CN218989473U

CN218989473U - Multi-temperature-zone induction heating silicon carbide single crystal growth device in vacuum environment

Info

Publication number: CN218989473U
Application number: CN202320219550.7U
Authority: CN
Inventors: 赵科新; 金成林; 孙浩; 王海涛; 王学峰
Original assignee: Shenyang Tianke Heda Semiconductor Equipment Co ltd
Current assignee: Shenyang Tianke Heda Semiconductor Equipment Co ltd
Priority date: 2023-02-15
Filing date: 2023-02-15
Publication date: 2023-05-09
Anticipated expiration: 2033-02-15

Abstract

The utility model belongs to the technical field of silicon carbide crystal growth, and particularly relates to a multi-temperature-zone induction heating silicon carbide single crystal growth device in a vacuum environment. The utility model comprises a vacuum chamber, which is characterized in that: the bottom in the vacuum chamber is provided with a graphite growth chamber through a crucible rod, and at least two independently controlled heating induction coils are arranged outside the graphite growth chamber. The utility model optimizes the structure of the heating induction coil, can realize multi-region temperature control, has faster temperature rise, easier adjustment of the axial gradient of the temperature region, more uniform radial temperature and higher temperature control precision, solves the problem of air release of the coil in a vacuum environment, and has lower energy consumption.

Description

Multi-temperature-zone induction heating silicon carbide single crystal growth device in vacuum environment

Technical Field

The utility model belongs to the technical field of silicon carbide crystal growth, and particularly relates to a multi-temperature-zone induction heating silicon carbide single crystal growth device in a vacuum environment.

Background

The silicon carbide single crystal material can meet the current requirements of high-power and strong radiation devices due to the characteristics of wide forbidden band, high thermal conductivity, high breakdown electric field, high radiation resistance and the like, is an ideal substrate material for preparing high-temperature, high-frequency, high-power and radiation resistant devices, and is a brand-new corner in the fields of hybrid electric vehicles, high-voltage transmission, LED illumination, aerospace and the like, and the growing of high-quality silicon carbide crystals is the basis for realizing the excellent performance of the silicon carbide based devices.

The most mature method for growing silicon carbide crystal at present is to heat silicon carbide powder to 2200-2600 ℃ and sublimate the silicon carbide powder to cold end seed crystal under a certain protective atmosphere, the key technology of the method has two points, firstly, a proper temperature field is established, and stable gas phase silicon carbide transport flow from high temperature to low temperature is formed; second, vapor phase silicon carbide can be epitaxially grown on the substrate. At the same time, the pressure of the gas in the growth chamber needs to be controlled during the growth process. There are two methods for generating high temperature, one is high-current graphite body heating, and the other is medium-frequency induction heating. The former method has low heating speed, graphite body is easily gasified when heated at high temperature, the service life of a heating body is seriously influenced, and the latter method has high heating speed, the service life of a copper induction coil of the heating body is long, meanwhile, less heat insulation material is needed, and a growth chamber is easy to reach high vacuum, so that a commercial silicon carbide crystal is grown by adopting an induction heating furnace generally.

The induction heating uses an intermediate frequency power supply to supply power to an induction coil, and the induction coil generates an alternating magnetic field around under the action of intermediate frequency alternating current. The electromagnetic induction of the alternating magnetic field causes the surface layer of the high-density graphite crucible arranged in the induction coil to generate closed induction current, namely eddy current, and the electric energy of the high-density current generated by the surface of the graphite crucible under the action of the eddy current is converted into heat energy, so that the temperature of the surface layer of the crucible is increased, the heat energy is conducted into the crucible, and the carbonization arranged at the bottom of the crucible is heatedA silicon raw material, and heating the gas inside the graphite crucible by heat radiation, including Si, siC, si generated by sublimation and decomposition of the silicon carbide raw material ₂ C、SiC ₂ An isogas phase component. The silicon carbide seed crystal is arranged at the top of the crucible and is in a relatively low temperature region, and the silicon carbide powder is arranged in a high temperature region. The gas phase component is transmitted to a low temperature area under the drive of a temperature gradient, and silicon carbide crystals are deposited and grown on the surface of the silicon carbide seed crystal (the temperature gradient is the drive of the growth of the silicon carbide crystals).

The coils used in the prior technical proposal are uniformly distributed, silicon carbide powder is positioned in a heating coil, and eddy current generated by an induction coil directly heats a graphite crucible in the area where the silicon carbide powder is positioned, and the graphite crucible directly heats the silicon carbide powder through heat conduction; the seed crystal is positioned at the upper part of the heating coil and is heated mainly by the heat radiation of the graphite crucible, and the seed crystal is positioned in a relatively low-temperature area. Thus, the temperature gradient between the seed crystal and the silicon carbide powder is determined by the relative positions of the induction coil and the silicon carbide powder and seed crystal. In the crystal growth process, silicon carbide powder is continuously consumed, the height difference between the top of the silicon carbide powder and a seed crystal is continuously changed, the temperature gradient between the seed crystal and the silicon carbide powder is also changed along with the change of the height difference, and after the silicon carbide powder sublimates, silicon carbide cannot obtain stable temperature growth crystallization at the seed crystal, so that the growth of large-size silicon carbide crystals is not facilitated. When growing large-sized crystals, the graphite growth chamber, quartz tube and induction coil are correspondingly increased in size, and the wall thickness of the quartz tube is correspondingly increased, which results in poor coupling between the induction coil and the graphite growth chamber, and lower induction efficiency, making it difficult to generate a desired growth temperature in the graphite growth chamber. Thus, the growth apparatus of this structure has a large limitation on the size of the grown crystal.

Therefore, it is necessary to provide a silicon carbide growing device, which changes the thermal field structural design, optimizes the temperature gradient between silicon carbide powder and seed crystal, and realizes the growth of silicon carbide crystals with large size and high effective thickness.

Disclosure of Invention

The utility model aims at the problems, overcomes the defects of the prior art, and provides a multi-temperature-zone induction heating silicon carbide single crystal growth device in a vacuum environment.

In order to achieve the above object of the present utility model, the present utility model adopts the following technical scheme, and the present utility model includes a vacuum chamber, characterized in that: the bottom in the vacuum chamber is provided with a graphite growth chamber through a crucible rod, and at least two independently controlled heating induction coils are arranged outside the graphite growth chamber.

As a preferable mode of the utility model, the heating induction coil is provided with two sub-coils, and the two sub-coils respectively correspond to the upper part and the lower part of the graphite growth chamber.

As another preferable mode of the utility model, the heating induction coil is provided with three sub-induction coils which respectively correspond to the upper part, the middle part and the lower part of the graphite growth chamber.

Further, the heating induction coil and the graphite growth chamber are arranged coaxially.

Further, the upper end of the vacuum chamber is provided with a sealing cover which can be opened.

Further, an air inlet is formed in the bottom of the vacuum chamber, and an air extraction opening is formed in the middle of the side wall of the vacuum chamber.

Further, an upper temperature measuring hole is formed in the top of the vacuum chamber, and a lower temperature measuring hole is formed in the bottom of the vacuum chamber.

Further, the crucible rod is arranged in a lifting structure.

Further, the vacuum chamber is arranged to be of a metal double-layer water cooling structure.

Further, a heat insulating material layer is arranged outside the graphite growth chamber.

The utility model has the beneficial effects that: the utility model eliminates the defect caused by the clamping of the vacuum chamber wall between the heating induction coil and the crystal growth chamber, and can conveniently change the size of the graphite growth chamber by adjusting the thickness of the heat insulation material layer so as to achieve the purpose of changing the size of the grown crystal; meanwhile, as a double-layer quartz tube is not arranged between the heating induction coil and the graphite growth chamber, the direct coupling efficiency of the heating induction coil and the graphite growth chamber is greatly improved, the heating induction coil can be designed to be large in size, and the graphite growth chamber can be well coupled even if the size of the graphite growth chamber is changed in a large range, so that large-size SiC crystals can be grown without large equipment transformation.

The utility model optimizes the structure of the heating induction coil, can realize multi-region temperature control, has faster temperature rise, easier adjustment of the axial gradient of the temperature region, more uniform radial temperature and higher temperature control precision, solves the problem of air release of the coil in a vacuum environment, and has lower energy consumption.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is a cross-sectional view A-A of fig. 1.

Fig. 3 is a B-B cross-sectional view of fig. 1.

Fig. 4 is a schematic diagram of a heating induction coil structure of the present utility model comprising two sub-induction coils.

In the drawing, a crucible rod is 1, a graphite growth chamber is 2, a heating induction coil is 3, a supporting frame is 4, a vacuum chamber is 5, a sealing cover is 6, an air inlet is 7, a binding post is 8, an extraction opening is 9, an upper temperature measuring hole is 10, and a lower temperature measuring hole is 11.

Detailed Description

The utility model comprises a vacuum chamber 5 characterized in that: the graphite growing chamber 2 is arranged at the bottom in the vacuum chamber 5 through the crucible rod 1, and at least two independently controlled heating induction coils 3 are arranged outside the graphite growing chamber 2.

As a preferable mode of the present utility model, the heating induction coil 3 is provided with two sub-coils corresponding to the upper and lower portions of the graphite growth chamber 2, respectively.

As another preferable aspect of the present utility model, the heating induction coil 3 is provided with three sub-induction coils corresponding to the upper, middle and lower portions of the graphite growth chamber 2, respectively.

Further, the heating induction coil 3 and the graphite growth chamber 2 are arranged coaxially.

Further, an openable sealing cover 6 is arranged at the upper end of the vacuum chamber 5.

Further, an air inlet 7 is formed in the bottom of the vacuum chamber 5, and an air extraction opening 9 is formed in the middle of the side wall of the vacuum chamber 5.

Further, the top and bottom of the vacuum chamber are provided with an upper temperature measuring hole 10 and a lower temperature measuring hole 11, respectively.

Further, the crucible rod 1 is arranged in a lifting structure.

Further, the vacuum chamber 5 is provided with a metal double-layer water cooling structure.

Further, a heat insulating material layer is arranged outside the graphite growth chamber 2.

The sub-induction coils may also be provided in plurality.

As shown in fig. 1 to 4, a vacuum chamber 5 of the utility model is of a double-layer water-cooling structure, and a spiral cooling water channel is arranged in the double-layer water-cooling structure; a supporting frame 4 is arranged in a vacuum chamber 5 of the utility model, and a heating induction coil 3 is fixed on the supporting frame 4; the crucible rod 1 is arranged at the bottom of the vacuum chamber 5, the lower end of the crucible rod 1 extends out of the vacuum chamber 5 and is connected with a lifting driving mechanism (not shown), and the lifting driving mechanism can be a driving motor screw nut assembly or a telescopic cylinder or a manually lifted screw nut assembly; the lifting driving mechanism can adjust the height position of the crucible rod 1, the graphite growth chamber 2 is arranged at the upper end of the crucible rod 1, and along with the height change of the crucible rod 1, the optimal position relation between the graphite growth chamber 2 and the heating induction coil 3 can be adjusted.

The side wall of the vacuum chamber 5 can be provided with an air suction hole and a power supply structure, a binding post 8 which is connected with the inside and the outside of the vacuum chamber 5 is arranged in the power supply structure, two ends of the induction coil are connected with the binding post 8 in the vacuum chamber 5, and the binding post 8 outside the vacuum chamber 5 is connected with a power supply; each induction coil is independently controlled through a binding post 8 connected with the induction coil, and the induction coil can be better suitable for temperature control in the silicon carbide crystal growth process.

When the utility model is used, an operator firstly fixes the graphite growth chamber 2 added with silicon carbide powder and seed crystals at the bottom of the vacuum chamber 5 with a double-layer water-cooling structure, then coats a heat insulation material layer outside the graphite growth chamber 2, and then respectively installs an induction coil at the upper part and the lower part of the outer side of the heat insulation material layer, and the two induction coils are respectively connected with a temperature controller (not shown). Closing the sealing cover 6, pumping the vacuum chamber 5 to reach a preset vacuum degree, filling high-purity argon, respectively connecting the two sub-induction coils, heating the graphite growth chamber 2, starting a pressure control device (not shown), and controlling the pressure in the vacuum chamber 5 to ensure that the vacuum chamber 5 reaches a constant temperature and constant pressure state until crystals with preset sizes grow.

It should be understood that the foregoing detailed description of the present utility model is provided for illustration only and is not limited to the technical solutions described in the embodiments of the present utility model, and those skilled in the art should understand that the present utility model may be modified or substituted for the same technical effects; as long as the use requirement is met, the utility model is within the protection scope of the utility model.

Claims

1. The utility model provides a many temperature zones induction heating carborundum single crystal growing device under vacuum environment, includes vacuum chamber (5), its characterized in that: the inner bottom of the vacuum chamber (5) is provided with a graphite growth chamber (2) through a crucible rod (1), and at least two independently controlled heating induction coils (3) are arranged outside the graphite growth chamber (2).

2. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the heating induction coil (3) is provided with two sub-coils which respectively correspond to the upper part and the lower part of the graphite growth chamber (2).

3. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the heating induction coil (3) is provided with three sub-induction coils which respectively correspond to the upper part, the middle part and the lower part of the graphite growth chamber (2).

4. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the heating induction coil (3) and the graphite growth chamber (2) are arranged coaxially.

5. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the upper end of the vacuum chamber (5) is provided with an openable sealing cover (6).

6. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the bottom of the vacuum chamber (5) is provided with an air inlet (7), and the middle part of the side wall of the vacuum chamber (5) is provided with an air extraction opening (9).

7. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the top of the vacuum chamber is provided with an upper temperature measuring hole (10), and the bottom of the vacuum chamber is provided with a lower temperature measuring hole (11).

8. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the crucible rod (1) is arranged to be of a lifting structure.

9. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the vacuum chamber (5) is of a metal double-layer water cooling structure.

10. The apparatus for multi-temperature zone induction heating silicon carbide single crystal growth in a vacuum environment of claim 1, wherein: the graphite growth chamber (2) is externally provided with a heat insulation material layer.