JP5505359B2 - Heater output control method and single crystal manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for controlling the heater output of a single crystal manufacturing apparatus.

As one method for producing a silicon single crystal, which is a substrate material for semiconductor integrated circuits, etc., the Czochralski method (hereinafter also referred to as CZ method) in which a cylindrical single crystal ingot is pulled up from a raw material melt in a crucible is used. ing.
In this CZ method, a quartz crucible placed in a chamber of a single crystal manufacturing apparatus is filled with polycrystalline silicon as a raw material, and the raw material is heated and melted by a cylindrical heater surrounding a graphite crucible for supporting the quartz crucible. After that, the seed crystal attached to the seed chuck is immersed in the melt, and the single crystal is grown by pulling up the seed chuck while rotating the seed chuck and the crucible in the same direction or in the opposite direction (see, for example, Patent Document 1).

In the growth of such a single crystal ingot, the heater temperature is detected by a radiation thermometer, and the heater output is controlled so that a predetermined temperature pattern is obtained while feeding back the detected heater temperature to the control mechanism, thereby making the chamber The temperature inside is controlled.
Such temperature control is important in order to make the single crystal ingot to be grown have a desired diameter. If the diameter variation is large, productivity and crystal quality are affected.

Japanese Patent Laid-Open No. 3-97688

Generally, a graphite material is used for in-furnace parts (a heater, a crucible, a heat insulating material, etc.) of a single crystal manufacturing apparatus. In these in-furnace parts, thinning and oxide deposition occur with the progress of operation. For this reason, the heater output control, which was initially appropriate, is no longer appropriate as the operation progresses, and there is a gap between the furnace temperature when the standard temperature pattern is obtained and the actual furnace temperature. End up.
The deviation of this temperature pattern is the shape of the cone part formed by the temperature gradient when the crystal is manufactured using the standard temperature pattern, and the actual furnace in the straight body part forming process as shown in FIG. Appears as a deviation from the temperature pattern. FIG. 11 is (a) a schematic diagram of a single crystal ingot, (b) a graph showing a deviation from a standard temperature pattern by the apparatus, and (c) a graph showing a standard temperature pattern.

In particular, in the shape of the cone portion of the single crystal ingot to be grown, the effect of temperature tends to appear as a difference in cone portion formation time. FIG. 12 is a diagram showing the difference in cone shape depending on the effect of temperature. This is because, even if the temperature pattern is the same, if the effect on the melt temperature (the degree of heat transfer) is reduced, the first half of the cone portion formation is delayed. If the temperature effect is standard, there will be almost no deviation from the standard temperature pattern, but the cone shape will be the desired shape.If the temperature effect is weak, the cone shape will be longer than the desired shape and the temperature effect will be stronger. In this case, the cone shape changes to a flat shape rather than the desired shape.
When manufacturing crystals using a standard temperature pattern, aim for the desired cone part shape (cone part formation time) and set the MAX-MIN value of the deviation from the temperature pattern between the straight body part of 30-170 cm. In the case of 1, it is aimed (reference) that the deviation amount of the actual temperature pattern with respect to the standard temperature pattern in the straight body part forming step is within 10%. However, in a single crystal manufacturing apparatus having a particularly large temperature pattern deviation, the cone part forming time is 30 minutes or more different from the standard, and the deviation from the standard temperature pattern during the straight body part forming process is 20% or more. There was a case.

In a device with a large deviation of the actual temperature pattern from such a standard temperature pattern, troubles (productivity deterioration) due to poor shape of the cone part of the grown ingot, diameter fluctuation, and crystal quality This is a problem.
Therefore, in the prior art, a temperature pattern is prepared for each single crystal manufacturing apparatus so that the same crystal quality can be obtained. However, with such a method, as the number of devices increases, equipment changes, or deterioration of the in-furnace parts over time, it is necessary to modify the pattern each time, resulting in deterioration of productivity due to pattern management. . Even in this case, variations in the quality and diameter of the crystal were caused by the deviation of the temperature pattern due to the above-described operation.

  The present invention has been made in view of the above-mentioned problems, and performs temperature control during single crystal ingot growth to suppress crystal quality variation and grow a high quality single crystal ingot with high productivity. It is an object of the present invention to provide a heater output control method and a single crystal manufacturing apparatus that can be used.

  In order to achieve the above object, the present invention provides a single crystal manufacturing apparatus for growing a single crystal ingot by forming a throttle part, a cone part, a straight body part, and a round part by the Czochralski method. In this method, the output of the heater is controlled while detecting, and a correlation equation between the growth rate at the time of forming the narrowed portion and the cone portion forming time in a reference single crystal manufacturing apparatus is obtained in advance. When growing a single crystal ingot with a crystal manufacturing apparatus, the growth rate and cone portion formation time at the time of forming the narrowed portion are measured, and the correlation equation is calculated from the measured growth rate and cone portion forming time at the time of forming the narrowed portion. There is provided a heater output control method characterized in that a control signal is corrected based on the control signal, and the output of the heater of the other single crystal manufacturing apparatus is controlled by the corrected control signal.

  Further, the present invention controls the output of the heater while detecting the temperature of the heater by the Czochralski method, and forms a throttle part, a cone part, a straight body part, and a rounded part to grow a single crystal ingot. A single crystal manufacturing apparatus, which obtains a correlation formula between the growth rate at the time of forming the narrowed portion and the cone portion forming time in a reference single crystal manufacturing apparatus in advance, and the single crystal ingot in another single crystal manufacturing apparatus The growth rate and cone portion formation time during the formation of the narrowed portion are measured, and the control signal is corrected based on the correlation equation from the measured growth rate and cone portion formation time during the narrowed portion formation. Thus, the single crystal manufacturing apparatus is characterized in that the output of the heater of the other single crystal manufacturing apparatus is controlled by the corrected control signal.

  By performing such heater output control, it is possible to perform accurate heater output control by suppressing temperature pattern deviation due to individual differences between apparatuses and temperature pattern deviation during operation. Further, since a single crystal ingot having the same quality can be grown using a common temperature pattern in a plurality of apparatuses, productivity is improved. As described above, by using the method and apparatus of the present invention, a high-quality single crystal ingot can be grown with high productivity by accurate temperature control.

At this time, it is preferable that the control signal is corrected by gain and offset adjustment so that the growth rate at the time of forming the narrowed portion and the cone forming time overlap with the correlation equation.
By correcting in this way, the control signal can be corrected easily and accurately.

At this time, it is preferable to obtain the correlation formula according to the charge amount of the raw material in the growth of the single crystal ingot or the diameter of the single crystal ingot to be grown.
Thus, the control signal can be corrected with higher accuracy by obtaining the correlation equation for each charge amount of the raw material in the growth of the single crystal ingot or the diameter of the single crystal ingot to be grown.

At this time, the growth rate at the time of forming the narrowed portion at the time of obtaining the correlation equation and the growth rate at the time of forming the narrowed portion to be measured in the other single crystal manufacturing apparatus are started from 20 minutes before the start of forming the cone portion. It is preferable to set the average growth rate between any of the above.
With such an average growth rate at the end of the narrowed portion formation, since the correlation with the cone portion formation time is more clearly obtained, the accuracy of control signal correction is further improved.

The growth rate and cone portion formation time at the time of forming the drawn portion in the other single crystal manufacturing apparatus are measured during the growth of the single crystal ingot of the product, and the measured growth rate and cone shape at the time of forming the drawn portion are measured. Preferably, the control signal is corrected based on the correlation equation from the part formation time, and the straight body part of the single crystal ingot of the product is formed while controlling the output of the heater by the corrected control signal.
As described above, if the growth rate and the cone part formation time during the narrowed part formation are measured and fed back before the start of the straight body part forming process for the same single crystal ingot, the control signal is corrected and the single crystal ingot grows. It is possible to suppress the diameter variation of the straight body portion with high accuracy every time, and to more efficiently suppress the deviation of the temperature pattern during operation.

  As described above, by using the method of the present invention, a high-quality single crystal ingot can be grown with high productivity by accurate temperature control.

It is the schematic which shows an example of the single crystal manufacturing apparatus of this invention. It is a graph which shows the relationship between the cone part formation time measured in this invention, and an aperture | diaphragm | squeeze part growth rate. It is a graph which shows the relationship between the cone part formation time measured in this invention, and an aperture | diaphragm | squeeze part growth rate. It is a flowchart at the time of controlling the heater output of a single-crystal manufacturing apparatus by this invention. It is a graph which shows the relationship between the correction coefficient calculated | required in this invention, and cone part formation time. It is a graph which shows the relationship between the cone part formation time measured in this invention, and the drawing final stage average growth rate. It is a graph which shows the input signal and output signal before and behind correction performed in this invention. It is a graph which shows the relationship between the cone part formation time measured in the Example, and the drawing final stage average growth rate. It is a graph which shows the relationship between the cone part formation time measured in the Example, and the drawing final stage average growth rate, and the relationship between the cone part formation time after correction | amendment, and the drawing final stage average growth rate. It is a graph which shows the gap | deviation degree with respect to the standard temperature pattern before and behind correction | amendment measured in the Example. (A) The schematic diagram of a single crystal ingot, (b) The graph which shows the deviation from the standard temperature pattern by an apparatus, (c) The graph which shows a standard temperature pattern. It is a figure which shows the difference in the cone part shape by the effect of temperature.

Hereinafter, the present invention will be described in detail as an example of an embodiment with reference to the drawings, but the present invention is not limited thereto.
The present invention provides a single crystal manufacturing apparatus for growing a single crystal ingot by forming a throttle part, a cone part, a straight body part and a rounded part by the Czochralski method, and detecting the heater output while detecting the temperature of the heater. A method for controlling and an apparatus for producing a single crystal.

  FIG. 1 shows an apparatus for producing a single crystal according to the present invention. A single crystal production apparatus 10 shown in FIG. 1 includes a graphite crucible 11 in a chamber 20, a quartz crucible 12 supported by the graphite crucible 11, and a single crystal ingot 18 from a raw material melt 17 contained therein. A pulling mechanism 19 for pulling up, a heater 13 for heating the raw material melt 17, a heat insulating member 21 outside the heater 13, a radiation thermometer 15 for measuring the temperature of the heater 13, and a heater measured by the radiation thermometer 15 13 is provided with a control mechanism 16 for controlling the output of the heater 13 while feeding back the temperature of 13, and a crucible rotating shaft 14 for rotating the graphite crucible 11 and the quartz crucible 12.

And the single crystal ingot 18 is grown as follows using such a single crystal manufacturing apparatus 10.
First, the polycrystalline raw material in the quartz crucible 12 is heated and melted to obtain a raw material melt 17. Then, a step of reducing the diameter to form dislocations generated when the raw material melt 17 is brought into contact with the seed crystal (formation of a narrowed portion), and subsequently a step of expanding the diameter to a predetermined diameter (formation of a cone portion) Do. Thereafter, a step of crystal growth (straight barrel portion formation) is subsequently performed with the expanded diameter, and finally a step of reducing the diameter from a predetermined diameter (rounding portion formation) is performed in order to finish the growth. Then, the single crystal ingot 18 grown through these steps is separated from the raw material melt 17 to finish the crystal growth.

During the growth of such a single crystal ingot, the heater output is controlled while detecting the temperature of the heater 13 measured by the radiation thermometer 15 using the heater output control method of the present invention, and the furnace temperature is set to a desired temperature. To.
Here, the temperature pattern as shown in FIG. 11C is obtained in advance by obtaining a heater temperature pattern during growth so as to obtain a desired crystal diameter or the like, and when the actual single crystal ingot is grown, Output control is performed while detecting the temperature of the heater so as to obtain a temperature pattern. Conventionally, even if the temperature in the furnace is the same, the temperature pattern varies between devices due to individual differences between devices, changes over time, or operating conditions. There was a need to ask. For this reason, in reality, operation is performed with a deviation, and productivity and cost are deteriorated due to time and labor for obtaining a temperature pattern. However, according to the present invention described below, single crystal ingots having a desired diameter and quality can be similarly grown using a common temperature pattern in a plurality of apparatuses.

  In the present invention, first, a correlation equation between a growth rate at the time of forming a narrowed portion and a cone portion forming time in a single crystal manufacturing apparatus based on a standard is obtained. As a specific method for obtaining this correlation equation, for example, there is the following method.

First, based on a single crystal manufacturing apparatus (No. A) having a small deviation from the standard temperature pattern (a desired diameter can be obtained by using the standard temperature pattern), the No. A machine is used to The growth rate and the cone formation time at that time are measured to obtain a correlation formula.
At this time, the growth rate of the squeezing part forming step to be measured is from 20 minutes before the start of cone part formation to the start of cone part formation, particularly from 15 minutes before the start of cone part formation to the start of cone part formation (the throttle part is about The average growth rate during the growth of 40 mm or less is preferred. With such an average growth rate at the final stage of the narrowed portion formation, the correlation with the cone portion formation time is more clearly obtained, so that accurate correction can be performed.
At this time, the cone portion formation time is defined as the time from the formation of the narrowed portion to the end of cone portion formation (diameter expansion). FIG. 2 shows a value obtained by dividing the average growth rate in the final stage of the narrowed portion formation (from 20 minutes before the start of cone portion formation to the start of cone portion formation) by the average value of the whole and the cone portion formation time at the growth rate. It is a graph which shows the relationship with the value (cone formation time difference) which subtracted the average value of those all data. In this case, the number of data to be measured is preferably 10 or more in consideration of variations and the like.

As shown in FIG. 2, a clear correlation equation (characteristic curve) that can be approximated by the following equation appears between the growth rate at the time of forming the narrowed portion and the cone portion forming time. The faster the growth rate during the formation of the narrowed portion, the shorter the cone portion formation time (cone portion shape).
Y = A · X + B (Formula 1)
Here, Y: cone portion formation time, X: growth rate at the time of drawing portion formation, A: inclination, B: intercept.

Then, when growing a single crystal ingot with another single crystal production apparatus (No. B), the growth rate and cone portion formation time at the time of forming the narrowed portion were measured, and the measured growth rate and cone at the time of forming the narrowed portion were measured. From the part formation time, the control signal is corrected based on the above correlation equation.
Using the single crystal manufacturing device (B machine) that controls the actual heater output, the growth rate of the drawing part forming process when growing the same type of single crystal ingot as investigated in machine A, and the cone at that time The part formation time is measured under the same conditions as in Unit A to obtain a plurality of data. In this case, the same standard temperature pattern is used as the temperature pattern for heater output control.

FIG. 3 shows a value obtained by dividing the average growth rate at the end of the narrowed portion formation (from 20 minutes before the start of cone portion formation to the start of cone portion formation) in Unit A and Unit B by the average value of all data of the average growth rate of Unit A. And a graph showing a relationship between a value obtained by subtracting an average value of all data of the cone part formation time of Unit A from the cone part formation time at the growth rate.
When comparing machine B with machine A, the slopes of the approximate equations are almost the same, but when compared with the same throttle growth rate, machine B has a shorter cone formation time. From this, it can be seen that Unit B tends to have a higher temperature effect and a stronger cone expansion (flat shape). That is, the difference in the cone formation time when viewed at the same throttle growth rate indicates the temperature pattern deviation itself.

From such measurement results, the control mechanism 16 of the apparatus 10 in FIG. 1 corrects the control signal to reduce the deviation of the temperature pattern shown in FIG. FIG. 4 shows a flowchart of the control mechanism.
The control mechanism 16 shown in FIG. 4 feeds back the heater temperature detected by the radiation thermometer 15 to the temperature controller 22 and controls the heater output so that the temperature of the set temperature pattern is obtained. In the present invention, for example, a temperature correction device 23 can be provided between the radiation thermometer 15 and the temperature controller 22 in order to correct an output signal from the radiation thermometer 15.

The correction method can be performed as follows.
If the ratio of the input signal (output signal from the radiation thermometer) Vi to the temperature correction device and the output signal Vo from the temperature correction device is the temperature correction coefficient K, it can be expressed as the following equation 2.
K = Vo / Vi (Formula 2)

Next, in order to make the effect of temperature the same, a method for obtaining an appropriate value of K can be performed by the following procedure.
In order to confirm the effect of temperature on K under the same operating conditions (charge amount, crystal quality, crystal diameter), the narrowed portion and the cone portion are formed by intentionally changing K. The initial value of K is 1 (no correction). When the cone portion is formed by changing K, the respective narrowed portion growth rate and cone portion formation time are substituted into Equation 1. The inclination A is fixed, and the cone portion formation time Y at the reference drawn portion growth rate is obtained. When plotted on the horizontal axis as K and the vertical axis as the cone formation time Y, there is a relationship as shown in FIG. 5, and the following approximate expression (formula 3) is obtained from this.
Y = C · K + D (Formula 3)

  From Equation 3 and FIG. 5, the change in the effect of temperature on K (change in cone portion formation time) can be grasped. FIG. 5 shows the cone formation time when K = 0.8, 0.9, 1.1, and 1.2. In FIG. 5, when K is changed by 0.1, the cone is formed. It can be seen that the part formation time changes by about 10 minutes (C≈100). In this case, it is preferable to take two or more data from the viewpoint of accuracy.

Next, the measurement result of the growth temperature and cone portion formation time at the time of formation of the narrowed portion of Unit B is substituted into Equation 1 (A is fixed), and the cone portion formation time at the growth temperature at the time of forming the narrowed portion is used as a reference. Is compared with the data of Unit A, a graph relationship as shown in FIG. 6 can be obtained.
In the case of FIG. 6, the difference (ΔT) in the cone portion formation time between Unit A and Unit B is about 20 minutes, so that the value of the correction coefficient K can be determined by substituting this into Equation 3. .

Furthermore, since the signal value is shifted by performing gain adjustment by multiplying the input signal (Vi) from the radiation thermometer by K with the correction coefficient K determined above, it is preferable to further perform offset adjustment. When the offset for adjusting 50% of the full scale of the input signal is β, the output signal Vo after the offset adjustment is expressed by the following Expression 4.
Vo = K · Vi + β (Formula 4)
Here, Vi: input signal, Vo: output signal, K: temperature correction coefficient, and β: offset.
Further, the offset β is expressed by the following Expression 5.
β = 0.5 · (1-K) (Formula 5)

FIG. 7 shows the input signal before correction, the input signal after gain adjustment by the correction coefficient K, and the input signal after gain and offset adjustment. As shown in FIG. 7, it can be seen that the output can be properly adjusted by the offset adjustment when the entire signal output is shifted by the gain adjustment.
When the single crystal ingot is grown in Unit B, the same standard temperature pattern can be used in Unit A and Unit B by performing heater output control using the corrected control signal as described above, and both The crystal quality such as the diameter of the single crystal ingot grown by the machine can be made equal.

In addition, it is preferable to obtain the equation 1 of the correlation formula according to the charge amount of the raw material in the growth of the single crystal ingot or the diameter of the single crystal ingot to be grown.
Since the correlation between the growth rate at the time of forming the narrowed portion and the cone portion forming time changes depending on the charge amount, the diameter of the ingot to be grown, etc., the heater output can be controlled more accurately by obtaining as described above. is there.

In addition, after obtaining the correction coefficient K and the offset β, K and β can be used to correct the control signal when growing the single crystal ingot again. Before entering the straight body part forming step of the measured single crystal ingot, the measurement result is fed back, and the heater output can be controlled with the corrected control signal in the straight body part growth of the single crystal ingot. preferable.
Thereby, it can correct | amend appropriately at the time of each single crystal ingot growth, the shift | offset | difference of the temperature pattern in operation can be eliminated more finely, and crystal quality improves more.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
(Examples and comparative examples)
A crucible with a diameter of 26 inches (660 mm) was charged with 180 kg of polycrystalline raw material, and a silicon single crystal ingot with a diameter of 200 mm in the straight body was grown by the Czochralski method. This growth was performed while controlling the heater output by the method of the present invention described above.

Based on the single crystal manufacturing apparatus (No. A) having a small temperature pattern deviation, growth was performed while controlling the temperature using another single crystal manufacturing apparatus (No. B).
FIG. 8 shows the results of measuring the average growth rate and the time for forming the cone part at the end of the throttle part (from 20 minutes before the start of cone part formation to the start of cone part formation) of Units A and B. The average growth rate on the horizontal axis is a value obtained by dividing each data by the average value of the entire data of the average growth rate at the end of the throttle part of Unit A. Further, the cone portion formation time difference on the vertical axis is a value obtained by subtracting the average value of the entire cone portion formation time data of Unit A from each data of the cone portion formation time.

The approximate expression (Equation 1) of the data of Unit A in FIG.
Y = −112X + 112 (A = −112, B = 112)
It became. Here, Y is the cone portion formation time, and X is the growth rate at the time of the narrowed portion formation.

Next, as a result of examining the relationship (Formula 3) between the temperature correction coefficient K and the cone portion formation time Y at the drawn portion growth rate as a reference,
Y = 99K-97 (C = 99, D = -97)
It became.

Next, after completion of the cone part formation process of Unit B, the difference (ΔT) in the cone part formation time when compared with the reference throttle part growth rate of Unit A and Unit B is 20 minutes, and the temperature coefficient obtained from this Is
20 = 99K-97
K ≒ 1.18
It became.

Also, from equation 5, the offset β is
β = 0.5 · (1-1.18)
= -0.09
It became.

Cone part formation time and squeezed part growth when a single crystal ingot is grown while controlling the heater output with the same standard temperature pattern by the control signal adjusted with the correction coefficient K and offset β obtained above using Unit B A graph plotting velocity data is shown in FIG.
As shown in FIG. 9, after correction of the control signal, the machine B has the same relationship between the cone part formation time and the throttle part growth rate as the machine A.

  Further, when the MIN-MAX value of the deviation from the temperature pattern between the straight body portions 30 to 170 cm is 1, the degree of deviation from the standard temperature pattern during the straight body portion forming process is as shown in FIG. The former (before correction of the control signal) was 14%, but after the temperature correction, it was about 6%, and the factor of diameter fluctuation could be reduced.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

DESCRIPTION OF SYMBOLS 10 ... Single crystal manufacturing apparatus, 11 ... Graphite crucible, 12 ... Quartz crucible,
13 ... heater, 14 ... crucible rotation axis, 15 ... radiation thermometer,
16 ... Control mechanism, 17 ... Raw material melt, 18 ... Single crystal ingot,
DESCRIPTION OF SYMBOLS 19 ... Pulling mechanism, 20 ... Chamber, 21 ... Heat insulation member 22 ... Temperature controller, 23 ... Temperature correction apparatus.

Claims (10)

In a single crystal manufacturing apparatus that grows a single crystal ingot by forming a throttle part, a cone part, a straight body part and a rounded part by the Czochralski method, a method for controlling the output of the heater while detecting the temperature of the heater. There,
In advance, a correlation equation between the growth rate at the time of forming the drawn portion and the cone portion forming time in the reference single crystal manufacturing apparatus is obtained, and when the single crystal ingot is grown in another single crystal manufacturing apparatus, the drawn portion Measure the growth speed and cone part formation time at the time of formation, and correct the control signal based on the correlation equation from the measured growth speed and cone part formation time at the time of the narrowed part formation, and by the corrected control signal The heater output control method characterized by controlling the output of the heater of the other single crystal manufacturing apparatus. 2. The control signal is corrected by gain and offset adjustment so that the measured growth rate at the time of forming the narrowed portion and the cone portion forming time are brought close to the correlation equation. The heater output control method described in 1.   3. The heater output control method according to claim 1, wherein the correlation equation is obtained according to a charge amount of a raw material in growth of a single crystal ingot or a diameter of a single crystal ingot to be grown.   The growth rate at the time of forming the narrowed portion when obtaining the correlation equation and the growth rate at the time of forming the narrowed portion to be measured in the other single crystal manufacturing apparatus can be arbitrarily set from 20 minutes before the start of cone portion formation to the start of cone portion formation. The heater output control method according to any one of claims 1 to 3, wherein the average growth rate is between the two.   The growth rate and cone portion formation time at the time of forming the drawn portion in the other single crystal manufacturing apparatus are measured during the growth of the single crystal ingot of the product, and the measured growth rate and cone shape at the time of forming the drawn portion are measured. From the part formation time, the control signal is corrected based on the correlation equation, and the straight body part of the single crystal ingot of the product is formed while controlling the output of the heater by the corrected control signal. The heater output control method according to any one of claims 1 to 4. This is a single crystal manufacturing apparatus that grows a single crystal ingot by forming a throttle part, a cone part, a straight body part and a round part by controlling the output of the heater while detecting the temperature of the heater by the Czochralski method. And
In advance, a correlation equation between the growth rate at the time of forming the drawn portion and the cone portion forming time in the reference single crystal manufacturing apparatus is obtained, and when the single crystal ingot is grown in another single crystal manufacturing apparatus, the drawn portion Measure the growth speed and cone part formation time at the time of formation, and correct the control signal based on the correlation equation from the measured growth speed and cone part formation time at the time of the narrowed part formation, and by the corrected control signal A single crystal manufacturing apparatus for controlling the output of the heater of the other single crystal manufacturing apparatus. In the correction of the control signal, the control signal is corrected by gain and offset adjustment so that the measured growth speed at the time of forming the narrowed portion and the cone portion forming time are brought close to the correlation equation. The single crystal manufacturing apparatus according to claim 6.   The single-crystal manufacturing apparatus according to claim 6 or 7, wherein the correlation equation is obtained according to a charge amount of a raw material in growth of a single-crystal ingot or a diameter of a single-crystal ingot to be grown.   The growth rate at the time of forming the narrowed portion when obtaining the correlation equation and the growth rate at the time of forming the narrowed portion to be measured in the other single crystal manufacturing apparatus are arbitrary from 20 minutes before the start of cone portion formation to the start of cone portion formation. The single crystal manufacturing apparatus according to any one of claims 6 to 8, wherein the average growth rate is between.   The growth rate and cone portion formation time when forming the drawn portion in the other single crystal manufacturing apparatus are measured during the growth of the single crystal ingot of the product, and the measured growth rate and cone shape when forming the drawn portion are measured. From the part formation time, the control signal is corrected based on the correlation equation, and the straight body part of the single crystal ingot of the product is formed while controlling the output of the heater by the corrected control signal. The single crystal manufacturing apparatus according to any one of claims 6 to 9, wherein:

Images