Multi-temperature-zone SiC crystal growing furnace

Abstract

The invention belongs to the technical field of crystal growth, and particularly relates to a multi-temperature-zone SiC crystal growth furnace, which comprises a furnace body, a plurality of temperature zones and a plurality of temperature zones, the top heating assembly is used for heating the top of the furnace body; the bottom heating assembly is used for heating the bottom of the furnace body; the side surface heating assembly is used for heating the side surface of the furnace body; the top heating assembly, the bottom heating assembly and the side face heating assembly are arranged on the top face, the bottom face and the side face of the furnace body respectively. According to the crystal growth furnace, the top heating assembly, the bottom heating assembly and the side face heating assembly are arranged on the top face, the bottom face and the side face of the furnace body correspondingly, the periphery of the furnace body can be evenly heated, and the situation that due to the size of the furnace body, temperature distribution is too uneven, and the yield of the crystal growth furnace is affected is prevented; and the high yield of the crystal growth furnace can be well ensured, and the product consistency is good.

Description

Technical Field

[0001] The invention belongs to the technical field of crystal growth, and particularly relates to a multi-temperature zone SiC crystal growth furnace. Background Art

[0002] SiC material, with its unique large bandgap, high critical breakdown field strength, high electron mobility, high thermal conductivity and other characteristics, has become an ideal material for making high-temperature, high-frequency, high-power, radiation-resistant, short-wave luminescent and optoelectronic integrated devices. The unique physical properties of SiC material determine its application in important fields such as artificial satellites, rockets, radars, communications, fighters, non-interference electronic ignition devices, jet engine sensors, etc. Therefore, all developed countries have invested a lot of manpower and material resources in related technical research.

[0003] The commonly used preparation method for large-diameter SiC crystals is physical vapor transport (PVT). The equipment is a PVT single crystal furnace. SiC powder is placed at the bottom of a closed graphite crucible, a seed crystal is fixed on the top of the crucible, and graphite insulation material is placed outside the crucible. The crucible is heated by medium-frequency induction, and the powder reaches the sublimation point to produce Si, C, SiC2, and Si2C molecules. Driven by the axial temperature gradient, they are transferred from the surface of the raw material to the surface of the seed crystal, condensed on the surface of the seed crystal, and slowly crystallized to achieve the purpose of growing crystals.

[0004] During the traditional single-coil heating PVT growth of SiC crystals, Si atmosphere overflows from the pores of the crucible, corrodes the insulation material, causing continuous loss of insulation and constant changes in the temperature gradient of the temperature field. It is difficult to ensure the stability of the growth process and the consistency between furnaces, resulting in low SiC crystal yield and poor consistency, which ultimately leads to high prices for SiC single crystal wafers and limits their commercial promotion and application.

[0005] The prior art designs a new growth device to grow SiC single crystals to improve the yield and consistency of SiC materials and reduce their costs to meet the requirements for the development of domestic electronic devices. The specific application number is (2020113738457).

[0006] Although the above technology can improve the yield and consistency of SiC materials to a certain extent, its heating is limited to the sides of the vacuum chamber, and there is no heating structure on the top and bottom surfaces. Since the vacuum chamber has a certain diameter, there will be a temperature difference from the outside to the inside of the vacuum chamber. The temperature of the top and bottom surfaces of the vacuum chamber will also be different from the temperature of the sides, which still limits the improvement of the consistency of crystal growth. Summary of the invention

[0007] In order to solve the above problems, this article mainly provides a multi-temperature zone SiC crystal growth furnace, which has a high yield and good product consistency.

[0008] Another object of the present invention is to provide a multi-temperature zone SiC crystal growth furnace, which has accurate temperature detection and good temperature control effect.

[0009] In order to achieve the above object, the technical solution of the present invention is as follows.

[0010] A multi-temperature zone SiC crystal growth furnace, characterized in that it comprises:

[0011] A furnace body, which is provided with a growth cavity for crystal growth;

[0012] A top heating assembly, used for heating the top of the furnace body;

[0013] A bottom heating assembly, used for heating the bottom of the furnace body;

[0014] A side heating assembly is used to heat the side of the furnace body;

[0015] The top heating assembly, the bottom heating assembly and the side heating assembly are respectively arranged on the top surface, the bottom surface and the side surface of the furnace body.

[0016] In the present invention, by respectively arranging a top heating component, a bottom heating component and a side heating component on the top, bottom and side of the furnace body, the furnace body can be evenly heated on all sides to prevent the temperature distribution from being too uneven due to the volume of the furnace body, thereby affecting the yield of the crystal growth furnace. This can well ensure that the yield of the crystal growth furnace is high and the product consistency is good.

[0017] Furthermore, the furnace body includes a shell, an insulation layer and a crucible provided with a growth cavity, the insulation layer is coated on the outer surface of the crucible, a receiving cavity is provided in the shell, the insulation layer and the crucible are both arranged in the receiving cavity, the top heating component and the bottom heating component are both arranged in the receiving cavity, and the two correspond to the top and the bottom of the crucible respectively, and the side heating component is arranged around the side of the shell. The arrangement of the above structure ensures the normal operation of the furnace body. The crucible is used as a container for crystal growth, the insulation layer realizes the basic insulation function, the shell provides the overall structural strength of the product, and can also further improve the insulation effect. The top heating component and the bottom heating component are both arranged in the receiving cavity, which can effectively reduce the overall heat energy loss of the product, and can also shorten the distance of induction heating and improve the heating effect.

[0018] Furthermore, the shell includes a middle shell, an upper shell and a lower shell. After the upper shell and the lower shell are respectively covered on the upper and lower sides of the middle shell, the three form a containing cavity. A lower cavity is formed between the insulation layer and the lower shell, and an upper cavity is formed between the insulation layer and the upper shell. The top heating component is located in the upper cavity, and the bottom heating component is located in the lower cavity. The insulation layer is a conventional insulation material. The setting of the upper cavity and the lower cavity can better realize the heating of the top heating component and the bottom heating component, and can also cooperate with the vacuum pump to better realize the vacuum effect inside the crucible, that is, after the crucible forms a vacuum environment, it is equivalent to that there are multiple cavities outside the crucible to improve the airtightness.

[0019] Furthermore, the top heating assembly, the bottom heating assembly and the side heating assembly all include induction heating coils, and the furnace body also includes a power supply, and the power supply and the induction heating coils are electrically connected. The induction heating coil is a preferred heating method of the present invention, and only needs to be connected to a power supply, and an induced magnetic field can be generated by powering on, so that the crucible heats up. The power supply is preferably a capacitor.

[0020] Furthermore, the side heating assembly includes multiple groups of induction heating coils, which are evenly surrounded by the shell from top to bottom, and each group of induction heating coils is connected to a power supply. The side heating assembly includes multiple groups of induction heating coils, each group of induction heating coils is independent of each other, and can realize multi-temperature zone control of the furnace from top to bottom, that is, by controlling the power of the induction heating coils in different areas, different temperatures in different positions can be achieved.

[0021] Furthermore, the furnace body also includes a top temperature detector, a bottom temperature detector and a side temperature detector, and the detection ends of the top temperature detector, the bottom temperature detector and the side temperature detector correspond to the top, bottom and side of the crucible respectively, and the shell and the insulation layer are provided with detection holes extending to the surface of the crucible for detection by the top temperature detector, the bottom temperature detector and the side temperature detector. The provision of the top temperature detector, the bottom temperature detector and the side temperature detector can detect the temperature of the crucible in real time, so as to better control the operation of the top heating component, the bottom heating component and the side heating component in real time. The provision of the detection hole can prevent the influence of the shell and the insulation layer on the temperature detection, and further improve the accuracy of the temperature detection.

[0022] Furthermore, the furnace body also includes a vacuum mechanism, which is connected to the growth cavity of the crucible to evacuate or break the vacuum of the growth cavity. The vacuum mechanism can provide an ideal crystal growth environment for the growth cavity, which is more conducive to ensuring the quality of crystal growth.

[0023] Furthermore, the furnace body also includes a frame, which includes a first cavity, a second cavity and a third cavity, the second cavity is below the first cavity, the third cavity is to the right of the first cavity, the shell is installed in the first cavity, and the top surface of the shell is exposed at the top of the frame, the vacuum mechanism is installed in the second cavity, and a mounting plate is provided in the third cavity, and a mounting position for installing a side temperature detector is provided on the mounting plate. The setting of the frame can provide a stable installation space for each structure, and through the position setting of the first cavity, the second cavity and the third cavity, each structure can be installed reasonably, and can work well as long as it is installed.

[0024] Furthermore, the furnace body also includes a cover opening mechanism, the output end of which is fixedly connected to the upper shell to drive the upper shell to open or close. The setting of the cover opening mechanism can facilitate opening the upper shell, and then facilitate opening the insulation layer and the crucible to take in and put in materials.

[0025] Furthermore, the cover opening mechanism includes a mounting plate, a lifting cylinder and a translation cylinder, the lifting cylinder is mounted on the mounting plate, the mounting plate is fixed on the frame, the output shaft of the lifting cylinder is fixedly connected to the upper shell to drive the upper shell to open or close, and the output end of the translation cylinder is fixedly connected to the mounting plate to drive the mounting plate and the upper shell to perform translational movement. Preferably, a slider is provided on the mounting plate, and a slide rod is also provided on the frame, the slider is sleeved on the slide rod, and when the translation cylinder is connected to the mounting plate and performs telescopic movement, the mounting plate can slide on the slide rod through the slider under the drive of the translation cylinder. Such a structure is not only stable, but also simple. The lifting cylinder can also be connected to the upper shell by providing a slider on the mounting block, the slider is sleeved on the slide rod, and the slide rod is connected to the upper shell, thereby ensuring the stability of opening and closing of the upper shell.

[0026] Furthermore, the furnace body also includes a blocking device for blocking or opening the detection hole. The blocking device can be set to block the detection hole according to specific circumstances and needs, so that the temperature detector cannot detect the temperature inside the furnace, or the detection hole can be opened to allow the temperature detector to detect the temperature inside the furnace. The setting of the blocking device is mainly to overcome the problems found in long-term verification, that is, when the detection hole is connected to the outside for a long time, the temperature inside the furnace detected by the temperature detector through the detection hole will be inaccurate. If the detection hole is closed when the temperature detector is not detecting, and the detection hole is opened again in the few seconds when it is required to detect, such periodic detection can greatly improve the accuracy of the temperature detector's detection.

[0027] Furthermore, the blocking device includes a fixed rod, a fixed block, a blocking plate, a trigger plate and an electromagnet that attracts or repels the trigger plate, the fixed block is fixedly connected to the inner side of the shell, the fixed rod is rotatably connected to the fixed block, the blocking plate and the trigger plate are both fixedly connected to the fixed rod, and the blocking plate corresponds to the position of the detection hole, and the electromagnet is arranged on the outer side of the shell, and the electromagnet corresponds to the position of the trigger plate. During specific operation, by energizing an electromagnet, or energizing multiple electromagnets in turn, the repulsion and attraction of the trigger plate can be achieved, so that the trigger plate drives the fixed rod to rotate on the fixed block, and then the blocking plate rotates with the fixed rod, so that the blocking plate blocks the detection hole or does not block the detection hole.

[0028] The beneficial effect of the present invention is that by respectively arranging a top heating component, a bottom heating component and a side heating component on the top, bottom and side of the furnace body, the furnace body can be evenly heated on all sides to prevent the temperature distribution from being too uneven due to the volume of the furnace body, thereby affecting the yield of the crystal growth furnace. The high yield of the crystal growth furnace and good product consistency can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a first angle structural schematic diagram of a multi-temperature zone SiC crystal growth furnace.

[0030] Figure 2 This is a second angle structural schematic diagram of a multi-temperature zone SiC crystal growth furnace.

[0031] Figure 3 This is a third angle structural diagram of a multi-temperature zone SiC crystal growth furnace.

[0032] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure of AA.

[0033] Figure 5 yes Figure 4 A partial enlarged view of point A in the middle.

[0034] Figure 6 yes Figure 4 A partial enlarged view of point B in the middle.

[0035] Figure 7 It is a schematic diagram of the cross-sectional structure of a multi-temperature zone SiC crystal growth furnace from a three-dimensional angle.

[0036] Figure 8 yes Figure 7 A partial enlarged view of point C in the middle.

[0037] Fig. 9 It is a structural schematic diagram of the cover opening mechanism.

[0038] Fig.10It is a schematic diagram of the structure of the shell, power supply, heating coil and electromagnet.

[0039] Fig.11 It is a schematic diagram of the structure of the blocking device.

[0040] Fig.12 It is a part of the circuit principle schematic diagram of the present invention.

[0041] Fig.13 It is another part of the circuit principle schematic diagram of the present invention, and Fig.12 Together they form a complete circuit schematic diagram.

[0042] 1. furnace body; 10. growth chamber; 11. shell; 12. insulation layer; 13. crucible; 110. containing chamber; 111. middle shell; 112. upper shell; 113. lower shell; 1101. lower chamber; 1102. upper chamber;

[0043] 2. Top heating component;

[0044] 3. Bottom heating component;

[0045] 4. Side heating assembly;

[0046] 5. Heating coil;

[0047] 6. Power supply;

[0048] 7. Top temperature detector;

[0049] 8. Bottom temperature detector;

[0050] 9. Side temperature detector;

[0051] 101. Detection hole;

[0052] 102. Vacuum mechanism;

[0053] 103, frame; 1031, first cavity; 1032, second cavity; 1033, third cavity;

[0054] 104, mounting plate;

[0055] 105, cover opening mechanism; 1051, mounting block; 1052, lifting cylinder; 1053, translation cylinder;

[0056] 106. Slider;

[0057] 107. Slider;

[0058] 108. blocking device; 1081. fixing rod; 1082. fixing block; 1083. blocking plate; 1084. trigger plate; 1085. electromagnet. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0060] See also Figure 1-3 This embodiment provides a multi-temperature zone SiC crystal growth furnace, characterized in that it includes:

[0061] A furnace body 1 is provided with a growth chamber 10 for crystal growth;

[0062] A top heating assembly 2, used for heating the top of the furnace body 1;

[0063] A bottom heating assembly 3, used for heating the bottom of the furnace body 1;

[0064] A side heating assembly 4, used for heating the side of the furnace body 1;

[0065] The top heating assembly 2 , the bottom heating assembly 3 and the side heating assembly 4 are respectively arranged on the top surface, the bottom surface and the side surface of the furnace body 1 .

[0066] In the present invention, by respectively arranging a top heating component 2, a bottom heating component 3 and a side heating component 4 on the top, bottom and side of the furnace body 1, the furnace body 1 can be evenly heated on all sides to prevent the temperature distribution from being too uneven due to the volume of the furnace body 1, thereby affecting the yield of the crystal growth furnace. This can well ensure that the yield of the crystal growth furnace is high and the product consistency is good.

[0067] In this embodiment, the furnace body 1 includes a shell 11, an insulation layer 12 and a crucible 13 provided with a growth cavity 10, the insulation layer 12 is coated on the outer surface of the crucible 13, a housing cavity 110 is provided in the shell 11, the insulation layer 12 and the crucible 13 are both arranged in the housing cavity 110, the top heating component 2 and the bottom heating component 3 are both arranged in the housing cavity 110, and the two correspond to the top and the bottom of the crucible 13 respectively, and the side heating component 4 is arranged around the side of the shell 11. The above-mentioned structural arrangement ensures the normal operation of the furnace body 1, the crucible 13 is used as a container for crystal growth, the insulation layer 12 realizes the basic insulation function, the shell 11 provides the structural strength of the product as a whole, and can also further improve the insulation effect. The top heating component 2 and the bottom heating component 3 are both arranged in the housing cavity 110, which can effectively reduce the overall heat energy loss of the product, and can also shorten the distance of induction heating and improve the heating effect.

[0068] In this embodiment, the shell 11 includes a middle shell 111, an upper shell 112 and a lower shell 113. After the upper shell 112 and the lower shell 113 are respectively covered on the upper and lower sides of the middle shell 111, the three form a accommodating cavity 110, a lower cavity 1101 is formed between the thermal insulation layer 12 and the lower shell 113, an upper cavity 1102 is formed between the thermal insulation layer 12 and the upper shell 112, the top heating component 2 is located in the upper cavity 1102, and the bottom heating component 3 is located in the lower cavity 1101. The thermal insulation layer 12 is a conventional thermal insulation material. The setting of the upper cavity 1102 and the lower cavity 1101 can better realize the heating of the top heating component 2 and the bottom heating component 3, and can also cooperate with the vacuum pump to better realize the vacuum effect inside the crucible 13, that is, after the crucible 13 forms a vacuum environment, it is equivalent to that there are multiple cavities outside the crucible 13 to improve the airtightness.

[0069] In this embodiment, the top heating assembly 2, the bottom heating assembly 3 and the side heating assembly 4 all include an induction heating coil 5, and the furnace body also includes a power supply 6, and the power supply 6 is electrically connected to the induction heating coil 5. The induction heating coil 5 is a preferred heating method of the present invention, and only needs to be connected to a power supply, and an induced magnetic field can be generated by powering on, so that the crucible heats up. The power supply 6 is preferably a capacitor.

[0070] In this embodiment, the side heating assembly 4 includes a plurality of groups of induction heating coils 5, which are uniformly surrounded by the shell 11 from top to bottom, and each group of induction heating coils 5 is connected to a power supply 6. The side heating assembly 4 includes a plurality of groups of induction heating coils 5, each group of induction heating coils 5 is independent of each other, and can realize multi-temperature zone control of the furnace from top to bottom, that is, by controlling the power of the induction heating coils 5 in different areas, different temperatures at different positions can be achieved.

[0071] In this embodiment, the furnace body also includes a top temperature detector 7, a bottom temperature detector 8 and a side temperature detector 9. The detection ends of the top temperature detector 7, the bottom temperature detector 8 and the side temperature detector 9 correspond to the top, the bottom and the side of the crucible 13 respectively. The shell 11 and the insulation layer 12 are provided with detection holes 101 extending to the surface of the crucible 13 for detection by the top temperature detector 7, the bottom temperature detector 8 and the side temperature detector 9. The provision of the top temperature detector 7, the bottom temperature detector 8 and the side temperature detector 9 can detect the temperature of the crucible 13 in real time, so as to better control the operation of the top heating component 7, the bottom heating component 8 and the side heating component 9 in real time. The provision of the detection hole 101 can prevent the influence of the shell 11 and the insulation layer 12 on the temperature detection, and further improve the accuracy of the temperature detection.

[0072] In this embodiment, the furnace body further includes a vacuum mechanism 102, which is connected to the growth chamber 10 of the crucible 13 to evacuate or break the vacuum of the growth chamber 10. The vacuum mechanism 102 can provide an ideal crystal growth environment for the growth chamber 10, which is more conducive to ensuring the quality of crystal growth. The vacuum mechanism 102 is a structure composed of a conventional vacuum pump and a vacuum pipeline, and the vacuum pump is connected to the growth chamber 10 of the crucible 13 through a vacuum pipeline.

[0073] In this embodiment, the furnace body further includes a frame 103, the frame 103 includes a first cavity 1031, a second cavity 1032 and a third cavity 1033, the second cavity 1032 is below the first cavity 1031, the third cavity 1033 is to the right of the first cavity 1031, the shell 11 is installed in the first cavity 1031, and the top surface of the shell 11 is exposed at the top of the frame 103, the vacuum mechanism 102 is installed in the second cavity 1032, and the third cavity 1033 is provided with a mounting plate 104, and the mounting plate 104 is provided with a mounting position for installing the side temperature detector 9. The setting of the frame 103 can provide a stable installation space for each structure, and through the position setting of the first cavity 1031, the second cavity 1032 and the third cavity 1033, each structure can be installed reasonably, and can work well as long as it is installed.

[0074] In this embodiment, the furnace body further includes a cover opening mechanism 105, the output end of which is fixedly connected to the upper shell 112 to drive the upper shell 112 to open or close. The setting of the cover opening mechanism 105 can facilitate opening the upper shell 112, and then facilitate opening the insulation layer 12 and the crucible 13 to take in and put in materials.

[0075] In this embodiment, the cover opening mechanism 105 includes a mounting block 1051, a lifting cylinder 1052 and a translation cylinder 1053. The lifting cylinder 1052 is mounted on the mounting block 1051, and the mounting block 1051 is fixed on the frame 103. The output shaft of the lifting cylinder 1052 is fixedly connected to the upper shell 112 to drive the upper shell 112 to open or close. The output end of the translation cylinder 1053 is fixedly connected to the mounting block 1051 to drive the mounting block 1051 and the upper shell 112 to perform translational motion. Preferably, a slider 106 is provided on the mounting block 1051, and a slide bar 107 is also provided on the frame 103. The slider 106 is sleeved on the slide bar 107. When the translation cylinder 1053 is connected to the mounting block 1051 and performs telescopic motion, the mounting block 1051 can slide on the slide bar 107 through the slider 106 under the drive of the translation cylinder 1053. Such a structure is not only stable, but also simple. The lifting cylinder 1052 can also be formed by setting a slider 106 on the mounting block 1051, wherein the slider 106 is sleeved on the slide rod 107 and connected to the upper shell 112 through the slide rod 107, thereby ensuring the stability of the opening and closing of the upper shell 112.

[0076] In this embodiment, the furnace body further includes a blocking device 108 for blocking or opening the detection hole 101. The blocking device 108 can be set to block the detection hole 101 according to specific circumstances and needs, so as to prevent the temperature detector 9 from detecting the temperature in the furnace, or to open the detection hole 101 so as to allow the temperature detector 9 to detect the temperature in the furnace. The setting of the blocking device 108 is mainly to overcome the problem found in long-term verification, that is, when the detection hole 101 is connected to the outside for a long time, the temperature in the furnace detected by the temperature detector 9 through the detection hole 101 will be inaccurate. If the detection hole 101 is closed when the temperature detector 9 is not detecting, and the detection hole 101 is opened again in the few seconds when detection is required, such periodic detection can greatly improve the detection accuracy of the temperature detector 9.

[0077] In this embodiment, the blocking device 108 includes a fixed rod 1081, a fixed block 1082, a blocking plate 1083, a trigger plate 1084 and an electromagnet 1085 that attracts or repels the trigger plate. The fixed block 1082 is fixedly connected to the inner side of the shell 11, the fixed rod 1081 is rotatably connected to the fixed block 1082, the blocking plate 1083 and the trigger plate 1084 are both fixedly connected to the fixed rod 1081, and the blocking plate 1083 corresponds to the position of the detection hole 101 to close or open the detection hole 101, and the electromagnet 1085 is arranged on the outer side of the shell 11, and the electromagnet 1085 corresponds to the position of the trigger plate 1084. During specific operation, by energizing one electromagnet 1085 or energizing multiple electromagnets 1085 in turn, repulsion and attraction of the trigger plate 1084 can be achieved, so that the trigger plate 1084 drives the fixed rod 1081 to rotate on the fixed block 1082, and then the blocking plate 1083 rotates with the fixed rod 1081, so that the blocking plate 1083 blocks the detection hole 101 or does not block the detection hole 101.

[0078] See also Figure 12-13The top heating component 2, the bottom heating component 3 and the side heating component 4 of the present invention respectively include a group of induction heating coils 5, a group of induction heating coils 5 and four groups of induction heating coils 5, each group of induction heating coils is connected in parallel with a capacitor to form LC parallel resonant circuits A1, A2, A3, A4, A5 and A6, the resonant circuit A1 is connected in parallel with a transformer B1, the resonant circuit A2 is connected in parallel with a transformer B2, the resonant circuit A3 is connected in parallel with a transformer B3, the resonant circuit A4 is connected in parallel with a transformer B4, the resonant circuit A5 is connected in parallel with a transformer B5, and the resonant circuit A6 is connected in parallel with a transformer B6, wherein one end of the transformer B1 is connected to an inverter 1, one end of the transformer B2 is connected to an inverter 2, one end of the transformer B3 is connected to an inverter 3, one end of the transformer B4 is connected to an inverter 4, one end of the transformer B5 is connected to an inverter 5, and one end of the transformer B6 is connected to an inverter 6, and the inverter is preferably a bridge IGBT inverter. All inverters are connected to the same voltage regulation circuit.

[0079] In addition, a capacitor and an inductor are connected in series between each resonant circuit and the transformer.

[0080] The present invention also includes a current and voltage detection module, which is used to detect the current (A1) and voltage (A1) of the resonance circuit A1, the current (A2) and voltage (A2) of the resonance circuit A2, the current (A3) and voltage (A3) of the resonance circuit A3, the current (A4) and voltage (A4) of the resonance circuit A4, the current (A5) and voltage (A5) of the resonance circuit A5, and the current (A6) and voltage (A6) of the resonance circuit A6;

[0081] Specifically, the current (A1) and the voltage (A1) are input to the filter 1, and after filtering, they enter the frequency tracking phase locking unit 1 for frequency tracking and phase locking; after being processed by the frequency tracking phase locking unit 1, a frequency signal f1 is generated, and then the frequency signal f1 is processed into a PFM pulse frequency modulation signal to control the operation of the inverter 1, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. The filter 1 is a bandpass filter, which is used to filter out interference signals generated by other resonant circuits, and the frequency tracking phase locking unit 1 is a conventional technology.

[0082] The current (A2) and voltage (A2) are input to filter 2, and after filtering, they enter the frequency tracking phase locking unit 2 for frequency tracking and phase locking; after being processed by the frequency tracking phase locking unit 2, a frequency signal f2 is generated, and then the frequency signal f2 is processed into a PFM pulse frequency modulation signal to control the operation of inverter 2, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. Filter 2 is a bandpass filter used to filter out interference signals generated by other resonant circuits, and the frequency tracking phase locking unit 2 is a conventional technology.

[0083] The current (A3) and voltage (A3) are input to the filter 3, and after filtering, they enter the frequency tracking phase locking 3 unit for frequency tracking and phase locking; after being processed by the frequency tracking phase locking 3 unit, a frequency signal f3 is generated, and then the frequency signal f3 is processed into a PFM pulse frequency modulation signal to control the operation of the inverter 3, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. The filter 3 is a bandpass filter used to filter out interference signals generated by other resonant circuits, and the frequency tracking phase locking 3 unit is a conventional technology.

[0084] The current (A4) and voltage (A4) are input to the filter 4, and after filtering, they enter the frequency tracking and phase locking unit 4 for frequency tracking and phase locking; after being processed by the frequency tracking and phase locking unit 4, a frequency signal f4 is generated, and then the frequency signal f4 is processed into a PFM pulse frequency modulation signal to control the operation of the inverter 4, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. The filter 4 is a bandpass filter, which is used to filter out interference signals generated by other resonant circuits, and the frequency tracking and phase locking unit 4 is a conventional technology.

[0085] The current (A5) and voltage (A5) are input to the filter 5, and after filtering, they enter the frequency tracking and phase locking unit 5 for frequency tracking and phase locking; after being processed by the frequency tracking and phase locking unit 5, a frequency signal f5 is generated, and then the frequency signal f5 is processed into a PFM pulse frequency modulation signal to control the operation of the inverter 5, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. The filter 5 is a bandpass filter, which is used to filter out interference signals generated by other resonant circuits, and the frequency tracking and phase locking unit 5 is a conventional technology.

[0086] The current (A6) and voltage (A6) are input to the filter 6, and after filtering, they enter the frequency tracking phase locking 6 unit for frequency tracking and phase locking; after being processed by the frequency tracking phase locking 6 unit, a frequency signal f6 is generated, and then the frequency signal f6 is processed into a PFM pulse frequency modulation signal to control the operation of the inverter 6, thereby ensuring that the operating frequency of each path is consistent with itself and is not interfered by other paths. The filter 6 is a bandpass filter, which is used to filter out interference signals generated by other resonant circuits, and the frequency tracking phase locking 6 unit is a conventional technology.

[0087] Specifically, between filter 1 and frequency tracking phase-locked unit 1, current I1 and voltage U1 are output through voltage and current detection components, and similarly, between filter 2 and frequency tracking phase-locked unit 2, current I2 and voltage U2 are output, between filter 3 and frequency tracking phase-locked unit 3, current I3 and voltage U3 are output, between filter 4 and frequency tracking phase-locked unit 4, current I4 and voltage U4 are output, between filter 5 and frequency tracking phase-locked unit 5, current I5 and voltage U5 are output, between filter 6 and frequency tracking phase-locked unit 6, current I6 and voltage U6 are output, and finally I1-I6 and U1-U6 are all input to the averaging circuit, and the average current and average voltage are output after being processed by the averaging circuit, and then the average current and average voltage are input to the voltage regulating circuit mentioned above, and in this way, one voltage regulating circuit can simultaneously control the induction heating of six induction heating coils.

[0088] Finally, each of the top temperature detector, bottom temperature detector and side temperature detector inputs the real-time detected temperature into the corresponding thermostat, generates an ON / OFF signal, and enters the inverter together with the signal of the frequency tracking and locking unit to realize real-time stable temperature control.

[0089] The above structure can form a closed-loop control to achieve total power control of the entire circuit, and the structure is simple and reliable.

[0090] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-temperature zone SiC crystal growth furnace, characterized in that: include: A furnace body, which is provided with a growth cavity for crystal growth; A top heating assembly, used for heating the top of the furnace body; A bottom heating assembly, used for heating the bottom of the furnace body; A side heating assembly is used to heat the side of the furnace body; The top heating assembly, the bottom heating assembly and the side heating assembly are respectively arranged on the top surface, the bottom surface and the side surface of the furnace body.

2. A multi-temperature zone SiC crystal growth furnace according to claim 1, characterized in that: The furnace body includes a shell, an insulation layer and a crucible with a growth cavity, the insulation layer is coated on the outer surface of the crucible, a receiving cavity is provided in the shell, the insulation layer and the crucible are both arranged in the receiving cavity, the top heating component and the bottom heating component are both arranged in the receiving cavity, and the two correspond to the top and the bottom of the crucible respectively, and the side heating component is arranged around the side of the shell.

3. The multi-temperature zone SiC crystal growth furnace according to claim 2, characterized in that: The shell includes a middle shell, an upper shell and a lower shell. After the upper shell and the lower shell are respectively covered on the upper and lower sides of the middle shell, the three form a accommodating cavity. A lower cavity is formed between the insulation layer and the lower shell, and an upper cavity is formed between the insulation layer and the upper shell. The top heating component is located in the upper cavity, and the bottom heating component is located in the lower cavity.

4. The multi-temperature zone SiC crystal growth furnace according to claim 1, characterized in that: The top heating assembly, the bottom heating assembly and the side heating assembly all include induction heating coils. The furnace body also includes a power supply, and the power supply is electrically connected to the induction heating coils.

5. The multi-temperature zone SiC crystal growth furnace according to claim 4, characterized in that: The side heating assembly includes a plurality of induction heating coils, which are evenly surrounded outside the shell from top to bottom, and each of the induction heating coils is connected to a power supply.

6. The multi-temperature zone SiC crystal growth furnace according to claim 2, characterized in that: The furnace body also includes a top temperature detector, a bottom temperature detector and a side temperature detector, the detection ends of the top temperature detector, the bottom temperature detector and the side temperature detector respectively correspond to the top, bottom and side of the crucible, and the shell and the insulation layer are both provided with detection holes extending to the surface of the crucible for detection by the top temperature detector, the bottom temperature detector and the side temperature detector.

7. The multi-temperature zone SiC crystal growth furnace according to claim 2, characterized in that: The furnace body also includes a vacuum mechanism, which is connected to the growth cavity of the crucible to evacuate or break the vacuum of the growth cavity; The furnace body also includes a frame, which includes a first cavity, a second cavity and a third cavity, the second cavity is below the first cavity, and the third cavity is to the right of the first cavity. The shell is installed in the first cavity, and the top surface of the shell is exposed at the top of the frame. The vacuum mechanism is installed in the second cavity. A mounting plate is provided in the third cavity, and a mounting position for installing a side temperature detector is provided on the mounting plate.

8. The multi-temperature zone SiC crystal growth furnace according to claim 3, characterized in that: The furnace body also includes a cover opening mechanism, the output end of which is fixedly connected to the upper shell to drive the upper shell to open or close; The cover opening mechanism includes a mounting plate, a lifting cylinder and a translation cylinder. The lifting cylinder is mounted on the mounting plate, and the mounting plate is fixed on a frame. The output shaft of the lifting cylinder is fixedly connected to the upper shell to drive the upper shell to open or close. The output end of the translation cylinder is fixedly connected to the mounting plate to drive the mounting plate and the upper shell to perform translational movement.

9. The multi-temperature zone SiC crystal growth furnace according to claim 6, characterized in that: The furnace body further comprises a blocking device for blocking or opening the detection hole.

10. The multi-temperature zone SiC crystal growth furnace according to claim 9, characterized in that: The blocking device includes a fixed rod, a fixed block, a blocking plate, a trigger plate and an electromagnet that attracts or repels the trigger plate. The fixed block is fixedly connected to the inner side of the shell, the fixed rod is rotatably connected to the fixed block, the blocking plate and the trigger plate are both fixedly connected to the fixed rod, and the blocking plate corresponds to the position of the detection hole. The electromagnet is arranged on the outer side of the shell, and the electromagnet corresponds to the position of the trigger plate.

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