution on the crystal surface. Specifically, an anti-reflective coating is applied to the outer side of the high-temperature resistant optical window to eliminate specular reflection interference. A structured light full-field scanner is installed at the location of the in-situ monitor. By setting up an in-situ monitoring mechanism outside the growth chamber 110 and achieving in-situ measurement through a vacuum-sealed interface, contamination of the growth environment is avoided.

[0072] Specifically, by pre-measuring and obtaining crystal growth rates, morphologies, and masses under different growth conditions, numerical calculations are used to obtain the temperature field distribution and nitrogen source concentration distribution within the molten metal corresponding to each growth condition, thereby establishing a relatively complete growth database and control strategy. When uneven crystal growth thickness is detected, based on the experience of the growth database and combined with artificial intelligence algorithms, the growth results are quickly matched with the database. The corresponding possible growth environment and control scheme are displayed on the computer interface. Based on the measurement results, the temperature field distribution, composition distribution, and flow conditions within the molten metal are deduced, and the current growth parameters, such as temperature, pressure, and rotation rate, are adjusted to ensure that the crystal grows to a smoother surface after entering the molten metal, avoiding warping and cracking due to uneven stress. This helps to obtain thicker gallium nitride bulk single crystals. For example, if a crack is detected in the crystal, the rotation rate can be adjusted to quickly bypass the crystal, reducing wasted time and materials due to ineffective growth. It should be noted that the control mechanism and its circuit structure, data processing system, etc., are known in the art, and their specific data processing procedures and logic are not limited here.

[0073] The embodiments of the present invention can combine numerical simulation and artificial intelligence to obtain crystal growth under different conditions. Based on the measured growth data, the overall situation of the current internal growth environment can be inferred, making the growth process visible, thereby enabling the growth of high-quality gallium nitride single crystals.

[0074] This invention provides a growth apparatus suitable for mass production of crystals using the liquid phase method. It allows for in-situ monitoring of the crystal growth process without affecting the crystal growth environment, obtaining information such as crystal thickness, uniformity, growth rate, and the presence of defects like cracks. Simultaneously, by combining the rapid matching function of artificial intelligence, the current internal growth environment of the molten metal is obtained through reverse engineering based on the growth results, and can be displayed on a computer in a graphical interface, making the control of the growth process clearer.

[0075] The present invention provides a growth apparatus suitable for mass production of crystals using liquid phase method. The growth parameters can be adjusted in real time according to the actual growth situation. The growth situation of each crystal is different, but they can all be monitored one by one, which effectively improves the growth quality of each crystal and enhances the controllability and repeatability of the crystal growth process, thereby increasing the crystal yield.

[0076] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A growth apparatus suitable for mass production of crystals using a liquid-phase method, characterized in that, include: The growth chamber has a first temperature zone, a second temperature zone, and a third temperature zone arranged sequentially from top to bottom along its own axis. The first temperature zone has a first temperature T1, the second temperature zone has a second temperature T2, and the third temperature zone has a third temperature T3, where T1 < T2 > T3. A first growth container with an open top is disposed in the growth chamber. The first growth container is used to contain seed crystals and liquid growth raw materials. The bottom region of the first growth container is located in the third temperature zone, and the top region is located in the second temperature zone. The temperature difference between the second temperature zone and the third temperature zone can cause the liquid growth raw materials in the first growth container to convect in the depth direction. A rotating lifting frame and multiple top-open second growth containers are disposed within the growth chamber. The rotating lifting frame includes a rotating shaft and multiple rotating arms, which are fixedly connected to the rotating shaft and radially distributed around the rotating shaft. The second growth containers are rotatably connected to the rotating arms. The rotating lifting frame is capable of rotating around the rotating shaft. The second growth containers are used to hold seed crystals and liquid-phase growth materials. The rotating lifting frame drives the second growth containers to rotate around the rotation center of the rotating lifting frame. The second growth containers maintain a fixed posture during rotation, and the rotation trajectory of the second growth containers is located within the first temperature zone. The second growth zone and the second growth container are smaller than the first growth container. The first growth container is located on the rotation trajectory of the second growth container. During rotation, the second growth container can be repeatedly immersed in the liquid growth material of the first growth container. While allowing the liquid growth material in the first growth container to enter the second growth container, the liquid growth material in the first growth container is disturbed. The first growth container and the seed crystal and liquid growth material located in the first growth container, and the second growth container and the seed crystal and liquid growth material located in the second growth container respectively form independent crystal growth systems.

2. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 1, characterized in that, include: The growth furnace comprises a first heat source, a second heat source, a third heat source, and a heat insulation mechanism. The growth furnace has a closed growth chamber inside. The first heat source, the second heat source, and the third heat source are sequentially arranged from top to bottom along the axial direction of the growth chamber on the inner wall of the growth chamber. The heat insulation mechanism is disposed between the second heat source and the first heat source and the third heat source, and separates the second heat source from the first heat source and the third heat source. The spaces corresponding to the growth chamber and the first heat source, the second heat source, and the third heat source respectively form the first temperature zone, the second temperature zone, and the third temperature zone.

3. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 1 or 2, characterized in that: The growth apparatus suitable for mass production of crystals using liquid phase method further includes a growth material supply mechanism, which is used to supply liquid phase growth materials to the first growth container and gas phase growth materials to the growth chamber.

4. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 2, characterized in that: The first heat source, the second heat source, the third heat source, and the heat insulation mechanism are all annular structures arranged circumferentially along the growth chamber.

5. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 4, characterized in that: The plurality of the second growth containers may be the same or different in size, the size including volume.

6. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 4, characterized in that: The inner wall surface of the growth chamber is an insulated structure.

7. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 2, characterized in that: The second growth container is connected to the spiral arm via a hinge or pivot connector.

8. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 2, characterized in that: The axial direction of the rotating shaft is parallel to the radial direction of the growth chamber.

9. The growth apparatus suitable for mass production of crystals using liquid phase method according to claim 3, characterized in that, Also includes: An in-situ monitoring mechanism and a control mechanism are provided. The in-situ monitoring mechanism is located outside the growth chamber and is used to obtain the growth thickness distribution and surface defect distribution of the crystal surface grown in the second growth container. The control mechanism is connected to the in-situ monitoring mechanism, the rotating lifting frame, the first heat source, the second heat source, the third heat source, and the growth raw material supply mechanism, and is used to adjust at least one of the rotation speed of the rotating lifting frame, the temperature field distribution in the growth chamber, and the concentration of the gas-phase growth raw material in the growth chamber.

10. The growth apparatus for mass production of crystals using liquid phase method according to claim 9, characterized in that: The growth furnace is equipped with a high-temperature resistant optical window, and the in-situ monitoring mechanism includes a structured light full-field scanner. The structured light full-field scanner scans the crystal growing in the second growth container through the high-temperature resistant optical window and obtains the growth thickness distribution, surface uniformity, and surface defect distribution of the crystal surface.

11. A method for mass production of crystals using a liquid-phase method, characterized in that, include: Provide a growth apparatus as described in any one of claims 1-10, suitable for mass production of crystals using a liquid phase method; Seed crystals and liquid phase growth materials are placed in the first growth container, and seed crystals are placed in the second growth container. The temperature of the first temperature zone is maintained at a first temperature T1, the temperature of the second temperature zone is maintained at a second temperature T2, and the temperature of the third temperature zone is maintained at a third temperature T3, where T1 < T2 > T3. Other growth conditions required for crystal growth are provided in the growth chamber. The rotating lifting frame is rotated to drive the second growth container and the seed crystal it carries to rotate along a selected rotation trajectory, so that the second growth container and the seed crystal it carries are repeatedly transferred between the first temperature zone and the second temperature zone, and repeatedly immersed in the liquid phase growth material in the first growth container. At the same time, the liquid phase growth material in the first growth container is disturbed by the repeatedly immersed second growth container, and crystals are grown on the surface of the seed crystal in the first growth container and the second growth container by liquid phase method to form crystals.

12. The method for mass production of crystals using the liquid phase method according to claim 11, characterized in that: The first temperature T1, the second temperature T2, and the third temperature T3 are all within the range of 700℃ to 1000℃.

13. The liquid-phase mass production method for crystal growth according to claim 11 or 12, characterized in that, include: The growth conditions in the growth chamber are adjusted to change at least one of the crystal growth thickness distribution and surface defects, so as to grow a crystal with uniform thickness distribution and no defects. The growth conditions include the temperature field distribution in the growth chamber, the pressure in the growth chamber, the concentration of the gas phase growth material in the growth chamber, and the residence time of the second growth container and the seed crystal it carries in the liquid phase growth material in the first growth container.

14. The method for mass production of crystals using the liquid phase method according to claim 13, characterized in that, Specifically, it includes: The growth thickness distribution cloud map of the crystal is obtained by measurement, and the growth conditions in the growth chamber are adjusted according to the growth thickness distribution cloud map to grow a crystal with uniform thickness distribution and no defects.

15. The liquid-phase mass production method for crystal growth according to claim 14, characterized in that, The growth method specifically includes: A growth database is constructed to establish the correspondence between crystal growth conditions and crystal growth rate, morphology, and quality. The growth conditions are adjusted based on the growth thickness distribution data of the crystal obtained from actual measurements.

16. The method for mass production of crystals using the liquid phase method according to claim 11, characterized in that: The size of the seed crystal in the first growth container is larger than the size of the seed crystal in the second growth container.

17. The method for mass production of crystals using the liquid phase method according to claim 11, characterized in that: The seed crystals in the multiple second growth containers may be the same or different in size.

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