Sapphire crystal growth furnace and crystal growth method

Abstract

The application relates to the technical field of sapphire crystal growth, in particular to a sapphire crystal growth furnace and a crystal growth method. The sapphire crystal growth furnace comprises a seed rod, the seed rod is used for carrying a seed crystal to initiate crystallization, a furnace body, the inside of the furnace body is provided with a furnace chamber, the top of the furnace body is provided with a seed crystal channel allowing the seed rod to pass through, a heat preservation structure, the heat preservation structure is located in the furnace chamber, the heat preservation structure is in a barrel shape, the heat preservation structure comprises a heat preservation side wall and a heat preservation top wall, the heat preservation side wall and the heat preservation top wall are surrounded to form a heat preservation cavity used for heat preservation of crystal growth, a through hole penetrating through the heat preservation top wall is formed in the heat preservation top wall, the through hole and the seed crystal channel are located in the same vertical space, and a protection mechanism, the protection mechanism is arranged between the heat preservation structure and the furnace body, and the protection mechanism is used for preventing pollutants floating up the through hole from polluting the seed crystal; through the trigger cooperation of a trigger assembly and a support of the seed rod, the technical effect of improving the crystal growth quality is achieved.

Description

Technical Field

[0001] This application relates to the field of sapphire crystal growth technology, and in particular to a sapphire crystal growth furnace and a crystal growth method. Background Technology

[0002] The Kyropoulos method is currently the mainstream technology for preparing large-size, high-quality sapphire single crystals. Its core process is as follows: high-purity alumina raw material is added into the crucible in one go, and the raw material is completely melted into alumina melt through high temperature boiling. Then, the seed crystal is lowered to the surface of the melt through the central through hole of the heat preservation barrel by the seed crystal rod. After the crystal is introduced, the sapphire single crystal is grown by precise temperature control.

[0003] In existing conventional processes, contamination is an unavoidable problem during the boiling stage: during high-temperature boiling, trace amounts of alkali metals, silicon, iron, and other impurities in the alumina raw material, as well as trace amounts of volatiles generated by the crucible and hot zone components at high temperatures, continuously drift upwards under thermal convection. Since the central through-hole of the insulation tank is open, contaminants diffuse directly upwards and contaminate the seed crystals suspended above the through-hole. Contaminated seed crystals are prone to difficulties in crystal pulling and crystal pulling failures, and the grown sapphire crystals are prone to defects such as dislocations and inclusions, seriously affecting crystal quality and even causing the entire batch of crystals to be scrapped.

[0004] Therefore, the core technical problem of the existing technology is that pollutants in the boiling stage can easily contaminate the seed crystal, resulting in more growth defects in sapphire crystals and lower yield and crystal quality. Summary of the Invention

[0005] This application provides a sapphire crystal growth furnace and a crystal growth method, which achieves the technical effect of improving the quality of crystal growth by cooperating with the triggering component and the seed crystal rod.

[0006] On the one hand, the sapphire crystal growth furnace provided in this application adopts the following technical solution: A sapphire crystal growth furnace, comprising: Seed crystal rod, the seed crystal rod being used to carry the seed crystal tractor; The furnace body has a furnace chamber inside, and a seed crystal channel is provided on the top of the furnace body to allow the seed crystal rod to pass through; A heat-insulating structure is located within the furnace chamber. The heat-insulating structure is barrel-shaped and includes heat-insulating sidewalls and a heat-insulating top wall. The sidewalls and top wall enclose a heat-insulating cavity for crystal growth. A through-hole is formed in the top wall, penetrating through the top wall. The through-hole and the seed crystal channel are located in the same vertical space. A protective mechanism is disposed between the insulation structure and the furnace body. The protective mechanism is used to prevent contaminants floating upwards from the through-holes from contaminating the seed crystal. The protective mechanism includes: A protective plate is movably disposed on the top of the insulation structure and can be switched to a blocked state covering the through hole and an open state allowing the through hole to be opened. A triggering component is disposed between the seed crystal rod and the protective plate, the triggering component and the protective plate being movably connected, and the triggering component being at least partially supported by the seed crystal rod; when the seed crystal rod is in a suspended state, the triggering component is supported by the seed crystal rod, and the protective plate remains in the blocked state to cover the through hole; when the seed crystal rod descends, the supporting effect of the seed crystal rod on the triggering component is released, and the triggering component triggers the protective plate to move along a first direction under the action of gravity, so that the protective plate gradually switches from the blocked state to the open state.

[0007] Preferably, at least two rollers are provided on one side of the protective plate in the first direction, and the rollers are in rolling cooperation with the heat-insulating top wall.

[0008] Preferably, a positioning baffle is provided on the heat-insulating top wall. The positioning baffle is located at the movable end of the protective plate along the first direction and is used to limit the movement of the protective plate. When the protective plate moves to abut against the positioning baffle, the protective plate is fully switched to the open state.

[0009] Preferably, the seed crystal rod is provided with a raised support portion, and the triggering component includes: A collar is fitted onto the seed crystal rod and is located above the annular support portion. The support portion is used to support the collar, so that the collar is suspended above the insulation top wall, and the collar can move freely along the axial direction of the seed crystal rod. The trigger rod is a rigid rod-shaped structure. The first end of the trigger rod is rotatably connected to the collar, and the second end of the trigger rod is rotatably connected to the protective plate, so that the trigger assembly and the protective plate are movably connected.

[0010] Preferably, the protective plate has a connecting part located on the side of the protective plate in a first direction, and the second end of the trigger rod is rotatably connected to the connecting part.

[0011] Preferably, the protective plate includes a first plate, which is flat and has a first contact surface facing the insulation structure. The first contact surface is adapted to the surface of the insulation top wall and is used to cover the through hole during the cooking stage to prevent pollutants in the insulation cavity from drifting upward.

[0012] Preferably, the protective plate further includes a second plate located in the opposite direction to the first plate along the first direction, and the second plate is fixedly connected to the first plate; the second plate has a second guide surface facing the heat insulation structure, and the second guide surface forms a fixed included angle θmax with the heat insulation top wall; the second guide surface is used to obliquely guide the pollutants that drift upward at the through hole, so that the pollutants are discharged obliquely along the inclined surface and block the seed crystal.

[0013] Preferably, the protective plate further includes a third plate, which is disposed between the first plate and the second plate, and is integrally fixedly connected to the first plate and the second plate respectively. The third plate has a third flow guiding surface facing the insulation structure, and the third flow guiding surface forms an angle θ with the top wall of the insulation. The angle θ gradually increases to θmax in a linear or arc-shaped manner in the opposite direction to the first direction. The third flow guiding surface is used to gradually increase the open area of ​​the through hole with the movement of the protective plate, so as to allow the gradient depressurization of the micro-positive pressure atmosphere in the insulation cavity.

[0014] On the other hand, the crystal growth method of the sapphire crystal growth furnace provided in this application adopts the following technical solution: A crystal growth method for a sapphire crystal growth furnace, comprising: High-purity alumina and other crystal growth raw materials are loaded into the crucible inside the furnace chamber; Insert the seed crystal rod into the seed crystal channel of the furnace body and keep the seed crystal rod in a suspended state. At this time, the seed crystal is suspended above the through hole. The trigger component is supported by the support on the seed crystal rod, causing the protective plate to move to the blocking state, so that the first plate of the protective plate completely covers and seals the through hole on the heat-insulating top wall; then the cooking process is started to melt the raw materials in the crucible at high temperature to form alumina melt; After the cooking process is completed, the seed crystal rod is controlled to move downward along its axis. The supporting effect of the seed crystal rod on the trigger component is released. Under its own force, the trigger component drives the protective plate to move in the first direction, causing the protective plate to disengage from the through hole, and the through hole gradually opens. The seed crystal rod continues to move downwards, passing through the through hole into the crucible inside the heat preservation cavity, carrying the seed crystal into contact with the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operations.

[0015] A crystal growth method for a sapphire crystal growth furnace, comprising: High-purity alumina and other crystal growth raw materials are loaded into the crucible inside the furnace chamber; Insert the seed crystal rod into the seed crystal channel of the furnace body and keep the seed crystal rod in a suspended state. At this time, the seed crystal is suspended above the through hole. The trigger component is supported by the support part on the seed crystal rod, causing the protective plate to move to the blocking state, so that the first plate of the protective plate completely covers and seals the through hole on the heat preservation top wall; then the cooking process is started, the raw materials in the crucible are melted at high temperature to form alumina melt, and the contaminants generated during the cooking process are blocked by the first plate and cannot contaminate the seed crystal upward. After the cooking process is completed, the seed crystal rod moves downward along its axis, the supporting effect of the seed crystal rod on the trigger component is released, and the trigger component drives the protective plate to slide along the first direction under its own force. As the protective plate continues to slide, the first plate gradually detaches from the through hole, and the third plate moves above the through hole. The angle θ between the third guide surface and the top wall of the insulation gradually increases to θmax in the opposite direction to the first direction. The open area of ​​the through hole gradually increases simultaneously, realizing the gradient decompression of the micro-positive pressure atmosphere in the insulation cavity. The stable and continuous airflow carries the pollutants trapped in the corners and crevices of the insulation cavity, such as the inner wall and thermal field gaps, and gradually discharges them obliquely along the third guide surface. As the seed crystal rod continues to move downward, it triggers the component to drive the protective plate to slide further, causing the second plate to move above the through hole. The second guide surface continuously guides the subsequent drifting contaminants at an angle, while blocking the contaminants from directly hitting the seed crystal. The seed crystal rod continues to move downwards, passing through the through hole into the crucible inside the heat preservation cavity, carrying the seed crystal into contact with the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operations.

[0016] In summary, this application includes at least one of the following beneficial technical effects: By coordinating the triggering component with the seed crystal rod, the through holes in the insulation top wall are automatically sealed and opened during the boiling and crystal pulling processes, without the need for additional driving components or manual intervention. This perfectly matches the process sequence of sapphire crystal growth using the Czochralski method. The triggering component drives the protective plate to move under its own gravity, while the seed crystal rod only serves to support and release the support. This method of directly driving the protective plate without the seed crystal rod effectively reduces the load on the seed crystal rod and avoids problems such as motion jamming and excessive load caused by seed crystal rod driving, thus improving the reliability and stability of the entire equipment. At the same time, the state switching of the protective plate and the lifting and lowering of the seed crystal rod are precisely synchronized, ensuring that the through holes are tightly sealed during the boiling stage and gradually opened during the crystal pulling stage, meeting the working conditions required for crystal growth. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the protective plate of the sapphire crystal growth furnace described in this application sealing the through holes; Figure 2 This is a schematic diagram showing the opening of the through-hole in the protective plate of the sapphire crystal growth furnace described in this application; Figure 3 This is a schematic diagram of crystal pulling when the protective plate of the sapphire crystal growth furnace described in this application opens the through hole; Figure 4 This is a schematic diagram of the protective plate and triggering mechanism of the sapphire crystal growth furnace described in this application; Figure 5 This is a schematic diagram of the triggering mechanism of the sapphire crystal growth furnace described in this application; Figure 6 This is a schematic diagram of the first and second plates in the protective plate of the sapphire crystal growth furnace described in this application; Figure 7 This is a schematic diagram of the first plate sealing the through-hole in one embodiment of the sapphire crystal growth furnace described in this application; Figure 8 This is a schematic diagram showing the second plate opening the through hole in one embodiment of the sapphire crystal growth furnace described in this application; Figure 9 This is a schematic diagram showing the first and second plates opening the through holes in one embodiment of the sapphire crystal growth furnace described in this application; Figure 10 This is a schematic diagram of crystal pulling when the first and second plates open the through-holes in one embodiment of the sapphire crystal growth furnace described in this application; Figure 11 This is a schematic diagram of the first plate, the second plate, and the third plate in the protective plate of the sapphire crystal growth furnace described in this application; Figure 12 This is a schematic diagram of the first plate sealing the through hole in another embodiment of the sapphire crystal growth furnace described in this application; Figure 13 This is a schematic diagram showing the third plate of the sapphire crystal growth furnace described in this application opening the through-hole; Figure 14 This is a schematic diagram of the second plate opening the through hole in another embodiment of the sapphire crystal growth furnace described in this application; Figure 15 This is a schematic diagram of the sapphire crystal growth furnace described in this application, showing the first, second, and third plates opening the through-holes before crystal extraction is about to begin. Figure 16 This is a schematic diagram of crystal pulling when the first, second, and third plates open the through holes in one embodiment of the sapphire crystal growth furnace described in this application; Figure 17 This is the first crystal growth method of the sapphire crystal growth furnace described in this application; Figure 18 This is the second crystal growth method for the sapphire crystal growth furnace described in this application.

[0018] Explanation of reference numerals in the attached drawings: 100, seed crystal rod; 110, seed crystal; 120, support part; 200, furnace body; 210, furnace chamber; 220, seed crystal channel; 300, insulation structure; 310, insulation side wall; 320, insulation top wall; 330, insulation cavity; 340, through hole; 350, roller; 360, positioning baffle; 400, protective mechanism; 410, protective plate; 411, first plate; 4111, first mating surface; 412, second plate; 4121, second guide surface; 413, third plate; 4131, third guide surface; 414, connecting part; 420, trigger assembly; 421, collar; 422, trigger rod; 500, crucible; 600, heater. Detailed Implementation

[0019] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used solely for the convenience of describing this application and simplifying the description. They 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, and therefore should not be construed as a limitation of this application.

[0020] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] To better understand the above technical solutions, a detailed description of the technical solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application.

[0022] During the boiling process, trace amounts of alkali metals, silicon, iron, and other impurities in the alumina raw material, as well as trace amounts of volatiles generated by the crucible 500 and the thermal insulation components at high temperatures, will continuously drift upwards under the influence of thermal convection within the furnace. Since the central through-hole 340 of the insulation tank is a reserved channel for the lifting and lowering of the seed crystal 110, it is normally open. Therefore, the aforementioned contaminants will directly diffuse upwards through the through-hole 340, suspending above the seed crystal 110.

[0023] Contaminated seed crystals 110 are prone to problems such as difficulty in crystal pulling and crystal pulling failure. The grown sapphire crystals are prone to defects such as dislocations and inclusions, which seriously affect the crystal quality and may even cause the entire batch of crystals to be scrapped. To solve the above problems, existing technologies mostly use fixed cover plates to block the through-holes 340 or simply optimize the airflow direction, which can only achieve two states of switching between completely closed and completely open through-holes 340. Such solutions have obvious drawbacks: on the one hand, the instantaneous complete opening of through-holes 340 will cause a sudden drop in pressure inside the insulation tank and a rapid decrease in airflow power inside the furnace, making it difficult to fully remove contaminants trapped in the corners of the insulation tank, the gaps in the hot zone, and other nooks and crannies, and there is still a risk of hidden contamination; on the other hand, contaminants have no directional flow structure and can easily rush directly to the seed crystal 110 after the through-holes 340 are opened, resulting in limited contamination control.

[0024] To address the above technical problems, this application proposes a sapphire crystal growth furnace, such as... Figure 1-3 As shown, the system includes a seed crystal rod 100, a furnace body 200, a heat insulation structure 300, and a protective mechanism 400. These components work together to achieve sapphire crystal growth and contamination control of the seed crystal 110. It should be noted that the heat insulation structure 300 contains a crucible 500 and a heater 600. The crucible 500 is used to hold the sapphire raw material, and the heater 600 is used to heat the raw material within the crucible 500. The seed crystal rod 100 passes through the furnace body 200 and the heat insulation structure 300 to enter the crucible 500 for crystal point formation. The molten sapphire raw material begins to grow on the seed crystal 110 of the seed crystal rod 100.

[0025] Specifically, the seed crystal rod 100 is used to carry the seed crystal 110 along its axial direction for vertical movement (generally referring to descent; in the Czochralski method, the seed crystal rod 100 does not require upward lifting), achieving contact crystal introduction and crystal growth between the seed crystal 110 and the alumina melt. Simultaneously, the seed crystal rod 100 also serves to support the trigger assembly 420. The seed crystal rod 100 is provided with a protruding support portion 120 to support the trigger assembly 420, thereby enabling the state switching of the protective plate 410.

[0026] The top of the furnace body 200 is provided with a seed crystal channel 220 that allows the seed crystal rod 100 to pass through. The seed crystal channel 220 extends through the top of the furnace body 200. The inner diameter of the seed crystal channel 220 is slightly larger than the outer diameter of the seed crystal rod 100, ensuring that the seed crystal rod 100 can move smoothly along its axial direction. At the same time, it ensures the airtightness of the furnace chamber 210, preventing the leakage of the inert atmosphere inside the furnace chamber 210 and the entry of outside air into the furnace chamber 210, which would affect crystal growth. The seed crystal channel 220 and the through hole 340 of the insulation structure 300 are located in the same vertical space, which can ensure that when the seed crystal rod 100 carries the seed crystal 110 down, it can smoothly pass through the seed crystal channel 220 and the through hole 340, accurately reach the surface of the alumina melt in the crucible 500, and complete the crystal pulling operation. This avoids the seed crystal 110 from failing to contact the melt properly due to positional deviation, or from colliding with the edge of the through hole 340 and causing damage to the seed crystal 110.

[0027] The insulation structure 300 is located inside the furnace chamber 210 and is arranged in a barrel shape. The insulation structure 300 is used to provide a stable insulation environment for crystal growth, maintain the temperature gradient inside the furnace chamber 210, ensure that the alumina melt can exist stably, and provide suitable temperature conditions for the growth of sapphire single crystals. The insulation structure 300 includes an insulation side wall 310 and an insulation top wall 320. The insulation side wall 310 and the insulation top wall 320 are integrally formed or fixedly connected by high-temperature resistant connectors. The two enclose the insulation cavity 330 for crystal growth insulation. The interior of the insulation cavity 330 is used to place the crucible 500, which contains high-purity alumina raw materials and molten alumina melt.

[0028] Both the insulated sidewall 310 and the insulated top wall 320 are made of high-temperature resistant materials with excellent thermal insulation performance, preferably carbon fiber composite insulation material or zirconium oxide insulation material. This effectively reduces heat loss within the insulated cavity 330, maintains the high-temperature environment within the cavity, and prevents the material from generating volatiles at high temperatures that could contaminate the alumina melt and the seed crystal 110. The insulated top wall 320 has a through-hole 340. The inner diameter of the through-hole 340 matches the outer diameter of the seed crystal rod 100, allowing the seed crystal rod 100 to carry the seed crystal 110 through. The through-hole 340 and the seed crystal channel 220 of the furnace body 200 are located in the same vertical space, ensuring smooth lifting and lowering of the seed crystal rod 100 without obstruction by the through-hole 340.

[0029] like Figure 1-3As shown, the protective mechanism 400 is located between the insulation structure 300 and the furnace body 200. The protective mechanism 400 prevents contaminants floating on the through-hole 340 from contaminating the seed crystal 110, ensuring the cleanliness of the seed crystal 110 and thus improving the growth quality of the sapphire crystal. The protective mechanism 400 includes two core parts: a protective plate 410 and a trigger component 420. These two parts cooperate to achieve the switching of the protective plate 410's state. The protective plate 410 is movably located on the top of the insulation structure 300, specifically on the upper surface of the insulation top wall 320. It can move along the insulation top wall 320, switching between a blocked state covering the through-hole 340 and an open state allowing the through-hole 340 to be open. The protective plate 410 is made of high-temperature oxidation-resistant and creep-resistant metal alloys or high-temperature ceramic materials, preferably molybdenum alloys or zirconia ceramics. This allows it to adapt to the high-temperature environment above the insulation top wall 320, preventing deformation, oxidation, or sintering at high temperatures, ensuring smooth movement and a long service life for the protective plate 410.

[0030] The protective plate 410 moves in the first direction, which is a horizontal direction parallel to the insulation top wall 320. The movement of the protective plate 410 along the first direction can achieve the sealing and opening of the through hole 340: when the protective plate 410 covers the through hole 340 and is in a sealed state, the protective plate 410 moves along the first direction, gradually moving away from the through hole 340, and finally opening the through hole 340. The size of the protective plate 410 is larger than the size of the through hole 340, ensuring that it can completely cover the through hole 340 when it is in a sealed state, blocking the upward drift of pollutants in the insulation cavity 330 and preventing pollutants from leaking through gaps.

[0031] The trigger component 420 is disposed between the seed crystal rod 100 and the protective plate 410. The trigger component 420 is used to convert the lifting action of the seed crystal rod 100 into the moving action of the protective plate 410, thereby realizing the automatic state switching of the protective plate 410. The trigger component 420 and the protective plate 410 are movably connected, and the trigger component 420 is at least partially supported on the seed crystal rod 100. This support and cooperation is different from the method in the prior art where the seed crystal rod 100 directly drives the protective plate 410, which can effectively reduce the load on the seed crystal rod 100 and improve the operational reliability of the protective mechanism 400.

[0032] The working state of the trigger component 420 corresponds to the lifting and lowering state of the seed crystal rod 100. When the seed crystal rod 100 is in a suspended state, it remains stationary. At this time, the trigger component 420 is supported by the seed crystal rod 100 and is in a state of force balance. This, in turn, causes the protective plate 410 to remain in a blocked state, completely covering the through hole 340 and blocking the upward drift of contaminants in the insulation cavity 330. At this time, the seed crystal 110 is suspended above the through hole 340 and will not... Contaminated by pollutants; when the seed crystal rod 100 descends, it moves downward along its axis, releasing its supporting effect on the trigger component 420. The trigger component 420 moves downward under its own gravity, thereby triggering the protective plate 410 to move along the first direction, gradually switching the protective plate 410 from a blocked state to an open state. As the protective plate 410 moves, the through hole 340 gradually opens, allowing the seed crystal rod 100 to carry the seed crystal 110 through, completing the crystal pulling operation.

[0033] It is understandable that the driving force of the trigger component 420 comes from its own gravity, rather than the driving force of the seed crystal rod 100. The seed crystal rod 100 only plays the role of supporting and releasing the support, which can effectively avoid the problem of increased load caused by the seed crystal rod 100 directly driving the protective plate 410. At the same time, it ensures that the state switching of the protective plate 410 is synchronized with the lifting and lowering action of the seed crystal rod 100, fully adapting to the process sequence of boiling and crystal pulling, and improving the operational stability and reliability of the entire equipment.

[0034] Furthermore, such as Figure 4 As shown, rollers 350 are added to the protective plate 410 to reduce the frictional resistance when the protective plate 410 moves, ensuring that the protective plate 410 can move smoothly under high temperature conditions. Specifically, at least two rollers 350 are provided on one side of the protective plate 410 in the first direction. The number of rollers 350 is preferably two, symmetrically arranged on the side of the protective plate 410 to ensure that the protective plate 410 is evenly stressed and will not deviate during movement. The rollers 350 are made of high temperature resistant and wear-resistant ceramic materials or metal alloys, preferably zirconia ceramic rollers 350, which can adapt to the high temperature environment above the insulation top wall 320 and avoid wear, deformation or sintering under high temperature. The roller 350 rolls in contact with the insulation top wall 320, that is, the bottom of the roller 350 contacts the upper surface of the insulation top wall 320. When the protective plate 410 moves in the first direction, the roller 350 rolls on the insulation top wall 320, converting the sliding friction between the protective plate 410 and the insulation top wall 320 into rolling friction, which greatly reduces the frictional resistance when the protective plate 410 moves.

[0035] Furthermore, such as Figure 1-3As shown, a positioning baffle 360 ​​is added to the insulation structure 300 to limit the travel of the protective plate 410, ensuring that the protective plate 410 can accurately switch to the open state. Specifically, a positioning baffle 360 ​​is provided on the insulation top wall 320. The positioning baffle 360 ​​is located at the end of the protective plate 410's movement along the first direction, that is, when the protective plate 410 moves to its maximum travel along the first direction, it will abut against the positioning baffle 360. The positioning baffle 360 ​​and the insulation top wall 320 are integrally formed, or are fixedly connected to the insulation top wall 320 through high-temperature resistant connectors. The material of the positioning baffle 360 ​​is the same as that of the insulation top wall 320 to ensure that it can adapt to high-temperature environments and avoid deformation or detachment under high temperatures. When the protective plate 410 moves to contact the positioning baffle 360, the protective plate 410 stops moving. At this time, the protective plate 410 is fully switched to the open state, and the through hole 340 is opened to the maximum extent. Its open area can ensure that the seed crystal rod 100 carrying the seed crystal 110 can pass through smoothly without being blocked by the edge of the through hole 340. At the same time, it can also ensure that the seed crystal 110 can accurately reach the surface of the alumina melt in the crucible 500 during the crystal pulling process. The positioning baffle 360 ​​can also play a positioning role, ensuring that the protective plate 410 reaches the same position every time it is opened, ensuring that the open area of ​​the through hole 340 is consistent, thereby ensuring the stability of the airflow in the furnace and avoiding airflow turbulence caused by inconsistent open areas of the through hole 340, which would affect the growth quality of the sapphire crystal.

[0036] Furthermore, such as Figure 5 As shown, a support portion 120 is provided on the seed crystal rod 100, and the triggering component 420 realizes the activation of the protective plate 410 by cooperating with the seed crystal rod 100 and the support portion 120. Specifically, the seed crystal rod 100 is provided with a protruding support portion 120. The support portion 120 is a ring structure or a point structure. The support portion 120 and the seed crystal rod 100 are integrally formed, or fixed to the seed crystal rod 100 by welding, threaded connection or other means. The material of the support portion 120 is the same as that of the seed crystal rod 100 to ensure that it has good high temperature resistance and creep resistance, and can stably support the trigger component 420. The outer diameter of the support portion 120 is larger than the outer diameter of the seed crystal rod 100 to ensure that the collar 421 can be stably supported on the ring support portion 120 without displacement or falling off. The upper surface of the support portion 120 is flat and can fit tightly with the lower surface of the collar 421 to ensure the stability of the support and prevent the collar 421 from shaking during the support process, thereby affecting the sealing state of the protective plate 410.

[0037] like Figure 1-3As shown in Figure 5, the trigger assembly 420 includes a collar 421 and a trigger rod 422. The collar 421 and the trigger rod 422 cooperate to connect the trigger assembly 420 with the seed crystal rod 100 and the protective plate 410, and to trigger the movement of the protective plate 410. The collar 421 is sleeved on the seed crystal rod 100 and is located above the annular support portion 120. The inner diameter of the collar 421 is slightly larger than the outer diameter of the seed crystal rod 100 to ensure that the collar 421 can move freely along the axial direction of the seed crystal rod 100 without jamming. The collar 421 is made of a high-temperature oxidation-resistant and creep-resistant metal alloy, preferably a molybdenum alloy or a tungsten-rhenium alloy, which can adapt to the high-temperature environment inside the furnace chamber 210 and avoid deformation, oxidation, or sintering at high temperatures. It should be noted that the dimensions of the seed crystal channel 220 and the through hole 340 need to be suitable for the collar 421 and the support portion 120 to pass through. The collar 421 is supported on the annular support portion 120. When the seed crystal rod 100 is in a suspended state, the collar 421 is supported by the annular support portion 120 and is in a suspended state. At this time, the collar 421 drives the protective plate 410 to maintain a blocked state through the trigger rod 422. When the seed crystal rod 100 descends, the annular support portion 120 moves downward with the seed crystal rod 100. The collar 421 loses the supporting function of the annular support portion 120 and moves downward along the axial direction of the seed crystal rod 100 under its own gravity. Then, through the trigger rod 422, it drives the protective plate 410 to move in the first direction, thereby realizing the opening of the protective plate 410.

[0038] like Figure 1-5 As shown, the trigger rod 422 is a rigid rod-shaped structure made of a high-temperature oxidation-resistant and creep-resistant metal alloy, preferably a molybdenum alloy, to ensure sufficient rigidity and strength to withstand the forces exerted by the trigger assembly 420 and the protective plate 410, preventing bending, deformation, or breakage at high temperatures. The length of the trigger rod 422 is adapted to the positions of the protective plate 410 and the collar 421, ensuring effective connection between the collar 421 and the protective plate 410 without affecting the movement of the protective plate 410 or the raising and lowering of the seed crystal rod 100.

[0039] like Figure 1-3As shown in Figure 5, the first end of the trigger rod 422 is rotatably connected to the collar 421, and the second end of the trigger rod 422 is rotatably connected to the protective plate 410. In this way, the rotatable connection ensures that the up-and-down movement of the collar 421 can be converted into the horizontal movement of the protective plate 410, realizing the transmission of force and the change of direction. Specifically, when the collar 421 moves downward under its own gravity, the first end of the trigger rod 422 rotates downward with the collar 421, thereby driving the second end of the trigger rod 422 to push the protective plate 410 to move in the first direction, so that the protective plate 410 switches from the blocked state to the open state. When the seed crystal rod 100 rises and resets, the annular support part 120 pushes the collar 421 to move upward, and the first end of the trigger rod 422 rotates upward with the collar 421, thereby driving the second end of the trigger rod 422 to pull the protective plate 410 to move in the opposite direction in the first direction, so that the protective plate 410 resets to the blocked state. The trigger rod 422 is preferably hinged to the collar 421 and the protective plate 410. The rotation is achieved through the hinge shaft, which ensures smooth rotation and avoids jamming. At the same time, it can withstand a certain impact force and improve the operational reliability of the trigger assembly 420.

[0040] Furthermore, such as Figure 4 As shown, the protective plate 410 has a connecting part 414, which ensures a stable and smooth rotational connection between the trigger rod 422 and the protective plate 410. The connecting part 414 is located on the side of the protective plate 410 in the first direction, and is integrally formed with the protective plate 410. The material is the same as that of the protective plate 410, ensuring that it has good high temperature resistance and creep resistance, and can stably connect the trigger rod 422. The connecting part 414 is preferably a lug structure, which protrudes outward from the protective plate 410. The lug has a through hole 340 for the hinge shaft to pass through, which facilitates the rotational connection between the second end of the trigger rod 422 and the connecting part 414. The second end of the trigger rod 422 is rotatably connected to the connecting part 414. Specifically, a hinge shaft passes through the through hole 340 of the connecting part 414 and the second end of the trigger rod 422 to achieve hinge connection. This connection method ensures smooth rotation between the trigger rod 422 and the protective plate 410, avoiding jamming, and can withstand the force transmitted by the trigger rod 422, preventing the connecting part 414 from breaking or being damaged. In addition, the connecting part 414 also prevents the trigger rod 422 from being directly connected to the main body of the protective plate 410, reducing stress concentration on the main body of the protective plate 410 and extending the service life of the protective plate 410.

[0041] In one embodiment, such as Figure 1-3As shown, the protective plate 410 includes a first plate 411, which has a flat plate structure and is made of high-temperature resistant, oxidation-resistant, and creep-resistant metal alloy or high-temperature ceramic material, possessing excellent high-temperature resistance and sealing performance. The size of the first plate 411 is larger than the size of the through hole 340 on the insulation top wall 320, ensuring that in the sealed state, the first plate 411 can completely cover the through hole 340, blocking the upward drift path of pollutants in the insulation cavity 330. The first plate 411 has a first bonding surface 4111 facing the insulation structure 300. The first bonding surface 4111 is flat and is adapted to the surface of the insulation top wall 320. That is, the flatness of the first bonding surface 4111 is consistent with the flatness of the insulation top wall 320. This ensures that when the first plate 411 covers the through hole 340, the first bonding surface 4111 can be tightly bonded to the upper surface of the insulation top wall 320 to achieve a seal and prevent pollutants from leaking from the gap between the first plate 411 and the insulation top wall 320, thereby contaminating the seed crystal 110.

[0042] During the boiling stage, the seed crystal rod 100 is in a suspended state, and the trigger component 420 is supported by the seed crystal rod 100, which drives the protective plate 410 to remain in a sealed state. At this time, the first contact surface 4111 of the first plate 411 is tightly attached to the heat insulation top wall 320, completely covering the through hole 340. The contaminants in the heat insulation cavity 330 are blocked by the first plate 411 and cannot drift upward, thus preventing the seed crystal 110 from being contaminated. The flat plate structure and sealed contact design of the first plate 411 can ensure the reliability of the sealing effect, providing a strong guarantee for the cleanliness of the seed crystal 110 during the boiling stage, thereby improving the success rate of subsequent crystal introduction and the quality of crystal growth.

[0043] In another embodiment, such as Figure 6-10 As shown, based on the first plate 411, the protective plate 410 also includes a second plate 412. The second plate 412 is located in the opposite direction to the first plate 411 along the first direction, and the second plate 412 is fixedly connected to the first plate 411, or is an integrally formed structure, to ensure a firm connection between the two and prevent detachment or separation at high temperatures. The material is the same as that of the protective plate 410, and is a high-temperature resistant, anti-oxidation, and anti-creep metal alloy or high-temperature ceramic material. The second plate 412 has a second guide surface facing the insulation structure 300. The second guide surface is an inclined plane, forming a fixed angle θmax with the insulation top wall 320. The value of θmax ranges from 25° to 45°. The setting of the second plate 412 can also continuously guide and block contaminants after the through hole 340 is fully open, ensuring the cleanliness of the seed crystal 110 during the crystal pulling process.

[0044] In other embodiments, such as Figure 11-16As shown, based on the first plate 411 and the second plate 412, a third plate 413 structure is added to the protective plate 410. The core function of the third plate 413 is to achieve the gradual opening of the through hole 340 and the gradient pressure relief within the insulation cavity 330, ensuring that pollutants in dead corners are fully discharged. The protective plate 410 also includes the third plate 413, which is disposed between the first plate 411 and the second plate 412. The third plate 413 is integrally fixedly connected to the first plate 411 and the second plate 412, forming an integrated protective plate 410 structure. This ensures a firm connection between the three and prevents detachment or separation at high temperatures. The material is the same as that of the protective plate 410, using a high-temperature oxidation-resistant and creep-resistant metal alloy or high-temperature ceramic material. The integrated protective plate 410 structure can improve the overall rigidity and stability of the protective plate 410, while also facilitating processing and manufacturing, and reducing production costs.

[0045] The third plate 413 has a third guide surface facing the insulation structure 300. The third guide surface is an inclined plane and forms an angle θ with the insulation top wall 320. The angle θ gradually increases to θmax in a linear or arc-shaped manner in the opposite direction to the first direction. The initial value of θ is in the range of 5° to 15°. The gradually increasing angle design allows for a gradual increase in the open area of ​​the through-hole 340, thereby achieving a gradient decompression of the slightly positive pressure atmosphere within the insulation cavity 330. During the cooking stage, the insulation cavity 330 is under a slightly positive pressure inert atmosphere (usually argon). If the through-hole 340 is suddenly fully opened, the pressure inside the insulation cavity 330 will drop sharply, and the airflow will rapidly decrease. It can only carry away contaminants near the through-hole 340, while contaminants trapped in the inner wall of the insulation cavity 330, the gaps in the thermal field, and other nooks and crannies cannot be carried away, still posing a risk of hidden contamination. The gradually increasing angle design of the third plate 413 allows the open area of ​​the through-hole 340 to gradually increase with the movement of the protective plate 410, thereby achieving a gradient decompression of the slightly positive pressure atmosphere within the insulation cavity 330 and preventing a sudden pressure drop.

[0046] Specifically, when the seed crystal rod 100 descends and the trigger component 420 drives the protective plate 410 to move along the first direction, the first plate 411 gradually disengages from the through hole 340, and the third plate 413 gradually moves above the through hole 340. As the protective plate 410 continues to move, the angle θ between the third guide surface and the insulation top wall 320 gradually increases in the opposite direction to the first direction. The area of ​​the through hole 340 covered by the third plate 413 gradually decreases, and the open area of ​​the through hole 340 gradually increases. The slightly positive pressure atmosphere in the insulation cavity 330 slowly depressurizes, forming a stable and continuous airflow. The stable and continuous airflow can penetrate deep into the dead corner area of ​​the insulation cavity 330, effectively carrying away the pollutants trapped in the corners and crevices of the insulation cavity 330, such as the inner wall and thermal field gaps, and fully removing them, thus achieving pollution control without dead corners throughout the entire process.

[0047] Meanwhile, the inclined design of the third guide surface can also guide the contaminants at an angle, preventing them from directly impacting the seed crystal 110 and further improving the cleanliness of the seed crystal 110. The gradient angle of the third plate 413 can be either linear or arc-shaped: linear gradient is simple in structure and easy to process; arc-shaped gradient makes the change in the open area of ​​the through hole 340 smoother and the gradient pressure relief effect more stable, and can be selected according to the actual working conditions.

[0048] Furthermore, this application also provides a crystal growth method for a sapphire furnace, such as... Figure 17 As shown, it includes: S11: Fill the crucible 500 in the furnace chamber 210 with crystal growth raw materials such as high-purity alumina; S12: Insert the seed crystal rod 100 into the seed crystal channel 220 of the furnace body 200 and keep the seed crystal rod 100 in a suspended state. At this time, the seed crystal 110 is suspended above the through hole 340. In other words, the seed crystal rod 100 is inserted into the seed crystal channel 220 of the furnace body 200 and kept suspended. At this time, the seed crystal 110 is suspended above the through hole 340. The seed crystal rod 100 is inserted into the seed crystal channel 220 at the top of the furnace body 200, and the lower end of the seed crystal rod 100 is fixed with the seed crystal 110. The position of the seed crystal rod 100 is adjusted so that it is kept suspended. At this time, the seed crystal 110 is suspended above the through hole 340 of the insulation top wall 320, maintaining a certain distance from the through hole 340 to avoid collision between the seed crystal 110 and the edge of the through hole 340, while ensuring that the seed crystal 110 is in a position where contaminants cannot come into contact with it. At this time, the annular support part 120 on the seed crystal rod 100 is below the collar 421, and the collar 421 is supported by the annular support part 120 and is in a suspended state. S13: The trigger component 420 is supported by the support part 120 on the seed crystal rod 100, causing the protective plate 410 to move to the blocking state, so that the first plate 411 of the protective plate 410 completely covers and seals the through hole 340 on the heat-insulating top wall 320; then the cooking process is started to melt the raw materials in the crucible 500 at high temperature to form alumina melt. The trigger component 420 is supported by the support part 120 on the seed crystal rod 100, causing the protective plate 410 to move to the blocking state, so that the first plate 411 of the protective plate 410 completely covers and seals the through hole 340 on the heat-insulating top wall 320; then the cooking process is started to melt the raw materials in the crucible 500 at high temperature to form alumina melt. As the collar 421 is supported by the annular support part 120, the collar 421 drives the protective plate 410 to move in the opposite direction in the first direction through the trigger rod 422, so that the first plate 411 of the protective plate 410 completely covers the through hole 340. The first contact surface 4111 of the first plate 411 is tightly attached to the heat insulation top wall 320 to achieve sealing and block the path of pollutants floating upward in the heat insulation cavity 330. After the cooking process is started, the heater 600 in the furnace chamber 210 starts to work, raising the temperature in the furnace chamber 210 to the melting point of alumina (about 2045°C). The high-purity alumina raw material in the crucible 500 gradually melts into alumina melt at high temperature. During the cooking process, trace amounts of alkali metals, silicon, iron, and other impurities in the alumina raw material, as well as trace amounts of volatiles generated by the crucible 500 and hot zone components at high temperatures, will continuously drift upwards under the action of thermal convection in the furnace. However, due to the sealing of the first plate 411, these contaminants are blocked in the heat preservation cavity 330 and cannot drift upwards. The contaminants are suspended above the through hole 340 in the seed crystal 110, ensuring the cleanliness of the seed crystal 110.

[0049] S14: After the cooking is completed, the seed crystal rod 100 is controlled to move downward along its axis. The supporting effect of the seed crystal rod 100 on the trigger component 420 is released. The trigger component 420 drives the protective plate 410 to move along the first direction under its own force, so that the protective plate 410 is disengaged from the through hole 340 and the through hole 340 is gradually opened. Specifically, after the boiling process is completed, the seed crystal rod 100 is controlled to move downward along its axial direction. The supporting effect of the seed crystal rod 100 on the trigger component 420 is released. Under its own force, the trigger component 420 drives the protective plate 410 to move in the first direction, causing the protective plate 410 to disengage from the through hole 340, and the through hole 340 gradually opens. After the boiling process is completed, heating is stopped or the power of the heater 600 is adjusted to maintain a stable temperature in the furnace chamber 210, ensuring that the alumina melt is at a suitable growth temperature. Subsequently, the seed crystal rod 100 is controlled to move downward along its axial direction. The annular support portion 120 on the seed crystal rod 100 moves downward along with the seed crystal rod 100. The collar 421 loses the supporting effect of the annular support portion 120 and moves downward along the axial direction of the seed crystal rod 100 under its own gravity.

[0050] When the collar 421 moves downward, it causes the first end of the trigger rod 422 to rotate downward. The second end of the trigger rod 422 pushes the protective plate 410 to move in the first direction, and the protective plate 410 begins to disengage from the through hole 340, which gradually opens. At this time, the slightly positive pressure atmosphere in the insulation cavity 330 begins to slowly depressurize, and the airflow carries the pollutants in the insulation cavity 330 out gradually. Because the protective plate 410 gradually disengages from the through hole 340, the open area of ​​the through hole 340 gradually increases, avoiding the attenuation of airflow power caused by a sudden drop in pressure, and ensuring that most of the pollutants can be carried out by the airflow.

[0051] S15: The seed crystal rod 100 continues to move downwards, passing through the through hole 340 into the crucible 500 inside the heat preservation cavity 330, carrying the seed crystal 110 to contact the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operation; that is, as the protective plate 410 continues to move along the first direction, the through hole 340 gradually opens to the maximum area. When the protective plate 410 abuts against the positioning baffle 360, the through hole 340 is fully open. At this time, the seed crystal rod 100 continues to move downwards, passing through the through hole 340 into the crucible 500 inside the heat preservation cavity 330, so that the seed crystal 110 at the lower end of the seed crystal rod 100 contacts the alumina melt, completing the crystal introduction operation.

[0052] Furthermore, this application also provides a crystal growth method for a sapphire furnace, such as... Figure 18 As shown, it includes: S21: Fill the crucible 500 in the furnace chamber 210 with crystal growth raw materials such as high-purity alumina; S22: Insert the seed crystal rod 100 into the seed crystal channel 220 of the furnace body 200 and keep the seed crystal rod 100 in a suspended state. At this time, the seed crystal 110 is suspended above the through hole 340. Specifically, insert the seed crystal rod 100 into the seed crystal channel 220 of the furnace body 200 and keep the seed crystal rod 100 in a suspended state. At this time, the seed crystal 110 is suspended above the through hole 340. Insert the seed crystal rod 100 from the seed crystal channel 220 and adjust the seed crystal rod 100 to a suspended state. The seed crystal 110 is suspended above the through hole 340 to avoid collision with the edge of the through hole 340. At the same time, the annular support part 120 on the seed crystal rod 100 supports the collar 421. The collar 421 is in a suspended state, which is ready for the subsequent sealing of the protective plate 410.

[0053] S23: The trigger component 420 is supported by the support part 120 on the seed crystal rod 100, causing the protective plate 410 to move to the blocking state, so that the first plate 411 of the protective plate 410 completely covers and seals the through hole 340 on the heat-insulating top wall 320; then the cooking process is started, and the raw materials in the crucible 500 are melted at high temperature to form alumina melt. The contaminants generated during the cooking process are blocked by the first plate 411 and cannot contaminate the seed crystal 110 upwards. The trigger component 420 is supported by the support portion 120 on the seed crystal rod 100, causing the protective plate 410 to move to a blocking state. This allows the first plate 411 of the protective plate 410 to completely cover and seal the through hole 340 on the heat-insulating top wall 320. Subsequently, the boiling process is initiated, melting the raw materials in the crucible 500 at high temperature to form alumina melt. Contaminants generated during the boiling process are blocked by the first plate 411 and cannot contaminate the seed crystal 110 upwards. Since the protective plate 410 is an integrated structure of the first plate 411, the third plate 413, and the second plate 412, in the blocking state, the first plate 411 completely covers the through hole 340. The third plate 413 and the second plate 412 are located in the opposite direction to the first plate 411 along the first direction, which does not affect the blocking effect of the first plate 411.

[0054] After the cooking process is completed, the seed crystal rod 100 is moved downward along its axis, the supporting effect of the seed crystal rod 100 on the trigger component 420 is released, and the trigger component 420 drives the protective plate 410 to slide along the first direction under its own force. Specifically, after the cooking process is completed, the seed crystal rod 100 is controlled to move downward along its axial direction, and the supporting effect of the seed crystal rod 100 on the trigger component 420 is released. The trigger component 420 drives the protective plate 410 to slide along the first direction under its own force. After the cooking process is completed, the furnace temperature is kept stable, and the seed crystal rod 100 is controlled to move downward. The annular support part 120 moves downward accordingly, and the collar 421 loses its support and moves downward under its own gravity. The trigger rod 422 pushes the protective plate 410 to slide along the first direction, and the first plate 411 begins to disengage from the through hole 340.

[0055] S24: The protective plate 410 continues to slide, causing the first plate 411 to gradually detach from the through hole 340, and the third plate 413 to move above the through hole 340. The angle θ between the third guide surface and the insulation top wall 320 gradually increases to θmax in the opposite direction to the first direction. The open area of ​​the through hole 340 gradually increases simultaneously, realizing the gradient depressurization of the micro-positive pressure atmosphere in the insulation cavity 330. The stable and continuous airflow carries the pollutants retained in the corners and crevices of the insulation cavity 330, such as the inner wall and thermal field gaps, and gradually discharges them obliquely along the third guide surface. Specifically, the protective plate 410 continues to slide, causing the first plate 411 to gradually detach from the through hole 340, and the third plate 413 to move above the through hole 340. The angle θ between the third guide surface and the insulation top wall 320 gradually increases to θmax in the opposite direction to the first direction. The open area of ​​the through hole 340 increases synchronously, realizing the gradient depressurization of the slightly positive pressure atmosphere in the insulation cavity 330. The stable and continuous airflow carries the pollutants trapped in the corners and crevices of the insulation cavity 330, such as the inner wall and thermal field gaps, and gradually discharges them obliquely along the third guide surface.

[0056] As the protective plate 410 continues to slide along the first direction, the first plate 411 gradually detaches from the through hole 340, and the third plate 413 begins to move above the through hole 340. At this time, the angle θ between the third guide surface and the insulation top wall 320 is at the initial angle, the open area of ​​the through hole 340 is small, and the slightly positive pressure atmosphere in the insulation cavity 330 begins to slowly depressurize, the airflow speed is gentle, and it can initially carry out the pollutants near the through hole 340. As the protective plate 410 continues to slide, the angle θ of the third guide surface gradually increases in the opposite direction of the first direction, and the open area of ​​the through hole 340 gradually increases in sync. The pressure in the insulation cavity 330 slowly decreases, the airflow dynamics remain stable, and it can penetrate deep into the dead corner area of ​​the insulation cavity 330, carrying away the pollutants retained in the corners and crevices of the insulation cavity 330 inner wall and thermal field gaps. After these pollutants come into contact with the third guide surface, they are gradually discharged obliquely along the slope, avoiding the residue of pollutants in the dead corner.

[0057] During this process, the gradient depressurization design avoids the sudden pressure drop and airflow power attenuation caused by instantaneous full opening, ensuring that all pollutants can be carried out by a stable and continuous airflow, achieving pollution control without dead angles throughout the entire process, and further improving the cleanliness of seed crystal 110; at the same time, the oblique guiding effect of the third guide surface can prevent pollutants from directly hitting seed crystal 110, reducing the risk of seed crystal 110 contamination.

[0058] S25: The seed crystal rod 100 continues to move downward, triggering the component 420 to drive the protective plate 410 to slide further, so that the second plate 412 moves above the through hole 340. The second guide surface continuously guides the subsequent drifting pollutants at an angle, while blocking the pollutants from directly hitting the seed crystal 110. Specifically, the seed crystal rod 100 continues to move downwards, triggering the component 420 to drive the protective plate 410 to slide further, causing the second plate 412 to move above the through hole 340. The second guide surface continuously guides the subsequently dispersed contaminants at an angle, while simultaneously blocking the contaminants from directly impacting the seed crystal 110. As the protective plate 410 continues to slide, the third plate 413 moves completely above the through hole 340, and after the included angle θ reaches θmax, the protective plate 410 continues to slide along the first direction. The third plate 413 gradually disengages from the through hole 340, and the second plate 412 begins to move above the through hole 340.

[0059] At this time, the through hole 340 is fully open, and the small amount of contaminants remaining in the insulation cavity 330 continue to drift upward. After contacting the second guide surface, they are discharged obliquely along the slope under the guidance of the second guide surface. At the same time, the inclined structure of the second plate 412 can act as a barrier for the seed crystal 110 above, preventing contaminants from directly hitting the seed crystal 110 and ensuring the cleanliness of the seed crystal 110 during the crystal pulling process.

[0060] S26: The seed crystal rod 100 continues to move downward, passes through the through hole 340 and enters the crucible 500 in the heat preservation cavity 330, carrying the seed crystal 110 to contact the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operation.

[0061] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0062] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A sapphire crystal growth furnace, characterized in that, include: Seed crystal rod (100), the seed crystal rod (100) is used to carry the seed crystal (110) to induce crystal growth; The furnace body (200) has a furnace chamber (210) inside, and a seed crystal channel (220) is provided on the top of the furnace body (200) to allow the seed crystal rod (100) to pass through. A heat-insulating structure (300) is located inside the furnace chamber (210). The heat-insulating structure (300) is barrel-shaped and includes a heat-insulating side wall (310) and a heat-insulating top wall (320). The heat-insulating side wall (310) and the heat-insulating top wall (320) enclose a heat-insulating cavity (330) for crystal growth. A through hole (340) is provided on the heat-insulating top wall (320). The through hole (340) and the seed crystal channel (220) are located in the same vertical space. A protective mechanism (400) is disposed between the insulation structure (300) and the furnace body (200). The protective mechanism (400) is used to prevent contaminants floating on the through hole (340) from contaminating the seed crystal (110). The protective mechanism (400) includes: The protective plate (410) is movably disposed on the top of the insulation structure (300) and can be switched to a blocked state covering the through hole (340) and an open state opening the through hole (340); the material of the protective plate is a high-temperature oxidation-resistant and creep-resistant metal alloy or a high-temperature ceramic material. A trigger component (420) is disposed between the seed crystal rod (100) and the protective plate (410). The trigger component (420) and the protective plate (410) are movably connected, and the trigger component (420) is at least partially supported on the seed crystal rod (100). When the seed crystal rod (100) is in a suspended state, the trigger component (420) is supported by the seed crystal rod (100), and the protective plate (410) remains in the blocked state to cover the through hole (340). When the seed crystal rod (100) descends, the supporting effect of the seed crystal rod (100) on the trigger component (420) is released, and the trigger component (420) triggers the protective plate (410) to move along a first direction under the action of gravity, so that the protective plate (410) gradually switches from the blocked state to the open state. The seed crystal rod (100) is provided with a protruding support portion (120), and the trigger assembly (420) includes: a collar (421), which is sleeved on the seed crystal rod (100) and is located above the annular support portion (120). The support portion (120) is used to support the collar (421) so that the collar (421) is suspended above the heat insulation top wall (320), and the collar (421) can move freely along the axial direction of the seed crystal rod (100); The trigger rod (422) is a rigid rod-shaped structure. The first end of the trigger rod (422) is rotatably connected to the collar (421), and the second end of the trigger rod (422) is rotatably connected to the protective plate (410) so that the trigger assembly (420) and the protective plate (410) are movably connected. The protective plate (410) has a connecting part (414), which is located on the side of the protective plate (410) in a first direction, and the second end of the trigger rod (422) is rotatably connected to the connecting part (414); The protective plate (410) includes a first plate (411), which is flat and has a first mating surface (4111) facing the insulation structure (300). The first mating surface (4111) is adapted to the surface of the insulation top wall (320) and is used to cover the through hole (340) during the cooking stage to prevent pollutants in the insulation cavity (330) from floating upward. The protective plate (410) further includes a second plate (412), which is located in the opposite direction to the first plate (411) along the first direction, and the second plate (412) is fixedly connected to the first plate (411); the second plate (412) has a second guide surface facing the heat insulation structure (300), and the second guide surface forms a fixed angle θmax with the heat insulation top wall (320); the second guide surface is used to obliquely guide the pollutants that drift upward at the through hole (340), so that the pollutants are discharged obliquely along the inclined surface and block the seed crystal (110). The protective plate (410) also includes a third plate (413), which is disposed between the first plate (411) and the second plate (412). The third plate (413) is integrally fixedly connected to the first plate (411) and the second plate (412). The third plate (413) has a third flow guide surface facing the insulation structure (300). The third flow guide surface forms an angle θ with the insulation top wall (320). The angle θ gradually increases to θmax in a linear or arc-shaped manner in the opposite direction to the first direction. The value range of θmax is 25° to 45°. The third flow guide surface is used to gradually increase the open area of ​​the through hole (340) with the movement of the protective plate (410) so as to release the gradient pressure of the micro-positive pressure atmosphere in the insulation cavity (330).

2. The sapphire crystal growth furnace according to claim 1, characterized in that, At least two rollers (350) are provided on one side of the protective plate (410) in the first direction, and the rollers (350) roll in cooperation with the heat-insulating top wall (320).

3. The sapphire crystal growth furnace according to claim 1, characterized in that, A positioning baffle (360) is provided on the heat-insulating top wall (320). The positioning baffle (360) is located at the movable end of the protective plate (410) along the first direction and is used to limit the movement of the protective plate (410). When the protective plate (410) moves to abut against the positioning baffle (360), the protective plate (410) is fully switched to the open state.

4. A crystal growth method for a sapphire crystal growth furnace as described in any one of claims 1-3, characterized in that, include: High-purity alumina crystal growth raw materials are loaded into the crucible (500) inside the furnace chamber (210); Insert the seed crystal rod (100) into the seed crystal channel (220) of the furnace body (200) and keep the seed crystal rod (100) suspended. At this time, the seed crystal (110) is suspended above the through hole (340). The trigger component (420) is supported by the support part (120) on the seed crystal rod (100), causing the protective plate (410) to move to the blocking state, so that the first plate (411) of the protective plate (410) completely covers and seals the through hole (340) on the heat-insulating top wall (320); then the cooking process is started to melt the raw materials in the crucible (500) at high temperature to form alumina melt; After the cooking process is completed, the seed crystal rod (100) is controlled to move downward along its axis. The supporting effect of the seed crystal rod (100) on the trigger component (420) is released. The trigger component (420) drives the protective plate (410) to move along the first direction under its own force, so that the protective plate (410) is disengaged from the through hole (340) and the through hole (340) is gradually opened. The seed crystal rod (100) continues to move downwards, passes through the through hole (340) and enters the crucible (500) in the heat preservation cavity (330), carrying the seed crystal (110) to contact the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operation.

5. A crystal growth method using the sapphire crystal growth furnace as described in claim 4, characterized in that, include: High-purity alumina crystal growth raw materials are loaded into the crucible (500) inside the furnace chamber (210); Insert the seed crystal rod (100) into the seed crystal channel (220) of the furnace body (200) and keep the seed crystal rod (100) suspended. At this time, the seed crystal (110) is suspended above the through hole (340). The trigger component (420) is supported by the support part (120) on the seed crystal rod (100), causing the protective plate (410) to move to the blocking state, so that the first plate (411) of the protective plate (410) completely covers and seals the through hole (340) on the heat-insulating top wall (320); then the cooking process is started, and the raw materials in the crucible (500) are melted at high temperature to form alumina melt. The contaminants generated during the cooking process are blocked by the first plate (411) and cannot contaminate the seed crystal (110) upward. After the cooking process is completed, the seed crystal rod (100) is controlled to move downward along its axis, the supporting effect of the seed crystal rod (100) on the trigger component (420) is released, and the trigger component (420) drives the protective plate (410) to slide along the first direction under its own force. The protective plate (410) continues to slide, causing the first plate (411) to gradually detach from the through hole (340), and the third plate (413) moves above the through hole (340). The angle θ between the third guide surface and the insulation top wall (320) gradually increases to θmax in the opposite direction to the first direction. The value of θmax is 25° to 45°. The open area of ​​the through hole (340) gradually increases in sync, realizing the gradient depressurization of the micro-positive pressure atmosphere in the insulation cavity (330). The stable and continuous airflow carries the pollutants retained in the inner wall and thermal field gaps of the insulation cavity (330) and gradually discharges them obliquely along the third guide surface. The seed crystal rod (100) continues to move downward, triggering the component (420) to drive the protective plate (410) to slide further, causing the second plate (412) to move above the through hole (340). The second guide surface continuously guides the subsequent drifting pollutants at an angle, while blocking the pollutants from directly hitting the seed crystal (110). The seed crystal rod (100) continues to move downwards, passes through the through hole (340) and enters the crucible (500) in the heat preservation cavity (330), carrying the seed crystal (110) to contact the alumina melt, completing the crystal introduction and subsequent sapphire single crystal growth operation.

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