JP5880415B2 - Single crystal manufacturing method - Google Patents

Description

  The present invention is based on the FZ method (floating zone method or floating zone melting method) in which a raw material crystal rod is heated and melted by an induction heating coil to form a floating zone and a semiconductor single crystal rod is manufactured by moving the floating zone. The present invention relates to a method for manufacturing a semiconductor single crystal rod.

FIG. 2 shows a single crystal manufacturing apparatus using a commonly used FZ method. A method of manufacturing a single crystal using the FZ single crystal manufacturing apparatus 30 will be described.
First, the raw crystal rod 1 is held by the upper holding jig 4 of the upper shaft 3 installed in the growth furnace 20. On the other hand, a single crystal seed (seed crystal) 8 having a small diameter is held by the lower holding jig 6 of the lower shaft 5 located below the raw crystal rod 1.

Next, the raw material crystal rod 1 is melted by the induction heating coil 7 and fused to the seed crystal 8. Thereafter, the narrowed portion 9 is formed by seed drawing to make dislocation-free. Then, by rotating the upper shaft 3 and the lower shaft 5 while lowering the raw material crystal rod 1 and the single crystal rod 2, a floating zone 10 (also referred to as a melting zone or a melt) is formed between the raw material crystal rod 1 and the single crystal rod 2. The floating zone 10 is moved to the upper end of the raw crystal rod 1 and zoned to grow the single crystal rod 2.
This single crystal growth is performed in an atmosphere in which a trace amount of nitrogen gas is mixed with Ar gas.

  Further, as the induction heating coil 7, an induction heating coil is used in which a single or multiple winding water made of copper or silver is circulated.

JP 2007-314374 A JP 2011-116570 A

  As a raw material used in the production of a single crystal by the FZ method as described above, a columnar crystal (including a polycrystal, a single crystal, an intermediate crystal grown by a polycrystal seed, and a dislocation crystal) is used. As this columnar crystal, a single crystal manufactured by the CZ method (Czochralski method) may be used as a raw material (see Patent Document 1 and Patent Document 2). Usually, a single crystal produced by the CZ method contains oxygen because oxygen from the crucible is mixed during production. Therefore, when this CZ single crystal is used as a raw material, the FZ crystal after zoning exceeds 0.1 ppma (JEIDA: using conversion factor by Japan Electronics Industry Promotion Association), and many exceed 0.25 ppma Contains oxygen.

  However, even with such a small amount of oxygen, donors are generated in the single crystal to be produced by simple oxygen or nitrogen and oxygen, which causes a change in resistivity particularly in a high resistivity region of 1000 Ωcm or more. Therefore, a method for reducing the oxygen concentration of a single crystal to be produced has been desired.

  The present invention has been made in view of the above-described problems. In particular, the oxygen concentration of a single crystal manufactured by the FZ method using a single crystal manufactured by the CZ method as a raw material (hereinafter sometimes referred to as FZ single crystal) is set. It is an object of the present invention to provide a method for producing a single crystal that can be easily reduced to 0.1 ppma or less.

  In order to achieve the above object, according to the present invention, a raw crystal rod is partially melted by an induction heating coil housed in a growth furnace to form a melting zone, and the melting zone is moved to move a single crystal A method for producing a single crystal by the FZ method, wherein the growth rate SE (mm / min) of the single crystal, which is the production condition of the single crystal, the pressure P (MPa) in the growth furnace, and the raw crystal Constant of relation Oi = a × SE + b × P + c × MO + d × D + e including oxygen concentration MO (ppma) of rod, diameter D (mm) of single crystal to be grown, and oxygen concentration Oi (ppma) of single crystal to be grown a step of obtaining a, b, c, d, e by multiple regression analysis; a step of determining manufacturing conditions of the single crystal using the relational expression; and a step of growing the single crystal under the determined manufacturing conditions. And including Method for producing a single crystal is provided to symptoms.

  With such a manufacturing method, it is possible to easily and reliably reduce the oxygen concentration of the single crystal to be manufactured, and particularly to manufacture a single crystal having an oxygen concentration of 0.1 ppma or less.

At this time, a single crystal rod containing oxygen produced by the CZ method can be used as the raw material crystal rod.
In the present invention, since the oxygen concentration of the produced single crystal can be reliably reduced, even when a low-cost single crystal rod containing oxygen produced by the CZ method is used as a raw material crystal rod, an FZ single crystal having a low oxygen concentration is obtained. be able to.

In the step of determining the manufacturing conditions for the single crystal, it is preferable to determine the oxygen concentration Oi of the single crystal to be grown to 0.1 ppma or less.
In this way, it is possible to reliably produce a single crystal having an oxygen concentration of 0.1 ppma or less without any change in resistivity.

In the step of obtaining the constants a, b, c, d, and e in the relational expression, a is 0.18553, b is 0.59418, c is 0.00834, d is 0.00024, and e is 0.29501. It can be.
If the constants a, b, c, d, and e obtained in advance are used in this way, manufacturing conditions for reducing the oxygen concentration of the single crystal to be grown can be determined more easily, and the process time can be reduced.

  And a step of preparing the raw crystal rod after the step of determining the manufacturing conditions of the single crystal, and in the step of determining the manufacturing conditions of the single crystal, the growth rate SE of the single crystal, the growth furnace Pressure P, the diameter D of the single crystal to be grown, and the oxygen concentration Oi of the single crystal to be grown are set to desired values, respectively, and the oxygen concentration MO of the raw crystal rod is calculated using the relational expression. In the step of determining and preparing the raw material crystal rod, the raw material crystal rod having the determined oxygen concentration MO is prepared, and in the step of growing the single crystal, the single crystal is prepared using the prepared raw material crystal rod. Can be grown.

  In this way, the growth rate SE of the desired single crystal, the pressure P in the growth furnace, the production conditions of the single crystal diameter D are determined, and appropriate for growing a single crystal with a target oxygen concentration Oi. The oxygen concentration MO of the raw material crystal rod can be determined, and a single crystal having the target oxygen concentration Oi can be reliably manufactured using the raw material crystal rod having the determined oxygen concentration MO.

  In addition, the method includes the step of preparing the raw material crystal rod before the step of determining the manufacturing conditions of the single crystal, and in the step of preparing the raw material crystal rod, the oxygen concentration MO of the prepared raw material crystal rod is measured. In the step of determining the manufacturing conditions of the single crystal, after determining the pressure P in the growth furnace, the diameter D of the single crystal, and the oxygen concentration Oi of the single crystal to desired values, the relational expression is used. In the step of calculating and determining the growth rate SE of the single crystal and growing the single crystal, the single crystal can be grown under the production conditions determined using the prepared raw material crystal rod.

  In this way, the oxygen concentration MO of the raw material crystal rod to be used, the pressure P in the desired growth furnace, the production conditions of the diameter D of the single crystal are determined, and the single crystal having the target oxygen concentration Oi is grown. An appropriate growth rate SE can be determined, and a single crystal having a target oxygen concentration Oi can be reliably manufactured under these determined conditions.

  In addition, the method includes the step of preparing the raw material crystal rod before the step of determining the manufacturing conditions of the single crystal, and in the step of preparing the raw material crystal rod, the oxygen concentration MO of the prepared raw material crystal rod is measured. In the step of determining the manufacturing conditions of the single crystal, after determining the growth rate SE of the single crystal, the diameter D of the single crystal, and the oxygen concentration Oi of the single crystal to desired values, the relational expression is used. In the step of calculating and determining the pressure P in the growth furnace and growing the single crystal, the single crystal can be grown under the determined manufacturing conditions using the prepared raw material crystal rod.

  In this way, when the oxygen concentration MO of the raw material crystal rod to be used, the growth rate SE of the desired single crystal, and the production conditions of the diameter D of the single crystal are determined, the single crystal having the target oxygen concentration Oi is grown. An appropriate pressure P in the growth furnace can be determined, and a single crystal having a target oxygen concentration Oi can be reliably manufactured under the determined conditions.

  In the present invention, the single crystal growth rate SE (mm / min), the pressure P (MPa) in the growth furnace, the oxygen concentration MO (ppma) of the raw crystal rod, and the diameter of the single crystal to be grown are the production conditions of the single crystal. D (mm) and the relational expression Oi = a × SE + b × P + c × MO + d × D + e including the oxygen concentration Oi (ppma) of the single crystal to be grown are respectively determined. Since the crystal is grown, the oxygen concentration of the single crystal to be produced can be easily and reliably reduced, and a single crystal having an oxygen concentration of 0.1 ppma or less can be produced. This makes it possible to produce a single crystal having a high resistivity with no change in resistivity.

It is a flowchart which shows an example of the manufacturing method of the single crystal of this invention. It is explanatory drawing explaining a mode that the manufacturing method of the single crystal of this invention is implemented using the single crystal manufacturing apparatus by FZ method. It is the figure which compared the oxygen concentration in the grown single crystal when the single crystal manufactured by CZ method was used as a raw material crystal | crystallization rod, and the case where a polycrystal was used. It is a figure which shows an example of the relationship between a growth rate and the oxygen concentration of FZ single crystal. It is a figure which shows an example of the relationship between the pressure of a growth furnace, and the oxygen concentration of FZ single crystal. It is a figure which shows an example of the relationship between the oxygen concentration of a raw material crystal rod, and the oxygen concentration of a FZ single crystal.

Hereinafter, although an embodiment is described about the present invention, the present invention is not limited to this.
The present inventor found that oxygen contained in the floating zone evaporates as SiOx from the surface of the floating zone during single crystal production by the FZ method, so that the oxygen concentration in the crystal produced by one zoning is the oxygen concentration of the raw crystal rod. However, as shown in FIG. 3, when a single crystal is produced by using the polycrystal as a raw material by the FZ method, the oxygen concentration is 0.1 ppma or less, which is almost unaffected by donor formation. On the other hand, when a single crystal rod produced by the CZ method is used as a raw material, it has been found that a desired oxygen concentration of 0.1 ppma or less cannot be obtained only by the above-described reduction effect.

Therefore, the present inventor determined the growth rate as an element for changing the time for evaporation of SiOx, the pressure of the growth furnace as an element for changing the amount of SiOx evaporation per unit time, and the oxygen concentration of the raw material crystal rod as an oxygen supply source. Attention was focused on the relationship between each element and the oxygen concentration of the grown FZ single crystal.
First, regarding the growth rate, the relationship between the growth rate and the oxygen concentration of the FZ single crystal when a single crystal having a diameter of 200 mm (8 inches) was manufactured was examined. As a result, as shown in FIG. 4, the slower the growth rate, the lower the oxygen concentration of the FZ single crystal, and the target oxygen concentration of 0.1 ppma or less when the growth rate is 0.85 mm / min or less. I understood that I can do it.

  Regarding the growth furnace pressure, the relationship between the growth furnace internal pressure and the oxygen concentration of the FZ single crystal when a single crystal having a diameter of 100 mm (4 inches) was manufactured was examined. As a result, as shown in FIG. 5, the lower the growth furnace pressure, the lower the oxygen concentration of the FZ single crystal. In calculation, the target is 0.1 ppma when the growth furnace pressure is set to −0.013 MPa or less. It is considered that the following oxygen concentration can be achieved.

  Further, regarding the oxygen concentration of the raw material crystal rod, the relationship between the oxygen concentration of the raw material crystal rod and the oxygen concentration of the FZ single crystal was examined at a diameter of 150 mm (6 inches). As a result, as shown in FIG. 6, the lower the oxygen concentration of the raw crystal rod, the lower the oxygen concentration of the FZ single crystal. In calculation, the target is to reduce the oxygen concentration of the FZ single crystal to 0.35 ppma or less. It is thought that the oxygen concentration of 0.1 ppma or less can be achieved.

  However, if the growth rate is set to 1.0 mm / min or less, the raw material supply rate becomes extremely slow, so that the molten state becomes non-uniform, and a phenomenon called hana in which the undissolved portion of the raw material grows in a wiggle shape occurs. It becomes easier, and the dropped Hana adheres to the solid-liquid interface and dislocation occurs, or a discharge trouble occurs, resulting in extremely poor operating conditions. Moreover, when the growth furnace internal pressure is lowered, the occurrence of discharge troubles due to the application of high-frequency voltage becomes significant. Furthermore, it is extremely difficult to make the oxygen concentration in the raw material 0.3 ppma or less in the production of a single crystal by the CZ method. That is, it is difficult to reduce the oxygen concentration to 0.1 ppma or less under only one condition.

Therefore, in order to stably produce an FZ single crystal having a low oxygen concentration of 0.1 ppma or less, it is optimal to combine a plurality of conditions of growth rate SE, growth furnace pressure P, and raw material crystal rod oxygen concentration MO. It is necessary to set appropriate conditions.
Therefore, the present inventor has, as means for setting optimum conditions, the growth rate SE, the growth furnace pressure P, the oxygen concentration MO of the raw material crystal rod, the diameter D of the growing single crystal, and the oxygen concentration Oi of the FZ single crystal. By performing multiple regression analysis on the data (data number N = 888), a relational expression for calculating the oxygen concentration of the FZ single crystal was obtained. Furthermore, the present inventor has come up with the idea that the optimum manufacturing conditions can be easily determined using this relational expression, thus completing the present invention.

First, an apparatus for producing a single crystal by the FZ method that can be used in the method for producing a single crystal of the present invention will be described.
As shown in FIG. 2 described above, the FZ single crystal manufacturing apparatus 30 includes a growth furnace 20, and an upper shaft 3 and a lower shaft 5 that can move up and down and rotate are provided in the growth furnace 20. Yes.
An upper holding jig 4 is attached to the upper shaft 3, and the raw crystal rod 1 is held by the upper holding jig 4. A seed crystal 8 is attached to the lower holding jig 6 attached to the lower shaft 5, and the FZ single crystal 2 is grown above the seed crystal 8.

  An induction heating coil 7 is disposed in the growth furnace 20. The raw material crystal rod 1 is heated and melted by the induction heating coil 7, and a floating zone 10 is formed between the manufactured FZ single crystal 2. The floating zone 10 is moved to the upper end of the raw material crystal rod 1 to perform zoning, and the single crystal 2 is grown. At this time, a doping gas or the like can be sprayed from the gas spray nozzle 11 to the floating zone 10 as necessary.

Here, the case of using the above-described FZ single crystal manufacturing apparatus will be described as an example of the method for manufacturing a single crystal of the present invention.
As shown in FIG. 1, first, data on the growth rate SE, the pressure P in the growth furnace, the oxygen concentration MO of the raw material crystal rod 1, the diameter D of the FZ single crystal 2, and the oxygen concentration Oi of the FZ single crystal 2 are collected. ((A) of FIG. 1). These data can be collected, for example, as manufacturing conditions when the FZ single crystal 2 is actually manufactured.
Next, using the collected data, constants a, b, c, d, and e of the relational expression Oi = a × SE + b × P + c × MO + d × D + e are obtained by multiple regression analysis ((B) in FIG. 1).

These steps (A) and (B) may be performed once in advance to obtain constants. For example, a is 0.18553, b is 0.59418, c is 0.00834, d is 0.00024, and e is 0.29501 and the relational expression can be as follows.
Oi = 0.185553 × SE + 0.59418 × P + 0.00834 × MO + 0.00024 × D + 0.29501 (1)
However, in order to further improve the accuracy, it is preferable to collect data for multiple regression analysis under the same operating conditions such as crystal rotation speed, eccentricity, work coil shape, and raw material diameter.

Next, using the above relational expression, the production conditions of the single crystal (growth rate SE, pressure P in the growth furnace 20, oxygen concentration MO of the raw crystal rod 1, the diameter D of the FZ single crystal 2, the FZ single crystal 2 Each of the oxygen concentrations Oi) is determined ((C) in FIG. 1).
In the step (C) for determining the manufacturing conditions, first, the target oxygen concentration Oi of the FZ single crystal 2 to be manufactured is determined. Here, the oxygen concentration Oi to be determined is preferably 0.1 ppma or less. Further, three of the remaining four manufacturing conditions (growth rate SE, pressure P in the growth furnace 20, oxygen concentration MO of the raw crystal rod 1 and diameter D of the FZ single crystal 2) are set to desired values. The remaining one condition is calculated from the relational expression and determined.

  Here, the growth rate SE can be determined within an allowable range in terms of operation trouble occurrence and quality. Moreover, the pressure P in the growth furnace 20 can be determined within a range that can be tolerated from the viewpoint of operational troubles such as the capability of the FZ single crystal manufacturing apparatus and electric discharge. Further, the oxygen concentration MO of the raw material crystal rod 1 can be determined within the allowable range from the viewpoint of the capability and operability of the CZ single crystal production apparatus when, for example, a single crystal rod produced by the CZ method is used. it can.

The case where the oxygen concentration MO of the raw material crystal rod 1 is calculated from the relational expression (1) and determined in the step (C) of determining the manufacturing conditions will be described below.
First, the growth rate SE, the pressure P in the growth furnace, and the diameter D of the FZ single crystal 2 are determined to desired values, respectively. Then, the determined oxygen concentration MO is calculated by substituting these determined conditions and the target oxygen concentration Oi into the relational expression (1).

A raw material crystal rod 1 having an oxygen concentration MO determined as described above is prepared. Here, for example, a single crystal rod having an oxygen concentration MO determined using a single crystal manufacturing apparatus by the CZ method can be manufactured.
Next, the FZ single crystal 2 is grown using the prepared raw material crystal rod 1 under the above determined conditions ((D) in FIG. 1). At this time, as shown in FIG. 2, the prepared raw crystal rod 1 is held by an upper holding jig 4 attached to the upper shaft 3 installed in the growth furnace 20. On the other hand, a single crystal seed (seed crystal) 8 having a small diameter is held by a lower holding jig 6 attached to a lower shaft 5 positioned below the raw crystal rod 1.

  Ar gas containing nitrogen gas is supplied from the lower part of the growth furnace 20 and exhausted from the upper part of the growth furnace, so that the pressure in the furnace is set to the pressure determined above. The held raw crystal rod 1 is melted by the induction heating coil 7 and fused to the seed crystal 8. Thereafter, the narrowed portion 9 is formed by seed drawing to make dislocation-free. A floating zone 10 is formed between the raw crystal rod 1 and the single crystal 2 by lowering the raw crystal rod 1 and the single crystal 2 having a predetermined diameter while rotating the upper shaft 3 and the lower shaft 5, and the floating zone 10 is moved to the upper end of the raw crystal rod 1 to perform zoning, and the single crystal 2 is grown at the growth rate determined above.

The case where the growth rate SE is determined by calculating from the relational expression (1) in the step (C) of determining the manufacturing conditions will be described below.
First, a raw material crystal rod is prepared using, for example, a single crystal manufacturing apparatus based on the CZ method. The oxygen concentration MO of the prepared raw crystal rod is measured and determined. Further, the pressure P in the growth furnace 20 and the diameter D of the FZ single crystal 2 are respectively determined to desired values, and the growth rate SE is determined by substituting the determined conditions and the target oxygen concentration Oi into the relational expression (1). Calculate and decide.
Next, the FZ single crystal 2 is grown using the prepared raw material crystal rod 1 under the above determined conditions ((D) in FIG. 1).

  Similarly, in the step (C) of determining the manufacturing conditions, the oxygen concentration MO of the prepared raw material crystal rod 1 is similarly measured when the pressure P in the growth furnace 20 is calculated from the relational expression (1). Then, the growth rate SE and the diameter D of the FZ single crystal 2 are respectively set to desired values. Thereafter, the pressure P in the growth furnace 20 is determined from the relational expression (1), and the FZ single crystal 2 is grown under these determined conditions ((D) in FIG. 1).

  With such a method for producing a single crystal of the present invention, it is possible to easily determine the production conditions for reducing the oxygen concentration of the produced single crystal to 0.1 ppma or less. Therefore, such an FZ single crystal with reduced oxygen concentration can be obtained with certainty.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples of the present invention, but the present invention is not limited thereto.

Example 1
Using the FZ single crystal manufacturing apparatus shown in FIG. 2, a silicon single crystal was manufactured according to the method for manufacturing a single crystal of the present invention, and the oxygen concentration was evaluated.
First, the growth rate SE was determined to be 1.5 mm / min, the pressure P in the growth furnace was 0.05 MPa, the diameter D of the FZ single crystal was 150 mm, and the target oxygen concentration Oi was determined to be 0.1 ppma. By substituting these into the relational expression (1), the oxygen concentration MO was determined to be 6 ppma.

Next, a silicon single crystal having an oxygen concentration of 6 ppma and a diameter of 130 mm was manufactured by the CZ method and prepared as a raw material crystal rod. Using this raw crystal rod, zoning was performed by the FZ method under the conditions determined above to produce a silicon single crystal.
A sample wafer was cut out from the seed crystal side of the straight body portion of the manufactured silicon single crystal, and the oxygen concentration in the silicon single crystal manufactured by infrared spectroscopy (FTIR) was measured. As a result, the oxygen concentration was reduced to 0.098 ppma and 0.1 ppma or less.

(Example 2)
Using the FZ single crystal manufacturing apparatus shown in FIG. 2, a silicon single crystal was manufactured according to the method for manufacturing a single crystal of the present invention, and the oxygen concentration was evaluated.
First, a silicon single crystal having a diameter of 130 mm was manufactured by the CZ method and prepared as a raw material crystal rod. When the oxygen concentration was measured, it was 13 ppma, so the oxygen concentration MO was determined to be 13 ppma.
Next, the pressure P in the growth furnace was determined to be 0.1 MPa, the diameter D of the FZ single crystal was 150 mm, and the target oxygen concentration Oi was determined to be 0.1 ppma. By substituting these into the relational expression (1), the growth rate SE was determined to be 1.0 mm / min.

Next, zoning was performed by the FZ method using the prepared raw material crystal rod under the conditions determined above to produce a silicon single crystal.
A sample wafer was cut out from the seed crystal side of the straight body portion of the manufactured silicon single crystal, and the oxygen concentration in the silicon single crystal manufactured by FTIR was measured. As a result, the oxygen concentration could be reduced to 0.095 ppma and 0.1 ppma or less.

(Example 3)
Using the FZ single crystal manufacturing apparatus shown in FIG. 2, a silicon single crystal was manufactured according to the method for manufacturing a single crystal of the present invention, and the oxygen concentration was evaluated.
First, a silicon single crystal having a diameter of 170 mm was manufactured by the CZ method and prepared as a raw material crystal rod. When the oxygen concentration was measured and found to be 8 ppma, the oxygen concentration MO was determined to be 8 ppma.
Next, the growth rate SE was determined to be 1.0 mm / min, the diameter D of the FZ single crystal was 200 mm, and the target oxygen concentration Oi was determined to be 0.1 ppma. By substituting these into the relational expression (1), the pressure P in the growth furnace was determined to be 0.15 MPa.

Next, zoning was performed by the FZ method using the prepared raw material crystal rod under the conditions determined above to produce a silicon single crystal.
A sample wafer was cut out from the seed crystal side of the straight body portion of the manufactured silicon single crystal, and the oxygen concentration in the silicon single crystal manufactured by FTIR was measured. As a result, the oxygen concentration could be reduced to 0.1 ppma and 0.1 ppma or less.

Further, when the sample wafer of about 1000 Ωcm of Example 1-3 was subjected to a heat treatment at 1200 ° C. for 100 minutes, the resistivity change amount was 10 times that of an FZ single crystal manufactured using a rod-shaped polycrystalline silicon crystal as a raw material. % Or less.
As described above, as shown in Example 1-3, the method for producing a single crystal according to the present invention uses the single crystal produced by the CZ method containing oxygen as a raw material, and the oxygen concentration of the single crystal produced by the FZ method is 0.1 ppma or less. It was confirmed that it can be easily reduced.

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

1 ... Raw material crystal rod, 2 ... Single crystal, 3 ... Upper shaft, 4 ... Upper holding jig,
5 ... Lower shaft, 6 ... Lower holding jig, 7 ... Induction heating coil, 8 ... Seed crystal,
9 ... throttle part, 10 ... floating zone, 11 ... nozzle for gas spraying,
20 ... Growth furnace, 30 ... FZ single crystal manufacturing apparatus.

Claims (7)

A method for producing a single crystal by an FZ method in which a raw material crystal rod is partially melted by an induction heating coil housed in a growth furnace to form a melting zone, and the melting zone is moved to grow a single crystal. ,
The single crystal growth rate SE (mm / min), the pressure P (MPa) in the growth furnace, the oxygen concentration MO (ppma) of the raw crystal rod, the growth conditions of the single crystal, Constants a, b, c, d, e of the relational expression Oi = a × SE + b × P + c × MO + d × D + e including the diameter D (mm) and the oxygen concentration Oi (ppma) of the single crystal to be grown are obtained by multiple regression analysis. Process,
Determining each of the manufacturing conditions of the single crystal using the relational expression;
And a step of growing the single crystal under the determined manufacturing conditions.   The method for producing a single crystal according to claim 1, wherein a single crystal rod containing oxygen produced by a CZ method is used as the raw material crystal rod.   The method for producing a single crystal according to claim 1 or 2, wherein, in the step of determining the production condition of the single crystal, an oxygen concentration Oi of the single crystal to be grown is determined to be 0.1 ppma or less.   In the step of obtaining the constants a, b, c, d, e of the relational expression, a is 0.18553, b is 0.59418, c is 0.00834, d is 0.00024, and e is 0.29501. The method for producing a single crystal according to any one of claims 1 to 3, wherein: Having the step of preparing the raw crystal rod after the step of determining the manufacturing conditions of the single crystal,
In the step of determining the manufacturing conditions of the single crystal, the growth rate SE of the single crystal, the pressure P in the growth furnace, the diameter D of the single crystal to be grown, and the oxygen concentration Oi of the single crystal to be grown are each desired. After determining the value, the oxygen concentration MO of the raw material crystal rod is calculated and determined using the relational expression,
In the step of preparing the raw material crystal rod, preparing the raw material crystal rod having the determined oxygen concentration MO,
The method for producing a single crystal according to any one of claims 1 to 4, wherein, in the step of growing the single crystal, the single crystal is grown using the prepared raw crystal rod. Having the step of preparing the raw crystal rod before the step of determining the manufacturing conditions of the single crystal,
In the step of preparing the raw material crystal rod, the oxygen concentration MO of the prepared raw material crystal rod is measured,
In the step of determining the manufacturing condition of the single crystal, after determining the pressure P in the growth furnace, the diameter D of the single crystal, and the oxygen concentration Oi of the single crystal to desired values, respectively, using the relational expression Calculating and determining the growth rate SE of the single crystal;
5. The method according to claim 1, wherein in the step of growing the single crystal, the single crystal is grown under the determined manufacturing conditions using the prepared raw material crystal rod. A method for producing a single crystal. Having the step of preparing the raw crystal rod before the step of determining the manufacturing conditions of the single crystal,
In the step of preparing the raw material crystal rod, the oxygen concentration MO of the prepared raw material crystal rod is measured,
In the step of determining the manufacturing condition of the single crystal, after determining the growth rate SE of the single crystal, the diameter D of the single crystal, and the oxygen concentration Oi of the single crystal to desired values, respectively, using the relational expression Calculating and determining the pressure P in the growth furnace,
5. The method according to claim 1, wherein in the step of growing the single crystal, the single crystal is grown under the determined manufacturing conditions using the prepared raw material crystal rod. A method for producing a single crystal.

Images