A system and method for real-time adjustment of a thermal field for crystal growth

Abstract

The application discloses a crystal growth thermal field real-time adjustment system, comprising an online temperature measurement unit, comprising at least three temperature measurement devices, for real-time acquisition of temperature signals of a plurality of circumferential directions of a heat preservation assembly; a lifting adjustment unit arranged below the heat preservation assembly, comprising a plurality of lifting support points arranged along the circumference of the furnace body, each lifting support point being driven by an independent driving component; and a control unit, the control unit being configured to: calculate a horizontal deviation vector of the thermal field in the heat preservation assembly according to the temperature signals collected by each temperature measurement device, determine the lifting direction and displacement of each lifting support point, and drive each lifting support point to lift cooperatively, so that the heat preservation assembly is compensated and adjusted in the direction opposite to the deviation direction, and after the compensation and adjustment, whether the deviation degree is reduced to within a preset threshold is judged according to the re-acquired temperature signals, if not, the above calculation and compensation adjustment are repeated. The application also discloses a crystal growth thermal field real-time adjustment method.

Description

Technical Field

[0001] This invention belongs to the field of crystal growth technology, and in particular relates to a real-time adjustment system and method for the thermal field of crystal growth. Background Technology

[0002] Crystal growth is the process by which a substance forms a crystal from a gaseous, liquid, or solid phase under specific physical and chemical conditions. The stability of the thermal field plays a decisive role in the quality of crystal growth. The morphology, growth rate, and growth quality of crystals such as sapphire, silicon carbide, and gallium oxide are all highly dependent on the stability of the thermal field.

[0003] Currently, the insulation structure of crystal growth furnaces typically employs soft felt wrapped around the hot zone, hard felt assembled into the hot zone, or porous fiber alumina and fiber zirconia as insulation materials. However, these insulation materials suffer from the following problems when used long-term in the high-temperature environment of crystal growth: First, the thermal expansion coefficients of various insulation components within the furnace differ, causing different degrees of expansion or contraction and relative displacement during heating and cooling, leading to a shift in the center of the hot zone. Second, even with the same insulation material, uneven radial temperature distribution within the hot zone results in inconsistent thermal expansion at different locations, causing uneven deformation of the insulation structure and tilting of the hot zone axis. Third, crystal growth involves multiple heating and cooling cycles, and the insulation material accumulates irreversible plastic deformation and positional shifts during repeated expansion and contraction. These problems ultimately disrupt the axial symmetry of the hot zone and cause a skewed temperature gradient, severely affecting the crystallization quality and even leading to crystal defects or growth failure.

[0004] In existing technologies, although there are solutions such as using platform positioning guide columns and guide holes to guide the expansion and contraction of the temperature field support platform in a fixed direction, or using retractable heat shields to adjust the local temperature, these solutions are all mechanical alignment or passive compensation methods in the static installation stage. On the one hand, they cannot sense the drift direction and amount of the thermal field center during the service process of the insulation structure in real time. On the other hand, they cannot implement dynamic active correction of the insulation components. Moreover, the hard constraint structure is prone to jamming or gaps after the insulation material undergoes fatigue deformation, and may even transfer the deformation stress to the crucible support shaft, exacerbating the thermal field offset.

[0005] Therefore, how to detect the horizontal tilt of the thermal field in real time and with discernible direction during crystal growth, and to implement dynamic compensation and adjustment of the insulation components, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a real-time adjustment system and method for the thermal field of crystal growth. This system enables online real-time correction of thermal field tilt, improves the axial and radial symmetry of the temperature gradient at the solid-liquid interface during crystal growth, suppresses thermal stress and structural defects in the crystal, and ultimately achieves stable mass production of large-size, high-quality crystals. It also effectively extends the overall service life of the insulation structure under repeated thermal shocks.

[0007] This invention provides a real-time adjustment system for the thermal field of crystal growth, comprising a furnace body and a heat insulation component disposed within the furnace body, and further comprising:

[0008] The online temperature measurement unit includes at least three temperature measuring devices, which are arranged around the circumference of the furnace body to collect temperature signals of the insulation component in multiple directions around the circumference in real time.

[0009] The lifting adjustment unit is located below the heat preservation component and includes multiple lifting support points arranged circumferentially along the furnace body. Each lifting support point is driven by an independent driving component.

[0010] The control unit is electrically connected to each of the temperature measuring devices and each of the driving components. The control unit is configured to: calculate the horizontal deviation vector of the thermal field inside the insulation component based on the temperature signals collected by each of the temperature measuring devices, wherein the horizontal deviation vector includes the deviation direction and the degree of deviation; when the degree of deviation exceeds a preset threshold, determine the lifting direction and displacement of each of the lifting support points based on the horizontal deviation vector, and drive each of the lifting support points to lift and lower in tandem, so that the insulation component can be adjusted in the opposite direction to the deviation direction; and after the adjustment, determine whether the degree of deviation has dropped to within the preset threshold based on the re-collected temperature signals. If not, repeat the above calculation and adjustment.

[0011] Preferably, in the above-mentioned real-time adjustment system for the thermal field of crystal growth, the temperature measuring device is an infrared thermometer or an infrared thermal imager. The temperature measuring device is installed on the top and / or side wall of the furnace body and is used to collect infrared radiation signals from the upper edge of the insulation component or the thermal field area.

[0012] Preferably, in the above-mentioned real-time adjustment system for the crystal growth thermal field, at least three temperature measuring devices are arranged at equal angular intervals along the circumference of the furnace body, and each lifting support point is arranged at equal angular intervals along the circumference of the furnace body. The circumferential orientation of each lifting support point corresponds one-to-one with the circumferential orientation of each temperature measuring device. The control unit determines the lifting support point corresponding to the deviation orientation based on the deviation orientation and drives the determined lifting support point to rise and fall.

[0013] Preferably, in the above-mentioned real-time adjustment system for the thermal field of crystal growth, the process of the control unit calculating the horizontal deviation vector includes: constructing a circumferential temperature sequence using the circumferential azimuth angle of each of the temperature measuring devices and the corresponding temperature signal; performing a Fourier transform on the circumferential temperature sequence and extracting the first-order fundamental component; using the phase of the first-order fundamental component as the deviation azimuth, and using the amplitude of the first-order fundamental component, or the product of the amplitude and a preset calibration coefficient, as the degree of deviation.

[0014] Preferably, in the above-mentioned real-time adjustment system for the crystal growth thermal field, the control unit determines the target lifting amount of each lifting support point according to the following formula. :

[0015] ;

[0016] Where D is the spatial offset corresponding to the degree of deviation. Let φ be the circumferential azimuth angle of the j-th lifting support point, and let φ be the azimuth angle corresponding to the deviation azimuth. The lifting support point located at the deviation azimuth descends, and the lifting support point located at the azimuth opposite to the deviation azimuth ascends. The remaining lifting support points share the displacement in a cosine ratio, and all the lifting support points move synchronously.

[0017] This invention provides a method for real-time adjustment of the thermal field in crystal growth, used in a crystal growth furnace. The furnace body is equipped with a heat-insulating component, and below the heat-insulating component are multiple lifting support points, each driven by an independent driving component. The method includes:

[0018] Temperature signals of the insulation component in multiple circumferential directions are collected in real time by at least three temperature measuring devices arranged along the circumference of the furnace body.

[0019] Based on the temperature signals collected by each of the temperature measuring devices, the horizontal deviation vector of the thermal field inside the insulation component is calculated, and the horizontal deviation vector includes the deviation direction and the degree of deviation.

[0020] The deviation is compared with a preset threshold. If the deviation exceeds the preset threshold, the process proceeds to the next step for adjustment; otherwise, the process returns to continue collecting temperature signals.

[0021] The lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the heat preservation component is adjusted in the opposite direction to the deviation direction;

[0022] The temperature signal is reacquired and calculated until the deviation is reduced to within the preset threshold.

[0023] Preferably, in the above-described real-time adjustment method for the thermal field of crystal growth, the step of calculating the horizontal deviation vector of the thermal field within the insulation component based on the temperature signals collected by each of the temperature measuring devices includes:

[0024] A circumferential temperature sequence is constructed using the circumferential azimuth angle of each of the temperature measuring devices and the corresponding temperature signal.

[0025] Perform a Fourier transform on the circumferential temperature sequence to obtain the harmonic components of each order;

[0026] The first-order fundamental component is extracted, and the phase of the first-order fundamental component is used as the deviation azimuth. The amplitude of the first-order fundamental component, or the product of the amplitude and a preset calibration coefficient, is used as the deviation degree. Harmonic components of the second order and above are filtered out and do not participate in the calculation of the horizontal deviation vector.

[0027] Preferably, in the above-described real-time adjustment method for the crystal growth thermal field, the step of determining the lifting direction and displacement of each of the lifting support points based on the horizontal deviation vector, and driving each of the lifting support points to lift and lower in tandem, so that the heat insulation component compensates and adjusts in the direction opposite to the deviation, includes:

[0028] The target lifting amount of each lifting support point is calculated according to the following formula. :

[0029] ;

[0030] Where D is the spatial offset corresponding to the degree of deviation. φ is the circumferential azimuth angle of the j-th lifting support point, and φ is the azimuth angle corresponding to the deviation azimuth; each of the driving components is driven to move synchronously, so that the heat preservation component performs translational compensation adjustment.

[0031] Preferably, in the above-mentioned real-time adjustment method for the crystal growth thermal field, the temperature measuring device is arranged in multiple layers along different heights on the side wall of the furnace body; during calculation, the horizontal deviation vector at the corresponding height is calculated based on the temperature signal collected by the temperature measuring device at each layer; during adjustment, the lifting support points are driven to lift differently according to the difference between the horizontal deviation vectors at the heights of each layer, so as to correct the inclination of the thermal field axis in space.

[0032] Preferably, in the above-mentioned real-time adjustment method for the thermal field of crystal growth, the acquisition step, the calculation step, the judgment step, the adjustment step, and the feedback step are continuously and cyclically executed throughout the entire process of heating, isothermalization, and cooling of crystal growth.

[0033] As described above, the crystal growth thermal field real-time adjustment system provided by the present invention includes a furnace body and a heat insulation component disposed within the furnace body, as well as an online temperature measurement unit comprising at least three temperature measuring devices arranged circumferentially along the furnace body to collect temperature signals of the heat insulation component in multiple circumferential directions in real time; a lifting adjustment unit disposed below the heat insulation component, comprising multiple lifting support points arranged circumferentially along the furnace body, each of which is driven by an independent driving component; and a control unit electrically connected to each of the temperature measuring devices and each of the driving components, the control unit being configured to: calculate the horizontal deviation vector of the thermal field within the heat insulation component based on the temperature signals collected by each of the temperature measuring devices. The quantities include the deviation direction and the degree of deviation. When the degree of deviation exceeds a preset threshold, the lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the thermal insulation component is adjusted in the opposite direction to the deviation direction. After the adjustment, the degree of deviation is judged according to the re-acquired temperature signal to see if it has dropped below the preset threshold. If not, the above calculation and adjustment are repeated. Therefore, online real-time correction of thermal field tilt can be achieved, improving the axial and radial symmetry of the temperature gradient at the solid-liquid interface of crystal growth, suppressing thermal stress and structural defects in the crystal, and ultimately achieving stable batch production of large-size, high-quality crystals, and effectively extending the overall service life of the thermal insulation structure under repeated thermal shock. The above-mentioned real-time adjustment method for the thermal field of crystal growth provided by the present invention has the same advantages. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 This is a schematic diagram illustrating the composition of an embodiment of a real-time adjustment system for the thermal field of crystal growth provided by the present invention.

[0036] Figure 2 A schematic diagram of the specific structure of a real-time adjustment system for the thermal field of crystal growth provided by the present invention;

[0037] Figure 3 This is a flowchart illustrating an embodiment of a method for real-time adjustment of the thermal field during crystal growth provided by the present invention. Detailed Implementation

[0038] The core of this invention is to provide a real-time adjustment system and method for the thermal field of crystal growth, which can realize online real-time correction of thermal field tilt, improve the axial and radial symmetry of the temperature gradient at the solid-liquid interface of crystal growth, suppress thermal stress and structural defects in the crystal, and ultimately achieve stable batch production of large-size, high-quality crystals, and effectively extend the overall service life of the insulation structure under repeated thermal shocks.

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] An example implementation of the real-time adjustment system for the thermal field of crystal growth provided by this invention. Figure 1 As shown, Figure 1 This is a schematic diagram illustrating an embodiment of a real-time adjustment system for the thermal field of crystal growth provided by the present invention. The system may include a furnace body and a heat insulation component disposed within the furnace body, and may further include:

[0041] The online temperature measurement unit 1 includes at least three temperature measuring devices arranged circumferentially around the furnace body. These devices are used to collect temperature signals from multiple circumferential positions of the insulation component in real time. It should be noted that the temperature measuring devices can achieve omnidirectional monitoring of the horizontal temperature distribution of the thermal field. The more temperature measuring devices there are, the more accurate the detection of the circumferential temperature distribution, and therefore the more accurate the calculated horizontal deviation vector of the thermal field. Of course, the number of temperature measuring devices can be reasonably selected according to the furnace size and monitoring accuracy requirements; there is no limitation here. Specifically, the temperature measuring devices can be installed on the top of the furnace body, on the side wall of the furnace body, or simultaneously on both the top and side walls, as long as they can collect temperature signals from multiple circumferential positions of the insulation component in real time.

[0042] The lifting adjustment unit 2, located below the insulation component, includes multiple lifting support points arranged circumferentially along the furnace body. Each lifting support point is driven by an independent drive component, allowing each support point to move independently. By applying different lifting displacements to the support points in different positions, the horizontal orientation of the insulation component can be adjusted. Specifically, the drive component can be a lifting motor, each electrically connected to a control unit. The control unit precisely controls the lifting direction and displacement of the corresponding support point by controlling the forward and reverse rotation and the stroke of each lifting motor. Of course, the drive component can also be a hydraulic cylinder, electric push rod, or other components capable of outputting linear displacement; there are no limitations on this.

[0043] Control unit 3 is electrically connected to each temperature measuring device and each driving component. The control unit is configured to: calculate the horizontal deviation vector of the thermal field inside the insulation component based on the temperature signals collected by each temperature measuring device. The horizontal deviation vector includes the deviation direction and the degree of deviation. When the degree of deviation exceeds a preset threshold, determine the lifting direction and displacement of each lifting support point based on the horizontal deviation vector, and drive each lifting support point to lift and lower in tandem, so that the insulation component can be adjusted in the opposite direction to the deviation direction. After the adjustment, determine whether the degree of deviation has dropped to within the preset threshold based on the re-collected temperature signal. If not, repeat the above calculation and adjustment.

[0044] Therefore, the control unit integrates real-time measurement, real-time calculation, real-time execution, and real-time feedback into a closed-loop control circuit: the online temperature measurement unit collects temperature signals in real time, the control unit calculates the horizontal deviation vector of the thermal field in real time, and drives the lifting adjustment unit to perform compensation adjustment when the deviation exceeds the preset threshold. After adjustment, the temperature signal is collected again to verify the adjustment effect. If the deviation still does not drop below the preset threshold, the above calculation and compensation adjustment are repeated until the thermal field returns to the center state, so that the physical center of the thermal field is always forcibly corrected and locked on the theoretical growth axis of the crystal.

[0045] refer to Figure 2 , Figure 2 The present invention provides a schematic diagram of a real-time adjustment system for the thermal field of crystal growth. The system may include a furnace body 21, a crucible 22 disposed inside the furnace body 21, a melt 23 located inside the crucible 22, an induction coil 24 located on the outer periphery of the crucible, and a heat-insulating material 25. It also includes a support tray 26 and a lifting rod 27, a lifting control motor 28 for adjusting the angle of the thermal field, an observation window 29 opened on the upper part of the furnace body 21, and an infrared temperature measuring device 20 corresponding to the observation window 29. The number of these observation windows and infrared temperature measuring devices can be multiple, which can be selected according to actual needs.

[0046] As described above, the embodiment of the real-time adjustment system for the crystal growth thermal field provided by the present invention includes a furnace body and a heat-insulating component disposed within the furnace body, as well as an online temperature measurement unit including at least three temperature measuring devices arranged circumferentially around the furnace body for real-time acquisition of temperature signals from multiple circumferential directions of the heat-insulating component; a lifting adjustment unit disposed below the heat-insulating component, including multiple lifting support points arranged circumferentially around the furnace body, each lifting support point being driven by an independent driving component; and a control unit electrically connected to each temperature measuring device and each driving component, configured to: calculate the horizontal deviation vector of the thermal field within the heat-insulating component based on the temperature signals acquired by each temperature measuring device, wherein the horizontal deviation vector includes... This includes the deviation direction and degree of deviation; when the degree of deviation exceeds a preset threshold, the lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the thermal insulation component is adjusted in the opposite direction to the deviation direction; and after the compensation adjustment, the degree of deviation is judged according to the re-acquired temperature signal to see if it has dropped to within the preset threshold. If not, the above calculation and compensation adjustment are repeated. Therefore, it can realize online real-time correction of thermal field tilt, improve the axial and radial symmetry of the temperature gradient at the solid-liquid interface of crystal growth, suppress thermal stress and structural defects in crystal, and finally realize the stable batch production of large-size, high-quality crystals, and effectively extend the overall service life of the thermal insulation structure under repeated thermal shock.

[0047] In a specific embodiment of the above-mentioned real-time adjustment system for the thermal field of crystal growth, the temperature measuring device can be an infrared thermometer or an infrared thermal imager. The temperature measuring device can be set on the top and / or side wall of the furnace body to collect infrared radiation signals from the upper edge of the insulation component or the thermal field area.

[0048] Specifically, an infrared thermometer or infrared thermal imager obtains the temperature signal at the corresponding location by collecting infrared radiation signals from the upper edge of the insulation component or the hot zone. The propagation of the infrared radiation signal is not affected by the high-temperature atmosphere inside the furnace, and it can capture the temperature distortion signal on the horizontal cross section of the hot zone at the first moment when the insulation structure undergoes thermal expansion and deformation. This overcomes the deficiency of traditional thermocouple single-point temperature measurement, which can only determine the temperature level but cannot determine the direction of deviation. Of course, in other embodiments, the temperature measuring device can also use other temperature measuring elements such as thermocouples, which is not limited here.

[0049] In another specific embodiment of the above-mentioned real-time adjustment system for the crystal growth thermal field, at least three temperature measuring devices are arranged at equal angular intervals along the circumference of the furnace body, and each lifting support point is arranged at equal angular intervals along the circumference of the furnace body. The circumferential orientation of each lifting support point corresponds one-to-one with the circumferential orientation of each temperature measuring device. The control unit determines the lifting support point corresponding to the deviation orientation based on the deviation orientation and drives the determined lifting support point to rise and fall.

[0050] It should be noted that the circumferential orientation of each lifting support point corresponds one-to-one with the circumferential orientation of each temperature measuring device, forming a directional mapping relationship. This allows the control unit to directly translate the orientation of temperature anomalies into the lifting action of the corresponding lifting support point, eliminating complex coordinate conversions and achieving low-latency, precise physical correction. For example, when the temperature signal collected by a temperature measuring device in a certain orientation is too high, it indicates that the thermal field is biased towards that orientation. The control unit drives the lifting support point corresponding to the deviation orientation to descend, and / or drives the lifting support point in the opposite orientation to the deviation orientation to rise, causing the insulation component to compensate and adjust in the opposite direction to the deviation orientation.

[0051] In another specific embodiment of the above-mentioned real-time adjustment system for the thermal field of crystal growth, the process of the control unit calculating the horizontal deviation vector includes: constructing a circumferential temperature sequence using the circumferential azimuth angle of each temperature measuring device and the corresponding temperature signal; performing a Fourier transform on the circumferential temperature sequence and extracting the first-order fundamental component; using the phase of the first-order fundamental component as the deviation azimuth, and using the amplitude of the first-order fundamental component, or the product of the amplitude and a preset calibration coefficient, as the degree of deviation.

[0052] In a preferred embodiment of the above-mentioned real-time adjustment system for the crystal growth thermal field, the control unit can determine the target lifting amount of each lifting support point according to the following formula. :

[0053] ;

[0054] Where D represents the spatial offset corresponding to the degree of deviation. Let φ be the circumferential azimuth angle of the j-th lifting support point, and φ be the azimuth angle corresponding to the deviation azimuth. The lifting support point located at the deviation azimuth descends, and the lifting support point located at the azimuth opposite to the deviation azimuth ascends. The remaining lifting support points share the displacement in a cosine ratio, and all lifting support points move synchronously.

[0055] The spatial offset D corresponding to the degree of deviation can be determined in advance through calibration experiments: using the pre-calibrated calibration coefficient K (unit: ...). The product of the amplitude of the first-order fundamental component and the calibration coefficient K is used as the spatial offset D, thereby converting the deviation of the temperature signal layer into the actual offset of the insulation component in the horizontal direction, so that the target lifting and lowering of each lifting support point matches the actual offset of the thermal field, avoiding over-adjustment or under-adjustment.

[0056] An example implementation of the real-time adjustment method for the thermal field of crystal growth provided by this invention is as follows: Figure 3 As shown, Figure 3This is a schematic diagram of an embodiment of a real-time adjustment method for the thermal field of crystal growth provided by the present invention. The method is used in a crystal growth furnace, which has a heat-insulating component inside. Below the heat-insulating component are multiple lifting support points, each driven by an independent driving component. The method may include:

[0057] S1: By using at least three temperature measuring devices arranged along the circumference of the furnace body, the temperature signals of the insulation components in multiple directions along the circumference are collected in real time.

[0058] Specifically, the temperature measuring devices can be evenly arranged around the circumference of the furnace body. Each temperature measuring device collects the temperature signal of the insulation component in the corresponding position in the circumference in real time, and transmits the collected temperature signal to the control unit to realize all-round real-time monitoring of the temperature distribution in the horizontal direction of the thermal field.

[0059] S2: Based on the temperature signals collected by each temperature measuring device, calculate the horizontal deviation vector of the thermal field inside the insulation component. The horizontal deviation vector includes the deviation direction and the degree of deviation.

[0060] It should be noted that when the thermal field deviates horizontally, the temperature distribution of the insulation component in the circumferential direction will be distorted, that is, the temperature at the deviation location will be higher and the temperature at the location opposite to the deviation location will be lower. Therefore, by calculating the temperature signals collected by each temperature measuring device, the deviation location and degree of the thermal field center on the horizontal plane can be quantitatively obtained, overcoming the defect of traditional single-point temperature measurement that cannot determine the direction of deviation.

[0061] S3: Compare the deviation with the preset threshold. If the deviation exceeds the preset threshold, proceed to the next step for adjustment; otherwise, return to continue collecting temperature signals.

[0062] The preset threshold can be pre-set according to the requirements of the crystal growth process for the symmetry of the thermal field. If the deviation does not exceed the preset threshold, it indicates that the thermal field is in a centered state and no adjustment is needed. The temperature signal will continue to be collected for monitoring. If the deviation exceeds the preset threshold, it indicates that the thermal field has tilted significantly, and the next step is to adjust it.

[0063] S4: Determine the lifting direction and displacement of each lifting support point based on the horizontal deviation vector, and drive each lifting support point to lift and lower in tandem, so that the insulation component can be adjusted to compensate in the opposite direction to the deviation.

[0064] Specifically, the control unit determines the lifting support point corresponding to the deviation position based on the deviation position, drives the lifting support point located at the deviation position to descend, and / or drives the lifting support point located at the opposite position to the deviation position to rise. The remaining lifting support points share the corresponding displacement according to the degree of deviation. All lifting support points rise and fall in coordination, so that the heat preservation component is adjusted in the opposite direction to the deviation position.

[0065] S5: Reacquire and calculate the temperature signal until the deviation drops to within the preset threshold.

[0066] After adjustment, the temperature signal is reacquired and calculated to verify the adjustment effect. If the deviation is still not reduced to within the preset threshold, the above calculation, judgment and adjustment process is repeated until the deviation is reduced to within the preset threshold and the thermal field is restored to the centering state, thus forming a closed-loop control loop of real-time measurement, real-time calculation, real-time judgment, real-time adjustment and real-time feedback.

[0067] In a specific embodiment of the above-mentioned real-time adjustment method for the thermal field of crystal growth, calculating the horizontal deviation vector of the thermal field within the insulation component based on the temperature signals collected by each temperature measuring device may include:

[0068] A circumferential temperature sequence is constructed using the circumferential azimuth angle of each temperature measuring device and the corresponding temperature signal.

[0069] Specifically, assume that n temperature measuring devices are arranged along the circumference of the furnace body at the same horizontal height. The circumferential azimuth angle of the i-th temperature measuring device is The actual measured temperature is The control unit constructs a circumferential temperature sequence with a period of 2π from the circumferential azimuth angle of each temperature measuring device and the corresponding temperature signal. .

[0070] Fourier transform of the circumferential temperature sequence yields the harmonic components of each order.

[0071] Circumferential temperature sequence By performing a Discrete Fourier Transform, the discrete circumferential temperature sequence can be decomposed into harmonic components of various orders. The mathematical form of the first-order fundamental component is: , φ is the amplitude of the first-order fundamental component, representing the intensity of the circumferential temperature non-uniformity of the thermal field, and φ is the phase of the first-order fundamental component, representing the azimuth angle of the location with the highest temperature.

[0072] The first-order fundamental component is extracted, and its phase is used as the deviation azimuth. The amplitude of the first-order fundamental component, or the product of its amplitude and a preset calibration coefficient, is used as the degree of deviation. Harmonic components of the second order and above are filtered out and do not participate in the calculation of the horizontal deviation vector.

[0073] It should be noted that second-order and higher harmonic components correspond to local distortions in the temperature distribution or measurement noise. Filtering these out and using only the first-order fundamental component for calculation ensures long-term stability and signal-to-noise ratio in deviation determination under harsh environments such as high-temperature dust and localized thermal disturbances inside the furnace. Furthermore, calibration coefficients can be pre-determined through calibration experiments, and the product of the amplitude of the first-order fundamental component and the calibration coefficients can be used as the degree of deviation, thereby converting the non-uniformity of the temperature plane into the actual spatial offset of the insulation component in the horizontal direction.

[0074] In another specific embodiment of the above-mentioned real-time adjustment method for the crystal growth thermal field, the lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the heat preservation component is adjusted in the opposite direction to the deviation direction to compensate for the adjustment.

[0075] Calculate the target lifting amount for each lifting support point using the following formula. :

[0076] ;

[0077] Where D represents the spatial offset corresponding to the degree of deviation. Let φ be the circumferential azimuth angle of the j-th lifting support point, and φ be the azimuth angle corresponding to the deviation from the azimuth. Each driving component is driven to move synchronously, so that the insulation component can make translational compensation adjustment.

[0078] It should be noted that the physical meaning of this formula is as follows: the lifting support point located at the off-center position descends, pulling down the insulation component on that side; the lifting support point located at the opposite position to the off-center position rises, pushing up the insulation component on that side; the remaining lifting support points share the displacement in a cosine ratio; and all lifting support points move synchronously, so that the insulation component makes a translational compensation adjustment in space, conforming to the physical reverse process of thermal field deviation, thereby achieving a single adjustment without overshoot or oscillation.

[0079] In another specific embodiment of the above-mentioned real-time adjustment method for the crystal growth thermal field, the temperature measuring devices are arranged in multiple layers at different heights on the side wall of the furnace body; during the calculation, the horizontal deviation vector at the corresponding height is calculated according to the temperature signal collected by the temperature measuring devices of each layer; during the adjustment, the lifting support points are driven to lift and lower differently according to the difference between the horizontal deviation vectors at the heights of each layer, so as to correct the inclination of the thermal field axis in space.

[0080] It should be noted that the insulation structure will undergo uneven deformation when the radial temperature distribution is uneven, causing the thermal field axis to tilt in space. That is, there are differences in the horizontal deviation vector at different heights. By arranging multiple layers of temperature measuring devices at different heights on the side wall of the furnace body, the horizontal deviation vector at each layer height is calculated separately, and the lifting support points are driven to lift differently according to the difference between the horizontal deviation vectors at each layer height. This can not only correct the offset of the thermal field center on the horizontal plane, but also correct the tilt of the thermal field axis in space, thereby further improving the axial symmetry of the thermal field.

[0081] In a preferred embodiment of the above-mentioned real-time adjustment method for the thermal field of crystal growth, the acquisition step, calculation step, judgment step, adjustment step and feedback step are continuously and cyclically executed throughout the entire process of heating, isothermal and cooling of crystal growth, so as to ensure that the thermal field is in a normal state more often.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A real-time adjustment system for the thermal field of crystal growth, comprising a furnace body and a heat-insulating component disposed within the furnace body, characterized in that, Also includes: The online temperature measurement unit includes at least three temperature measuring devices, which are arranged around the circumference of the furnace body to collect temperature signals of the insulation component in multiple directions around the circumference in real time. The lifting adjustment unit is located below the heat preservation component and includes multiple lifting support points arranged circumferentially along the furnace body. Each lifting support point is driven by an independent driving component. The control unit is electrically connected to each of the temperature measuring devices and each of the driving components, and the control unit is configured to: calculate the horizontal deviation vector of the thermal field inside the thermal insulation component based on the temperature signals collected by each of the temperature measuring devices, wherein the horizontal deviation vector includes the deviation direction and the deviation degree; When the deviation exceeds a preset threshold, the lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the heat insulation component is adjusted to compensate in the opposite direction to the deviation; and after the compensation adjustment, the deviation is determined according to the re-acquired temperature signal to see if it has dropped to within the preset threshold. If not, the above calculation and compensation adjustment are repeated.

2. The real-time adjustment system for the thermal field of crystal growth according to claim 1, characterized in that, The temperature measuring device is an infrared thermometer or an infrared thermal imager. The temperature measuring device is installed on the top and / or side wall of the furnace body and is used to collect infrared radiation signals from the upper edge of the insulation component or the thermal field area.

3. The real-time adjustment system for the thermal field of crystal growth according to claim 1, characterized in that, At least three temperature measuring devices are arranged at equal angular intervals along the circumference of the furnace body, and each lifting support point is arranged at equal angular intervals along the circumference of the furnace body. The circumferential orientation of each lifting support point corresponds one-to-one with the circumferential orientation of each temperature measuring device. The control unit determines the lifting support point corresponding to the deviation orientation based on the deviation orientation and drives the determined lifting support point to rise and fall.

4. The real-time adjustment system for the thermal field of crystal growth according to any one of claims 1 to 3, characterized in that, The process by which the control unit calculates the horizontal deviation vector includes: constructing a circumferential temperature sequence using the circumferential azimuth angle of each temperature measuring device and the corresponding temperature signal; performing a Fourier transform on the circumferential temperature sequence and extracting the first-order fundamental component; using the phase of the first-order fundamental component as the deviation azimuth, and using the amplitude of the first-order fundamental component, or the product of the amplitude and a preset calibration coefficient, as the degree of deviation.

5. The real-time adjustment system for the thermal field of crystal growth according to claim 4, characterized in that, The control unit determines the target lifting amount of each lifting support point according to the following formula. : ； Where D is the spatial offset corresponding to the degree of deviation. Let φ be the circumferential azimuth angle of the j-th lifting support point, and let φ be the azimuth angle corresponding to the deviation azimuth. The lifting support point located at the deviation azimuth descends, and the lifting support point located at the azimuth opposite to the deviation azimuth ascends. The remaining lifting support points share the displacement in a cosine ratio, and all the lifting support points move synchronously.

6. A method for real-time adjustment of the thermal field during crystal growth, used in a crystal growth furnace, wherein a heat-insulating component is provided inside the furnace body, and multiple lifting support points, each driven by an independent driving component, are provided below the heat-insulating component, characterized in that... The method includes: Temperature signals of the insulation component in multiple circumferential directions are collected in real time by at least three temperature measuring devices arranged along the circumference of the furnace body. Based on the temperature signals collected by each of the temperature measuring devices, the horizontal deviation vector of the thermal field inside the insulation component is calculated, and the horizontal deviation vector includes the deviation direction and the degree of deviation. The deviation is compared with a preset threshold. If the deviation exceeds the preset threshold, the process proceeds to the next step for adjustment; otherwise, the process returns to continue collecting temperature signals. The lifting direction and displacement of each lifting support point are determined according to the horizontal deviation vector, and each lifting support point is driven to lift and lower in tandem, so that the heat preservation component is adjusted to compensate in the opposite direction to the deviation direction; The temperature signal is reacquired and calculated until the deviation is reduced to within the preset threshold.

7. The method for real-time adjustment of the thermal field during crystal growth according to claim 6, characterized in that, The step of calculating the horizontal deviation vector of the thermal field inside the insulation component based on the temperature signals collected by each of the temperature measuring devices includes: A circumferential temperature sequence is constructed using the circumferential azimuth angle of each of the temperature measuring devices and the corresponding temperature signal. Perform a Fourier transform on the circumferential temperature sequence to obtain the harmonic components of each order; The first-order fundamental component is extracted, and the phase of the first-order fundamental component is used as the deviation azimuth. The amplitude of the first-order fundamental component, or the product of the amplitude and a preset calibration coefficient, is used as the deviation degree. Harmonic components of the second order and above are filtered out and do not participate in the calculation of the horizontal deviation vector.

8. The method for real-time adjustment of the thermal field during crystal growth according to claim 7, characterized in that, The step of determining the lifting direction and displacement of each of the lifting support points based on the horizontal deviation vector, and driving each of the lifting support points to lift and lower in tandem, so that the insulation component can be adjusted to compensate in the direction opposite to the deviation, includes: The target lifting amount of each lifting support point is calculated according to the following formula. : ； Where D is the spatial offset corresponding to the degree of deviation. φ is the circumferential azimuth angle of the j-th lifting support point, and φ is the azimuth angle corresponding to the deviation azimuth; each of the driving components is driven to move synchronously, so that the heat preservation component performs translational compensation adjustment.

9. The method for real-time adjustment of the thermal field during crystal growth according to any one of claims 6 to 8, characterized in that, The temperature measuring devices are arranged in multiple layers at different heights on the side wall of the furnace body. During calculation, the horizontal deviation vector at the corresponding height is calculated based on the temperature signals collected by the temperature measuring devices at each layer. During adjustment, the lifting support points are driven to lift differently according to the difference between the horizontal deviation vectors at the heights of each layer, so as to correct the inclination of the thermal field axis in space.

10. The method for real-time adjustment of the thermal field during crystal growth according to any one of claims 6 to 8, characterized in that, The acquisition step, the calculation step, the judgment step, the adjustment step, and the feedback step are continuously and cyclically executed throughout the entire process of crystal growth, including heating, isothermal treatment, and cooling.

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