Vertical liquid phase epitaxial growth graphite tool, growth device and growth method

Abstract

The invention provides a vertical liquid phase epitaxial growth graphite tool, a growth device and a method, the graphite tool comprises a sample rack and a transmission rod, the sample rack comprises a sample rack base, a substrate rack for fixing a substrate and an adjusting assembly for driving the substrate rack to rotate between a horizontal growth position and an inclined liquid draining position; the substrate frame is connected to the sample frame base through the adjusting assembly, and the sample frame base is connected with the movable end of the transmission rod. Through the deflectable design of the substrate frame, the substrate frame is deflected to a horizontal growth position after the sample frame enters the mother liquor, the substrate is kept horizontal in the growth process, the thickness of an epitaxial layer and the uniformity of components are improved, meanwhile, the substrate frame is deflected to an inclined liquid draining level after growth is completed, and natural separation of the mother liquor and the substrate under the action of gravity is achieved; no mother liquor remains on the surface of the epitaxial layer and the utilization rate of the epitaxial surface is improved.

Description

Technical Field

[0001] This invention belongs to the field of liquid phase epitaxial growth technology of thin film materials, and specifically relates to a vertical liquid phase epitaxial growth graphite tooling, growth device and growth method. Background Technology

[0002] Liquid phase epitaxy (LPE) is a semiconductor thin film fabrication technique that grows a high-quality, oriented single-crystal thin film from a supersaturated mother liquor on a single-crystal substrate. It is widely used in the fabrication of high-efficiency solar cells and optoelectronic devices such as infrared detectors. For the fabrication of single-crystal thin films of semiconductors such as mercury cadmium telluride, indium gallium arsenide, and indium arsenide antimony, LPE is a classic and low-cost process. There are three main mature LPE methods: horizontal LPE, vertical LPE, and tilting LPE. Horizontal LPE uses the horizontal mechanical movement of a substrate slide to control the contact and separation between the substrate and the mother liquor, allowing for precise control of the epitaxial wafer thickness and meeting the requirements of multilayer growth. Vertical LPE involves vertically immersing the substrate in the mother liquor along with a sample holder; growth stops when the sample holder is lifted out of the mother liquor. The sample holder can hold multiple substrates, supporting mass production, and the mother liquor can be reused multiple times. It also offers high compatibility with substrate shapes, providing significant advantages in process cost and production capacity. Tilting-boat liquid phase epitaxy controls the contact and separation between the mother liquor and the substrate by tilting a graphite boat, making it suitable for growing semiconductor materials with complex compositions.

[0003] The uniformity of the mother liquor in contact with the substrate wafer in liquid phase epitaxy directly determines the thickness and compositional consistency of the epitaxial single crystal film. In vertical liquid phase epitaxy, the mother liquor exhibits a uniform distribution of components after homogenization. However, during each cooling and growth cycle, due to density differences among components, sedimentation easily occurs in large-volume semi-infinite mother liquor, resulting in compositional differences between layers at different heights. In conventional vertical liquid phase epitaxy, the substrate wafer is vertically immersed in the mother liquor, and the epitaxial surface remains vertical during growth. The entire substrate surface is in contact with mother liquor exhibiting compositional differences at different heights, leading to significant non-uniformity in epitaxial layer thickness and composition along the substrate placement direction. Summary of the Invention

[0004] The purpose of this invention is to provide a tooling and method for vertical liquid phase epitaxial growth of graphite, which can at least solve some of the defects existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A vertical liquid phase epitaxial growth graphite fixture includes a sample holder and a drive rod. The sample holder includes a sample holder base, a substrate holder for fixing a substrate, and an adjustment component for rotating the substrate holder between a horizontal growth position and an inclined liquid-spraying position. The substrate holder is connected to the sample holder base through the adjustment component, and the sample holder base is connected to the movable end of the drive rod.

[0007] Furthermore, there are multiple substrate holders, which are stacked and spaced apart from bottom to top.

[0008] Furthermore, the adjustment assembly includes a fixed limiting member and a movable limiting member arranged parallel to the axis of the transmission rod. The top of the fixed limiting member is fixedly connected to the sample holder base, and the side of the substrate holder is rotatably connected to both the fixed limiting member and the movable limiting member, and their rotation axes are all parallel to the horizontal plane.

[0009] Furthermore, when the substrate holder is in the horizontal growth position, the top of the movable limiting member abuts against the sample holder base, and / or the bottom of the movable limiting member is flush with the bottom of the fixed limiting member, and there is a certain distance between the movable limiting member and the fixed limiting member; when the substrate holder is in the inclined draining position, the movable limiting member is in contact with the fixed limiting member.

[0010] Furthermore, the substrate holder has an upper limit member and a lower limit member at both ends for limiting the substrate, and the upper surface of the lower limit member is not higher than the upper surface of the substrate.

[0011] Furthermore, the aforementioned vertical liquid phase epitaxial graphite growth fixture also includes a stirring base, with the sample holder placed inside the stirring base. The transmission rod is connected to the stirring base to drive the stirring base to move up and down to stir the mother liquor.

[0012] Furthermore, the stirring seat includes a stirring base and a stirring base, the stirring base being detachably connected to one end of the stirring base, the stirring base including an annular sidewall and a bottom plate, the annular sidewall having a closed section and a hollow section sequentially along its axial direction, the stirring base being connected to the end of the closed section, and the bottom plate being connected to the end of the hollow section.

[0013] Furthermore, the aforementioned vertical liquid phase epitaxial growth graphite fixture also includes a fixed cover for connecting to a growth container holding the mother liquor. The outer side of the stirring seat is slidably connected to the inner side of the fixed cover along the axial direction of the fixed cover, and one end of the transmission rod away from the sample holder extends through the fixed cover.

[0014] In addition, the present invention also provides a vertical liquid phase epitaxial growth apparatus, including the above-mentioned vertical liquid phase epitaxial growth graphite tooling and a growth container for holding mother liquor.

[0015] The present invention also provides a vertical liquid phase epitaxial growth method, which uses the above-mentioned vertical liquid phase epitaxial growth apparatus and includes the following process:

[0016] During the epitaxial growth process, the sample holder is positioned in the mother liquor by a transmission rod, and the substrate holder is deflected to a horizontal growth position by an adjustment component, so that the substrate on the substrate holder is in a horizontal state to start the epitaxial growth.

[0017] After epitaxial growth is completed, the sample holder is removed from the mother liquor, and at the same time, the substrate holder is tilted to the tilted drain position using the adjustment component, so that the substrate tilts and drains the residual mother liquor.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The vertical liquid phase epitaxial growth graphite fixture provided by the present invention has a deflectable design for the substrate holder, which allows the substrate holder to be deflected to a horizontal growth position after the sample holder enters the mother liquor. During the growth process, the substrate remains horizontal, which improves the thickness and composition uniformity of the epitaxial layer, thereby improving the yield of epitaxial materials. At the same time, after the growth is completed, the substrate holder is deflected to an inclined liquid-draining position, so that the mother liquor is naturally separated from the substrate under the action of gravity, ensuring that there is no mother liquor residue on the surface of the epitaxial layer and improving the utilization rate of the epitaxial surface.

[0020] (2) The vertical liquid phase epitaxial growth graphite tooling provided by the present invention adopts a multi-layer substrate frame structure design, which effectively improves the production capacity of epitaxial equipment.

[0021] (3) The vertical liquid phase epitaxial growth graphite fixture provided by the present invention achieves full stirring of the mother liquor by designing the stirring seat to move up and down, thus ensuring the uniformity of the mother liquor components at different heights.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a cross-sectional schematic diagram of the vertical liquid phase epitaxial growth apparatus in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the vertical liquid phase epitaxial growth process in an embodiment of the present invention;

[0025] Figure 3 These are microscopic images and five-point thickness composition of epitaxial wafers prepared using conventional vertical liquid phase epitaxial growth methods in this embodiment of the invention.

[0026] Figure 4 These are microscopic images and five-point thickness composition of epitaxial wafers prepared using the vertical liquid phase epitaxial growth method of this invention in this embodiment of the invention.

[0027] Explanation of reference numerals in the attached drawings: 1. Transmission rod; 2. Fixing cover; 3. Stirring base; 4. Sample rack; 41. Sample rack base; 42. Fixed limiting component; 43. Movable limiting component; 44. Substrate rack; 5. Stirring base; 51. Enclosed section; 52. Hollowed-out section; 53. Base plate; 6. Growth container; 7. Mother liquor. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an abutting connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] like Figure 1 and Figure 2 As shown, this embodiment provides a vertical liquid phase epitaxial growth graphite fixture, including a sample holder 4 and a transmission rod 1. The sample holder 4 includes a sample holder base 41, a substrate holder 44 for fixing a substrate, and an adjustment component for driving the substrate holder 44 to rotate between a horizontal growth position and an inclined liquid-lubricating position. The substrate holder 44 is connected to the sample holder base 41 through the adjustment component, and the sample holder base 41 is connected to the movable end of the transmission rod 1.

[0033] Furthermore, in order to achieve stirring of the mother liquor during the homogenization process, the vertical liquid phase epitaxial growth graphite fixture of this embodiment also includes a stirring seat. The sample holder 4 is placed inside the stirring seat, and the transmission rod 1 is connected to the stirring seat to drive the stirring seat to move up and down to stir the mother liquor.

[0034] Based on the vertical liquid phase epitaxial growth graphite fixture of this embodiment, this embodiment also provides a vertical liquid phase epitaxial growth apparatus, including the vertical liquid phase epitaxial growth graphite fixture of the above embodiment, and a growth container 6 for holding mother liquor; wherein the growth container 6 may be, but is not limited to, a crucible.

[0035] During liquid phase epitaxial growth, the mother liquor 7 is placed in the growth container 6. In this embodiment, the vertical liquid phase epitaxial growth graphite apparatus is positioned above the growth container 6. During the homogenization process of the mother liquor 7, the epitaxial furnace is heated to the homogenization temperature to fully melt the mother liquor 7. The transmission rod 1 drives the stirring seat to move up and down to fully stir the mother liquor 7. During this process, the sample holder 4 located inside the stirring seat is always positioned above the liquid surface of the mother liquor 7 (i.e., the sample holder 4 is not immersed in the mother liquor 7). During the epitaxial growth process, the transmission rod 1 positions the sample holder 4 in the mother liquor 7, and the adjustment component is used to deflect the substrate holder 44 to a horizontal growth position, thereby allowing the substrate on the substrate holder 44 to grow horizontally. Epitaxial growth begins in a horizontal position, ensuring that the epitaxial layers on the entire substrate grow at the same height in the mother liquor 7. This effectively avoids the problem of uneven epitaxial layer thickness and composition in the substrate placement direction caused by the epitaxial surface being in a vertical position during existing vertical liquid phase epitaxial growth processes, where the entire substrate comes into contact with mother liquor 7 at different heights and has different compositions. After epitaxial growth is completed, the sample holder 4 is detached from the mother liquor 7, and the substrate holder 44 is tilted to the inclined liquid-draining position using the adjustment component. This tilts the substrate, and the residual mother liquor on the substrate naturally separates from the substrate under the action of gravity, ensuring that there is no mother liquor residue on the surface of the epitaxial layer and improving the utilization rate of the epitaxial surface.

[0036] Preferably, the transmission rod 1 is made of carbon fiber material to improve its load-bearing and torsional mechanical properties; the sample holder 4 and the stirring seat are both made of high-purity graphite material.

[0037] To increase production capacity, the sample holder 4 can adopt a parallel multi-layer structure design, that is, multiple substrate holders 44 are designed, and the multiple substrate holders 44 are stacked and spaced apart from bottom to top. In this way, a single wheel can support the epitaxial growth of multiple substrates, thereby effectively improving the production capacity of epitaxial equipment.

[0038] In some embodiments, such as Figure 1As shown, the adjustment assembly includes a fixed limiting member 42 and a movable limiting member 43 arranged parallel to the axis of the transmission rod 1. That is, the fixed limiting member 42 and the movable limiting member 43 are arranged perpendicular to the sample holder base 41. The top of the fixed limiting member 42 is fixedly connected to the sample holder base 41. The side of the substrate holder 44 is rotatably connected to both the fixed limiting member 42 and the movable limiting member 43, and their rotation axes are parallel to the horizontal plane. By applying a force to the movable limiting member 43, the movable limiting member 43 moves relative to the fixed limiting member 42, thereby driving the substrate holder 44 to rotate, realizing the rotation of the substrate holder 44 between the horizontal growth position and the inclined dripping position.

[0039] Specifically, in this embodiment, the fixed limiting member 42 is a square frame structure formed by two fixed connecting rods and two horizontal connecting rods, and the movable limiting member 43 is a square frame structure formed by two movable connecting rods and two horizontal connecting rods. The two movable connecting rods of the movable limiting member 43 are arranged parallel to the two fixed connecting rods of the fixed limiting member 42, and the two horizontal connecting rods of the movable limiting member 43 are arranged parallel to the two horizontal connecting rods of the fixed limiting member 42. Two protruding cylinders are provided on each side of the substrate holder 44 as pivots. The two pivots on the same side are rotatably connected to the fixed connecting rods and movable connecting rods on the corresponding sides. When there are multiple substrate holders 44, the multiple substrate holders 44 are rotatably connected at equal intervals along the length direction of the fixed connecting rods and movable connecting rods on the corresponding sides through pivots.

[0040] To further optimize the above technical solution, an angle limiting structure can be designed for the sample holder 4 to ensure the deflection angle of the substrate holder 44. As a specific implementation, this embodiment achieves the limiting of the deflection angle of the substrate holder 44 by designing the relative positions and sizes of the fixed limiting member 42, the movable limiting member 43, the substrate holder 44, and the sample holder base 41. Specifically, when the substrate holder 44 is in the horizontal growth position, the top of the movable limiting member 43 abuts against the sample holder base 41, and / or the bottom of the movable limiting member 43 is flush with the bottom of the fixed limiting member 42, and there is a certain distance between the movable limiting member 43 and the fixed limiting member 42; when the substrate holder 44 is in the inclined drainage position, the movable limiting member 43 is in contact with the side of the fixed limiting member 42. Through this structural design, such as... Figure 2As shown, during the movement of the sample holder 4, when the top of the movable limiting member 43 touches the sample holder base 41, and / or when the bottom of the movable limiting member 43 is flush with the bottom of the fixed limiting member 42, the substrate holder 44 is in a horizontal state. In this state, the movable limiting member 43 is restricted by the sample holder base 41 and cannot continue to move upward, or the bottom of the movable limiting member 43 is flush with the bottom of the fixed limiting member 42, and the bottom of the stirring base 5 can no longer provide upward force for the movable limiting member 43 alone, thereby achieving the limitation of the deflection angle of the substrate holder 44; while the epitaxial After growth is complete, the sample holder 4 is lifted, and the movable limiting member 43 moves downward under its own gravity, simultaneously causing the substrate holder 44 to rotate and move closer to the fixed limiting member 42. When the movable limiting member 43 touches the fixed limiting member 42, the substrate holder 44 is tilted, and the movable limiting member 43 is restricted by the fixed limiting member 42 and cannot continue to move downward. In this embodiment, the deflection of the substrate holder 44 is limited by the structure of the sample holder 4 itself, eliminating the need to design an additional deflection limiting structure. This simplifies the graphite tooling structure and avoids the impact of additional structural design on epitaxial layer growth.

[0041] In an optimized implementation, to ensure the stability of the substrate on the substrate holder 44, especially when the substrate holder 44 is tilted, and to prevent the substrate from detaching from the substrate holder 44, it is preferable to design an assembly limiting structure for the substrate on the substrate holder 44. Specifically, an upper limit member and a lower limit member are respectively provided at both ends of the substrate holder 44 for limiting the substrate, and the upper surface of the lower limit member is not higher than the upper surface of the substrate. Preferably, the upper limit member and the lower limit member are respectively set at the upper and lower ends of the corresponding tilted draining position. The upper limit member can be, but is not limited to, a clamp, and the lower limit member can be, but is not limited to, a stepped structure. When the substrate holder 44 is tilted, the upper end of the substrate is pressed and clamped onto the substrate holder 44 by the clamp, while the lower step structure supports the substrate, thereby ensuring that the substrate does not undergo relative displacement relative to the substrate holder 44. The design that the upper surface of the lower limit member is not higher than the upper surface of the substrate ensures that when residual mother liquor is drained in the tilted state, no additional structure obstructs the mother liquor in the direction of gravity, ensuring zero residue of mother liquor.

[0042] In this embodiment, the substrate holder 44 adopts a square structure for growing square substrates. Of course, the substrate holder 44 can also support the growth of substrates of other shapes by modularly changing the fixtures and adjusting the design.

[0043] In this embodiment, the lower end of the transmission rod 1 is connected to the sample holder base 41 by screws, thereby driving the sample holder 4 to move up and down and rotate.

[0044] Regarding the specific structure of the stirring base, in some embodiments, such as Figure 1As shown, the stirring base includes a stirring base 5 and a stirring base 3. The stirring base 3 is detachably connected to one end of the stirring base 5 to facilitate the assembly of the sample holder 4 into the stirring base. Specifically, the stirring base 3 and the stirring base 5 are connected by screws. The sample holder 4 is placed inside the stirring base 5. The transmission rod 1 passes through the stirring base 3. The transmission rod 1 and the stirring base 3 are connected by a threaded rotation. Specifically, the lower part of the transmission rod 1 is provided with an external thread structure, and the stirring base 3 is provided with an internal thread structure that matches it. In this way, the connection and separation of the transmission rod 1 and the stirring base 3 can be controlled by rotating the transmission rod 1. During the homogenization process of mother liquor 7, the transmission rod 1 and the stirring base 3 are fixed together by a threaded connection. The up-and-down movement of the transmission rod 1 drives the stirring base to move up and down as a whole, thereby achieving full stirring of the mother liquor 7. During epitaxial growth, the transmission rod 1 is rotated to release the threaded connection between the transmission rod 1 and the stirring base 3. After that, the transmission rod 1 only drives the sample holder 4 to move, so that the sample holder 4 is immersed in the mother liquor 7. After the epitaxial growth is completed, the transmission rod 1 drives the sample holder 4 to detach from the mother liquor 7, and then continues to move so that the transmission rod 1 and the stirring base 3 are fixed together again by a threaded connection, which can then drive the stirring base to detach from the mother liquor 7.

[0045] In an optimized configuration, the stirring base 5 includes an annular sidewall and a base plate 53. The annular sidewall has a closed section 51 and a hollow section 52 in sequence along its axial direction. The stirring base 3 is connected to the end of the closed section 51, and the base plate 53 is connected to the end of the hollow section 52. During epitaxial growth, the hollow section 52 of the stirring base 5 is immersed in the mother liquor 7. The mother liquor 7 can enter the interior of the stirring base 5 to submerge all the substrate holders 44. The design of the closed section 51 can isolate the substrate holders 44 immersed in the mother liquor 7 from the outside, avoiding the influence of the external environment on epitaxial growth and further improving the quality of epitaxial growth. In this embodiment, the design of the bottom plate 53 on the stirring base 5 can, on the one hand, stir the mother liquor 7 up and down during the homogenization process, and on the other hand, provide power for the upward movement of the movable limiting member 43 of the sample holder 4 during the growth stage. When the lower end of the movable limiting member 43 of the sample holder 4 touches the bottom plate 53, the bottom plate 53 provides an upward support force to the movable limiting member 43, so that the movable limiting member 43 moves upward and realizes the horizontal deflection of the substrate holder 44. In this way, no additional power equipment and transmission structure need to be designed for the horizontal and tilting deflection movements of the substrate holder 44, saving the production cost of graphite tooling.

[0046] Furthermore, the vertical liquid phase epitaxial growth graphite fixture of this embodiment also includes a fixed cover 2 for connecting to the growth container 6 containing the mother liquor 7. The outer side of the stirring base and the inner side of the fixed cover 2 are slidably connected along the axial direction of the fixed cover 2. One end of the transmission rod 1 away from the sample holder 4 extends through the fixed cover 2. Specifically, the upper part of the fixed cover 2 is designed with a protruding outer edge for placement on the inner crucible. At the same time, several protruding ears are provided on the protruding outer edge to be embedded in the outer crucible groove to prevent the fixed cover 2 from rotating. The inner side wall of the fixed cover 2 is provided with several vertically arranged sliding grooves at intervals along its circumference. At the same time, the side wall of the stirring base 3 is provided with several sliders, which are slidably connected in the sliding grooves. This allows the stirring base to move up and down while preventing the stirring base 3 from rotating circumferentially due to the rotation of the transmission rod 1.

[0047] The following uses mercury cadmium telluride semiconductor thin film epitaxy as an example to illustrate the specific process of vertical liquid phase epitaxial growth in this embodiment:

[0048] S1. Epitaxial preparation: Select a substrate with appropriate composition and size, with a substrate thickness of 1mm, prepare a suitable volume of mother liquor, and select a mother liquor weight of 3kg to ensure that the mother liquor does not overflow the stirring base 5 during the homogenization heating stage, and that the mother liquor can overflow all substrate racks 44 during the growth stage; clean all components of the tooling.

[0049] S2. Assembly of epitaxial graphite tooling and substrate loading: The transmission rod 1 is fixed to the sample holder 4 by screws. The transmission rod 1 has its own thread and is connected to the stirring base 3. It can be joined and disassembled by the rotation of the transmission rod 1. The fixed cover 2 and the stirring base 3 are nested by a slider and a groove to prevent rotation.

[0050] Samples should be prepared in the following order:

[0051] S2.1. Mount the substrate onto the substrate holder 44;

[0052] S2.2, Install the substrate holder 44 onto the sample holder 4;

[0053] S2.3 Fix the transmission rod 1 to the sample holder 4, and tighten the transmission rod 1 to the stirring base 3 with threads;

[0054] S2.4. Fix the stirring base 5 to the stirring base 3 with screws;

[0055] S2.5. Insert the stirring base 3 into the fixing cover 2;

[0056] S2.6 Connect the transmission rod 1 to the transmission shaft on the epitaxial furnace body, and assemble it with the crucible containing the mother liquor 7. Then close the epitaxial furnace cavity.

[0057] S3. Homogenization of Mother Liquor: The epitaxial furnace is heated to the homogenization temperature to fully melt the mother liquor 7. The homogenization temperature is selected as 550℃. The transmission rod 1 drives the stirring seat to move up and down through the thread to fully stir the mother liquor 7. The range of up and down movement is between 5-65mm.

[0058] S4. Epitaxial Growth: After slow cooling to reach the growth temperature, the initial growth temperature is selected as 480℃. Before epitaxial growth, the sample holder 4 is loosened and separated from the stirring base 3 by rotating the transmission rod 1. Then the sample holder 3 descends, and the lower end of the stirring base 5 sinks into the mother liquor 7 by gravity. After the sample holder 4 is immersed in the mother liquor, the sample holder 4 is finally deflected to a horizontal angle by the buoyancy of the mother liquor 7 and the support force of the bottom plate 53 of the stirring base 5, and epitaxial growth begins. The growth temperature range is 10℃ and the growth time is 70min.

[0059] S5. End of growth: After reaching the end temperature, lift the sample rack 4. The sample rack 4 will tilt naturally under gravity to drain the residual mother liquor. Quickly cool the mother liquor. After the mother liquor cools to room temperature, weigh the mother liquor 7 after growth and add the same weight of mother liquor 7 to the mother liquor 7 to start the next round of growth.

[0060] Epitaxial wafers prepared using conventional vertical liquid phase epitaxial growth methods and epitaxial wafers prepared using the vertical liquid phase epitaxial growth method provided in this invention were examined under a microscope, and the results are as follows: Figure 3 and Figure 4 As shown, the epitaxial wafers prepared by the vertical liquid phase epitaxial growth method of the present invention have more uniform composition and thickness, thus improving the yield of epitaxial materials.

[0061] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A graphite jig for vertical liquid phase epitaxy growth, characterised in that: The sample holder comprises a sample holder base, a substrate holder for fixing a substrate, and an adjusting assembly for driving the substrate holder to rotate between a horizontal growth position and an inclined draining position, the substrate holder is connected to the sample holder base through the adjusting assembly, and the sample holder base is connected to a movable end of a transmission rod.

2. The vertical liquid phase epitaxy growth graphite fixture of claim 1, wherein: The substrate holder has a plurality of substrate holders which are arranged in a stacked manner from bottom to top.

3. The vertical liquid phase epitaxy growth graphite tooling of claim 1 or 2, wherein: The adjusting assembly comprises a fixed limiting piece and a movable limiting piece which are arranged parallel to the axis of the transmission rod, the top of the fixed limiting piece is fixedly connected to the sample holder base, and the side edges of the substrate holder are rotatably connected to the fixed limiting piece and the movable limiting piece, and the rotation axes thereof are parallel to the horizontal plane.

4. The vertical liquid phase epitaxy growth graphite fixture of claim 3, wherein: When the substrate holder is in the horizontal growth position, the top of the movable limiting piece abuts against the sample holder base, and / or the bottom of the movable limiting piece is flush with the bottom of the fixed limiting piece, and a certain spacing is provided between the movable limiting piece and the fixed limiting piece; when the substrate holder is in the inclined draining position, the movable limiting piece is in close contact with the fixed limiting piece.

5. The vertical liquid phase epitaxy growth graphite tooling of claim 1 or 2, wherein: The two ends of the substrate holder are respectively provided with upper and lower limiting pieces for limiting the substrate, and the upper surface of the lower limiting piece is not higher than the upper surface of the substrate.

6. The vertical liquid phase epitaxy growth graphite fixture of claim 1, wherein: The sample holder is arranged inside a stirring seat, and the transmission rod is in transmission connection with the stirring seat to drive the stirring seat to move up and down to stir the mother liquor.

7. The vertical liquid phase epitaxy growth graphite fixture of claim 6, wherein: The stirring seat comprises a stirring base and a stirring base, the stirring base is detachably connected to one end of the stirring base, the stirring base comprises a ring-shaped side wall and a bottom plate, the ring-shaped side wall has a closed section and a hollow section in sequence along the axis direction thereof, the stirring base is connected to the end of the closed section, and the bottom plate is connected to the end of the hollow section.

8. The vertical liquid phase epitaxy growth graphite fixture of claim 6, wherein: A fixing cover for connecting with a growth container containing the mother liquor is further provided, the outer side of the stirring seat is in sliding connection with the inner side of the fixing cover along the axis direction of the fixing cover, and the end of the transmission rod away from the sample holder penetrates out of the fixing cover.

9. A vertical liquid phase epitaxy growth apparatus, characterized by: The vertical liquid phase epitaxial growth graphite tooling comprises the vertical liquid phase epitaxial growth graphite tooling according to any one of claims 1-8, and a growth container for containing the mother liquor.

10. A method of vertical liquid phase epitaxial growth, characterized by: The vertical liquid phase epitaxial growth device according to claim 9 comprises the following process: During the epitaxial growth process, the sample holder is located in the mother liquor through the transmission rod, and the substrate holder is deflected to the horizontal growth position through the adjusting assembly, so that the substrate on the substrate holder is in a horizontal state to start the epitaxial growth; After the epitaxial growth is completed, the sample holder is separated from the mother liquor, and at the same time, the substrate holder is deflected to the inclined draining position through the adjusting assembly, so that the substrate is inclined to drain the residual mother liquor.

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