Crucible device of multi-dimensional coupling structure of large-size silicon carbide crystal growth thermal field

Abstract

The invention relates to the technical field of crystal growth, and discloses a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field. A multi-dimensional coupling mechanism; the multi-dimensional coupling mechanism is arranged in the crucible body, forward and reverse rotation of the driving motor and up-down movement of the lifting frame are achieved through the arranged multi-dimensional coupling mechanism, and the stirring blades can rotate in the horizontal plane and can also move in the vertical direction; meanwhile, the up-and-down movement of the heat conduction shell also realizes multi-dimensional heating of the upper and lower areas of the crystal, on one hand, the dynamic adjustment of the heating area and strength is realized, a more uniform and more controllable temperature gradient is favorably formed in the axial and radial directions of crystal growth, and on the other hand, the mixing of silicon carbide raw materials at the bottom of the crucible can be effectively promoted; local supersaturation or precipitation is prevented, the uniformity of gas phase transmission is ensured, a more stable and more sufficient material source is provided for crystal growth, and defects such as inclusions are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crystal growth, in particular to a crucible device with a multi-dimensional coupling structure of a thermal field for large-size silicon carbide crystal growth. BACKGROUND

[0002] Silicon carbide, as an important third-generation semiconductor material, has a wide band gap, a high critical breakdown electric field, a high thermal conductivity, a high electron saturation drift speed and other excellent characteristics, and has great application potential in the fields of high-temperature, high-voltage, high-frequency and high-power electronic devices, such as new energy vehicles, photovoltaic power generation, 5G communication, power electronics and aerospace. In the process of growing large-size silicon carbide crystals, the design and control of the thermal field are key factors that determine the quality of the crystals. The thermal field not only needs to provide a high enough temperature to drive the sublimation of the raw material, but also needs to form a precise and stable temperature gradient to ensure the directional transmission and uniform deposition of the gas phase components and reduce the generation of internal defects of the crystals (such as microtubules, dislocations and inclusions).

[0003] According to Chinese Patent Publication No. CN116770423A, a double-induction heating growth device and method for large-diameter silicon carbide single crystals are disclosed. The double-induction heating growth device includes a graphite crucible, a first induction heating coil, and a second induction heating coil. The first induction heating coil and the second induction heating coil are arranged on the outer periphery of the graphite crucible. The first induction heating coil is located above the second induction heating coil. The first induction heating coil and the second induction heating coil do not overlap each other. The frequency of the induction power source corresponding to the first induction heating coil is 30-100 kHz, and the frequency of the induction power source corresponding to the second induction heating coil is 1-10 kHz. The present application adopts different frequency induction heating coils to effectively improve the radial temperature gradient at the silicon carbide seed crystal, maintain a lower heating power, improve the growth quality of large-diameter silicon carbide single crystals, and reduce production costs. However, the device still has some deficiencies. The double-induction heating mainly relies on the electromagnetic induction heating of the external coil, and the thermal field regulation mainly reflects the improvement of the radial temperature gradient. Although the coupling effect is brought about by the different frequencies, the thermal field adjustment is mainly carried out around the outer periphery of the crucible, and there is a lack of direct adjustment of the axial thermal field of the crystal, which limits its best effect in more complex growth conditions or in cases where the quality of the crystal is extremely high. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a crucible device with a multi-dimensional coupling structure of a thermal field for large-size silicon carbide crystal growth, which solves the above problems.

[0005] In order to achieve the above object, the present application is realized by the following technical scheme: a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field crucible device, comprising: Crucible pot body; Multi-dimensional coupling mechanism; the multi-dimensional coupling mechanism is arranged inside the crucible pot body, and is used for stirring the silicon carbide crystal while driving the multi-dimensional heating of the silicon carbide crystal; the multi-dimensional coupling mechanism comprises a fixed support, a driving motor, a threaded rod, a multi-dimensional lifting frame, a limiting sliding rail, a limiting sliding block, a movable piece, a compression spring, a fixed piece and a crystal stirring blade; Crucible heat dissipation mechanism; the crucible heat dissipation mechanism is arranged on both sides of the crucible pot body.

[0006] Preferably, the upper surface of the fixed support is provided with a driving motor in the middle, the output end of the driving motor is drivingly connected with a threaded rod, the lower end of the threaded rod is rotatably connected with the bottom of the crucible pot body, the outer side of the threaded rod is threadedly connected with a multi-dimensional lifting frame, the upper surface of the multi-dimensional lifting frame is fixedly connected with a heat conduction shell, the left and right sides of the heat conduction shell are fixedly connected with limiting sliding blocks, the two limiting sliding blocks are respectively slidingly connected with the inner sides of two limiting sliding rails, and the two limiting sliding rails are fixedly connected with the left and right sides of the inside of the crucible pot body.

[0007] Preferably, the outer side of the upper end of the threaded rod is fixedly connected with a fixed piece, the outer side of the lower end of the threaded rod is fixedly connected with a movable piece, the movable piece and the fixed piece are provided with a compression spring therebetween, the lower surface of the movable piece is provided with a crystal stirring blade, and the crystal stirring blade is fixedly connected with the threaded rod.

[0008] Preferably, the crucible heat dissipation mechanism comprises a heat dissipation support, a heat dissipation groove, a flow guide fan, a heat absorption support and heat exchange fins, the heat dissipation support is fixedly connected with the outer side of the fixed support, the side, close to the crucible pot body, of the fixed support is fixedly connected with a heat absorption support, and the inside of the heat absorption support is provided with a plurality of heat exchange fins.

[0009] Preferably, the inside of the heat dissipation support is provided with a heat dissipation groove, the inside of the heat dissipation groove is provided with a flow guide fan, the flow guide fan and the heat absorption support are provided with a motor therebetween, and the output end of the motor is drivingly connected with the flow guide fan.

[0010] Preferably, the upper side of the rear side of the crucible pot body is provided with a crystal placing box, the inside of the crystal placing box is provided with a plurality of large-size silicon carbide crystals, the outer side of the crystal placing box is fixedly connected with a driving motor, the output end of the driving motor is drivingly connected with a material guiding rotating blade, and one end, away from the output end of the driving motor, of the material guiding rotating blade is rotatably connected with the inside surface of the crystal placing box.

[0011] Preferably, the lower end of the crystal placing box is provided with a feeding pipe, and the lower end of the feeding pipe is arranged above the crucible pot body.

[0012] Preferably, the outer surface of the crucible pot is provided with three groups of heating coils, and a heat insulation ring is arranged between two adjacent heating coils and fixedly connected to the outer side of the crucible pot.

[0013] Preferably, the lower part of the crucible pot is provided with a heating furnace.

[0014] Preferably, the upper end of the compression spring is fixedly connected to the lower surface of the fixed sheet, and the lower end of the compression spring is fixedly connected to the upper surface of the movable sheet.

[0015] Advantages The present application provides a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field crucible device, which has the following advantages compared with the prior art: 1、In the present application, the output end of the driving motor drives the threaded rod to rotate after the driving motor is started, the lower end of the threaded rod is in transmission connection with the bottom of the crucible pot, so that the threaded rod can rotate stably, the outer side of the threaded rod is in meshing connection with the multi-dimensional lifting frame, when the threaded rod rotates, it drives the multi-dimensional lifting frame to move up and down along the threaded direction, the heat conduction shell moves up and down with the multi-dimensional lifting frame, which adjusts the heating position as needed during the crystal growth process, realizes the up-down multi-dimensional and dynamic heating of the silicon carbide crystal (especially the seed crystal region or the growth interface), when the threaded rod drives the multi-dimensional lifting frame to rise, the movable sheet is lifted, the compression spring is compressed, when the threaded rod drives the multi-dimensional lifting frame to descend in the reverse direction, the compression spring releases the elastic force and pushes the movable sheet and the crystal stirring blade below it to move downward until the stirring blade contacts the silicon carbide raw material or the crystal growth region at the bottom of the crucible, at this time, the continuous rotation of the threaded rod drives the stirring blade to rotate and stir, the compression spring plays a role of buffering and providing downward pressure, which ensures that the stirring blade can effectively contact and stir the raw material or the crystal surface, through the forward and reverse rotation of the driving motor and the up-down movement of the lifting frame, the stirring blade can not only rotate and stir in the horizontal plane, but also move in the vertical direction, so as to realize the up-down and multi-dimensional stirring of the silicon carbide crystal / raw material, and the up-down movement of the heat conduction shell also realizes the multi-dimensional heating of the upper and lower regions of the crystal, on the one hand, it realizes the dynamic adjustment of the heating area and intensity, which helps to form a more uniform and controllable temperature gradient in the axial and radial directions of the crystal growth, on the other hand, it can effectively promote the mixing of the silicon carbide raw material at the bottom of the crucible, prevent local supersaturation or precipitation, ensure the uniformity of the gas phase transmission, provide a more stable and sufficient material source for the crystal growth, and reduce defects such as inclusions; 2、In the application, when the crystal growth reaches the expected target or needs to be interrupted, the growth process is stopped, at this time, the inside of the crucible pot is full of high-temperature residual polysilicon, silicon carbide powder and possible unreacted raw materials, and the crucible itself is also in a high-temperature state, the crucible heat dissipation mechanism of the control system is started, the heat absorbing bracket fixed outside the fixed bracket and close to the crucible pot starts to work, the multiple heat exchange fins inside the heat absorbing bracket directly contact or are close to the high-temperature crucible, and a large amount of heat conducted on the surface of the crucible is rapidly absorbed. The flow guide fan inside the heat dissipation bracket starts to rotate under the drive of the motor, and the airflow generated by the flow guide fan forms a directional forced convection in the heat dissipation groove, the airflow flows through the heat absorbing bracket and the heat exchange fins thereof, the absorbed heat is rapidly transferred, and is discharged outside the system through the heat dissipation groove, so that efficient heat dissipation is realized. Compared with natural cooling, the active heat dissipation mechanism can significantly accelerate the cooling speed of the crucible and the residual materials inside the crucible, shorten the waiting time after the whole growth cycle, and improve the equipment turnover rate. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A front side perspective structure schematic view of a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application. Figure 2 An internal structure schematic view of a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application. Figure 3 A rear side perspective structure schematic view of a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application. Figure 4 A structure schematic view of a crucible pot in a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application. Figure 5 A structure schematic view of a multi-dimensional coupling mechanism in a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application. Figure 6 A structure schematic view of a crucible heat dissipation mechanism in a crucible device of a multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field is provided in the application.

[0017] LEGEND: 1, heating furnace; 2, crucible pot body; 3, crystal placement box; 4, heat conduction shell; 5, multi-dimension coupling mechanism; 501, fixed support; 502, driving motor; 503, threaded rod; 504, multi-dimension lifting frame; 505, limiting slide rail; 506, limiting slide block; 507, movable piece; 508, compression spring; 509, fixed piece; 510, crystal stirring blade; 6, crucible heat dissipation mechanism; 601, heat dissipation support; 602, heat dissipation groove; 603, flow guide fan; 604, heat absorption support; 605, heat exchange fin; 7, heating coil; 8, heat insulation ring; 9, material guiding rotating blade; 10, driving motor; 11, feeding pipe. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0019] Reference Figures 1-6 The present application provides two technical solutions, specifically including the following embodiments.

[0020] Embodiment one: A multi-dimensional coupling structure of a large-size silicon carbide crystal growth thermal field crucible device, comprising: a crucible pot body 2; a multi-dimensional coupling mechanism 5; the multi-dimensional coupling mechanism 5 is arranged inside the crucible pot body 2, and is used for stirring the silicon carbide crystal while driving the silicon carbide crystal to be heated in multiple dimensions; the multi-dimensional coupling mechanism 5 comprises a fixed support 501, a driving motor 502, a threaded rod 503, a multi-dimensional lifting frame 504, a limiting sliding rail 505, a limiting sliding block 506, a movable piece 507, a compression spring 508, a fixed piece 509 and a crystal stirring blade 510, the middle of the upper surface of the fixed support 501 is provided with the driving motor 502, the output end of the driving motor 502 is drivingly connected with the threaded rod 503, the lower end of the threaded rod 503 is rotatably connected with the bottom of the crucible pot body 2, the outer side of the threaded rod 503 is threadedly connected with the multi-dimensional lifting frame 504, the upper surface of the multi-dimensional lifting frame 504 is fixedly connected with a heat-conducting shell 4, the left and right sides of the heat-conducting shell 4 are fixedly connected with the limiting sliding blocks 506, the limiting sliding blocks 506 are respectively slidingly connected with the inner sides of the two limiting sliding rails 505, the limiting sliding rails 505 are fixedly connected with the left and right sides of the inside of the crucible pot body 2, the outer side of the upper end of the threaded rod 503 is fixedly connected with the fixed piece 509, the outer side of the lower end of the threaded rod 503 is fixedly connected with the movable piece 507, the compression spring 508 is arranged between the movable piece 507 and the fixed piece 509, the lower surface of the movable piece 507 is provided with the crystal stirring blade 510, the crystal stirring blade 510 is fixedly connected with the threaded rod 503, the upper end of the compression spring 508 is fixedly connected with the lower surface of the fixed piece 509, and the lower end of the compression spring 508 is fixedly connected with the upper surface of the movable piece 507.

[0021] When the driving motor 502 is started, its output end drives the threaded rod 503 to rotate. Since the lower end of the threaded rod 503 is rotationally connected to the bottom of the crucible pot 2, the threaded rod 503 can rotate stably. The outer side of the threaded rod 503 is connected to the multi-dimensional lifting frame 504 through thread engagement. When the threaded rod 503 rotates, it drives the multi-dimensional lifting frame 504 to move up and down along the thread direction. The heat-conducting shell 4 moves up and down with the multi-dimensional lifting frame 504. The purpose is to adjust the heating position according to the needs during the crystal growth process, so as to realize the multi-dimensional and dynamic heating of the silicon carbide crystal, especially the seed crystal area or the growth interface. When the threaded rod 503 drives the multi-dimensional lifting frame 504 to rise, the movable piece 507 is lifted, and the compression spring 508 is compressed. When the threaded rod 503 reversely rotates to drive the multi-dimensional lifting frame 504 to descend, the compression spring 508 releases the elastic force and pushes the movable piece 507 and the crystal stirring blade 510 below it to move downward until the stirring blade contacts the silicon carbide raw material or the crystal growth area at the bottom of the crucible. At this time, the continuous rotation of the threaded rod 503 will drive the stirring blade to rotate and stir. The compression spring 508 plays a buffering and downward pressure-providing role, ensuring that the stirring blade can effectively contact and stir the raw material or the crystal surface. Through the forward and reverse rotation of the driving motor 502 and the up and down movement of the lifting frame, the stirring blade can not only rotate and stir in the horizontal plane, but also move in the vertical direction, so as to realize the up and down and multi-dimensional stirring of the silicon carbide crystal / raw material. At the same time, the up and down movement of the heat-conducting shell 4 also realizes the multi-dimensional heating of the upper and lower areas of the crystal. On the one hand, it realizes the dynamic adjustment of the heating area and intensity, which helps to form a more uniform and more controllable temperature gradient in the axial and radial directions of the crystal growth. On the other hand, it can effectively promote the mixing of the silicon carbide raw material at the bottom of the crucible, prevent local supersaturation or precipitation, ensure the uniformity of gas phase transmission, provide a more stable and sufficient material source for crystal growth, and reduce defects such as inclusions.

[0022] Example two: On the basis of embodiment one, the crucible heat dissipation mechanism 6; the crucible heat dissipation mechanism 6 is arranged on both sides of the crucible pot body 2, the crucible heat dissipation mechanism 6 includes heat dissipation support 601, heat dissipation groove 602, flow fan 603, heat absorption support 604 and heat exchange fin 605, heat dissipation support 601 is fixedly connected on the outside of fixed support 501, fixed support 501 is fixedly connected with heat absorption support 604 on the side close to crucible pot body 2, heat absorption support 604 is internally provided with a plurality of heat exchange fins 605, heat dissipation support 601 is internally provided with heat dissipation groove 602, heat dissipation groove 602 is internally provided with flow fan 603, motor is arranged between flow fan 603 and heat absorption support 604, the output end of motor is in transmission connection with flow fan 603, the upper side of the rear side of crucible pot body 2 is provided with crystal placing box 3, a plurality of large-size silicon carbide crystals are arranged in the inside of crystal placing box 3, drive motor 10 is fixedly connected on the outside of crystal placing box 3, the output end of drive motor 10 is in transmission connection with guide rotating blade 9, one end of guide rotating blade 9 away from the output end of drive motor 10 is in transmission connection with the inside surface of crystal placing box 3, feed pipe 11 is arranged on the lower end of crystal placing box 3, the lower end of feed pipe 11 is arranged above crucible pot body 2, three groups of heating coils 7 are arranged on the outer surface of crucible pot body 2, heat insulation ring 8 is arranged between adjacent two heating coils 7, heat insulation ring 8 is fixedly connected on the outside of crucible pot body 2, heating furnace 1 is arranged below crucible pot body 2, when the crystal growth reaches the expected target or needs to be interrupted, the growth process stops, at this time, the inside of crucible pot body 2 is filled with high-temperature residual polysilicon, silicon carbide powder and possible unreacted raw materials, the crucible itself is also in a high-temperature state, the crucible heat dissipation mechanism 6 of the control system is started, the heat absorption support 604 fixed on the outside of the fixed support 501 and close to the crucible pot body 2 starts to work, the multiple heat exchange fins 605 in the inside of the heat absorption support 604 directly contact or are close to the high-temperature crucible, rapidly absorb a large amount of heat conducted on the surface of the crucible, the flow fan 603 in the inside of the heat dissipation support 601 starts to rotate under the driving of the motor. The airflow generated by the flow fan 603 forms directional forced convection in the heat dissipation groove 602, the airflow flows through the heat absorption support 604 and the heat exchange fins 605 thereof, the absorbed heat is rapidly transferred and discharged outside the system through the heat dissipation groove 602, realizing efficient heat dissipation. Compared with natural cooling, the active heat dissipation mechanism can significantly accelerate the cooling speed of the crucible and the residual materials in the inside thereof, shorten the waiting time after the whole growth period, and improve the equipment turnover rate.

[0023] The above only describes the preferred embodiments of the present application and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the present application.

Claims

1. A crucible device with a multi-dimensional coupled structure for the thermal field of large-scale silicon carbide crystal growth, characterized by: include: Crucible pot body (2); A multi-dimensional coupling mechanism (5); the multi-dimensional coupling mechanism (5) is arranged inside the crucible pot body (2), and the multi-dimensional coupling mechanism (5) is used to stir the silicon carbide crystal while driving the silicon carbide crystal to heat up and down in multiple dimensions; the multi-dimensional coupling mechanism (5) includes a fixed bracket (501), a drive motor (502), a threaded rod (503), a multi-dimensional lifting frame (504), a limiting slide rail (505), a limiting slider (506), a movable plate (507), a pressing spring (508), a fixed plate (509) and a crystal stirring blade (510); Crucible heat dissipation mechanism (6); the crucible heat dissipation mechanism (6) is arranged on both sides of the crucible pot body (2).

2. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 1, characterized in that: A driving motor (502) is provided in the middle of the upper surface of the fixed bracket (501), the output end of the driving motor (502) is transmission-connected to a threaded rod (503), the lower end of the threaded rod (503) is rotatably connected to the bottom of the crucible pot body (2), the outer side of the threaded rod (503) is threadedly connected to a multi-dimensional lifting frame (504), the upper surface of the multi-dimensional lifting frame (504) is fixedly connected to a heat-conducting shell (4), the left and right sides of the heat-conducting shell (4) are fixedly connected to limiting sliders (506), the limiting sliders (506) are respectively slidably connected to the inner sides of two limiting slide rails (505), and the limiting slide rails (505) are fixedly connected to the left and right sides of the interior of the crucible pot body (2).

3. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 2, characterized in that: The outer side of the upper end of the threaded rod (503) is fixedly connected to a fixed plate (509), the outer side of the lower end of the threaded rod (503) is fixedly connected to a movable plate (507), a compression spring (508) is provided between the movable plate (507) and the fixed plate (509), and a crystal stirring blade (510) is provided on the lower surface of the movable plate (507), and the crystal stirring blade (510) is fixedly connected to the threaded rod (503).

4. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 1, characterized in that: The crucible heat dissipation mechanism (6) comprises a heat dissipation bracket (601), a heat dissipation slot (602), a guide fan (603), a heat absorption bracket (604) and heat exchange fins (605); the heat dissipation bracket (601) is fixedly connected to the outside of the fixed bracket (501); a heat absorption bracket (604) is fixedly connected to a side of the fixed bracket (501) close to the crucible pot body (2); and a plurality of heat exchange fins (605) are arranged inside the heat absorption bracket (604).

5. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 4, characterized in that: A heat dissipation slot (602) is provided inside the heat dissipation bracket (601), a guide fan (603) is provided inside the heat dissipation slot (602), a motor is provided between the guide fan (603) and the heat absorption bracket (604), and an output end of the motor is transmission-connected to the guide fan (603).

6. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 1, characterized in that: A crystal placement box (3) is provided above the rear side of the crucible pot body (2), a plurality of large-sized silicon carbide crystals are provided inside the crystal placement box (3), a drive motor (10) is fixedly connected to the outside of the crystal placement box (3), an output end of the drive motor (10) is transmission-connected to a material guide rotating blade (9), and an end of the material guide rotating blade (9) away from the output end of the drive motor (10) is transmission-connected to the inner surface of the crystal placement box (3).

7. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 6, characterized in that: A feed pipe (11) is provided at the lower end of the crystal placement box (3), and the lower end of the feed pipe (11) is arranged above the crucible pot body (2).

8. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 1, characterized in that: Three groups of heating coils (7) are provided on the outer surface of the crucible pot body (2), and a heat insulating ring (8) is provided between two adjacent heating coils (7), and the heat insulating ring (8) is fixedly connected to the outer side of the crucible pot body (2).

9. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 1, characterized in that: A heating furnace (1) is provided below the crucible pot body (2).

10. The crucible device with a multi-dimensional coupling structure for the thermal field of large-scale silicon carbide crystal growth according to claim 3, characterized in that: The upper end of the compression spring (508) is fixedly connected to the lower surface of the fixed plate (509), and the lower end of the compression spring (508) is fixedly connected to the upper surface of the movable plate (507).

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