Multi-temperature-zone SiC crystal growing furnace

Abstract

The utility model belongs to the technical field of crystal growth, and particularly relates to a multi-temperature-zone SiC crystal growing 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 utility model, the top heating component, the bottom heating component and the side surface heating component are respectively arranged on the top surface, the bottom surface and the side surface of the furnace body, so that the periphery of the furnace body can be uniformly heated, and the situation that the yield of the crystal growth furnace is influenced due to non-uniform temperature distribution caused by the volume of the furnace body 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] This invention belongs to the field of crystal growth technology, and specifically relates to a multi-temperature zone SiC crystal growth furnace. Background Technology

[0002] With its unique characteristics such as a large bandgap, high critical breakdown field strength, high electron mobility, and high thermal conductivity, SiC material has become an ideal material for fabricating high-temperature, high-frequency, high-power, radiation-resistant, short-wavelength light-emitting, and optoelectronic integrated devices. The unique physical properties of SiC determine its applications in important fields such as artificial satellites, rockets, radar, communications, fighter jets, interference-free electronic ignition devices, and jet engine sensors. Therefore, developed countries have invested significant human and material resources in related technological research.

[0003] The commonly used method for preparing large-diameter SiC crystals is the Physical Vapor Transport (PVT) method. The equipment used is a PVT single crystal furnace. SiC powder is placed at the bottom of a sealed graphite crucible, and a seed crystal is fixed on the top of the crucible. Graphite insulation material is placed on the outside of the crucible. The crucible is heated by medium-frequency induction heating. When the powder reaches its sublimation point, Si, C, SiC2, and Si2C molecules are generated. Driven by the axial temperature gradient, these molecules are transported from the surface of the raw material to the surface of the seed crystal, where they condense and slowly crystallize, thus achieving the purpose of crystal growth.

[0004] In the traditional single-coil heated PVT process for growing SiC crystals, the Si atmosphere overflows from the pores of the crucible, eroding the insulation material and causing continuous loss of insulation. The temperature gradient of the temperature field changes constantly, making it difficult to ensure the stability of the growth process and the consistency between furnace cycles. This results in low yield and poor consistency of SiC crystals, ultimately leading to high cost of SiC single crystal wafers and limiting their commercial application.

[0005] The existing technology designs a new growth device for growing SiC single crystals to improve the yield and consistency of SiC materials, reduce their cost, and meet the requirements of domestic electronic device development. The specific application number is (2020113738457).

[0006] While the above-mentioned technologies can improve the yield and consistency of SiC materials to some extent, their heating is limited to the sides of the vacuum chamber, and there are no heating structures 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 temperatures of the top and bottom surfaces of the vacuum chamber will also differ from the temperatures of the sides. This still limits the improvement of the consistency of crystal growth. Utility Model Content

[0007] To address the aforementioned issues, this paper presents a multi-temperature zone SiC crystal growth furnace, which boasts high yield and excellent product consistency.

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

[0009] To achieve the above objectives, the technical solution of this utility model is as follows.

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

[0011] The furnace body contains a growth chamber for crystal growth;

[0012] Top heating element for heating the top of the furnace body;

[0013] Bottom heating element, used to heat the bottom of the furnace body;

[0014] Side heating assembly, used to heat the sides of the furnace body;

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

[0016] In this invention, by setting a top heating component, a bottom heating component, and a side heating component on the top, bottom, and sides of the furnace body respectively, the furnace body can be heated evenly all around, preventing the temperature distribution from being too uneven due to the furnace body's size, which would affect the yield of the crystal growth furnace. This ensures a high yield and good product consistency in the crystal growth furnace.

[0017] Furthermore, the furnace body includes a shell, an insulation layer, and a crucible with a growth chamber. The insulation layer covers the outer surface of the crucible. A receiving cavity is provided within the shell, and both the insulation layer and the crucible are disposed within this cavity. The top heating assembly and the bottom heating assembly are both disposed within the receiving cavity, corresponding to the top and bottom of the crucible, respectively. The side heating assembly is arranged around the sides of the shell. This structural design ensures the normal operation of the furnace body. The crucible serves as a container for crystal growth, the insulation layer provides basic insulation, and the shell provides overall structural strength and further enhances the insulation effect. The placement of the top and bottom heating assemblies within the receiving cavity effectively reduces overall heat loss and shortens the induction heating distance, thus improving the heating effect.

[0018] Furthermore, the shell comprises a middle shell, an upper shell, and a lower shell. The upper and lower shells respectively cover the upper and lower sides of the middle shell, forming a receiving 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 uses conventional insulation material. The upper and lower cavities allow for better heating of the top and bottom heating components and, in conjunction with a vacuum pump, better achieve a vacuum effect inside the crucible. In other words, after a vacuum environment is formed inside the crucible, it is equivalent to having multiple cavities outside the crucible to enhance its airtightness.

[0019] Furthermore, the top heating assembly, bottom heating assembly, and side heating assembly all include induction heating coils, and the furnace body also includes a power supply, which is electrically connected to the induction heating coils. The induction heating coil is a preferred heating method of this invention; it only requires connection to a power supply to generate an induced magnetic field, causing the crucible to heat up. The power supply is preferably a capacitor.

[0020] Furthermore, the side heating assembly includes multiple sets of induction heating coils, which are evenly wound around the outer shell from top to bottom. Each set of induction heating coils is connected to a power source. The side heating assembly, with its multiple sets of independent induction heating coils, enables multi-temperature zone control of the furnace body from top to bottom. That is, by controlling the power of the induction heating coils in different areas, different temperatures can be achieved at different locations.

[0021] Furthermore, the furnace body also includes a top temperature detector, a bottom temperature detector, and a side temperature detector. The detection ends of the top, bottom, and side temperature detectors correspond to the top, bottom, and side of the crucible, respectively. Both the shell and the insulation layer are provided with detection holes extending to the crucible surface for the top, bottom, and side temperature detectors to perform their detection. The presence of these detectors allows for real-time temperature monitoring of the crucible, thereby enabling better real-time control of the top, bottom, and side heating components. The detection holes prevent the shell and insulation layer from affecting temperature detection, further improving the accuracy of temperature readings.

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

[0023] Furthermore, the furnace body also includes a frame, which comprises a first chamber, a second chamber, and a third chamber. The second chamber is located below the first chamber, and the third chamber is located to the right of the first chamber. The housing is installed within the first chamber, with its top surface protruding from the top of the frame. The vacuum mechanism is installed within the second chamber, and a mounting plate is provided within the third chamber. The mounting plate has mounting positions for side temperature detectors. The frame design provides stable installation space for each structure, and the strategic placement of the first, second, and third chambers ensures a rational installation process, allowing for seamless integration and operation once installed.

[0024] Furthermore, the furnace body also includes a lid-opening mechanism, the output end of which is fixedly connected to the upper shell to drive the upper shell to open or close. The lid-opening mechanism facilitates the opening of the upper shell, thereby facilitating the opening of the insulation layer and the crucible for loading and unloading materials.

[0025] Furthermore, the opening mechanism includes a mounting plate, a lifting cylinder, and a translating cylinder. The lifting cylinder is mounted on the mounting plate, which is fixed to the frame. The output shaft of the lifting cylinder is fixedly connected to the upper shell to open or close the upper shell. The output end of the translating cylinder is fixedly connected to the mounting plate to drive the mounting plate and the upper shell to translate. Preferably, a slider is provided on the mounting plate, and a sliding rod is provided on the frame. The slider is sleeved on the sliding rod. When the translating cylinder connects to the mounting plate and performs telescopic movement, the mounting plate can slide on the sliding rod via the slider under the drive of the translating cylinder. This structure is not only stable but also simple. The lifting cylinder can also be configured by providing a slider on the mounting block, with the slider sleeved on the sliding rod, and connected to the upper shell via the sliding rod, thereby ensuring the smoothness of opening and closing the upper shell.

[0026] Furthermore, the furnace body also includes a blocking device for blocking or opening the probe hole. The blocking device can be configured to either block the probe hole, preventing the temperature detector from detecting the temperature inside the furnace, or open the probe hole, allowing the temperature detector to detect the temperature inside the furnace. The blocking device primarily addresses a problem discovered during long-term testing: when the probe hole is continuously connected to the outside, the temperature detector's readings of the furnace interior become inaccurate. By closing the probe hole when it is not detecting and then opening it again for the few seconds needed to detect, this periodic detection significantly improves the accuracy of the temperature detector.

[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 inside of the housing, the fixed rod is rotatably connected to the fixed block, and both the blocking plate and the trigger plate are fixedly connected to the fixed rod, with the blocking plate corresponding to the position of the detection hole. The electromagnet is located on the outside of the housing, and its position corresponds to the position of the trigger plate. In actual operation, by energizing one electromagnet or by energizing multiple electromagnets in turn, the trigger plate can be repelled or attracted. This causes the trigger plate to drive the fixed rod to rotate on the fixed block, and the blocking plate rotates with the fixed rod, thus allowing the blocking plate to either block or not block the detection hole.

[0028] The beneficial effect of this utility model is that by setting a top heating component, a bottom heating component, and a side heating component on the top, bottom, and sides of the furnace body respectively, the furnace body can be heated evenly all around, preventing the temperature distribution from being too uneven due to the furnace body's volume, which would affect the yield of the crystal growth furnace. This can effectively ensure a high yield of the crystal growth furnace and good product consistency. Attached Figure Description

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

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

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

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

[0033] Figure 5 yes Figure 4 A magnified view of a portion of point A in the middle.

[0034] Figure 6 yes Figure 4 A magnified view of a section at point B in the middle.

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

[0036] Figure 8 yes Figure 7 A magnified view of a section at point C.

[0037] Figure 9 This is a schematic diagram of the opening mechanism.

[0038] Figure 10It is a structural diagram of the housing, power supply, heating coil and electromagnet.

[0039] Figure 11 This is a schematic diagram of the blocking device.

[0040] Figure 12 This is a part of the circuit principle diagram of this utility model.

[0041] Figure 13 This is another part of the circuit schematic diagram of this utility model, and... Figure 12 Together they form a complete circuit schematic diagram.

[0042] 1. Furnace body; 10. Growth chamber; 11. Shell; 12. Insulation layer; 13. Crucible; 110. Receiving cavity; 111. Middle shell; 112. Upper shell; 113. Lower shell; 1101. Lower cavity; 1102. Upper cavity;

[0043] 2. Top heating element;

[0044] 3. Bottom heating element;

[0045] 4. Side heating assembly;

[0046] 5. Heating coil;

[0047] 6. Power supply;

[0048] 7. Top temperature sensor;

[0049] 8. Bottom temperature sensor;

[0050] 9. Side temperature sensor;

[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. Opening mechanism; 1051. Mounting block; 1052. Lifting cylinder; 1053. Translation cylinder;

[0056] 106. Slider;

[0057] 107. Sliding rod;

[0058] 108. Blocking device; 1081. Fixing rod; 1082. Fixing block; 1083. Blocking plate; 1084. Trigger plate; 1085. Electromagnet. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

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

[0061] The furnace body 1 has a growth chamber 10 for crystal growth inside;

[0062] Top heating assembly 2 is used to heat the top of furnace body 1;

[0063] Bottom heating component 3 is used to heat the bottom of furnace body 1;

[0064] Side heating assembly 4 is used to heat the side of furnace body 1;

[0065] The top heating component 2, the bottom heating component 3, and the side heating component 4 are respectively installed on the top, bottom, and side surfaces of the furnace body 1.

[0066] In this invention, by setting a top heating component 2, a bottom heating component 3, and a side heating component 4 on the top, bottom, and side surfaces of the furnace body 1 respectively, the furnace body 1 can be heated evenly around its perimeter. This prevents the temperature distribution from being too uneven due to the size of the furnace body 1, which would affect the yield of the crystal growth furnace. This invention can effectively ensure a high yield of the crystal growth furnace and good product consistency.

[0067] In this embodiment, the furnace body 1 includes a shell 11, an insulation layer 12, and a crucible 13 with a growth chamber 10. The insulation layer 12 covers the outer surface of the crucible 13. A receiving cavity 110 is provided inside the shell 11. The insulation layer 12 and the crucible 13 are both disposed within the receiving cavity 110. A top heating assembly 2 and a bottom heating assembly 3 are both disposed within the receiving cavity 110, corresponding to the top and bottom of the crucible 13, respectively. Side heating assemblies 4 are arranged around the sides of the shell 11. This structure ensures the normal operation of the furnace body 1. The crucible 13 serves as a container for crystal growth. The insulation layer 12 provides basic insulation, and the shell 11 provides overall structural strength and further enhances insulation. The placement of the top heating assembly 2 and the bottom heating assembly 3 within the receiving cavity 110 effectively reduces overall heat loss and shortens the induction heating distance, thus improving the heating effect.

[0068] In this embodiment, the shell 11 includes a middle shell 111, an upper shell 112, and a lower shell 113. The upper shell 112 and the lower shell 113 cover the upper and lower sides of the middle shell 111, respectively, forming a receiving cavity 110. A lower cavity 1101 is formed between the insulation layer 12 and the lower shell 113, and an upper cavity 1102 is formed between the 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 insulation layer 12 is a conventional insulation material. The upper cavity 1102 and the lower cavity 1101 can better achieve the heating of the top heating component 2 and the bottom heating component 3, and can also work with the vacuum pump to better achieve the vacuum effect inside the crucible 13. That is, after the crucible 13 forms a vacuum environment, it is equivalent to the existence of 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 induction heating coils 5. The furnace body also includes a power supply 6, which is electrically connected to the induction heating coils 5. The induction heating coil 5 is a preferred heating method of this invention; it only needs to be connected to a power supply to generate an induced magnetic field, causing the crucible to heat up. The power supply 6 is preferably a capacitor.

[0070] In this embodiment, the side heating assembly 4 includes multiple sets of induction heating coils 5, which are evenly wound around the outer shell 11 from top to bottom. Each set of induction heating coils 5 is connected to a power supply 6. The side heating assembly 4 includes multiple sets of induction heating coils 5, each set of induction heating coils 5 is independent of each other, which can realize multi-temperature zone control of the furnace body from top to bottom. That is, by controlling the power of the induction heating coils 5 in different areas, different temperatures can be achieved at different locations.

[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, bottom, and side temperature detectors 7 and 8 correspond to the top, bottom, and side of the crucible 13, respectively. Both 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, bottom, and side temperature detectors 7 and 8. The placement of the top, bottom, and side temperature detectors 7 and 8 allows for real-time detection of the temperature of the crucible 13, thereby enabling better real-time control of the top heating assembly 7, bottom heating assembly 8, and side heating assembly 9. The detection holes 101 prevent the shell 11 and insulation layer 12 from affecting temperature detection, further improving the accuracy of temperature detection.

[0072] In this embodiment, the furnace body also includes a vacuum mechanism 102, which is connected to the growth chamber 10 of the crucible 13 to evacuate or break the vacuum in 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 conventional combination of a vacuum pump and a vacuum pipeline, with the vacuum pump connected to the growth chamber 10 of the crucible 13 via a vacuum pipeline.

[0073] In this embodiment, the furnace body also includes a frame 103, which includes a first cavity 1031, a second cavity 1032, and a third cavity 1033. The second cavity 1032 is below the first cavity 1031, and the third cavity 1033 is to the right of the first cavity 1031. A housing 11 is installed inside the first cavity 1031, with its top surface protruding from the top of the frame 103. A vacuum mechanism 102 is installed inside the second cavity 1032, and a mounting plate 104 is provided inside the third cavity 1033. The mounting plate 104 has mounting positions for mounting a side temperature detector 9. The frame 103 provides a stable installation space for each structure, and the positions of the first cavity 1031, second cavity 1032, and third cavity 1033 ensure that each structure is installed reasonably and can work well together once installed.

[0074] In this embodiment, the furnace body also includes a lid opening mechanism 105. The output end of the lid opening mechanism 105 is fixedly connected to the upper shell 112 to drive the upper shell 112 to open or close. The lid opening mechanism 105 facilitates the opening of the upper shell 112, thereby facilitating the opening of the insulation layer 12 and the crucible 13 for taking out and putting in materials.

[0075] In this embodiment, the 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, which is fixed to the frame 103. The output shaft of the lifting cylinder 1052 is fixedly connected to the upper shell 112 to open or close the upper shell 112. 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 movements. Preferably, a slider 106 is provided on the mounting block 1051, and a sliding rod 107 is also provided on the frame 103. The slider 106 is sleeved on the sliding rod 107. When the translation cylinder 1053 connects to the mounting block 1051 and performs telescopic movements, the mounting block 1051 can slide on the sliding rod 107 via the slider 106 under the drive of the translation cylinder 1053. This structure is not only stable but also simple. The lifting cylinder 1052 can also be equipped with a slider 106 on the mounting block 1051. 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 smooth opening and closing of the upper shell 112.

[0076] In this embodiment, the furnace body also includes a blocking device 108 for blocking or opening the detection hole 101. The blocking device 108 can be configured to either block the detection hole 101, preventing the temperature detector 9 from detecting the temperature inside the furnace, or open the detection hole 101, allowing the temperature detector 9 to detect the temperature inside the furnace. The blocking device 108 is primarily designed to overcome a problem discovered during long-term testing: when the detection hole 101 is continuously connected to the outside, the temperature detector 9 may detect inaccurate temperatures inside the furnace. By closing the detection hole 101 when the temperature detector 9 is not detecting, and then opening it again for the few seconds required for detection, this periodic detection significantly improves the 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 housing 11, and 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. The electromagnet 1085 is disposed on the outer side of the housing 11, and the position of the electromagnet 1085 corresponds to that of the trigger plate 1084. In actual operation, by energizing one electromagnet 1085 or by energizing multiple electromagnets 1085 in turn, the trigger plate 1084 can be repelled and attracted. Thus, the trigger plate 1084 drives the fixed rod 1081 to rotate on the fixed block 1082, and 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 Figure 12-13The top heating assembly 2, bottom heating assembly 3, and side heating assembly 4 of this utility model each include one set of induction heating coils 5, one set of induction heating coils 5, and four sets of induction heating coils 5, respectively. Each set of induction heating coils is connected in parallel with capacitors to form LC parallel resonant circuits A1, A2, A3, A4, A5, and A6. Resonant circuit A1 is connected in parallel with transformer B1, resonant circuit A2 with transformer B2, resonant circuit A3 with transformer B3, resonant circuit A4 with transformer B4, resonant circuit A5 with transformer B5, and resonant circuit A6 with transformer B6. One end of transformer B1 is connected to inverter 1, one end of transformer B2 is connected to inverter 2, one end of transformer B3 is connected to inverter 3, one end of transformer B4 is connected to inverter 4, one end of transformer B5 is connected to inverter 5, and one end of transformer B6 is connected to inverter 6. The inverters are preferably bridge-type IGBT inverters. All inverters are connected to the same voltage regulating circuit.

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

[0080] This utility model also includes a current and voltage detection module for detecting the current (A1) and voltage (A1) of resonant circuit A1, the current (A2) and voltage (A2) of resonant circuit A2, the current (A3) and voltage (A3) of resonant circuit A3, the current (A4) and voltage (A4) of resonant circuit A4, the current (A5) and voltage (A5) of resonant circuit A5, and the current (A6) and voltage (A6) of resonant circuit A6.

[0081] Specifically, the current (A1) and voltage (A1) are input to filter 1, filtered, and then fed into the frequency tracking phase-locked loop (PLL) unit 1 for frequency tracking and phase locking. After processing by the PLL unit 1, a frequency signal f1 is generated. This frequency signal f1 is then processed into a PFM pulse frequency modulation signal to control the operation of inverter 1, thereby ensuring that the operating frequency of each circuit is consistent with its own and is not interfered with by other circuits. Filter 1 is a bandpass filter used to filter out interference signals generated by other resonant circuits, and the PLL unit 1 uses conventional technology.

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

[0083] The current (A3) and voltage (A3) are input to filter 3, and after filtering, they enter the frequency tracking phase-locked loop (PLL) unit 3 for frequency tracking and phase locking. After processing by the frequency tracking PLL unit 3, a frequency signal f3 is generated. This frequency signal f3 is then processed into a PFM pulse frequency modulation signal to control the operation of inverter 3, thereby ensuring that the operating frequency of each circuit is consistent with its own and is not interfered with by other circuits. Filter 3 is a bandpass filter used to filter out interference signals generated by other resonant circuits, and the frequency tracking PLL unit 3 uses conventional technology.

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

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

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

[0087] Specifically, filter 1 outputs current I1 and voltage U1 to frequency tracking phase-locked loop 1 unit through components such as voltage and current detection components. Similarly, filter 2 outputs current I2 and voltage U2 to frequency tracking phase-locked loop 2 unit, filter 3 outputs current I3 and voltage U3 to frequency tracking phase-locked loop 3 unit, filter 4 outputs current I4 and voltage U4 to frequency tracking phase-locked loop 4 unit, filter 5 outputs current I5 and voltage U5 to frequency tracking phase-locked loop 5 unit, and filter 6 outputs current I6 and voltage U6 to frequency tracking phase-locked loop 6 unit. Finally, I1-I6 and U1-U6 are all input to the averaging circuit. After processing by the averaging circuit, the average current and average voltage are output. Then, the average current and average voltage are input to the voltage regulating circuit mentioned above. In this way, one voltage regulating circuit can simultaneously control the induction heating coils of six circuits.

[0088] Finally, each of the top, bottom, and side temperature sensors inputs the real-time detected temperature to its corresponding temperature controller, generating an ON / OFF signal. This signal, along with the signal from the frequency tracking lock-in unit, enters the inverter to achieve real-time stable temperature control.

[0089] The above structure can form a closed-loop control, realizing the overall power control of the circuit. The structure is simple and reliable.

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

Claims

1. A multi-temperature zone SiC crystal growth furnace, characterized in that, include: The furnace body contains a growth chamber for crystal growth; Top heating element for heating the top of the furnace body; Bottom heating element, used to heat the bottom of the furnace body; Side heating assembly, used to heat the sides of the furnace body; The top heating assembly, bottom heating assembly, and side heating assembly are respectively installed on the top, bottom, and side surfaces of the furnace body.

2. The 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 chamber. The insulation layer covers the outer surface of the crucible. The shell has a receiving cavity, and the insulation layer and the crucible are both located in the receiving cavity. The top heating component and the bottom heating component are both located in the receiving cavity, and they correspond to the top and bottom of the crucible, respectively. 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 housing includes a middle shell, an upper shell, and a lower shell. The upper shell and the lower shell cover the upper and lower sides of the middle shell respectively, forming a receiving cavity. The insulation layer and the lower shell form a lower cavity, and the insulation layer and the upper shell form an upper cavity. 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, bottom heating assembly, and side heating assembly all include induction heating coils. The furnace body also includes a power supply, which is electrically connected to the induction heating coils.

5. A multi-temperature zone SiC crystal growth furnace according to claim 4, characterized in that, The side heating assembly includes multiple sets of induction heating coils, which are evenly wrapped around the outer side of the housing from top to bottom, and each set of induction heating coils is connected to a power source.

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 correspond to the top, bottom, and side of the crucible, respectively. 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.

7. A 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 chamber of the crucible to evacuate or break the vacuum in the growth chamber. The furnace body also includes a frame, which includes a first chamber, a second chamber, and a third chamber. The second chamber is located below the first chamber, and the third chamber is located to the right of the first chamber. The housing is installed in the first chamber, and the top surface of the housing protrudes from the top of the frame. The vacuum mechanism is installed in the second chamber, and a mounting plate is provided in the third chamber. The mounting plate has mounting positions for installing side temperature detectors.

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

9. A multi-temperature zone SiC crystal growth furnace according to claim 6, characterized in that, The furnace body also includes a blocking device for blocking or opening the probe hole.

10. A 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 inside of the housing, 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 located on the outside of the housing, and the electromagnet corresponds to the position of the trigger plate.

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