8-inch silicon carbide crystal growing furnace

Abstract

The invention discloses an 8-inch silicon carbide crystal growing furnace. The 8-inch silicon carbide crystal growing furnace comprises an equipment main body and a heating mechanism, the equipment body comprises a rack, four supporting assemblies are arranged at the bottom of the rack, a furnace body is installed on the top of the rack, and a crucible body is installed in the furnace body. According to the 8-inch silicon carbide crystal growing furnace provided by the invention, the crucible lifting and rotating assembly comprising the electric push rod, the supporting plate and the rotating motor and the coil lifting assembly comprising the bracket rod and the lifting motor are arranged, so that when the coil lifting assembly cannot work accurately, the lifting function of the crucible lifting and rotating assembly is used; and the crucible body and the heating coil are driven to do axial reciprocating motion, so that functional deficiency of equipment is avoided, a double-guarantee effect is achieved, and the use stability of the equipment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of crystal growth devices, and in particular to an 8-inch silicon carbide crystal growth furnace. Background Art

[0002] Most commercial semiconductor integrated circuit crystals are grown using the physical vapor transport (PVT) method. The basic principle of crystal growth is to place the raw material at the bottom of a graphite crucible, heat the crucible using the skin effect through an induction coil, and after reaching a certain temperature, the source material decomposes into gas and evaporates to the seed crystal area at the top of the crucible. After a series of chemical reactions, SiC is generated, and crystallizes on the surface of the seed crystal through a certain axial and radial temperature gradient to obtain single-crystal silicon carbide with a certain structure. The silicon carbide crystal growth furnace is a device specifically used to prepare high-quality silicon carbide single crystals. The device sublimates silicon carbide powder at high temperature by precisely controlling parameters such as temperature, pressure and atmosphere, and then vapor-transports and condenses and crystallizes on the seed crystal to form high-quality silicon carbide single crystals. The silicon carbide crystal growth furnace can produce silicon carbide single crystals ranging in size from 4 inches to 8 inches.

[0003] The existing document with announcement number CN115094513A discloses a silicon carbide crystal growth furnace, including a furnace body and a crucible, wherein the crucible is placed in the furnace body; further comprising a heating mechanism; the heating mechanism comprises a heating coil, a heating coil lifting assembly and a crucible rotating assembly; the heating coil is arranged through the furnace body, and the heating coil located inside the furnace body is wound around the crucible and arranged with a gap between the crucible; the heating coil lifting assembly is connected to the heating coil; the crucible rotating assembly is connected to the crucible. The crucible rotating assembly is controlled to drive the crucible to rotate at a set speed, overcoming physical factors such as the difference in the placement position of the crucible, the thickness of the crucible, and the strength of the magnetic field of the heating coil, thereby ensuring uniform radial temperature distribution inside the crucible; the heating coil lifting assembly is controlled to drive the heating coil in the furnace body to rise and fall at a certain speed, which can not only achieve different temperatures for different axial gradients inside the crucible, but also prevent defects such as micro-pipe dislocation caused by vibration of the mobile charging device.

[0004] In this scheme, the heating coil lifting assembly is controlled to drive the heating coil in the furnace body to rise and fall at a certain speed. When the heating coil lifting assembly fails, no axial relative movement can occur between the heating coil and the material in the crucible, which leads to certain disadvantages.

[0005] Therefore, it is necessary to provide an 8-inch silicon carbide crystal growth furnace to solve the above technical problems. Summary of the invention

[0006] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides an 8-inch silicon carbide crystal growth furnace that can use multiple methods to make the heating coil and the crucible produce axial relative movement.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] An 8-inch silicon carbide crystal growth furnace comprises: an equipment body and a heating mechanism. The equipment body comprises a frame, four supporting components are arranged at the bottom of the frame, a furnace body is installed on the top of the frame, and a crucible body is installed in the furnace body; the heating mechanism comprises a power supply, a slot circuit cabinet, a heating coil, an upper infrared high temperature measuring instrument, a lower infrared high temperature measuring instrument, a side infrared high temperature measuring instrument, a coil lifting component and a crucible rotating lifting component.

[0009] Preferably, the coil lifting assembly comprises a plurality of evenly mounted support rods, the support rods are connected to the heating coil, a lifting motor is installed at the bottom of the crucible body, and the lifting motor is connected to the support rods.

[0010] Preferably, the crucible lifting and rotating assembly includes an electric push rod installed at the bottom of the furnace body, a support plate is installed in the furnace body, the support plate is connected to the electric push rod, a rotating motor is installed on the top of the support plate, and the output shaft of the rotating motor is fixedly connected to the bottom of the crucible body.

[0011] Preferably, an annular track is installed at the bottom of the crucible body, and a plurality of supporting wheels are installed at the top of the supporting plate, and the tops of the supporting wheels are in contact with the track.

[0012] Preferably, a first insulation ring is installed at the bottom of the crucible body, and a second insulation ring is installed at the top of the support plate.

[0013] Preferably, spiral blades are installed on the outer side of the first thermal insulation ring.

[0014] Preferably, a plurality of sleeves are installed on the support rod, a clamp is installed on the sleeve, and an anti-dropping tongue is installed in the clamp.

[0015] Preferably, the support assembly comprises a connecting column, a base plate and a plurality of damping shock absorbers.

[0016] Preferably, a plurality of pressure sensors and drivers are mounted on the base plate.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention provides a crucible lifting and rotating assembly including an electric push rod, a support plate and a rotating motor, and a coil lifting assembly including a support rod and a lifting motor. When the coil lifting assembly cannot work accurately, the lifting function of the crucible lifting and rotating assembly can be used to drive the crucible body and the heating coil to produce axial reciprocating movement, thereby avoiding functional loss of the equipment, playing a dual protection role, and improving the stability of the equipment.

[0019] (2) The present invention can provide a certain degree of thermal insulation protection for the rotating electrical machine by providing the first thermal insulation ring and the second thermal insulation ring;

[0020] (3) The present invention can facilitate the heat circulation inside the furnace body by installing spiral blades on the outer side of the first heat insulation ring, making the temperature inside the furnace body more uniform;

[0021] (4) The present invention can conveniently connect and fix the support rod and the heating coil by providing a sleeve, a fastening screw and a clamp;

[0022] (5) The present invention can improve the seismic resistance of the equipment by providing a support assembly including a connecting column, a plate and a plurality of damping shock absorbers, thereby facilitating the improvement of the functional stability of the equipment and the improvement of product quality;

[0023] (6) The present invention can improve the operating stability of the equipment by installing multiple pressure sensors and drivers on the bottom plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a furnace body in an 8-inch silicon carbide crystal growth furnace provided by the present invention;

[0025] Figure 2 for Figure 1 A magnified schematic diagram of part A;

[0026] Figure 3 for Figure 1 A schematic diagram of the structure of the first thermal insulation ring in the 8-inch silicon carbide crystal growth furnace shown;

[0027] Figure 4 for Figure 1 A schematic diagram of the structure of the fixture in the 8-inch silicon carbide crystal growth furnace shown;

[0028] Figure 5 for Figure 1 The schematic diagram of the structure of the equipment body in the 8-inch silicon carbide crystal growth furnace shown;

[0029] Figure 6 for Figure 1 A schematic diagram of the structure of the support assembly in the 8-inch silicon carbide crystal growth furnace shown;

[0030] Figure 7 for Figure 1 Schematic diagram of the structure of the support assembly in the 8-inch silicon carbide crystal growth furnace shown.

[0031] Among them, the names corresponding to the figure marks are: 1-furnace body, 2-crucible body, 3-heating coil, 4-trough cabinet, 5-power supply, 6-support rod, 7-lifting motor, 8-electric push rod, 9-support plate, 10-rotating motor, 11-upper infrared high temperature measuring instrument, 12-lower infrared high temperature measuring instrument, 13-side infrared high temperature measuring instrument, 15-wheel frame, 16-support wheel, 17-track, 18-first insulation ring, 19-second insulation ring, 20-spiral leaf, 21-sleeve, 22-fastening screw, 23-clamp, 24-anti-drop tongue, 25-frame, 26-support assembly, 27-connecting column, 28-base plate, 29-damping shock absorber, 30-pressure sensor, 31-driver. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments of the present invention include but are not limited to the following embodiments.

[0033] Embodiment 1:

[0034] like Figure 1-7As shown, the 8-inch silicon carbide crystal growth furnace provided by the present invention is used to produce 8-inch silicon carbide crystals, including: an equipment body, a heating mechanism, a vacuum mechanism, a gas path mechanism, a cooling mechanism and a control mechanism. The vacuum mechanism, the gas path mechanism, the cooling mechanism and the control mechanism can all adopt the technical solutions disclosed in CN115094513A, which will not be repeated here. In this embodiment, the equipment body includes a frame 25, four support assemblies 26 are provided at the bottom of the frame 25, a furnace body 1 is installed on the top of the frame 25, and a crucible body 2 is installed in the furnace body 1; the heating mechanism includes a power supply 5, a slot cabinet 4, a heating coil 3, an upper infrared high temperature measuring instrument 11, a lower infrared high temperature measuring instrument 12, a side infrared high temperature measuring instrument 13, a coil lifting assembly and a crucible rotation lifting assembly; the coil lifting assembly includes a plurality of evenly installed support rods 6, and the support rods 6 are connected to the heating coil 3. The crucible body 2 is used to support the heating coil 3. A lifting motor 7 is installed at the bottom of the crucible body 2. The lifting motor 7 is connected to the support rod 6. The lifting motor 7 drives the support rod 6 to rise and fall. The power supply 5 and the slot circuit cabinet 4 are used together to increase and decrease the temperature of the heating coil 3. The principle adopts the technical solution disclosed in CN115094513A, which will not be repeated here. The upper infrared high-temperature measuring instrument 11, the lower infrared high-temperature measuring instrument 12 and the side infrared high-temperature measuring instrument 13 are used to monitor the temperature of various positions inside the crucible, and there are multiple side infrared high-temperature measuring instruments 13. Through the multi-directional and multi-point detection method, the crystal growth temperature control is more accurate, thereby improving the product quality. The crucible lifting and rotating assembly includes an electric push rod 8 installed at the bottom of the furnace body 1, a support plate 9 is installed in the furnace body 1, the support plate 9 is connected to the electric push rod 8, a rotating motor 10 is installed on the top of the support plate 9, and the output shaft of the rotating motor 10 is fixedly connected to the bottom of the crucible body 2. The electric push rod 8 can push the support plate 9 to rise and fall, thereby raising and lowering the crucible body 2. This mode is used to enable the crucible body 2 to still produce axial movement with the heating coil 3 when the coil lifting assembly cannot work properly. The rotating motor 10 can drive the crucible body 2 to rotate, overcoming physical factors such as the difference in the placement position of the crucible, the thickness of the crucible, the strength of the magnetic field of the heating coil, etc., thereby ensuring uniform radial temperature distribution inside the crucible.

[0035] By providing a crucible lifting and rotating assembly including an electric push rod 8, a support plate 9 and a rotating motor 10, and a coil lifting assembly including a support rod 6 and a lifting motor 7, when the coil lifting assembly cannot work accurately, the lifting function of the crucible lifting and rotating assembly can be used to drive the crucible body 2 and the heating coil 3 to produce axial reciprocating movement, thereby avoiding functional loss of the equipment, playing a dual protection role, and improving the stability of the equipment.

[0036] Embodiment 2:

[0037] like Figure 1-2As shown, a circular track 17 is installed at the bottom of the crucible body 2, a plurality of wheel frames 15 are installed on the top of the support plate 9, a support wheel 16 is installed on the top of the wheel frame 15, and the top of the support wheel 16 is in contact with the track 17. When in use, when the crucible body 2 is rotated horizontally, the track 17 rotates and drives the support wheel 16 to roll, and the stability of the crucible body 2 during rotation is improved by supporting at multiple points.

[0038] By installing an annular track 17 at the bottom of the crucible body 2 and installing multiple support wheels 16 on the support plate 9, the contact points between the support plate 9 and the crucible body 2 are increased, the stability of the crucible body 2 during rotation is improved, which is conducive to improving product quality.

[0039] Embodiment 3:

[0040] like Figure 1 As shown, a first insulation ring 18 is installed at the bottom of the crucible body 2, and a second insulation ring 19 is installed on the top of the support plate 9. The first insulation ring 18 and the second insulation ring 19 are both made of insulation materials, and a gap therebetween is extremely small, which provides good insulation. When in use, the high-temperature gas inside the furnace body is blocked by the first insulation ring 18 and the second insulation ring 19, so that the rotating motor 10 can be more effectively protected.

[0041] The first heat insulating ring 18 and the second heat insulating ring 19 can provide a certain heat insulating protection for the rotating electrical machine 10 .

[0042] Embodiment 4:

[0043] like Figure 3 As shown, a spiral blade 20 is installed on the outer side of the first insulation ring 18. When in use, the first insulation ring 18 rotates with the crucible body 2, so that the spiral blade 20 rotates, draws the scarce air upward, increases the hot air circulation speed at the bottom of the crucible body 2, and makes the temperature inside the furnace body 1 more uniform.

[0044] By installing the spiral blades 20 on the outer side of the first heat-insulating ring 18 , it is possible to facilitate the heat circulation inside the furnace body 1 , so that the temperature inside the furnace body 1 is more uniform.

[0045] Embodiment 5:

[0046] like Figure 4 As shown, a plurality of sleeves 21 are installed on the bracket rod 6, a fastening screw 22 is installed on the sleeve 21, and a clamp 23 is rotatably installed on the sleeve 21. The clamp 23 is in the shape of a "6" and is used to clamp the heating coil 3. An anti-slip tongue 24 is installed in the clamp 23. When in use, the height of the sleeve 21 is adjusted, and the clamp 23 is rotated so that its opening faces the heating coil 3, the heating coil 3 is clamped into the clamp 23, the anti-slip tongue 24 is clamped into the heating coil 3, and then the fastening screw 22 is tightened to fix the height of the sleeve 21.

[0047] By providing the sleeve 21 , the fastening screws 22 and the clamp 23 , the support rod 6 and the heating coil 3 can be conveniently connected and fixed.

[0048] Embodiment 6:

[0049] like Figure 6 As shown, in this embodiment, the support assembly 26 includes a connecting column 27, which is fixedly connected to the bottom of the frame 25. A bottom plate 28 is provided at the bottom of the connecting column 27, and the bottom plate 28 touches the ground for use. A plurality of damping shock absorbers 29 are installed between the bottom plate 28 and the connecting column 27 through a connecting ball head. When in use, when encountering vibration, the vibration is weakened by the plurality of damping shock absorbers 29, thereby reducing the impact of the vibration on the furnace body 1, thereby making the product quality more stable.

[0050] By providing a support assembly 26 including a connecting column 27, a plate 28 and a plurality of damping shock absorbers 29, the anti-seismic capability of the device can be improved, thereby facilitating the improvement of the functional stability of the device and the improvement of product quality.

[0051] Embodiment 7:

[0052] like Figure 7 As shown, a plurality of pressure sensors 30 and a driver 31 are installed on the base plate 28. When the pressure sensor 30 contacts the ground, the dispersed plurality of pressure sensors 30 detect the magnitude of the force in different directions of the base plate 28, and then the driver 31 drives the pressure sensor 30 to move up and down, so that the pressure at each position is averaged, thereby making the device more stable.

[0053] By installing a plurality of pressure sensors 30 and drivers 31 on the bottom plate 28 , the operational stability of the device can be improved.

[0054] Working principle: When in use, the lifting motor 7 drives the support rod 6 to rise and fall, and then the heating coil 3 to rise and fall, and cooperates with the rotating motor 10 to drive the crucible body 2 to rotate, thereby overcoming physical factors such as the difference in the placement of the crucible, the thickness of the crucible, the strength of the magnetic field of the heating coil, etc., so as to ensure that the radial temperature distribution inside the crucible is uniform, which can not only achieve different temperatures for different axial gradients inside the crucible, but also eliminate defects such as micropipe dislocation caused by vibration of the mobile loading device.

[0055] When the lifting motor 7 fails and the support rod 6 can no longer be lifted, the backup plan is activated at this time. The plan is to start the electric push rod 8, which can push the support plate 9 to lift and lower the crucible body 2, so that the equipment can still operate normally, avoiding the risk of product scrapping and reduced production efficiency caused by equipment maintenance.

Claims

1. An 8-inch silicon carbide crystal growth furnace, characterized in that: include: Equipment body and heating mechanism; The main body of the device comprises a frame (25), four supporting components (26) are arranged at the bottom of the frame (25), a furnace body (1) is installed on the top of the frame (25), and a crucible body (2) is installed in the furnace body (1); The heating mechanism comprises a power supply (5), a tank circuit cabinet (4), a heating coil (3), an upper infrared high temperature measuring instrument (11), a lower infrared high temperature measuring instrument (12), a side infrared high temperature measuring instrument (13), a coil lifting assembly and a crucible rotating lifting assembly.

2. The 8-inch silicon carbide crystal growth furnace according to claim 1, characterized in that: The coil lifting assembly comprises a plurality of support rods (6), wherein the support rods (6) are connected to the heating coil (3); a lifting motor (7) is installed at the bottom of the crucible body (2), and the lifting motor (7) is connected to the support rods (6).

3. The 8-inch silicon carbide crystal growth furnace according to claim 1, characterized in that: The crucible lifting and rotating assembly comprises an electric push rod (8) installed at the bottom of the furnace body (1); a support plate (9) is installed in the furnace body (1); the support plate (9) is connected to the electric push rod (8); a rotating motor (10) is installed on the top of the support plate (9); and the rotating motor (10) is fixedly connected to the bottom of the crucible body (2).

4. The 8-inch silicon carbide crystal growth furnace according to claim 3, characterized in that: An annular track (17) is installed at the bottom of the crucible body (2), and a plurality of support wheels (16) are installed at the top of the support plate (9), wherein the support wheels (16) are in contact with the track (17).

5. The 8-inch silicon carbide crystal growth furnace according to claim 3, characterized in that: A first heat-insulating ring (18) is installed at the bottom of the crucible body (2), and a second heat-insulating ring (19) is installed at the top of the support plate (9).

6. The 8-inch silicon carbide crystal growth furnace according to claim 5, characterized in that: A spiral blade (20) is installed on the outer side of the first heat insulation ring (18).

7. The 8-inch silicon carbide crystal growth furnace according to claim 2, characterized in that: A plurality of sleeves (21) are installed on the support rod (6), a clamp (23) is installed on the sleeve (21), and an anti-dropping tongue (24) is installed in the clamp (23).

8. The 8-inch silicon carbide crystal growth furnace according to claim 1, characterized in that: The support assembly (26) comprises a connecting column (27), a base plate (28) and a plurality of damping shock absorbers (29).

9. The 8-inch silicon carbide crystal growth furnace according to claim 8, characterized in that: A plurality of pressure sensors (30) and drivers (31) are mounted on the base plate (28).

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