Seed crystal protection device and method of using the same

Abstract

The application provides a seed crystal protection device and an application method thereof, and relates to the technical field of single crystal growth. The seed crystal protection device comprises a device main body and a matching structure. The device main body is provided with a first accommodating cavity, and one side of the first accommodating cavity is provided with an opening. The matching structure is connected with the device main body. The matching structure has a connected state and a separated state. In the connected state, the matching structure is suitable for being connected with a connecting device, so that the seed crystal assembled in the connecting device is accommodated in the first accommodating cavity through the opening. The first accommodating cavity can wrap the seed crystal and reduce the probability of contamination of the seed crystal. Meanwhile, in the separated state, the matching structure is suitable for being separated from the connecting device, and the device main body can fall into a reaction container located on the side of the seed crystal away from the connecting device. Therefore, the wrapping restriction on the seed crystal can be removed, and the seed crystal can normally grow crystals under the action of the melt in the reaction container.

Description

Technical Field

[0001] This application belongs to the field of single crystal growth technology, specifically relating to a seed crystal protection device and a method for applying the seed crystal protection device. Background Technology

[0002] When preparing silicon carbide (SiC) crystals using the top seed crystal solution growth method (i.e., liquid phase method), transition metal elements such as silicon, aluminum, cadmium, cerium, and titanium, as well as rare earth metal elements, need to be added to the reaction vessel as fluxes. These fluxes can enhance the carbon melting capacity of the flux system.

[0003] In the initial stage of flux heating and melting, some components in the flux undergo gas phase volatilization. The volatilized gas phase components migrate upward under the influence of a carrier gas at a certain pressure and adhere to the surface of the seed crystal, destroying the complete single crystal structure of the seed crystal surface and subsequently forming growth defects on the seed crystal. Summary of the Invention

[0004] This application aims to provide a seed crystal protection device and a method for applying the seed crystal protection device, at least to solve the problem that the gas phase components after the solvent evaporates destroy the single crystal integrity structure of the seed crystal surface, thereby forming growth defects on the seed crystal.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a seed crystal protection device, which includes: a device body and a cooperating structure; The main body of the device has a first receiving cavity, and one side of the first receiving cavity has an opening. The mating structure is connected to the main body of the device. The mating structure has a connected state and a separated state. In the connected state, the mating structure is adapted to connect with the connecting device so that the seed crystal assembled in the connecting device is received in the first receiving cavity through the opening; In the separated state, the mating structure is adapted to separate from the connecting device, and the main body of the device can fall into the reaction vessel located on the side of the seed crystal away from the connecting device.

[0006] Optionally, the mating structure is a lifting ring, which is connected to the end of the device body near the opening; In the connected state, the lifting ring is adapted to engage with the hook of the connecting device.

[0007] Optionally, the number of the lifting rings is at least three; At least three of the aforementioned cranes are arranged in an equally spaced array around the center of mass axis of the device body in the circumferential direction; and / or, Each of the aforementioned rings is adapted to engage with an inclined extension of one of the aforementioned hooks, the inclined extension being inclined relative to the circumferential tangent direction about the centroidal axis of the connecting device, the inclined extension extending inclinedly toward the seed crystal.

[0008] Optionally, the seed crystal protection device further includes a counterweight structure; The main body of the device has a second receiving cavity, which is separated from the first receiving cavity; at least part of the counterweight structure is received in the second receiving cavity, and the counterweight structure is connected to the main body of the device.

[0009] Optionally, the number of the counterweight structures is at least three, and the at least three counterweight structures are arranged in an equally spaced array around the center of mass axis of the device body in the circumferential direction; and / or, The counterweight structure is made of a material that can provide a fluxing effect to the melt inside the reaction vessel.

[0010] Optionally, the seed crystal protection device further includes a baffle structure; The partition structure is arranged circumferentially along the inner wall of the device body and is connected to the device body; in the connected state, the partition structure can form a gap with the connecting device.

[0011] Optionally, on a projection plane perpendicular to the centroidal axis of the device body, the projected area of ​​the outer wall of the device body at the end furthest from the opening is larger than the projected area of ​​the outer wall of the device body at the end closest to the opening; and / or, On a projection plane perpendicular to the centroidal axis of the device body, the projected area of ​​the inner wall of the device body away from the opening is greater than the projected area of ​​the inner wall of the device body closer to the opening.

[0012] Optionally, the device body is adapted to be electrically connected to a conductive detection structure, which is adapted to detect the contact state between the device body and the melt inside the reaction vessel.

[0013] Secondly, embodiments of this application propose an application method for a seed crystal protection device, the method being applied to the seed crystal protection device as described in any one of the first aspects, the method comprising: The mating structure is connected to the connecting device, and the seed crystal is accommodated in the first receiving cavity through the opening; Drive the connecting device to move, so as to move the main body of the device toward the reaction vessel until the preset separation conditions are met; In response to the separation condition, the mating structure is separated from the connecting device so that the main body of the device falls into the reaction vessel.

[0014] Optionally, the mating structure is a lifting ring, and the number of the lifting rings is at least three; each of the lifting rings is adapted to engage with an inclined extension of the connecting device, the inclined extension being inclined relative to the circumferential tangent direction about the centroidal axis of the connecting device, and the inclined extension extending inclinedly toward the direction close to the seed crystal; Separating the mating structure from the connecting device includes: Drive the connecting device to rotate until the mating structure disengages from the inclined extension that is engaged.

[0015] In the embodiments of this application, the seed crystal protection device includes a device body and a mating structure. The device body has a first receiving cavity with an opening on one side. The mating structure is connected to the device body. Therefore, when the mating structure is connected to the connecting device, the seed crystal assembled on the connecting device can be received in the first receiving cavity through the opening. At this time, the first receiving cavity can enclose the seed crystal, thereby protecting it and preventing gaseous components generated by flux volatilization in the reaction vessel from adhering to the seed crystal surface during the initial stage of melting, reducing the probability of seed crystal contamination. Simultaneously, when the mating structure is separated from the connecting device, the device body loses the fixed support of the connecting device and can naturally fall into the reaction vessel on the side of the seed crystal away from the connecting device, thereby releasing the enclosing restriction on the seed crystal and ensuring that the seed crystal can grow normally under the action of the melt in the reaction vessel.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein: Figure 1 A cross-sectional view of a crystal growth furnace provided in an embodiment of this application, cut along a vertical plane. Figure 2 for Figure 1 The center circle shows a magnified view of part A. Figure 3 for Figure 2 A cross-sectional view of the crystal growth furnace cut along the BB line; Figure 4 for Figure 3 The center circle shows a magnified view of part C. Figure 5 A schematic diagram of the structure of a hook provided in an embodiment of this application; Figure 6 This is a flowchart illustrating the application method of the seed crystal protection device provided in the embodiments of this application.

[0018] Figure label: 110: Main body of the device; 111a: First receiving cavity; 111b: Opening; 112a: Second receiving cavity; 120: Fitting structure; 130: Counterweight structure; 140: Partition structure; 140a: Gap; 210: Connecting device; 211: Hook; 2111: Inclined extension; 2112: Transition part; 2113: First arc transition part; 212: Connecting component; 213: Connecting shaft; 214: Seed crystal mounting plate; 2141: Annular protrusion; 220: Seed crystal; 230: Reaction vessel; 240: Melt; 250: Graphite pad paper; 260: Heating device; 270: Conductivity detection structure. Detailed Implementation

[0019] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] To clearly understand the technical solution of this application, the application scenarios of the seed crystal protection device and the application method of the seed crystal protection device will be explained first.

[0024] Silicon carbide is a third-generation semiconductor material with physical properties such as high breakdown field strength, high thermal conductivity, high temperature resistance and radiation resistance, and has broad application prospects in the fields of power electronic devices and radio frequency devices.

[0025] Currently, the mainstream methods for preparing silicon carbide single crystals mainly include physical vapor transport method, high-temperature chemical vapor deposition method, and top seed solution growth method. Among them, the top seed solution growth method, also known as the liquid phase method, has advantages such as lower growth temperature (about 1800℃), easy process control, and easy crystal diameter expansion growth, and has become one of the mainstream processes for preparing silicon carbide single crystals.

[0026] The crystal growth furnace used in the liquid phase method includes a connecting device, a seed crystal, and a reaction vessel. The seed crystal is assembled on the connecting device, and the reaction vessel is located on the side of the seed crystal away from the connecting device. The reaction vessel can hold molten material, which is melted by heating to form a melt. Under a matched temperature field, silicon carbide single crystals can grow continuously and stably along the surface of the seed crystal.

[0027] When preparing silicon carbide crystals using the top seed solution growth method, transition metal elements such as aluminum, cadmium, cerium, and titanium, as well as rare earth metal elements, need to be added to the reaction vessel as fluxes. These fluxes can enhance the carbon melting capacity of the molten material system.

[0028] In the initial stage of the melting process, some components in the flux undergo gaseous volatilization. Under the influence of a carrier gas at a certain pressure, the volatilized gaseous components migrate upwards and adhere to the surface of the seed crystal, destroying the complete single-crystal structure of the seed crystal surface and subsequently forming growth defects on the seed crystal.

[0029] Therefore, this application provides a seed crystal protection device and a method for applying the seed crystal protection device to solve some or all of the technical problems existing in the prior art. The seed crystal protection device and its application method provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios.

[0030] like Figure 1and Figure 2 As shown, the seed crystal protection device provided according to some embodiments of this application includes a device body 110 and a mating structure 120; the device body 110 has a first receiving cavity 111a, and an opening 111b is provided on one side of the first receiving cavity 111a; the mating structure 120 is connected to the device body 110; the mating structure 120 has a connected state and a separated state; in the connected state, the mating structure 120 is adapted to be connected to the connecting device 210 so that the seed crystal 220 assembled in the connecting device 210 is received in the first receiving cavity 111a through the opening 111b; in the separated state, the mating structure 120 is adapted to be separated from the connecting device 210, and the device body 110 can fall into the reaction vessel 230 located on the side of the seed crystal 220 away from the connecting device 210.

[0031] In the embodiments of this application, the seed crystal protection device includes a device body 110 and a mating structure 120. The device body 110 has a first receiving cavity 111a, and one side of the first receiving cavity 111a has an opening 111b. The mating structure 120 is connected to the device body 110. Based on this, when the mating structure 120 is connected to the connecting device 210, the seed crystal 220 assembled on the connecting device 210 can be received in the first receiving cavity 111a through the opening 111b. At this time, the first receiving cavity 111a can enclose the seed crystal 220, thereby protecting the seed crystal 220 and preventing the gaseous components generated by the evaporation of flux in the reaction vessel 230 from adhering to the surface of the seed crystal 220 during the initial stage of the molten material heating and melting, thus reducing the probability of the seed crystal 220 being contaminated. At the same time, when the cooperating structure 120 separates from the connecting device 210, the main body 110 of the device loses the fixed support of the connecting device 210 and can naturally fall into the reaction container 230 on the side of the seed crystal 220 away from the connecting device 210, thereby releasing the restriction on the seed crystal 220 and ensuring that the seed crystal 220 can grow normally under the action of the melt 240 in the reaction container 230.

[0032] Specifically, the liquid-phase silicon carbide crystal growth method is a technique that relies on the high-temperature solution dissolution and precipitation mechanism to prepare silicon carbide crystals. A carbon source is dissolved in a melt 240 formed by a silicon-based flux. Driven by a temperature gradient, carbon reaches a supersaturated state at the seed crystal 220 and combines with silicon, subsequently precipitating layer by layer on the surface of the seed crystal 220 to form silicon carbide single crystals.

[0033] The liquid-phase silicon carbide crystal growth process is divided into three stages: melt melting, seed crystal remelting, and crystal growth. The melt melting stage involves heating the molten material and flux to a complete melt, forming melt 240. This stage is the same as the aforementioned stage of molten material heating and melting. After the melt melting stage is completed and before the seed crystal remelting stage begins, the mating structure 120 is separated from the connecting device 210. The seed crystal remelting stage is a pretreatment process before formal crystal growth. It involves slightly melting the surface of the seed crystal 220 to remove surface impurities, ensuring a pure silicon carbide structure serves as the template for subsequent crystal growth. This process must be carried out after the mating structure 120 is separated from the connecting device 210, and the main body of the device 110 has fallen into the reaction vessel 230, allowing the seed crystal 220 to fully contact the melt 240. The crystal growth stage is a process in which silicon carbide single crystals grow layer by layer along the surface of the seed crystal 220 under the continuous action of temperature gradient, relying on the dissolution and precipitation mechanism of carbon in the melt 240. This process requires ensuring that the seed crystal 220 is not contaminated by impurities and maintains good contact with the melt 240.

[0034] The crystal growth furnace used in the liquid phase method in this application also includes a seed crystal protection device, which is mainly used to protect the seed crystal 220 during the melt melting stage.

[0035] The seed crystal protection device includes a main body 110 and a mating structure 120. Both the main body 110 and the mating structure 120 can fall into the reaction vessel 230 on the side of the seed crystal 220 opposite to the connecting device 210. The reaction vessel 230 contains melt 240. The main body 110 and the mating structure 120 can be made of a material that can melt into the melt 240. After melting, the main body 110 and the mating structure 120 can coexist compatiblely with the components such as the melt and flux in the melt 240, without damaging the compositional stability of the melt 240 or introducing impurities into the melt 240 that would interfere with the growth of silicon carbide crystals. This material can be graphite. The main body 110 and the mating structure 120 can serve as raw materials required for the growth of silicon carbide crystals.

[0036] The main body 110 has a first receiving cavity 111a. The first receiving cavity 111a has an opening 111b on its upper side along the centroidal axis of the main body 110. The opening 111b is used for the seed crystal 220 to enter and be stored inside the first receiving cavity 111a. On a projection plane perpendicular to the centroidal axis of the main body 110, the orthographic projection of the wall of the first receiving cavity 111a covers the orthographic projection of the seed crystal 220, and the orthographic projection of the opening 111b covers the orthographic projection of the seed crystal 220. At the same time, along the centroidal axis of the main body 110, the cavity depth of the first receiving cavity 111a is greater than the size of the seed crystal 220. Based on this, the first receiving cavity 111a can provide a complete storage space for the seed crystal 220.

[0037] The mating structure 120 is connected to the main body 110 of the device. The connection method can be a hinged or other rotating connection, or a threaded or snap-fit ​​connection, or the mating structure 120 can be integrally formed with the main body 110 of the device. The mating structure 120 can be connected to or separated from the connecting device 210. In one embodiment, the mating structure 120 adopts a lifting ring structure, and the connecting device 210 is equipped with a hook that engages with the lifting ring. The mating structure 120 can be arranged on the side of the main body 110 near the opening 111b, or it can be arranged around at least part of the circumference of the main body 110 of the device. In another embodiment, the mating structure 120 adopts a limiting structure, and the growth furnace is equipped with a telescopic structure. When the telescopic structure extends, it can be inserted into the limiting structure, so that the connecting device 210 is indirectly connected to the mating structure 120 through the telescopic structure. When the telescopic structure retracts, it is released from the limiting structure, so that the mating structure 120 and the connecting device 210 can be separated.

[0038] When the mating structure 120 and the connecting device 210 are mated together, the mating structure 120 is in a connected state, and the main body 110 is fixed in a preset working position by means of the mating structure 120 and the connecting device 210. The first receiving cavity 111a can completely enclose and cover the seed crystal 220, thereby blocking the gaseous components generated by the melting and volatilization of the flux in the reaction vessel 230, reducing the probability of gaseous components adhering to and contaminating the surface of the seed crystal 220, protecting the integrity of the single crystal structure on the surface of the seed crystal 220, and thus suppressing the generation of crystal growth defects. When in the connected state, the main body 110 can remain continuously immersed in the preset position above the melt 240 until the working conditions are met and the device switches to the separation state. Then, the main body 110 sinks into the bottom of the reaction vessel 230 by itself, ensuring that the seed crystal 220 is always contained and protected in the first receiving cavity 111a during the melting stage of the melt. The main body 110 can also move down towards the reaction vessel 230 along with the connecting device 210. After moving to the preset position, it switches to the separation state and detaches from the connecting device 210.

[0039] The separation state is the working condition in which the mating structure 120 and the connecting device 210 are disconnected and detached from each other. After entering the separation state, the main body 110 and the connecting device 210 are no longer constrained. The main body 110 and the mating structure 120 can fall under their own gravity or fall into the reaction vessel 230 together under the action of the growth furnace supporting structure. The first receiving cavity 111a simultaneously releases the covering and limiting of the seed crystal 220. The seed crystal 220 is completely exposed to the melt 240 environment in the reaction vessel 230, and can complete the seed crystal remelting and subsequent single crystal growth process under the action of the melt 240.

[0040] The switching between the connected and separated states can be determined based on the actual process conditions. It can be based on the duration of the connected state, triggering separation at the end of the melt melting stage; it can also be based on the downward movement distance of the main body 110 along with the connecting device 210, triggering separation after the connecting device 210 has moved a preset distance; it can also be based on the real-time temperature of the molten material or melt 240 within the reaction vessel 230, triggering separation when the temperature reaches the process set value and is about to enter the seed crystal remelting stage; or it can be based on the distance between the main body 110 and the melt 240, triggering separation when the main body 110 moves down to reach a preset distance from the melt 240.

[0041] Optionally, such as Figures 1 to 4 As shown, the fitting structure 120 is a lifting ring, which is connected to the end of the device body 110 near the opening 111b; in the connected state, the lifting ring is suitable for engaging with the hook 211 of the connecting device 210.

[0042] In the embodiments of this application, by setting the mating structure 120 as a lifting ring and connecting the lifting ring to the end of the device body 110 near the opening 111b, the lifting ring and the device body 110 form an integral structure. In the connected state, by means of the engagement between the lifting ring and the hook 211 of the connecting device 210, the device body 110 can be suspended and fixed, and the device body 110 can be positioned and constrained to ensure that the device body 110 maintains a preset position in the connected state.

[0043] Specifically, the mating structure 120 is configured as a lifting ring. As a specific implementation of the mating structure 120, the lifting ring is used to engage with the hook 211 of the connecting device 210, thereby achieving the suspension, fixation, and positioning constraint of the device body 110. The shape of the lifting ring can be circular, elliptical, or square, etc., and the inner diameter of the lifting ring is adapted to the size of the hook 211's engagement portion. This ensures that the lifting ring and hook 211 can be stably engaged, reducing the probability of detachment or loosening during the engagement process.

[0044] The lifting ring is located at one end of the device body 110 near the opening 111b. The lifting ring is connected to the device body 110. The connection method can be a rotatable connection or a detachable connection, or the lifting ring and the device body 110 can be integrally formed.

[0045] The number of hooks 211 is consistent with the number of rings. There can be multiple rings, which can be evenly spaced around the device body 110 near the end of the opening 111b.

[0046] Furthermore, the connecting device 210 includes a hook 211, a connecting component 212, a connecting shaft 213, and a seed crystal mounting plate 214.

[0047] The connecting shaft 213 is a shaft structure, and its shape can be cylindrical or prismatic, etc. The connecting shaft 213 is used to support the weight of the hook 211, connecting component 212, seed crystal protection device, and seed crystal 220. Furthermore, the connecting shaft 213 is connected to the drive device of the crystal growth furnace. The drive device drives the connecting shaft 213 to rotate or move, thereby causing the seed crystal protection device and seed crystal 220 to rotate or move synchronously to adapt to the crystal growth process requirements. In addition, the connecting shaft 213 is movably connected to the shell of the crystal growth furnace, allowing it to rotate and slide relative to the shell, ensuring the flexibility of its movement.

[0048] Among them, such as Figure 1 As shown, the shell can be a hollow structure located above the reaction vessel 230 and directly connected to the reaction vessel 230.

[0049] The shape of the connecting component 212 can be designed as a ring, a ring bracket, or multiple evenly spaced connecting arms. The connecting component 212 is arranged circumferentially around the connecting shaft 213. The connecting component 212 can be located in the middle of the connecting shaft 213, at one end close to the seed crystal mounting plate 214, or at one end far from the seed crystal mounting plate 214. The connecting component 212 is connected to the connecting shaft 213, and the connection method can be a detachable connection such as a threaded connection or a keyed connection. Alternatively, the connecting component 212 and the connecting shaft 213 can be integrally formed to enhance the structural strength of the connecting shaft 213 and ensure the overall stability of the connecting device 210.

[0050] Hook 211 is a component in the connecting device 210 specifically designed for engaging with the lifting ring. Hook 211 enables a detachable connection between the connecting device 210 and the mating structure 120. Hook 211 may specifically include a transition portion and a hooking portion. The transition portion connects to the connecting shaft 213, and the hooking portion engages with the lifting ring. The transition portion can extend vertically, along the axis of mass of the connecting shaft 213, or be inclined relative to the vertical or axis of mass of the connecting shaft 213. The hooking portion is fixedly connected to the transition portion or integrally formed. The hooking portion can extend horizontally or be inclined relative to the horizontal. The shape of the hooking portion is adapted to the lifting ring, specifically a hook shape, a U-shape, or a groove shape, ensuring stable engagement with the lifting ring and reducing the probability of detachment after engagement.

[0051] The seed crystal mounting plate 214 is a component in the connecting device 210 used for assembling the seed crystal 220. The seed crystal mounting plate 214 can be circular in shape, and its surface can have mounting grooves or threaded holes for fixing the seed crystal 220, ensuring the stability of the seed crystal 220 after assembly. The seed crystal mounting plate 214 is located at the end of the connecting shaft 213 near the reaction vessel 230. The seed crystal mounting plate 214 is connected to the connecting shaft 213, and the connection method can be a detachable connection such as a threaded connection or a key connection, or the seed crystal mounting plate 214 and the connecting shaft 213 can be integrally formed.

[0052] Optionally, such as Figure 3 and Figure 4 As shown, the number of lifting rings is at least three; the at least three lifting rings are arranged in an equally spaced array around the center of mass axis of the main body 110 of the device.

[0053] In the embodiments of this application, the number of lifting rings is set to at least three, and the at least three lifting rings are arranged in an equally spaced array around the centroidal axis of the device body 110 in the circumferential direction. This enables the overall center of gravity of the lifting rings to coincide with the centroidal axis of the device body 110, thereby improving the overall force balance and structural stability of the device body 110 when it is suspended.

[0054] Specifically, the number of lifting rings is limited to at least three. The number of lifting rings can be any number of three, four, or more, with four being the preferred setting. Compared to an arrangement with only two lifting rings, a number of at least three lifting rings can form a ring-shaped multi-point constraint structure, improving the anti-swaying, anti-deflection, and anti-tilting capabilities of the main body 110 of the device in the connected state.

[0055] The main body 110 of the device has a centroidal axis, which is a central axis running vertically through the center of the main body 110. At least three lifting rings are arranged in an array at equal intervals along the circumference of the main body 110, with the centroidal axis of the main body 110 as the central reference. Taking four lifting rings as an example, the four lifting rings are arranged at equal intervals of 90° between each other along the circumference, with the centroidal axis of the main body 110 as the central reference.

[0056] It should be noted that, in Figure 1 In the schematic diagram shown, the centroid axis of the connecting shaft 213 is outlined using a dashed line; the centroid axes of the main body 110 and the connecting device 210 can be collinear with the centroid axis of the connecting shaft 213.

[0057] Optionally, such as Figures 3 to 5As shown, the number of lifting rings is at least three; each lifting ring is adapted to engage with the inclined extension 2111 of a hook 211, the inclined extension 2111 being inclined relative to the circumferential tangent direction of the centroid axis of the connecting device 210, and the inclined extension 2111 extending inclinedly toward the direction close to the seed crystal 220.

[0058] In the embodiments of this application, the number of lifting rings is set to at least three, so that each lifting ring can be individually engaged with the inclined extension 2111 of the corresponding hook 211. Furthermore, the inclined extension 2111 is inclined in the circumferential tangent direction relative to the centroidal axis of the connecting device 210, and extends inclined towards the direction close to the seed crystal 220. The inclined extension 2111 can form an oblique guide structure, which facilitates the alignment and engagement between the lifting ring and the inclined extension 2111, and also facilitates their separation.

[0059] Specifically, the hook 211 is provided with an inclined extension 2111, which is a structural section on the hook 211 that directly forms a hook-and-loop engagement with the lifting ring. The inclined extension 2111 can directly constitute the hook-and-loop part of the hook 211 in the aforementioned embodiment. The shape of the inclined extension 2111 can be a straight rod or a bent rod, etc.

[0060] It should be noted that, Figure 5 The dashed line represents the circumferential tangent direction corresponding to the centroidal axis of the connecting device 210. Specifically, the circumferential tangent direction refers to the direction formed by the tangent at any point on the centroidal axis of the connecting device 210, which is a circle around the centroidal axis in a horizontal plane with any point on the circle as the center.

[0061] The inclined extension 2111 is arranged with the centroidal axis of the connecting device 210 as the basis for its arrangement, and is inclined relative to the circumferential tangent direction surrounding the centroidal axis, while extending inclinedly towards the seed crystal 220. For example, the inclined angle of the inclined extension 2111 relative to the circumferential tangent direction of the centroidal axis of the connecting device 210 is 3° to 5°.

[0062] The inclined extension 2111 can form an inclined guide structure, which can guide the lifting ring to be aligned, making it easy for the lifting ring and the inclined extension 2111 to be aligned and attached, and also easy for the two to be separated later. By rotating the connecting device 210 relative to the lifting ring in the corresponding direction, the connection state and separation state between the mating structure 120 and the connecting device 210 can be switched.

[0063] In addition, the hook 211 is also provided with the transition portion 2112 in the aforementioned embodiment. The transition portion 2112 is connected to the connecting member 212 and the inclined extension portion 2111 respectively. The transition portion 2112 can extend vertically along the centroidal axis of the connecting device 210, or it can be inclined relative to the centroidal axis.

[0064] Furthermore, such as Figure 5 As shown, one end of the inclined extension 2111 is connected to the transition portion 2112, and the other end of the inclined extension 2111 has a first arc transition portion 2113. The first arc transition portion 2113 is provided on the side of the inclined extension 2111 near the connecting shaft 213. The first arc transition portion 2113 can guide the lifting ring to detach from the inclined extension 2111.

[0065] Optionally, such as Figures 1 to 4 As shown, the seed crystal protection device also includes a counterweight structure 130; the main body 110 of the device has a second receiving cavity 112a, which is separated from the first receiving cavity 111a; at least a portion of the counterweight structure 130 is received in the second receiving cavity 112a, and the counterweight structure 130 is connected to the main body 110 of the device.

[0066] In the embodiments of this application, at least a portion of the counterweight structure 130 is housed inside the second receiving cavity 112a of the device body 110, so that the counterweight structure 130 is connected to the device body 110. The counterweight structure 130 can be used to increase the overall weight and density of the device body 110, thereby allowing the device body 110 to sink more smoothly into the bottom of the reaction vessel 230.

[0067] Specifically, the seed crystal protection device also includes a counterweight structure 130, which is used to increase the overall weight and density of the device body 110. The density of the counterweight structure 130 is greater than that of the device body 110 and the melt 240. The counterweight structure 130 can be melted into the melt 240. For example, the counterweight structure 130 is made of materials such as chromium, aluminum, cadmium, cerium, and titanium.

[0068] The counterweight structure 130 can be block-shaped, strip-shaped, or ring-shaped. When the counterweight structure 130 is block-shaped, the number of counterweight structures 130 can be multiple, and the multiple counterweight structures 130 are arranged in an equally spaced array around the centroidal axis of the device body 110. When the counterweight structure 130 is strip-shaped, at least a portion of the counterweight structure 130 is located inside the second receiving cavity 112a. When the counterweight structure 130 is ring-shaped, the counterweight structure 130 can be continuously or intermittently arranged around at least a portion of the device body 110.

[0069] Meanwhile, a second receiving cavity 112a is provided inside the main body 110 of the device. The second receiving cavity 112a is a cavity space specifically used to accommodate the counterweight structure 130. The second receiving cavity 112a is separated from the first receiving cavity 111a, which can reduce the probability of structural interference between the counterweight structure 130 and the seed crystal 220 placed inside the first receiving cavity 111a. At the same time, it can prevent the gaseous components formed by the evaporation of flux in the reaction vessel 230 from entering the first receiving cavity 111a through the second receiving cavity 112a. The second receiving cavity 112a can be a closed cavity structure, in which case the counterweight structure 130 can be completely housed inside the second receiving cavity 112a; the second receiving cavity 112a can also be a semi-closed cavity structure, in which case only at least a portion of the counterweight structure 130 needs to be housed inside the second receiving cavity 112a.

[0070] At least a portion of the counterweight structure 130 is housed inside the second receiving cavity 112a. The counterweight structure 130 and the main body 110 of the device form a fixed assembly connection. The assembly method between the two can be interference fit, adhesive fixation, snap-fit ​​limiting or threaded locking, etc.

[0071] Furthermore, the second receiving cavity 112a is located on the side of the device body 110 away from the opening 111b, and the counterweight structure 130 can lower the center of gravity of the device body 110 to improve the overall stability of the device body 110 in the connected suspension state.

[0072] It should be noted that, in Figure 3 In the schematic diagram shown, the second receiving cavity 112a is in an invisible position, so the outline of the second receiving cavity 112a is schematically outlined by dashed lines.

[0073] Optionally, such as Figures 1 to 4 As shown, the number of counterweight structures 130 is at least three, and the at least three counterweight structures 130 are arranged in an equally spaced array around the center of mass axis of the main body 110 of the device.

[0074] In the embodiments of this application, the number of counterweight structures 130 is set to at least three, and the at least three counterweight structures 130 are arranged in an equally spaced array around the centroidal axis of the device body 110 in the circumferential direction. This enables the overall center of gravity of the counterweight structure 130 to coincide with the centroidal axis of the device body 110, thereby improving the overall force balance and structural stability of the device body 110 when it is suspended.

[0075] The number of counterweight structures 130 can be understood by referring to the number of lifting rings, and will not be repeated here.

[0076] Optionally, the counterweight structure 130 is made of a material that can provide a fluxing effect on the melt 240 within the reaction vessel 230.

[0077] In the embodiments of this application, the counterweight structure 130 is made of a material that can produce a fluxing effect on the melt 240 inside the reaction vessel 230, and can play an auxiliary fluxing role on the melt 240 inside the reaction vessel 230.

[0078] Specifically, the counterweight structure 130 can be melted into the melt 240. The counterweight structure 130 can play an auxiliary role in melting the melt 240 inside the reaction vessel 230. The counterweight structure 130 can be made of materials such as chromium, aluminum, cerium and titanium.

[0079] Optionally, such as Figure 1 and Figure 2 As shown, the seed crystal protection device also includes a partition structure 140; the partition structure 140 is arranged circumferentially along the inner wall of the device body 110, and the partition structure 140 is connected to the device body 110; in the connected state, the partition structure 140 can form a gap 140a with the connecting device 210.

[0080] In the embodiments of this application, the partition structure 140 is arranged circumferentially along the inner wall of the device body 110 and connected to the device body 110. In the connected state, it can block a portion of the opening 111b, reducing the probability that gaseous components generated by flux volatilization will enter the first receiving cavity 111a through the opening 111b, thereby further reducing the probability of seed crystal contamination. Simultaneously, in the connected state, the partition structure 140 can form a gap 140a with the connecting device 210, which can improve the smoothness of separation between the mating structure 120 and the connecting device 210.

[0081] Specifically, the seed crystal protection device also includes a baffle structure 140, which is arranged around the inner wall of the device body 110. The baffle structure 140 is connected to the device body 110, and the connection method can be a snap-fit ​​or interference fit, or the baffle structure 140 is integrally formed with the device body 110.

[0082] Meanwhile, the partition structure 140 can form a gap 140a with the connecting device 210. This gap 140a can reduce the probability of the partition structure 140 or the connecting device 210 coming into contact with each other due to slight shaking during the separation process, thereby reducing the risk of poor separation and improving the smoothness of separation between the mating structure 120 and the connecting device 210.

[0083] Furthermore, such as Figure 1 and Figure 2As shown, the connecting device 210 includes a seed crystal mounting disk 214. An annular protrusion 2141 is circumferentially provided on the outer wall of the seed crystal mounting disk 214, protruding from the outer wall of the seed crystal mounting disk 214 in a direction away from the connecting shaft 213. The annular protrusion 2141 can block the opening 111b region corresponding to the gap 140a, further reducing the probability of gaseous components generated by flux volatilization entering the first receiving cavity 111a through the opening 111b.

[0084] Furthermore, in the connected state, the annular protrusion 2141 can form a gap with the inner wall of the device body 110 to improve the smoothness of separation between the mating structure 120 and the connecting device 210.

[0085] Meanwhile, along the centroidal axis of the connecting device 210, the annular protrusion 2141 is located on the side of the partition structure 140 away from the seed crystal 220, and the annular protrusion 2141 is spaced apart from the first partition structure 140. The distance between the annular protrusion 2141 and the first partition structure 140 is greater than the displacement of the mating structure 120 relative to the connecting device 210 during the separation of the mating structure 120 from the connecting device 210. Based on this, structural interference between the annular protrusion 2141 and the first partition structure 140 can be avoided during the process of the seed crystal mounting plate 214 driving the seed crystal 220 into the first receiving cavity 111a through the opening 111b, and during the separation of the mating structure 120 from the connecting device 210.

[0086] Optionally, such as Figure 1 As shown, on the projection plane perpendicular to the centroidal axis of the device body 110, the orthographic projection area of ​​the outer wall of the device body 110 at the end away from the opening 111b is greater than the orthographic projection area of ​​the outer wall of the device body 110 at the end closer to the opening 111b.

[0087] In the embodiments of this application, on the projection plane perpendicular to the centroidal axis of the device body 110, the orthographic projection area of ​​the outer wall of the device body 110 away from the opening 111b is set to be larger than the orthographic projection area of ​​the outer wall of the device body 110 near the opening 111b. This allows the device body 110 to present an overall shape structure that is smaller at the top and larger at the bottom, reducing the fluid resistance encountered by the device body 110 during its descent into the melt 240, thereby facilitating the smooth sinking of the device body 110 into the melt 240.

[0088] Furthermore, the main body 110 of the device includes a bottom wall and a side wall that is arranged around the bottom wall and connected to the bottom wall. The bottom wall and the side wall enclose each other to form a first receiving cavity 111a. A second arc transition part is provided at the junction of the bottom wall and the side wall. The second arc transition part can not only disperse structural stress and avoid stress concentration, but also play a role in smoothing and guiding the melt 240 during the process of immersing the main body 110 into the melt 240.

[0089] The counterweight structure 130 and the outer wall of the main body 110 adopt a shape structure that is smaller at the top and larger at the bottom. The two work together to increase the speed at which the main body 110 sinks into the bottom of the melt 240, and prevent the main body 110 from floating on the top of the melt 240, thereby ensuring that the seed crystal remelting stage and the crystal growth stage proceed normally.

[0090] Optionally, such as Figure 1 As shown, on the projection plane perpendicular to the centroidal axis of the device body 110, the projected area of ​​the inner wall of the device body 110 away from the opening 111b is greater than the projected area of ​​the inner wall of the device body 110 closer to the opening 111b.

[0091] In the embodiments of this application, on the projection plane perpendicular to the centroidal axis of the device body 110, the orthographic projection area of ​​the inner wall of the device body 110 away from the opening 111b is set to be larger than the orthographic projection area of ​​the inner wall of the device body 110 near the opening 111b. This allows the device body 110 to present an inner wall structure that is smaller at the top and larger at the bottom. This structure can reduce the probability that the gaseous components formed by the evaporation of flux in the reaction vessel 230 will pass through the gap between the inner wall of the device body 110 and the connecting device 210 and then adhere to the surface of the seed crystal 220.

[0092] Furthermore, the partition structure 140 is arranged circumferentially along the inner wall of the device body 110. At the same time, on the projection plane perpendicular to the centroidal axis of the device body 110, the projected area of ​​the inner wall of the device body 110 away from the opening 111b is larger than the projected area of ​​the inner wall of the device body 110 near the opening 111b. This can reduce the gap distance between the inner wall of the device body 110 and the seed crystal mounting disk 214, and further reduce the probability that the gaseous components generated by flux volatilization will enter the first receiving cavity 111a through the opening 111b.

[0093] Optionally, the device body 110 is adapted to be electrically connected to the conductive detection structure 270, which is adapted to detect the contact state between the device body 110 and the melt 240 in the reaction vessel 230.

[0094] In the embodiments of this application, the conductive detection structure 270 is electrically connected to the device body 110, and the conductive detection structure 270 detects the contact state between the device body 110 and the melt 240 inside the reaction vessel 230. Based on this, the change in the continuity of the conductive circuit formed by the device body 110, the conductive detection structure 270, and the melt 240 can be used to determine whether the device body 110 is in contact with the melt 240.

[0095] Specifically, the crystal growth furnace also includes a conductive detection structure 270, which is a detection component with conductive conduction and signal acquisition and transmission functions, and can be installed on the reaction vessel 230, the connecting device 210, or the shell of the crystal growth furnace.

[0096] The conductive detection structure 270 is used to detect the contact state between the device body 110 and the melt 240 inside the reaction vessel 230. During operation, it can utilize the conductive properties of the melt 240 itself to construct an electrical circuit. When the device body 110 is not moved to a position in contact with the melt 240 along with the connecting device 210, the electrical circuit consisting of at least the device body 110, the melt 240, and the reaction vessel 230 remains open. When the device body 110 moves downward and comes into contact with the melt 240, the electrical circuit switches from an open state to a conductive state. By identifying the change in the circuit's open / closed state, it can be determined whether the device body 110 has formed contact with the melt 240.

[0097] The electrical circuit can consist only of the main body 110, the melt 240 and the reaction vessel 230. In this case, the main body 110 and the reaction vessel 230 can be electrically connected through a conductive strip made of graphite. The electrical circuit can also include a shell connecting the connecting device 210 and the crystal growth furnace, so that the shell is electrically connected to the connecting device 210 and the reaction vessel 230 respectively, forming a complete conductive link.

[0098] When the main body 110 of the device moves downward along with the connecting device 210 toward the reaction vessel 230, once the conductive detection structure 270 detects that the main body 110 of the device is in contact with the melt 240, the mating structure 120 can be switched from the original connected state to the separated state.

[0099] like Figure 1 As shown, the conductive detection structure 270 can be installed in the hollow cavity of the support seat on the side of the reaction vessel 230 away from the connecting shaft 213; in other embodiments of this application, the conductive detection structure 270 can also be installed in the hollow cavity of the connecting shaft 213 of the connecting device 210. The conductive detection structure 270 achieves indirect electrical communication with the device body 110 through the connecting device 210 or the reaction vessel 230.

[0100] This application also provides an application method for a seed crystal protection device, which is applied to the seed crystal protection device in the above embodiments, such as... Figure 6 As shown, the method includes: S101. Connect the mating structure to the connecting device, and allow the seed crystal to be received in the first receiving cavity through the opening.

[0101] S102. Drive the connecting device to move so that the main body of the device moves toward the reaction vessel until the preset separation conditions are met.

[0102] S103. In response to the separation condition, the mating structure is separated from the connecting device so that the main body of the device falls into the reaction vessel.

[0103] In the embodiments of this application, the seed crystal protection device includes a device body 110 and a mating structure 120. The device body 110 has a first receiving cavity 111a, and one side of the first receiving cavity 111a has an opening 111b. The mating structure 120 is connected to the device body 110. Based on this, when the mating structure 120 is connected to the connecting device 210, the seed crystal 220 assembled on the connecting device 210 can be received in the first receiving cavity 111a through the opening 111b. At this time, the first receiving cavity 111a can enclose the seed crystal 220, thereby protecting the seed crystal 220 and preventing the gaseous components generated by the evaporation of flux in the reaction vessel 230 from adhering to the surface of the seed crystal 220 during the initial stage of the molten material heating and melting, thus reducing the probability of the seed crystal 220 being contaminated. At the same time, when the cooperating structure 120 separates from the connecting device 210, the main body 110 of the device loses the fixed support of the connecting device 210 and can naturally fall into the reaction container 230 on the side of the seed crystal 220 away from the connecting device 210, thereby releasing the restriction on the seed crystal 220 and ensuring that the seed crystal 220 can grow normally under the action of the melt 240 in the reaction container 230.

[0104] The separation conditions can be understood by referring to the actual process conditions for switching between the connected and separated states in the above embodiments, and will not be repeated here.

[0105] Optionally, such as Figures 1 to 4 As shown, the mating structure 120 is a lifting ring, and the number of lifting rings is at least three; each lifting ring is adapted to engage with an inclined extension 2111 of the connecting device 210, the inclined extension 2111 is inclined relative to the circumferential tangent direction of the centroid axis of the connecting device 210, and the inclined extension 2111 extends inclined towards the direction close to the seed crystal 220; then, the separation of the mating structure from the connecting device in S103 includes: driving the connecting device to rotate until the mating structure disengages from the inclined extension of the engagement.

[0106] In the embodiments of this application, the mating structure 120 is configured as at least three lifting rings, each lifting ring forming a hook-fit with the inclined extension 2111 corresponding to the connecting device 210; the inclined extension 2111 is inclined in the circumferential tangent direction relative to the centroidal axis of the connecting device 210 and extends inclined towards the seed crystal 220. Under this structure, only the connecting device 210 needs to be driven to rotate, so that the lifting ring can be disengaged from the inclined extension 2111.

[0107] For example, the transition portion 2112 is connected to one end of the inclined extension portion 2111, and the lifting ring is engaged and limited at the other end of the inclined extension portion 2111 away from the transition portion 2112, with the lifting ring in a clockwise position corresponding to the transition portion 2112. Under this assembly and limiting relationship, the drive connecting device 210 can be rotated counterclockwise to disengage the lifting ring from the engaged inclined extension portion 2111.

[0108] In some embodiments of this application, when the end of the device body 110 facing the melt 240 comes into contact with the melt 240, the device body 110 is subjected to the combined effects of the buoyancy and surface tension of the melt 240. The melt 240 exerts a lifting force on the device body 110 from the melt 240 towards the device body 110. As the connecting device 210 continues to move the device body 110 downward toward the melt 240, this lifting force causes the downward movement speed of the device body 110 to lag behind the movement speed of the hook 211 of the connecting device 210, thereby creating a relative displacement between the lifting ring and the hook 211. This relative displacement allows the lifting ring and the hook 211 to separate on their own.

[0109] To further ensure the separation of the lifting ring from the hook 211, while the lifting force causes the lifting ring and hook 211 to separate on their own, the connecting device 210 can also be actively driven to rotate, so that the lifting ring can disengage from the inclined extension 2111 of the hook 211.

[0110] This application also provides a crystal growth furnace, including the seed crystal protection device described in the above embodiments.

[0111] In embodiments of this application, the crystal growth furnace includes a seed crystal protection device, such as... Figure 1 and Figure 2As shown, the seed crystal protection device includes a main body 110 and a mating structure 120. The main body 110 has a first receiving cavity 111a, and one side of the first receiving cavity 111a has an opening 111b. The mating structure 120 is connected to the main body 110. Based on this, when the mating structure 120 is connected to the connecting device 210, the seed crystal 220 assembled on the connecting device 210 can be received in the first receiving cavity 111a through the opening 111b. At this time, the first receiving cavity 111a can enclose the seed crystal 220, thereby protecting the seed crystal 220 and preventing the gaseous components generated by the evaporation of flux in the reaction vessel 230 from adhering to the surface of the seed crystal 220 during the initial stage of the molten material heating and melting, thus reducing the probability of the seed crystal 220 being contaminated. At the same time, when the cooperating structure 120 separates from the connecting device 210, the main body 110 of the device loses the fixed support of the connecting device 210 and can naturally fall into the reaction container 230 on the side of the seed crystal 220 away from the connecting device 210, thereby releasing the restriction on the seed crystal 220 and ensuring that the seed crystal 220 can grow normally under the action of the melt 240 in the reaction container 230.

[0112] Optionally, the crystal growth furnace also includes a connecting device 210, a seed crystal 220, and a reaction vessel 230, the interior of which is adapted to hold the melt 240.

[0113] Optionally, such as Figure 1 and Figure 2 As shown, the crystal growth furnace also includes a graphite pad 250, which is connected between the seed crystal mounting plate 214 and the seed crystal 220. The graphite pad 250 serves as a high-temperature flexible isolation buffer and temperature uniformity protection, which can reduce the probability of microcracks and edge damage caused by direct rigid contact between the seed crystal mounting plate 214 and the seed crystal 220, and can also balance heat transfer and buffer thermal stress, so that the seed crystal 220 is protected from the effects of assembly extrusion stress and temperature difference impact in the high-temperature crystal growth environment.

[0114] Optionally, such as Figure 1 As shown, the crystal growth furnace also includes a heating device 260, which is arranged around the circumference of the reaction vessel 230. The heating device 260 is suitable for heating the molten material and flux inside the reaction vessel 230 to obtain a melt 240.

[0115] This application also provides a method for using a crystal growth furnace, which is applied to the crystal growth furnace described in the above embodiments. Before the melt melting stage, the method includes: S201. Connect the mating structure and seed crystal to the connecting device respectively, and add molten material and flux into the reaction vessel.

[0116] After S201 is completed, the melting stage begins, and S202 is executed.

[0117] S202. The molten material and flux in the reaction vessel are heated by a heating device until the melting stage of the melt is completed.

[0118] After S202 is executed, before entering the seed crystal remelting stage, S203 is executed.

[0119] S203, drive the connecting device to move closer to the reaction vessel.

[0120] S204. When the conductive detection structure detects that the main body of the device is in contact with the melt, it responds to the preset separation conditions.

[0121] S205. Drive the connecting device to rotate until the preset rotation stop condition is met.

[0122] The rotation stopping condition can be either the connecting device rotating at a preset angle or the connecting device rotating for a preset duration.

[0123] S206. In response to a preset rotation stop condition, control the connecting device to stop rotating.

[0124] Throughout the entire process of the connecting device's rotation, from start to stop, the device continuously moves towards the reaction vessel, causing the lifting ring to separate from the inclined extension of the hook under the combined action of the lifting force applied by the melt and the rotational force of the connecting device. Once the lifting ring separates from the hook, it and the main body of the device can sink together to the bottom of the reaction vessel under their own weight.

[0125] S207. In response to a preset movement stop condition, control the connecting device to stop moving.

[0126] When the relative positional relationship between the seed crystal and the melt surface meets a preset condition, it is determined that the movement stop condition is met. The relative positional relationship between the seed crystal and the melt surface can be determined by the movement stroke and movement time of the connecting device, or by the driving step length of the driving device that is connected to the connecting device. The relative positional relationship between the seed crystal and the melt surface can be that the seed crystal is in contact with the melt surface, or that the seed crystal is partially immersed in the melt. This application does not make specific limitations.

[0127] After S207 is completed, the process proceeds sequentially to the seed crystal remelting stage and the crystal growth stage, until the silicon carbide single crystal growth process is finished.

[0128] It is understood that the application methods of the seed crystal protection device and the crystal growth furnace in this application can be executed by a processing device. The processing device can be a processor installed inside the crystal growth furnace, or it can be a terminal designed independently of the crystal growth furnace. The processing device is used to drive the various execution devices connected to it to perform corresponding actions; for example, connecting the mating structure and the seed crystal to the connecting device through assembly fixtures, and adding molten material and flux into the reaction vessel; or, for example, heating the molten material and flux through a heating device; or, for example, driving the connecting device to move or rotate through a driving device.

[0129] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0130] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A seed crystal protection device, characterized in that, The seed crystal protection device includes: a device body (110) and a matching structure (120). The main body (110) of the device has a first receiving cavity (111a), and an opening (111b) is provided on one side of the first receiving cavity (111a). The mating structure (120) is connected to the main body (110); the mating structure (120) has a connected state and a separated state. In the connected state, the mating structure (120) is adapted to be connected to the connecting device (210) so that the seed crystal (220) assembled in the connecting device (210) is received in the first receiving cavity (111a) through the opening (111b); In the separated state, the mating structure (120) is adapted to separate from the connecting device (210), and the main body of the device (110) can fall into the reaction vessel (230) located on the side of the seed crystal (220) away from the connecting device (210).

2. The seed crystal protection device according to claim 1, characterized in that, The fitting structure (120) is a lifting ring, which is connected to one end of the device body (110) near the opening (111b); In the connected state, the shackle is adapted to engage with the hook (211) of the connecting device (210).

3. The seed crystal protection device according to claim 2, characterized in that, The number of lifting rings is at least three; At least three of the aforementioned cranes are arranged in an equally spaced array around the center of mass axis of the device body (110) in the circumferential direction; and / or, Each of the said rings is adapted to engage with an inclined extension (2111) of a hook (211), the inclined extension (2111) being inclined relative to the circumferential tangent direction about the centroidal axis of the connecting device (210), the inclined extension (2111) extending inclined toward the seed crystal (220).

4. The seed crystal protection device according to any one of claims 1-3, characterized in that, The seed crystal protection device also includes a counterweight structure (130). The main body (110) of the device has a second receiving cavity (112a), which is separated from the first receiving cavity (111a); at least part of the counterweight structure (130) is received in the second receiving cavity (112a), and the counterweight structure (130) is connected to the main body (110).

5. The seed crystal protection device according to claim 4, characterized in that, The number of the counterweight structures (130) is at least three, and the at least three counterweight structures (130) are arranged in an equally spaced array around the center of mass axis of the device body (110) in the circumferential direction; and / or, The counterweight structure (130) is made of a material that can provide a fluxing effect on the melt inside the reaction vessel (230).

6. The seed crystal protection device according to any one of claims 1-3, characterized in that, The seed crystal protection device also includes a baffle structure (140). The partition structure (140) is arranged circumferentially along the inner wall of the device body (110), and the partition structure (140) is connected to the device body (110); in the connected state, the partition structure (140) can form a gap (140a) with the connecting device (210).

7. The seed crystal protection device according to any one of claims 1-3, characterized in that, On a projection plane perpendicular to the centroidal axis of the device body (110), the orthographic projection area of ​​the outer wall of the device body (110) at the end away from the opening (111b) is greater than the orthographic projection area of ​​the outer wall of the device body (110) at the end closer to the opening (111b); and / or, On the projection plane perpendicular to the centroidal axis of the device body (110), the orthographic projection area of ​​the inner wall of the device body (110) away from the opening (111b) is greater than the orthographic projection area of ​​the inner wall of the device body (110) closer to the opening (111b).

8. The seed crystal protection device according to any one of claims 1-3, characterized in that, The device body (110) is adapted to be electrically connected to the conductive detection structure (270), which is adapted to detect the contact state between the device body (110) and the melt in the reaction vessel (230).

9. A method for applying a seed crystal protection device, characterized in that, The method is applied to the seed crystal protection device as described in any one of claims 1-8, and the method includes: The mating structure (120) is connected to the connecting device (210), and the seed crystal (220) is received in the first receiving cavity (111a) through the opening (111b); Drive the connecting device (210) to move, so as to move the main body of the device (110) toward the reaction vessel (230) until the preset separation conditions are met; In response to the separation condition, the mating structure (120) is separated from the connecting device (210) so that the device body (110) falls into the reaction vessel (230).

10. The application method of the seed crystal protection device according to claim 9, characterized in that, The fitting structure (120) is a lifting ring, and the number of the lifting rings is at least three; each of the lifting rings is adapted to engage with an inclined extension (2111) of the connecting device (210), the inclined extension (2111) being inclined relative to the circumferential tangent direction around the centroidal axis of the connecting device (210), and the inclined extension (2111) extending inclinedly toward the direction close to the seed crystal (220); Separating the mating structure (120) from the connecting device (210) includes: Drive the connecting device (210) to rotate until the mating structure (120) disengages from the inclined extension (2111) that is engaged.

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