Single crystal growth method, single crystal growth equipment and control device thereof

Abstract

The invention provides a single crystal growth method, single crystal growth equipment and a control device thereof, and the method comprises the following steps: in an equal-diameter growth stage, recording an initial function between the actual diameter of a crystal bar and time t as D = F0 (t), when F0 (t) meets a preset condition, locking the pulling rate of a crystal, and when F0 (t) meets the preset condition, locking the pulling rate of the crystal; the initial function is subjected to segmented correction according to measurement results of actual diameters of the crystal bar at n subsequent different measurement moments in sequence to obtain a corrected segmented function D = Fh (t), Fh '(t) at the corresponding moment is calculated, and the heating power in the single crystal furnace is adjusted by comparing Fh' (t) / (Ah * omegah) with a set value x, so that accurate control over the diameter of the crystal bar is achieved, and the accuracy of the diameter of the crystal bar is improved. And the actual diameter fluctuation amplitude is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal growth, and in particular to a single crystal growth method, single crystal growth equipment and a control device thereof. Background Art

[0002] In the process of single crystal equal diameter growth, in order to grow a perfect crystal, the crystal growth rate needs to be locked, that is, the crystal growth rate is the same as the set rate. When the crystal growth rate is locked, the crystal rod diameter is usually controlled by instantaneously changing the heating power or heating temperature, and the crystal rod diameter is controlled by temperature pulses (or power pulses).

[0003] However, since the heat transfer of the single crystal furnace has a certain thermal hysteresis, it is impossible to achieve accurate control during the regulation process, and it is difficult to accurately control the diameter of the crystal rod. The method of controlling the diameter of the crystal rod in the single crystal furnace needs to be improved. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a single crystal growth method and a single crystal growth device and a control device thereof. The single crystal growth method corrects the initial function and uses F h '(t) / (A h ω h ) is compared with the set value x to adjust the heating power in the single crystal furnace, thereby achieving precise control of the crystal rod diameter.

[0005] According to the single crystal growth method of the first embodiment of the present invention, the method comprises: in the equal diameter growth stage, the initial function between the theoretical diameter of the crystal rod and the time t is recorded as D=F0(t), F0(t)=A0*sin(ω0*t+Φ)+d, or, F0(t)=A0*cos(ω0*t+Φ)+d, d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, and Φ is the initial phase; when F0(t) meets the preset conditions, the pulling rate of the crystal is locked, and the initial function is piecewise corrected by using the measurement results of the actual diameter of the crystal rod at subsequent n different measurement times in sequence to obtain the corrected piecewise function D=F h (t), F h (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, D = F h(t) includes multiple sub-functions: the function between the actual diameter of the crystal rod at time t0 and time t is the initial function D=F0(t); the function between the actual diameter of the crystal rod after calibration at time t1 and time t is D=F1(t); and, t z The function between the actual diameter of the crystal rod after calibration and time t is D = F z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z The time is the zth measurement time after the preset conditions are met, z is a positive integer and 2≤z≤n; calculate F′ at the corresponding time h (t), if F' h (t) / (A h *ω h )≥set value x, then increase the heating power by ΔP1; if F' h (t) / (A h *ω h )<0 and |F' h (t) / (A h *ω h )|≥ set value x, then reduce the heating power and the reduction amount is ΔP2, where A h ,ω h t h The amplitude and angular frequency at the moment, the setting value x>0, wherein, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement is equal to the corresponding parameter of the former measurement, and the other is obtained by calculation to achieve a correction.

[0006] According to the single crystal growth method of the embodiment of the present invention, by continuously correcting the parameters A and ω in the initial function, the function model can be adjusted more accurately, which is beneficial to improving the accuracy of the corrected function and making it better fit the actual data, so that the corrected function can be more timely prepared to reflect the changing trend and speed of the actual diameter of the crystal rod at the current moment compared to the initial function, so that the corrected function can regulate the crystal rod, which can make the actual change of the crystal rod in the equal diameter stage relatively less volatile, which is beneficial to more stable fluctuations in the actual diameter of the crystal rod and conducive to growing perfect crystals with uniform diameter.

[0007] In some embodiments, the initial function is segmentedly corrected using the measurement results of the actual diameter of the crystal rod at subsequent n different measurement moments, including: when F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at the first measurement moment t1, the corresponding parameter A1 is equal to the initial corresponding parameter A0, and ω1 is obtained by calculation to achieve a correction; or, the corresponding parameter ω1 is equal to the initial corresponding parameter ω0, and A1 is obtained by calculation to achieve a correction.

[0008] In some embodiments, in p consecutive corrections, at least one correction is performed to calculate the parameter A, and at least one correction is performed to calculate the parameter ω, where p is a positive integer and p≥2.

[0009] In some embodiments, in any two adjacent calibrations, one calibration is performed by calculating the parameter A, and the other calibration is performed by calculating the parameter ω.

[0010] In some embodiments, the equal diameter growth stage includes multiple sub-stages that are performed sequentially over time, the set values ​​x corresponding to the multiple sub-stages are different, and the set values ​​x of the multiple sub-stages decrease in chronological order.

[0011] In some embodiments, the current equal diameter length of the crystal rod is L, the target equal diameter length of the crystal rod is L', and when: 100mm≤L<300mm, x=x1, When 300mm≤L<L'-500mm, x=x2, When L'-500mm≤L≤L', x=x3, 0.01≤x3≤1 / 2, where L'≥1300mm.

[0012] In some embodiments, when 300 mm ≤ L < L' / 2, When L' / 2≤L<L'-500mm,

[0013] In some embodiments, when F0(t)=A0*sin(ω0*t+Φ)+d, the preset condition is F0(t)=d, and F′0(t)>0; when F0(t)=A0*cos(ω0*t+Φ)+d, the preset condition is F0(t)=d+A0.

[0014] In some embodiments, when F0(t) meets a preset condition, a measurement is performed every preset time, and the preset time is less than 1 minute.

[0015] In some embodiments, ΔP1=m1*|F' h (t) / (A h *ω h )|, ΔP2=m2*|F' h (t) / (Ah *ω h )|, m1 and m2 are both temperature control coefficients, 0 <m1≤15、0<m2≤15。

[0016] In some embodiments, the heating power is changed by a top heater on the upper side of the crucible, m1≤1, m2≤1; or, the heating power is changed by a side heater on the outer periphery of the crucible, 1≤m1≤5, 1≤m2≤5; or, the heating power is changed by a bottom heater on the lower side of the crucible, 5≤m1≤15, 5≤m2≤15.

[0017] In some embodiments, F' h (t) / (A h *ω h )<set value x, if F h (t)>d, and F′ h (t)>0, increase the actual liquid port distance; if F h (t)>d, and F′ h (t)<0, reduce the actual liquid port distance; if F h (t)<d, and F′ h (t)<0, reduce the actual liquid port distance; if F h (t)<d, and F′ h (t)>0, increase the actual liquid mouth distance.

[0018] In some embodiments, the change in the crucible rising rate is Δv, Δv=|k*ΔD / Δt|, ΔD is the difference in crystal rod diameters between two adjacent measurement moments, Δt is the time interval between two adjacent measurement moments, and 0.1≤k≤2.

[0019] In some embodiments, the actual liquid port distance takes the target liquid port distance as the zero point and fluctuates within the range of -5 mm to 5 mm.

[0020] According to the control device of the single crystal growth equipment of the second aspect embodiment of the present invention, it includes: a measuring mechanism, a data processing mechanism, a judging mechanism and a power regulating mechanism, the measuring mechanism is used to measure the actual diameter D of the crystal rod, the data processing mechanism communicates with the measuring mechanism, and is used to simulate the initial function D=F0(t) between the actual diameter of the crystal rod and the time t, F0(t)=A0*sin(ω0*t+Φ)+d, or, F0(t)=A0*cos(ω0*t+Φ)+d, d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, Φ is the initial phase, the judging mechanism is used to judge whether F0(t) meets the preset conditions, when F0(t) meets the preset conditions, the pulling rate of the crystal is locked, and the initial function is segmentedly corrected by using the measurement results of the actual diameter of the crystal rod at subsequent n different measurement moments in turn, so as to obtain the corrected segmented function D=F h (t), Fh (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, D = F h (t) includes multiple sub-functions: the function between the actual diameter of the crystal rod at time t0 and time t is the initial function D=F0(t); the function between the actual diameter of the crystal rod after calibration at time t1 and time t is D=F1(t); and, t z The function D = F between the actual diameter of the crystal rod after calibration and time t z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z At the zth measurement moment after the preset conditions are met, z is a positive integer and 2≤z≤n, the data processing mechanism is used to, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement is equal to the corresponding parameter of the previous measurement, and the other is obtained by calculation to achieve a correction, the power adjustment mechanism is used to adjust the heating power, and the judgment mechanism is also used to judge F' h (t) / (A h *ω h ) and the set value x, if F' h (t) / (A h *ω h )≥set value x, the power regulation mechanism increases the heating power and the increase is ΔP1. If F' h (t) / (A h *ω h )<0 and |F' h (t) / (A h *ω h )|≥set value x, the power regulating mechanism reduces the heating power and the reduction amount is ΔP2.

[0021] According to the single crystal growth equipment of the third aspect embodiment of the present invention, it includes: a furnace body, a crucible, a heater and a control mechanism, the crucible is arranged in the furnace body and defines a containing space, the heater is arranged in the furnace body and is used to heat the crucible, the control device is the control device of the single crystal growth equipment according to the above-mentioned second aspect embodiment of the present invention, and the power adjustment mechanism is used to adjust the power of the heater.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a schematic flow chart of a single crystal growth method according to an embodiment of the present invention;

[0025] Figure 2 is a schematic flow chart of a single crystal growth method according to an embodiment of the present invention;

[0026] Figure 3 is a simulation curve of the initial function between the actual diameter of the crystal rod and time according to an embodiment of the present invention that meets the preset conditions, the solid line represents the functional relationship before F0(t) meets the preset conditions, and the dotted line represents the corrected function after F0(t) meets the preset conditions;

[0027] Figure 4 is a corrected function between the actual diameter of the crystal rod and time according to an embodiment of the present invention and a derivative of the corrected function;

[0028] Figure 5 is a curve of change in diameter of a crystal rod after correction in combination with liquid mouth distance control according to an embodiment of the present invention;

[0029] Figure 6 It is the fluctuation curve of the actual diameter of the lower crystal rod over time in the prior art;

[0030] Figure 7 is a fluctuation curve of the actual diameter of the crystal rod measured by controlling the diameter of the crystal rod according to the corrected function over time according to one embodiment of the present invention;

[0031] Figure 8 It is the fluctuation curve of the actual diameter of the crystal rod and the heater power over time in the prior art. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific processes and examples of materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0034] In the present invention, unless otherwise specified, the following terms and symbols have the following meanings: D is the actual diameter of the crystal rod, t is the time, D=F0(t) is the initial function between the actual diameter of the crystal rod and the time, D=F h (t) is the corrected function between the actual diameter of the crystal rod and time, d is the target diameter of the crystal rod, A is the amplitude, specifically the maximum difference between the actual diameter D of the crystal rod and the target diameter d of the crystal rod within one cycle, ω is the angular frequency, Ф is the initial phase, A0 is the initial amplitude, ω0 is the initial angular frequency, x is the set value, ΔP1 and ΔP2 are the changes in heating power, L is the current equal diameter length of the crystal rod, m1 and m2 are the temperature control coefficients, and Δv is the change in the crucible rising rate. The term "perfect crystal" used in this article does not mean an absolutely perfect crystal or a crystal without any defects, but allows the existence of a very small amount of one or more defects, which is not enough to cause a large change in certain electrical or mechanical properties of the crystal or the resulting wafer, resulting in the performance degradation of the electronic device made thereof.

[0035] Hereinafter, a method for growing a single crystal according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0036] like Figure 1 and Figure 2 As shown, the method of single crystal growth includes: in the equal diameter growth stage, the initial function between the actual diameter of the crystal rod and the time t is recorded as D = F0(t), F0(t) = A0*sin(ω0*t+Φ)+d (such as Figure 3 As shown), or, F0(t)=A0*cos(ω0*t+Φ)+d, d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, Φ is the initial phase, and D is the actual diameter of the crystal rod. It can be seen that the initial function is F0(t), A0>0, ω0>0.

[0037] When F0(t) meets the preset conditions, the pulling rate of the crystal is locked, and the initial function is piecewise corrected using the measurement results of the actual diameter of the crystal rod at the subsequent n different measurement moments to obtain the corrected piecewise function D = F h (t), Fh (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, where D = F h (t) includes multiple sub-functions: the function between the actual diameter of the crystal rod at time t0 and time t is the initial function D=F0(t); the function between the actual diameter of the crystal rod after calibration at time t1 and time t is D=F1(t); and, t z The function D = F between the actual diameter of the crystal rod after calibration and time t z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z The time is the zth measurement time after the preset conditions are met, z is a positive integer and 2≤z≤n, n is also a positive integer; calculate F′ at the corresponding time h (t), if F' h (t) / (A h *ω h )≥set value x, then increase the heating power by ΔP1; if F' h (t) / (A h *ω h )<0 and |F' h (t) / (A h *ω h )|≥ set value x (i.e. F' h (t) / (A h *ω h ) is greater than or equal to the set value x), the heating power is reduced by ΔP2, A h ,ω h t h The amplitude and angular frequency at the moment, the setting value x> 0. Among them, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement is equal to the corresponding parameter of the previous measurement, and the other is obtained by calculation to achieve a correction.

[0038] For example, taking the initial function F0(t)=A0*sin(ω0*t+Φ)+d as an example, A0, ω0 and Φ are all known. After F0(t) meets the preset conditions, the measurement result obtained by the subsequent first measurement is that the actual diameter of the crystal rod at time t1 is D1. The initial function is corrected by using the first measurement result to obtain the function D=F1(t) between the actual diameter D of the crystal rod at time t1 and time t; the measurement result obtained by the second measurement is that the actual diameter of the crystal rod at time t2 is D2. The initial function is corrected by using the second measurement result to obtain the function D=F2(t) between the actual diameter D of the crystal rod at time t2 and time t; the measurement result obtained by the third measurement is that the actual diameter of the crystal rod at time t3 is D3. The initial function is corrected by using the third measurement result to obtain the function D=F3(t) between the actual diameter D of the crystal rod at time t3 and time t; and so on, the measurement result obtained by the zth measurement is t z The actual diameter of the crystal rod at this moment is D z , use the above zth measurement result to correct the initial function to get t z The function between the actual diameter D of the crystal rod at the moment and the time t is D = F z (t); ...; the measurement result obtained by the nth measurement is t n The actual diameter of the crystal rod at this moment is D n , use the above nth measurement result to correct the initial function to get t n The function between the actual diameter D of the crystal rod at the moment and the time t is D = F n (t).

[0039] It can be seen that the above-mentioned time t1, time t2, ..., t n The time is the time corresponding to a single measurement of the actual diameter of the crystal rod, t z-1 Time and t z The time can correspond to two adjacent measurements, so the piecewise function D = F after the initial function is piecewise corrected by using the n measurement results in sequence h (t) may include:

[0040] At time t1, the function between the actual diameter of the crystal rod and time t is D = F1(t), F1(t) = A1*sin(ω1*t+Φ)+d;

[0041] At time t2, the function between the actual diameter of the crystal rod and time t is D = F2(t), F2(t) = A2*sin(ω2*t+Φ)+d;

[0042] At time t3, the function between the actual diameter of the crystal rod and time t is D = F3(t), F3(t) = A3*sin(ω3*t+Φ)+d;

[0043] …;

[0044] t z At the moment, the function between the actual diameter D of the crystal rod and time t is D = F z (t), F z (t) = A z *sin(ω z *t+Φ)+d;

[0045] …;

[0046] t n At the moment, the function between the actual diameter D of the crystal rod and time t is D = F n (t), F n (t) = A n *sin(ω n *t+Φ)+d.

[0047] Among them, A z >0,ω z >0, considering that the function parameters in the short term of two adjacent measurements are not much different, one of the parameters A and ω corresponding to the latter measurement is equal to the corresponding parameter of the previous measurement, and the other is obtained by calculation to achieve a correction, so as to facilitate the correction of the initial function and make the corrected function more accurately reflect the change of the actual diameter of the crystal rod over time. Therefore, by establishing the initial function and using multiple actual measurement results to correct the initial function in sections after the initial function meets the preset conditions, the corrected function can more accurately reflect the change of the actual diameter of the crystal rod over time, so as to facilitate the subsequent more timely regulation of the diameter of the crystal rod by the corrected function.

[0048] For example, for the functions D=F1(t) and D=F2(t), there are two ways to correct A2 and ω2: First, take A2=A1, and ω2 is calculated by substituting the actual diameter D2 of the crystal rod measured at time t2 into the function F2(t), that is, ω2 is calculated by the equation D2=A2*sin(ω2*t+Φ)+d, and A2, D2, t2, Φ, and d are all known; Second, take ω2=ω1, and A2 is calculated by substituting the actual diameter D2 of the crystal rod measured at time t2 into the function F2(t), that is, A2 is calculated by the equation D2=A2*sin(ω2*t+Φ)+d, and ω2, D2, t2, Φ, and d are all known. Similarly, in any two subsequent adjacent measurements, for the function F z (t) = A z *sin(ω z *t+Φ)+d and function F z+1 (t) = A z+1 *sin(ω z+1 *t+Φ)+d: Φ is a constant, A z+1 and ωz+1 There are two correction methods: First, take A z+1 =A z , and ω z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substitute into function F z+1 (t) is calculated, that is, ω z+1 By equation D z+1 =A z+1 *sin(ω z+1 *t+Φ)+d, A z+1 , D z+1 ,t z+1 and Φ, d are all known; second, take ω z+1 =ω z , while A z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substitute into function F z+1 (t) is calculated, that is, A z+1 By equation D z+1 =A z+1 *sin(ω z+1 *t+Φ)+d is calculated, ω z+1 , D z+1 ,t z+1 and Φ, d are known.

[0049] Then use the corrected function to calculate the corrected function F at the corresponding time h The first-order derivative F′ of (t) h (t), and according to F' h (t) / (A h *ω h ) value and the set value x to dynamically adjust the heating power. h (t) / (A h *ω h )≥ set value x, indicating that the actual diameter of the crystal rod is in the rising period, and the actual diameter of the crystal rod is growing rapidly. At this time, increasing the heating power to suppress the growth of the actual diameter of the crystal rod is conducive to making the actual diameter of the crystal rod fluctuate toward the target diameter, while F' h (t) / (A h *ω h )<0 and |F' h (t) / (A h *ω h)|≥set value x, indicating that the actual diameter of the crystal rod is in the shrinking period, and the actual diameter of the crystal rod is decreasing rapidly. At this time, reducing the heating power to suppress the decrease of the actual diameter of the crystal rod is conducive to making the actual diameter of the crystal rod fluctuate toward the target diameter, so that in the actual production process, the actual diameter of the crystal rod in the equal diameter growth stage tends to change more steadily, and the fluctuation period is shorter, which is conducive to improving the control accuracy of the actual diameter of the crystal rod, and is convenient for maintaining the stability of V / G in the equal diameter stage, so as to grow a perfect crystal with uniform diameter. It can be seen that the use of the corrected function can achieve precise control of temperature, which is helpful for actual control of the diameter of the crystal rod.

[0050] For example, after the initial function D=F0(t) is corrected, the function D=F1(t) at time t1 is obtained. At time t1 or from time t1 to time t2, F1'(t1) / (A1*ω1) is used to determine the adjustment of the heating power. F1'(t1) can be understood as the first derivative of the function F1(t) at time t1. Compared with the initial function, it can more accurately reflect the change trend of the diameter at the current moment and the speed of the change trend; after the correction, the function D=F2(t) at time t2 is obtained. F'2(t2) / (A2*ω2) is used to determine the adjustment of the heating power. F'2(t2) can be understood as the first derivative of the function F'2(t) at time t2. Compared with the initial function, it can more accurately reflect the change trend of the diameter at the current moment and the speed of the change trend; ...; after the correction, t z Function of time D = F z (t), using F' z (t z ) / (A z *ω z ) to determine the adjustment of heating power, F′ z (t z ) can be understood as function F′ z (t) at t z The first derivative at the time can more accurately reflect the change trend of the diameter at the current time and the speed of the change trend than the initial function; and so on. At this time, calculate F' at the corresponding time h (t) can be understood as calculating F h (t) The first derivative at the corresponding measurement time.

[0051] Of course, the embodiments of the present application are not limited to this. In some other examples, for time t1 to time t2 (i.e., t1≤t<t2), the corrected function is D=F1(t), and F1'(t1) / (A1*ω1) can be used to determine the adjustment of the heating power, or F1'(t y1 ) / (A1*ω1) to determine the adjustment of heating power, F1'(t y1 ) can be understood as the function F1(t) at t y1The first derivative at time t y1 The time is any time between t1 and t2. Compared with the initial function, it can more accurately reflect the change trend of the diameter at the current time and the speed of the change trend. For t2 to t3 (i.e., t2≤t<t3), the corrected function is D=F2(t). F′2(t2) / (A2*ω2) can be used to determine the adjustment of the heating power, and F'2(t y2 ) / (A2*ω2) to determine the adjustment of heating power, F'2(t y2 ) can be understood as the function F2(t) at t y2 The first derivative at time t y2 The time is any time between t2 and t3. Compared with the initial function, it can more accurately reflect the change trend of the diameter at the current time and the speed of the change trend; and so on. At this time, calculate F' at the corresponding time h (t) can be understood as calculating F h (t) The first derivative at any time between two adjacent measurement times.

[0052] Of course, there are some examples where z Time to t z+1 Time (t z ≤t<t z+1 ), the corrected function is D=F z (t), we can also use F' z (t z ) / (A z *ω z ) to determine the adjustment of heating power.

[0053] The above examples all use F0(t)=A0*sin(ω0*t+Φ)+d for correction and optimization. In the application of trigonometric functions, the sine function and the cosine function can be converted to each other through phase offset. Therefore, the derivation and optimization process of F0(t)=A0*cos(ω0*t+Φ)+d is similar to that of F0(t)=A0*sin(ω0*t+Φ)+d, and the detailed derivation process of F0(t)=A0*cos(ω0*t+Φ)+d will not be repeated here.

[0054] It is understandable that after locking the pulling rate of the crystal, due to the complexity of the actual crystal growth situation, there is a certain difference between the actual diameter change of the crystal rod and the initial function. Specifically, when the pulling rate is locked, when the heater performs temperature (or power) pulse control on the diameter of the crystal rod, due to the certain thermal hysteresis of the heat transfer of the single crystal furnace, when the pulse signal is too large and maintained for too long, it will cause thermal shock and heat accumulation, which can easily lead to unstable diameter or even out of control of the diameter, and even polycrystalline crystal. If the pulse signal is too small and the time is too short, the control effect cannot be achieved; for example, the change of crystal rod diameter and heating power in some technologies is as follows: Figure 8 As shown, the horizontal axis is the equal diameter length of the crystal rod, and the vertical axis is the measured value of the crystal rod diameter. The target diameter of the crystal rod is 308mm. When the equal diameter length of the crystal rod is 715mm-725mm, the actual diameter of the crystal rod is measured to be 310mm, with a deviation of 2mm. At this time, the heater performs a temperature rise pulse. Due to thermal hysteresis and continuous growth of the crystal rod, heat acts on the position where the equal diameter length of the crystal rod is 735mm-745mm (the crystal growth speed is approximately 2 minutes for every 1mm length), resulting in the actual measured diameter of 304mm at the 745mm position, with a deviation of 4mm.

[0055] To this end, the above-mentioned setting of the present application performs segmented correction on the initial function, and uses the corrected function as the basis for regulating the heating power, so that corresponding control measures can be taken on the crystal rod diameter more timely to reduce the thermal hysteresis time and make the actual crystal rod diameter fluctuation more stable. Figure 6 and Figure 7 As shown, Figure 6 The inventors have made a curve of the fluctuation of the diameter of the crystal rod over time in the actual growth process, in which the heating power is regulated according to a preset curve in the prior art. Figure 7 Based on the above-mentioned prior art, the inventors regulated the heating power based on a preset curve, and obtained a curve of the diameter fluctuation of the crystal rod over time during the actual growth process. It can be seen from the figure that the single crystal growth method of the present application can obviously make the actual diameter change of the crystal rod in the equal diameter stage more stable, and the fluctuation period is relatively short, which is conducive to improving the control accuracy of the actual diameter of the crystal rod.

[0056] According to the single crystal growth method of the embodiment of the present invention, by continuously correcting the parameters A and ω in the initial function, the function model can be adjusted more accurately, which is beneficial to improving the accuracy of the corrected function and making it better fit the actual data, so that the corrected function can be more timely prepared to reflect the changing trend and speed of the actual diameter of the crystal rod at the current moment compared to the initial function, so that the corrected function can regulate the crystal rod, which can make the actual change of the crystal rod in the equal diameter stage relatively less volatile, which is beneficial to more stable fluctuations in the actual diameter of the crystal rod and conducive to growing perfect crystals with uniform diameter.

[0057] In some embodiments, during the equal diameter growth stage, the actual diameter of the crystal rod is continuously collected within a preset time period to obtain the change of the actual diameter D of the crystal rod with time t. At this time, multiple discrete data are obtained. By analyzing these discrete data, the range of diameter fluctuation can be obtained, and the periodic law of the actual diameter of the crystal rod with time can also be obtained. By fitting a sine function or a cosine function to these discrete data, the amplitude A0 and ω0 can be directly obtained from the fitting result, so as to obtain A0 and ω0 that conform to the law of diameter change, so as to simulate the initial function F0(t) from the multiple discrete data; wherein, the preset time period can select the start time and the end time according to actual needs, for example, the start of the equal diameter stage can be used as the start time of the preset time period, and the preset time period can be 1h to 2h, but is not limited thereto. Of course, the preset time period can also end when the initial function fluctuates relatively evenly above and below the target diameter (that is, a part of the actual diameter of the crystal rod measured multiple times is greater than the target diameter and a part is less than the target diameter), and then it is determined whether F0(t) meets the preset conditions; of course, the moment when F0(t) meets the preset conditions can also be used as the end time of the preset time period.

[0058] Among them, when F0(t) meets the preset conditions, if the current moment t0 corresponds to a single measurement moment, that is, the actual diameter of the crystal rod is measured at the moment t0, or if the current moment t0 does not correspond to a single measurement moment, that is, the actual diameter of the crystal rod is not measured at the moment t0, then the actual diameter of the crystal rod corresponding to the current moment t0 can be directly calculated by the initial function.

[0059] In some embodiments, the initial function is corrected in sections using the measurement results of the actual diameter of the crystal rod at n different subsequent measurement moments, including: when F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at the first measurement moment t1, the corresponding parameter A1 is equal to the initial corresponding parameter A0, and ω1 is obtained by calculation to achieve a correction. Of course, in some other embodiments, the initial function is corrected in sections using the measurement results of the actual diameter of the crystal rod at n different subsequent measurement moments, including: when F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at the first measurement moment t1, the corresponding parameter ω1 is equal to the initial corresponding parameter ω0, and A1 is obtained by calculation to achieve a correction.

[0060] Therefore, the function D=F1(t) between the actual diameter of the crystal rod at time t1 and the time t is obtained, which is convenient for simplifying the correction of the function under the premise of more timely and accurate reflection of the change of the actual diameter of the crystal rod, and is convenient for making the subsequent functions F2(t), F3(t), ..., F n The acquisition of (t) can also better and more timely and accurately reflect the actual diameter change of the crystal rod, which is conducive to enhancing the stability of the system.

[0061] In some embodiments, in the p consecutive corrections, at least one correction is performed to calculate the parameter A, and at least one correction is performed to calculate the parameter ω, where p is a positive integer and p≥2. That is to say, in the p consecutive corrections, not all the parameter A is calculated and corrected, and not all the parameter ω is calculated and corrected, which is conducive to improving the error of only correcting one parameter for p consecutive times while increasing the error of another parameter, facilitating the reduction of error accumulation, and being able to adjust the function model more accurately, which is conducive to improving the accuracy of the parameter A and the parameter ω of the corrected function, so that it can better fit the actual data, and make the corrected function more timely and accurately reflect the change in the diameter of the crystal rod relative to the initial function.

[0062] For example, from the function F z (t) = A z *sin(ω z *t+Φ)+d to F z+p (t) = A z+p *sin(ω z+p *t+Φ)+d, it is calibrated p times continuously, for example, F z (t) to F z+2 (t) After 2 calibrations, F z (t) to F z+3 (t) After 3 corrections, among the p corrections, at least one correction is performed to obtain the parameter A by calculation through the equation, and at least one correction is performed to obtain the parameter ω by calculation through the equation. The number of corrections corresponding to the parameter A calculated by the equation and the number of corrections corresponding to the parameter ω calculated by the equation may be equal or different.

[0063] Take the initial function F0(t)=A0*sin(ω0*t+Φ)+d as an example:

[0064] (1) If p = 2, the self function F z (t) = A z *sin(ω z *t+Φ)+d to F z+2 (t) = A z+2 *sin(ω z+2 *t+Φ)+d, one of the following correction methods can be used: First, from the function F z (t) Corrected to function F z+1 (t), take A z+1 =A z ,ω z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take ωz+2 =ω z+1 , A z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substitute into the equation and calculate; Second, the self function F z (t) Corrected to function F z+1 (t), take ω z+1 =ω z , A z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take A z+2 =A z+1 ,ω z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate;

[0065] (2) If p = 3, the self function F z (t) = A z *sin(ω z *t+Φ)+d to F z+3 (t) = A z+3 *sin(ω z+3 *t+Φ)+d, one of the following correction methods can be used: First, from the function F z (t) Corrected to function F z+1 (t), take A z+1 =A z ,ω z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take ω z+2 =ω z+1 , A z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take ω z+3 =ω z+2 , A z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate; Second, the self function F z (t) Corrected to function Fz+1 (t), take A z+1 =A z ,ω z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take ω z+2 =ω z+1 , A z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take A z+3 =A z+2 ,ω z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate; Third, from the function F z (t) Corrected to function F z+1 (t), take A z+1 =A z ,ω z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take A z+2 =A z+1 ,ω z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take ω z+3 =ω z+2 , A z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate; Fourth, the self function F z (t) Corrected to function F z+1 (t), take ω z+1 =ω z , A z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take Az+2 =A z+1 ,ω z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take A z+3 =A z+2 ,ω z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate; Fifth, from the function F z (t) Corrected to function F z+1 (t), take ω z+1 =ω z , A z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take A z+2 =A z+1 ,ω z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take ω z+3 =ω z+2 , A z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate; Sixth, the self function F z (t) Corrected to function F z+1 (t), take ω z+1 =ω z , A z+1 By adding t z+1 The actual diameter D of the crystal rod measured at the moment z+1 Substituting into the equation, we can calculate that the self-function F z+1 (t) Corrected to function F z+2 (t), take ω z+2 =ω z+1 , A z+2 By adding t z+2 The actual diameter D of the crystal rod measured at the moment z+2 Substituting into the equation, we can calculate that the self-function F z+2 (t) Corrected to function F z+3 (t), take A z+3 =Az+2 ,ω z+3 By adding t z+3 The actual diameter D of the crystal rod measured at the moment z+3 Substitute into the equation and calculate.

[0066] It should be noted that only a specific sequence of two consecutive corrections and three consecutive corrections is shown here, but in actual applications, the order and number of corrections can be adjusted according to the specific data characteristics and optimization requirements. It is important to ensure that the parameters A and ω can be fully updated throughout the optimization process to improve the accuracy and reliability of the function model. In other words, p can be any positive integer greater than or equal to 2, for example, p can also be 4, 5 or more than 5.

[0067] In some embodiments, in any two adjacent calibrations, one calibration pair is used to calculate the parameter A, and the other calibration pair is used to calculate the parameter ω. By alternately fixing and updating the parameter A and the parameter ω, the corrected function can be closer to the actual crystal growth process, and each iteration is fine-tuned based on the result of the previous iteration, thereby reducing the accumulation of errors and improving the reliability of the function.

[0068] For example, the parameter A and the parameter ω obtained by calculation in the previous calibration are directly substituted into the next calibration calculation, that is, for the function F z (t) = A z *sin(ω z *t+Φ)+d, function F z+1 (t) = A z+1 *sin(ω z+1 *t+Φ)+d and function F z+2 (t) = A z+2 *sin(ω z+2 *t+Φ)+d: If A z+1 =A z ,ω z+1 By calculation, we can take ω z+2 =ω z+1 , A z+2 By calculation; if ω z+1 =ω z , A z+1 By calculation, we can take A z+2 =A z+1 ,ω z+2 It is obtained by calculation. Whether the parameter A or the parameter ω is substituted first for the correction calculation, as long as the principle of alternating updates is maintained and each update is ensured to be based on the latest measurement data and the result of the previous iteration, it is conducive to further improving the reliability and accuracy of the corrected function.

[0069] In some embodiments, the equal-diameter growth stage includes multiple sub-stages that proceed sequentially over time, and the set values ​​x corresponding to the multiple sub-stages are not equal, and the set values ​​x of the multiple sub-stages decrease in chronological order. In the equal-diameter growth stage of the crystal rod, as its equal-diameter length gradually increases, the thermal hysteresis time also changes accordingly. The longer the equal-diameter length, the shorter the thermal hysteresis time. In order to accurately match this dynamic change, an intelligent control strategy is adopted, that is, according to the different ranges of the equal-diameter length of the crystal rod, it is subdivided into multiple sub-stages, and an exclusive set value x is set for each sub-stage, that is, the temperature pulse start-up conditions of each sub-stage are different, and the temperature pulse generation conditions of each area are different. These set values ​​are adjusted step by step with the increase of the equal-diameter length, and the changes in the thermal hysteresis time can be adapted by flexibly adjusting the heating conditions, thereby ensuring the stability of the crystal rod growth process and achieving more precise heating control.

[0070] In some embodiments, the current equal diameter length of the crystal rod is L, the target equal diameter length of the crystal rod is L', and when: 100mm≤L<300mm, x=x1, When 300mm≤L<L'-500mm, x=x2, When L'-500mm≤L≤L', x=x3, 0.01≤x3≤1 / 2, where L'≥1300mm. The initial function may be a sine function or a cosine function.

[0071] For example, assuming that the target equal diameter length of the crystal rod is L'=2000mm, when the actual equal diameter length of the crystal rod is between 0≤L<100mm, in the initial stage of equal diameter crystallization, the protective gas (such as argon) and the water cooling jacket in the crystal growth equipment have a more severe impact on the crystal, and the actual diameter of the crystal rod fluctuates greatly. At this time, it is not easy to lock the pulling rate of the crystal; in the initial stage of equal diameter, when the current equal diameter length L of the crystal rod is between 100mm≤L<300mm, x=x1, In the initial stage of equal diameter, there is more liquid melt, the thermal hysteresis time is longer, and the temperature response caused by the change of heating power is relatively delayed. Therefore, the temperature pulse should not be too long, and a shorter temperature control time is required. At this time, |F' h (t) / (A h *ω h )|≥x1, temperature control is turned on, that is, F' h (t) / (A h *ω h )≥x1, increase the heating power, and F' h (t) / (A h *ω h )<0 and |F' h (t) / (A h *ω h)|≥x1, reduce the heating power; with the increase of the equal diameter length, the growth tends to be stable. In the middle of the equal diameter, when the current equal diameter length of the crystal rod is 300mm≤L<1500mm, the thermal hysteresis time is relatively shortened, x=x2, At this time |F' h (t) / (A h *ω h )|≥x2, temperature control is turned on, that is, F′ h (t) / (A h *ω h )≥x2, the heating power is increased, and F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥x2, reduce the heating power; in the later stage of equal diameter, when the current equal diameter length of the crystal rod is 1500mm≤L≤2000mm, the molten soup is further reduced, the remaining molten soup is small, the thermal hysteresis time is short, and the temperature control intervention time can be extended. At this time, x=x3, 0.01≤x3≤1 / 2, at this time |F′ h (t) / (A h *ω h )|≥x3 Turn on temperature control, that is, F′ h (t) / (A h *ω h )≥x3, the heating power is increased, and F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥x3, the heating power is reduced; in this way, the temperature control time is longer, and excessive heat accumulation will not occur. By setting the corresponding set value by changing the equal diameter length of the crystal rod, the intelligent adjustment of the temperature control conditions is realized, and the adverse effects that may be caused by heat accumulation are effectively avoided. It can be understood that in the equal diameter growth stage, changing the heating power can be understood as applying a temperature pulse, and the duration of the temperature pulse can be understood as the duration of maintaining the heating power after the heating power is changed.

[0072] Of course, the equal diameter growth stage can also be divided into two sub-stages, three sub-stages or more than four sub-stages. As the crystal rod grows, the temperature control conditions change to adapt to the changes in the growth of the crystal rod.

[0073] In some embodiments, when 300 mm ≤ L < L' / 2, When L' / 2≤L<L'-500mm, It can be seen that in the middle stage of equal diameter, the growth tends to be stable. When the equal diameter length is 300mm≤L<L'-500mm, x=x2, x2 can be further subdivided to improve the quality and growth efficiency of the crystal rod.

[0074] For example, assuming that the target equal diameter length of the crystal rod is L'=2000mm, when the current equal diameter length of the crystal rod is 300≤L<1000mm, the thermal hysteresis time is relatively shortened, x=x2, At this time |F′ h (t) / (A h *ω h )|≥x2, temperature control is turned on, that is, F′ h (t) / (A h *ω h )≥x2, the heating power is increased, and F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥x2, reduce the heating power; with the increase of the equal diameter length, the growth tends to be more stable, the current equal diameter length of the crystal rod is 1000mm≤L<1500mm, the diameter of the crystal rod in this sub-stage tends to be more stable, the melt is stable and reduced, and the thermal hysteresis time is further shortened, x=x2, |F′ h (t) / (A h *ω h )|≥x2Turn on temperature control, i.e. F′ h (t) / (A h *ω h )≥x2, the heating power is increased, and F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥x2, the heating power is reduced. By further subdividing the value range of x2, the heating power can be adjusted more accurately to adapt to small changes in the growth process of the crystal rod, which helps to reduce fluctuations in the growth process of the crystal rod, thereby improving the uniformity and consistency of the crystal rod. Optionally, the time period corresponding to L<L' / 10 can be used as the preset time period described in the full text to construct the initial function.

[0075] In some embodiments, when F0(t)=A0*sin(ω0*t+Φ)+d, the preset condition is F0(t)=d, and F′0(t)>0; when F0(t)=A0*cos(ω0*t+Φ)+d, the preset condition is F0(t)=d+A0. It can be seen that when F0(t)=A0*sin(ω0*t+Φ)+d, the preset condition is F0(t)=d, and F′0(t)>0, which ensures that the actual diameter D of the crystal rod at a certain time t is equal to the target diameter d, and the initial phase is 0, that is, Φ=0. At this time, Figure 3 As shown, the initial function D=F0(t) between the actual diameter of the crystal rod and time, F0(t)=A0*sin(ω0*t)+d, and the moment when the preset conditions are met indicates that the actual diameter D of the crystal rod is increasing with time t, which is convenient for correction from the initial position of a fluctuation cycle of the initial function, which is convenient for simplifying the correction and reducing the difficulty of calculation; when F0(t)=A0*cos(ω0*t+Φ)+d, the preset condition is F0(t)=d+A0, so that the actual diameter of the crystal rod at the moment when the crystal rod meets the preset conditions is equal to the maximum value of the fluctuation relative to the target diameter d, at which time the initial function is at the peak value, and the initial phase is 0, that is, Φ=0, that is, F0(t)=A0*cos(ω0*t)+d, and the parameters A and ω can be corrected subsequently. The simplified initial function makes the subsequent data processing and correction process easier to operate, and is convenient for correction from the initial position of a fluctuation cycle of the initial function, which is convenient for simplifying the correction and reducing the difficulty of calculation. Obviously, the above setting is conducive to reducing the error that is easily caused in the subsequent calibration process due to the initial phase Φ≠0 during the calibration process, and is conducive to further improving the calibration accuracy.

[0076] Of course, the preset condition can also be other conditions. Under other conditions, the initial phase of the initial function is not 0, that is, Φ≠0, and the subsequent correction calculation of the initial function can also be performed. Optionally, the initial phase Φ can be calculated when the initial function D=F0(t) is simulated, or the initial phase Φ can also be calculated by the actual diameter of the crystal rod at the current moment when the preset condition is met. Regardless of which method is used to obtain the initial phase Φ, Φ can be 0 or not equal to 0.

[0077] In some embodiments, after F(t) meets the preset conditions, measurements are taken every preset time, where the preset time is less than 1 min. During the growth of the ingot, the crystal growth rate is generally about 1 mm / min. Therefore, in adjacent measurements on both sides, the preset time is less than 1 min, so that the time interval between adjacent measurements on both sides has a good adaptability to the crystal growth rate. It is not easy for large errors to accumulate in the corresponding parameters between two measurements due to too long a measurement interval. These errors will gradually accumulate and affect the accuracy of the correction function and the control precision of the system, and then affect the quality of the final product. High-frequency measurements help reduce this error accumulation and improve the stability and reliability of the system.

[0078] Optionally, the preset time is less than 10 s, which can capture subtle changes in the diameter more timely, enabling the system to respond and adjust faster. With the increase in the measurement frequency, the system can obtain more real-time data points for correction calculations and make more precise control adjustments accordingly, thereby reducing the fluctuation range of the actual diameter of the ingot.

[0079] Furthermore, when the preset time is 1 s, real-time monitoring of the growth process is achieved, and any minor changes in the ingot diameter can be captured immediately. Through an almost continuous data stream, the system can more accurately evaluate the change trend of the diameter and make finer adjustments to maintain the stability of the diameter. High-frequency measurements and a fast feedback mechanism help enhance the overall stability of the system and reduce fluctuations and deviations caused by external interference.

[0080] In some embodiments, ΔP1 = m1 * |F′ h (t) / (A h *ω h )|, ΔP2 = m2 * |F′ h (t) / (A h *ω h )|, where both m1 and m2 are temperature control coefficients, 0 < m1 ≤ 15, 0 < m2 ≤ 15. Due to differences in the heat field insulation performance, heater capabilities, etc., the temperature control coefficients are different. For example, for a heat field with poor insulation performance, a larger temperature control coefficient is required so that more heat can act on the melt.

[0081] It can be seen that ΔP1 = m1 * |F′ h (t) / (A h *ω h )| represents the amount of heating power that the system needs to increase when the diameter is increasing, and ΔP2 = m2 * |F′ h (t) / (A h *ω h)| indicates that when the diameter is decreasing, the system needs to reduce the amount of heating power. The increase in heating power is positively correlated with the actual diameter growth rate of the crystal rod, and the decrease in heating power is positively correlated with the actual diameter reduction rate of the crystal rod. By associating the adjustment amount of heating power with the absolute value of the diameter change rate, it is convenient to make the temperature pulse match the actual diameter fluctuation of the crystal rod more closely, and the system can control the stability of the diameter more accurately. When the diameter deviates from the target value, the system can immediately adjust the heating power according to the degree and direction of the deviation, so as to quickly restore the equal diameter growth state of the crystal rod, which helps to reduce the fluctuation range of the diameter and improve the stability and consistency of the growth process.

[0082] It can be understood that the change of heating power can be regulated by any one or more heaters of the single crystal growth equipment.

[0083] In some embodiments, the heating power is changed by a top heater on the upper side of the crucible, m1≤1, m2≤1, for example, m1 and m2 are 0.2, 0.5, 0.7 or 1, etc.; or, the heating power is changed by a side heater on the outer periphery of the crucible, 1≤m1≤5, 1≤m2≤5, for example, m1 and m2 are 1.2, 2.5, 3.7, 4.3 or 5, etc.; or, the heating power is changed by a bottom heater on the lower side of the crucible, 5≤m1≤15, 5≤m2≤15, for example, m1 and m2 are 5.8, 6.5, 7.7, 8.3, 9, 11, 13, 14 or 15, etc. When the same temperature pulse is required, different heaters are set at different positions and at different distances from the crystal rod. Different heaters have different corresponding thermal hysteresis. Different heaters can be used to change different heating powers to meet the actual needs of the crystal rod. Different heater settings correspond to different temperature control coefficients, so that after the corresponding heater changes the heating power, the temperature pulse brought about by it can be more matched with the temperature pulse required for controlling the actual diameter change of the crystal rod. The system can select the most suitable heater and adjustment strategy based on the current actual diameter of the crystal rod and the target diameter of the crystal rod. This flexibility helps to optimize the growth process and improve the quality and production efficiency of the crystal rod.

[0084] It can be understood that if the single crystal growth equipment includes a top heater, the top heater is relatively close to the solid-liquid interface of the molten liquid in the crucible, and the top heater plays a dominant role in the adjustment of the heating power, ensuring efficient heat transfer, and also enabling the top heater to directly affect the overall growth process of the crystal rod; if the single crystal growth equipment includes a bottom heater, the bottom heater is relatively far from the solid-liquid interface of the molten liquid in the crucible. For this reason, the above-mentioned setting of the present application matches and corresponds to the temperature control coefficients of different heaters with the heaters to meet the crystal rod regulation requirements.

[0085] It can be understood that in the process of controlling the diameter of the crystal rod, as long as the corresponding heating power can be met, one of the three heaters or a random combination of the three heaters can be used to synergistically control the temperature change without affecting the growth process of the crystal rod.

[0086] In some embodiments, Figure 2 As shown, F′ h (t) / (A h *ω h )<set value x, the actual diameter change rate of the crystal rod is small, and the diameter is basically in the peak area. In order to prevent diameter deviation, the diameter is controlled by the liquid nozzle distance at this time, which can be adjusted in the following different situations:

[0087] First, if F h (t)>d, and F′ h (t)>0, increase the actual liquid mouth distance, at this time the actual diameter of the crystal rod is larger than the target diameter of the crystal rod, the change rate of the actual diameter of the crystal rod is positive, the actual diameter of the crystal rod is still increasing, and is basically in the diameter peak area, at this time the actual liquid mouth distance can be increased to change the change rate of the actual diameter of the crystal rod, so as to make the change rate of the actual diameter of the crystal rod decrease from a positive value or change to a negative value, the actual diameter of the crystal rod gradually decreases to approach the target diameter of the crystal rod, thereby ensuring the stability of the crystal rod diameter during the production process.

[0088] Second, if F′ h (t)>0, and F′ h (t)<0, reduce the actual liquid mouth distance, at this time the actual diameter of the crystal rod is larger than the target diameter of the crystal rod, the rate of change of the actual diameter of the crystal rod is negative, the actual diameter of the crystal rod is constantly decreasing, by reducing the actual liquid mouth distance, changing the rate of change of the actual diameter of the crystal rod, so that the actual diameter of the crystal rod is not easily excessively reduced to be too smaller than the target diameter of the crystal rod; illustratively, by adjusting the rising rate of the crucible and the pulling rate of the seed crystal at the same time, the system can achieve fine control of the growth rate and diameter of the crystal rod, ensuring that the actual diameter of the crystal rod can gradually approach and stabilize within the range of the target diameter of the crystal rod, the pulling rate of the seed crystal is the pulling rate of the crystal, the initial adjustment of the seed crystal pulling rate can be adjusted based on the crystal pulling rate locked when F(t) meets the preset conditions, and the subsequent adjustment of the seed crystal pulling rate can be adjusted based on the current moment.

[0089] It can be understood that in the process of reducing the actual liquid mouth distance, in order to prevent the liquid level of the melt in the crucible from exceeding the solid-liquid interface, the above-mentioned setting of the present application changes the seed crystal pulling rate so that the liquid level of the melt will not exceed the solid-liquid interface while reducing the actual liquid mouth distance, which is beneficial to reduce the risk of crystal rod breakage.

[0090] Third, if F h (t)<d, and F′h (t)<0, reduce the actual liquid mouth distance, at this time the actual diameter of the crystal rod is smaller than the target diameter of the crystal rod, the change rate of the actual diameter of the crystal rod is negative, and the actual diameter of the crystal rod is constantly decreasing. By reducing the actual liquid mouth distance, the change rate of the actual diameter of the crystal rod is changed, and the change rate of the actual diameter of the crystal rod increases from a negative value or increases to a positive value, so that the actual diameter of the crystal rod continues to increase and gradually approaches the target diameter of the crystal rod, ensuring the stability of the crystal rod diameter during the production process.

[0091] Fourth, if F h (t)<d, and F′ h (t)>0, increase the actual liquid mouth distance, at this time the actual diameter of the crystal rod is smaller than the target diameter of the crystal rod, the change rate of the actual diameter of the crystal rod is positive, and the actual diameter of the crystal rod is increasing. By decreasing and increasing the actual liquid mouth distance, the change rate of the actual diameter of the crystal rod is reduced, which makes it easier for the actual diameter of the crystal rod to increase continuously, and it is not easy to increase to a value that is too large than the target diameter of the crystal rod, thereby ensuring the stability of the diameter of the crystal rod during the production process.

[0092] The liquid mouth distance is the distance between the lower end of the guide tube and the solid-liquid interface. By adjusting the liquid mouth distance, the temperature gradient in the melt can be adjusted, thereby affecting the growth rate of the crystal rod.

[0093] It can be seen that the liquid mouth distance can be changed by adjusting the rising rate of the crucible and the pulling rate of the seed crystal, and the actual diameter of the crystal rod can be controlled by temperature pulse control and liquid mouth distance control. It ensures that the actual diameter of the crystal rod can fluctuate within the target diameter range of the crystal rod throughout the growth process, and the fluctuation amplitude and fluctuation period are reduced, with a faster control response. In addition, by adjusting the rising rate of the crucible and the pulling rate of the seed crystal at the same time, the relative position of the crystal rod and the molten soup liquid surface remains unchanged.

[0094] It can be understood that the "changing the crucible rising rate" and "changing the seed crystal pulling rate" in the above scheme of the present application are directly adjusted based on the current moment. For example, the crucible rising rate at the current moment is v. If the crucible rising rate needs to be increased, and the increase is Δv, then the crucible rising rate is directly increased from v to the target rising rate v+Δv. Similarly, if the crucible rising rate needs to be reduced, and the reduction is Δv, then the crucible rising rate is directly reduced from v to the target rising rate v-Δv. Obviously, when v-Δv>0, the crucible is still in an ascending state; if v-Δv<0, the crucible is in a descending state. In addition, when the liquid mouth distance is used to control the actual diameter of the crystal rod, the heating power can be regulated according to a preset curve. The setting of the preset curve is well known to those skilled in the art and will not be repeated here.

[0095] Optionally, F′ hThe relationship between (t) and 0 can be determined by the results of two consecutive measurements. If the actual diameter of the crystal rod obtained in the latter measurement is larger than the actual diameter of the crystal rod obtained in the previous measurement, then F′ h (t)>0, if the actual diameter of the crystal rod obtained by the later measurement is larger than the actual diameter of the crystal rod obtained by the previous measurement, then F′ h (t)<0. Of course, the judgment can also be made by directly taking the derivative of the corrected function.

[0096] In some embodiments, the change in the crucible rising rate is Δv, Δv=|k*ΔD / Δt|, ΔD is the difference in the diameter of the crystal rod between two adjacent measurement moments, and Δt is the time interval between two adjacent measurement moments, for example, ΔD / Δt=(D z+1 -D z ) / (t z+1 -t z ), where 0.1≤k≤2. Therefore, the rate of change of the crucible rising rate is positively correlated with |ΔD / Δt|, which is the absolute value of the ratio of the difference between the actual diameter of the crystal rod measured in two adjacent measurements to the time interval between the two corresponding adjacent measurement moments. That is, the greater the difference between the actual direct measurement results of the crystal rod in two adjacent measurements, the greater the change in the crucible rising rate, which is convenient for implementing timely matching control measures for the crystal rod diameter.

[0097] For example, k can be 0.1, 0.5, 0.8, 1, 1.3, 1.6, 1.8, or 2, etc.

[0098] In some embodiments, the actual liquid mouth distance takes the target liquid mouth distance as the zero point and fluctuates within the range of -5mm to 5mm. The setting of the target liquid mouth distance has process requirements in the process of preparing the crystal rod, which can ensure the relative stability of factors such as the temperature gradient and the melt during the crystal growth process. The target liquid mouth distance needs to be maintained within a relatively stable range. When the liquid mouth distance is controlled by changing the rising speed of the crucible, it is necessary to ensure that the actual liquid mouth distance fluctuates within the range of the target liquid mouth distance and does not affect the V / G value too much, thereby achieving the stability of the crystal rod growth process and improving production efficiency. In other words, the process of reducing the actual liquid mouth distance in the above scheme will not reduce the actual liquid mouth distance to a value less than the minimum value of the actual liquid mouth distance. Similarly, the process of increasing the actual liquid mouth distance will not increase the actual liquid mouth distance to a value exceeding the maximum value of the actual liquid mouth distance.

[0099] It can be understood that based on the fluctuation of the actual diameter of the crystal rod, the adjustment of the actual liquid mouth distance also fluctuates to a certain extent. Therefore, in the two adjacent processes of increasing the actual liquid mouth distance and reducing the actual liquid mouth distance, regardless of the order of the two processes, when the two processes are adjusted, the actual liquid mouth distance tends to be adjusted to the target liquid mouth distance.

[0100] The control device of the single crystal growth equipment according to the embodiment of the present invention includes: a measuring mechanism, a data processing mechanism, a judgment mechanism and a power adjustment mechanism. The measuring mechanism is used to measure the actual diameter D of the crystal rod, and can measure the actual diameter D of the crystal rod in real time and accurately, providing basic data for subsequent data processing and judgment.

[0101] The data processing mechanism communicates with the measuring mechanism, and is used to construct an initial function D=F0(t) between the actual diameter of the crystal rod and the time t, F0(t)=A0*sin(ω0*t+Φ)+d, or F0(t)=A0*cos(ω0*t+Φ)+d, d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, Φ is the initial phase, which can intuitively reflect the changing trend of the crystal rod diameter over time.

[0102] The judging mechanism is used to judge whether F0(t) meets the preset conditions. When F0(t) meets the preset conditions, the pulling rate of the crystal is locked. The data processing mechanism sequentially uses the measurement results of the actual diameter of the crystal rod at the subsequent n different measurement moments to perform segmented correction on the initial function to obtain the corrected segmented function D=F h (t), F h (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, D = F h (t) includes multiple sub-functions: the function between the actual diameter of the crystal rod at time t0 and time t is the initial function D=F0(t); the function between the actual diameter of the crystal rod after calibration at time t1 and time t is D=F1(t); and, t z The function D = F between the actual diameter of the crystal rod after calibration and time t z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z The time is the zth measurement time after the preset condition is met, z is a positive integer and 2≤z≤n; the data processing mechanism is used for realizing a correction by obtaining, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement being equal to the corresponding parameter of the previous measurement, and the other being obtained by calculation.

[0103] The power adjustment mechanism is used to adjust the heating power, and the judgment mechanism is also used to judge F' h (t) / (A h *ω h ) and the set value x, if F′ h (t) / (A h *ω h )≥set value x, the power regulation mechanism increases the heating power by ΔP1. If F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥ set value x, the power adjustment mechanism reduces the heating power and the reduction amount is ΔP2. By judging F′ h (t) / (A h *ω h ) and the set value x, and accurately adjust the heating power to achieve fine control of the crystal rod diameter, which is beneficial to make the actual diameter of the crystal rod fluctuate towards the target diameter. As a result, in the actual production process, the actual diameter of the crystal rod in the equal diameter stage tends to change more smoothly, and the fluctuation period is shorter, which is beneficial to improve the control accuracy of the actual diameter of the crystal rod.

[0104] In some embodiments, the data processing mechanism sequentially uses the measurement results of the actual diameter of the crystal rod at the subsequent n different measurement moments to perform segmented correction on the initial function. At this time, the data processing mechanism is constructed as follows: when F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at the moment t1 is measured for the first time, and the corresponding parameter A1 is equal to the initial corresponding parameter A0, and ω1 is obtained by calculation to achieve a correction; or, the judgment mechanism is constructed as follows: when F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at the moment t1 is measured for the first time, and the corresponding parameter ω1 is equal to the initial corresponding parameter ω0, and A1 is obtained by calculation to achieve a correction.

[0105] In some embodiments, the data processing mechanism is configured such that, in p consecutive corrections, at least one correction is performed to calculate the parameter A, and at least one correction is performed to calculate the parameter ω, where p is a positive integer and p≥2.

[0106] In some embodiments, the judgment mechanism is used to judge whether F0(t) meets the preset condition. When F0(t)=A0*sin(ω0*t+Φ)+d, the preset condition is F0(t)=d, and F′0(t)>0; when F0(t)=A0*cos(ω0*t+Φ)+d, the preset condition is F0(t)=d+A0. In some embodiments, when the judgment mechanism judges that F0(t) meets the preset condition, the measuring mechanism performs a measurement every preset time, and the preset time is less than 1 minute.

[0107] In some embodiments, the data processing mechanism is configured such that, in any two adjacent corrections, one correction is performed to calculate the parameter A, and the other correction is performed to calculate the parameter ω.

[0108] In some embodiments, the power regulation mechanism is configured as follows: ΔP1 = m1*|F′ h (t) / (A h *ω h )|, ΔP2=m2*|F′ h (t) / (A h *ω h )|, m1 and m2 are both temperature control coefficients, 0 <m1≤15、0<m2≤15。

[0109] In some embodiments, the control device further includes a driving mechanism, which is used to drive the crucible to rise and fall, and the driving mechanism communicates with the judgment mechanism to control the crucible to rise and fall according to the judgment mechanism. h (t) / (A h *ω h )<set value x: If the judgment mechanism further determines that F h (t)>d, and F′ h (t)>0, increase the actual liquid port distance; if F h (t)>d, and F′ h (t)<0, reduce the actual liquid port distance; if F h (t)<d, and F′ h (t)<0, reduce the actual liquid port distance; if F h (t)<d, and F′ h (t)>0, increase the actual liquid mouth distance.

[0110] In some embodiments, the driving mechanism is configured such that the change in the crucible rising rate is Δv, Δv=|k*ΔD / Δt|, ΔD is the difference in crystal rod diameters between two adjacent measurement moments, Δt is the time interval between two adjacent measurement moments, and 0.1≤k≤2.

[0111] In some embodiments, the driving mechanism is configured such that the driving mechanism drives the crucible to rise and fall to change the actual liquid port distance, and the actual liquid port distance fluctuates within a range of -5 mm to 5 mm with the target liquid port distance as the zero point.

[0112] According to an embodiment of the present invention, the single crystal growth device comprises: a furnace body, a crucible, a heater and a control mechanism. The furnace body provides a stable and closed environment for the growth of the crystal rod, which helps to form a stable thermal field and reduces the influence of temperature fluctuations, impurity pollution and the like on the growth process of the crystal rod. The crucible is arranged in the furnace body and defines a holding space. The crucible is used to hold the raw materials for the growth of the crystal rod. By adjusting the parameters such as the position, rotation speed and lifting speed of the crucible, the temperature gradient, melt and other conditions in the growth process of the crystal rod can be controlled, thereby affecting the quality of the crystal rod. The heater is arranged in the furnace body and used to heat the crucible. It is the main heat source in the growth process of the crystal rod. By heating the raw materials in the crucible to make them reach a molten state, the necessary conditions for the growth of the crystal rod are provided. The control device is the control device of the crystal rod growth device according to the above embodiment of the present invention. The power adjustment mechanism is used to adjust the power of the heater. The actual diameter of the crystal rod and other parameters are monitored in real time by the measuring mechanism, and the data is transmitted to the data processing mechanism for analysis and processing, which helps to achieve precise control of the growth process of the crystal rod. These mechanisms are arranged in the crystal rod growth device and each plays an important role, and together achieves precise control and optimization of the growth process of the crystal rod.

[0113] In the description of this specification, the description with reference to the terms "one embodiment", "another embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0114] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for growing a single crystal, characterized in that: include: In the equal diameter growth stage, the initial function between the actual diameter of the crystal rod and the time t is recorded as D=F0(t), F0(t)=A0*sin(ω0*t+Φ)+d, or F0(t)=A0*cos(ω0*t+Φ)+d, d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, and Φ is the initial phase; When F0(t) meets the preset conditions, the pulling rate of the crystal is locked, and the initial function is piecewise corrected using the measurement results of the actual diameter of the crystal rod at the subsequent n different measurement moments to obtain the corrected piecewise function D = F h (t), F h (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, D = F h (t) includes multiple sub-functions: The function between the actual diameter of the crystal rod at time t0 and time t is the initial function D = F0 (t); The function D=F1(t) between the actual diameter of the crystal rod after calibration at time t1 and time t; and t z The function D = F between the actual diameter of the crystal rod after calibration and time t z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z The time is the zth measurement time after the preset condition is met, where z is a positive integer and 2≤z≤n; Calculate F′ at the corresponding time h (t), if F′ h (t) / (A h *ω h )≥set value x, then increase the heating power by ΔP1; if F h '(t) / (A h *ω h )<0 and |F h '(t) / (A h *ω h )|≥ set value x, then reduce the heating power and the reduction amount is ΔP2, where A h ,ω h t h The amplitude and angular frequency at the moment, setting value x>0, Among them, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement is equal to the parameter corresponding to the former measurement, and the other is obtained by calculation to achieve a correction.

2. The method for growing a single crystal according to claim 1, characterized in that: The step of sequentially using the measurement results of the actual diameter of the crystal rod at subsequent n different measurement moments to perform segmented correction on the initial function includes: When F0(t) meets the preset conditions, the actual diameter D1 of the crystal rod at time t1 is measured for the first time. The corresponding parameter A1 is equal to the initial corresponding parameter A0, and ω1 is obtained by calculation to achieve a correction; or, The corresponding parameter ω1 is equal to the initial corresponding parameter ω0, and A1 is obtained by calculation to achieve a correction.

3. The method for growing a single crystal according to claim 1, characterized in that: In the p consecutive calibrations, at least one calibration is performed to calculate the parameter A, and at least one calibration is performed to calculate the parameter ω, where p is a positive integer and p≥2.

4. The method for growing a single crystal according to claim 3, characterized in that: In any two adjacent calibrations, one calibration is performed by calculating the parameter A, and the other calibration is performed by calculating the parameter ω.

5. The method for growing a single crystal according to claim 1, characterized in that: The equal-diameter growth stage includes a plurality of sub-stages that are performed sequentially over time, the set values ​​x corresponding to the plurality of sub-stages are not equal, and the set values ​​x of the plurality of sub-stages decrease in chronological order.

6. The method for growing a single crystal according to claim 5, characterized in that: The current equal diameter length of the crystal rod is L, the target equal diameter length of the crystal rod is L', and the following conditions are satisfied: When 100mm≤L<300mm, x=x1, When 300mm≤L<L'-500mm, x=x2, When L'-500mm≤L≤L', x=x3, 0.01≤x3≤1 / 2, where L'≥1300mm.

7. The method for growing a single crystal according to claim 6, characterized in that: When 300mm≤L<L' / 2, When L' / 2≤L<L'-500mm, 8. The method for growing a single crystal according to claim 1, characterized in that: When F0(t)=A0*sin(ω0*t+Φ)+d, the preset condition is F0(t)=d, and F0'(t)>0; When F0(t)=A0*cos(ω0*t+Φ)+d, the preset condition is F0(t)=d+A0.

9. The method for growing a single crystal according to claim 1, characterized in that: When F0(t) meets the preset conditions, a measurement is performed every preset time, and the preset time is less than 1 minute.

10. The method for growing a single crystal according to claim 1, characterized in that: ΔP1=m1*|F′ h (t) / (A h *ω h )|, ΔP2=m2*|F′ h (t) / (A h *ω h )|, m1 and m2 are both temperature control coefficients, 0 <m1≤15、0<m2≤15。 11. The method for growing a single crystal according to claim 10, characterized in that: Change the heating power through the top heater on the upper side of the crucible, m1≤1, m2≤1; or, Change the heating power by the side heaters on the periphery of the crucible, 1≤m1≤5, 1≤m2≤5; or, The heating power is changed by the bottom heater on the lower side of the crucible, 5≤m1≤15, 5≤m2≤15.

12. The method for growing a single crystal according to any one of claims 1 to 11, characterized in that: F′ h (t) / (A h *ω h )<set value x, If F h (t)>d, and F h '(t)>0, increase the actual liquid mouth distance; if F h (t)>d, and F h '(t)<0, reduce the actual liquid mouth distance; if F h (t)<d, and F h '(t)<0, reduce the actual liquid mouth distance; if F h (t)<d, and F h '(t)>0, increase the actual liquid mouth distance.

13. The method for growing a single crystal according to claim 12, characterized in that: The change in the crucible rising rate is Δv, Δv=|k*ΔD / Δt|, ΔD is the difference in the diameter of the crystal rod between two adjacent measuring moments, Δt is the time interval between two adjacent measuring moments, and 0.1≤k≤2.

14. The method for growing a single crystal according to claim 12, characterized in that: The actual liquid port distance takes the target liquid port distance as the zero point and fluctuates within the range of -5 mm to 5 mm.

15. A control device for a single crystal growth device, characterized in that: include: A measuring mechanism, wherein the measuring mechanism is used to measure the actual diameter D of the crystal rod; A data processing mechanism, which communicates with the measuring mechanism and is used to simulate an initial function D=F0(t) between the actual diameter of the crystal rod and the time t, F0(t)=A0*sin(ω0*t+Φ)+d, or F0(t)=A0*cos(ω0*t+Φ)+d, where d is the target diameter of the crystal rod, A0 is the initial amplitude, ω0 is the initial angular frequency, and Φ is the initial phase; A judging mechanism, wherein the judging mechanism is used to judge whether F0(t) satisfies a preset condition. When F0(t) satisfies the preset condition, the pulling rate of the crystal is locked, and the initial function is corrected in sections using the measurement results of the actual diameter of the crystal rod at subsequent n different measurement moments in sequence, so as to obtain a corrected sectionwise function D=F h (t), F h (t) = A h *sin(ω h *t+Φ)+d, or, F h (t) = A h *cos(ω h *t+Φ)+d, where A h is the corrected amplitude, ω h is the corrected angular frequency, D = F h (t) includes multiple sub-functions: the function between the actual diameter of the crystal rod at time t0 and time t is the initial function D=F0(t); the function between the actual diameter of the crystal rod after calibration at time t1 and time t is D=F1(t); and, t z The function D = F between the actual diameter of the crystal rod after calibration and time t z (t), F z (t) = A z *sin(ω z *t+Φ)+d, or, F z (t) = A z *cos(ω z *t+Φ)+d,t z The time is the zth measurement time after the preset condition is met, z is a positive integer and 2≤z≤n, and the data processing mechanism is used for, in two adjacent measurements, one of the parameters A and ω corresponding to the latter measurement is equal to the parameter corresponding to the previous measurement, and the other is obtained by calculation to achieve a correction; The power adjustment mechanism is used to adjust the heating power, and the judgment mechanism is also used to judge F h '(t) / (A h *ω h ) and the set value x, if F h '(t) / (A h *ω h )≥set value x, the power adjustment mechanism increases the heating power by ΔP1. If F′ h (t) / (A h *ω h )<0 and |F′ h (t) / (A h *ω h )|≥set value x, the power regulating mechanism reduces the heating power and the reduction amount is ΔP2.

16. A single crystal growth device, characterized in that: include: A furnace body and a crucible, wherein the crucible is arranged in the furnace body and defines a containing space; A heater, the heater is disposed in the furnace body and is used to heat the crucible; A control device, wherein the control device is the control device of the single crystal growth equipment according to claim 15, and the power adjustment mechanism is used to adjust the power of the heater.

Images