JPH05208887A - Method for growing silicon single crystal rod by fz process and apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain a silicon single crystal rod having uniform electrical resistivity distribution comparable to that of a neutron-irradiated silicon single crystal rod and microscopically uniformized dopant distribution in the crosssection in the direction of diameter by applying a vertical magnetic field in the direction of the growth axis and a horizontal magnetic field perpendicular to the vertical field at the same time to a molten zone in the growth of a silicon single crystal rod having large diameter. CONSTITUTION:The FZ growing apparatus 22a has a chamber 24 and is provided with an upper shaft 26 and a lower shaft 28. A raw material rod 30 of a polycrystalline silicon having a prescribed diameter is attached to the upper shaft 26 and a seed crystal 32 is attached to the lower shaft 28. The raw material rod 30 is melted with a high-frequency coil 34, welded to the seed crystal 32, made to be dislocation-free with a throttle 36 and lowered at an extremely low speed while rotating both shafts until the molten zone 38 reaches the upper end of the raw material to obtain a single crystal 40 by FZ process. The chamber wall 24a has a narrowing step 42 under the high-frequency coil 34 and a 1st solenoid coil 44 is placed at the stepped part. A 2nd solenoid coil 48 is placed in such a manner as to encircle the axis line 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and an apparatus for growing a large-diameter silicon single crystal ingot by the FZ method (float zone method, floating zone melting method), and particularly, in a diametrical section of the single crystal ingot. The present invention relates to a method and an apparatus for growing a silicon single crystal ingot having a uniform electric resistivity.

[0002]

2. Description of the Related Art The FZ method and the CZ method are conventionally known as methods for growing a silicon single crystal ingot. FZ
The method is a method of growing a silicon single crystal ingot by using the device 22 having the entire structure as shown in FIG.

The FZ method growth apparatus 22 includes a chamber 24.
And an upper shaft 26 and a lower shaft 28 in the chamber 24.
Is provided. A raw material rod 30 of silicon polycrystalline having a predetermined diameter is attached to the upper shaft 26, and a seed crystal 32 is attached to the lower shaft 28. After the raw material rod 30 is melted by the high frequency coil 34, it is fused to the seed crystal 32 and the diaphragm 3
Dislocation-free by 6 and the raw material rod 3 while rotating both shafts
It is possible to obtain a single crystal 40 by the FZ method by lowering 0 at a minute speed and moving the melting zone 38 to the upper end of the raw material.

On the other hand, the CZ method (Czochralski)
Method, pulling method), the tip of a seed crystal having a desired crystal orientation is attached to a large-capacity silicon melt, and the pulling shaft on which the seed crystal is attached is rotated to pull up a silicon single crystal rod having a desired diameter. Is the way to get.

The distribution of the electrical resistivity in the cross section in the diameter direction of the obtained silicon single crystal ingot is divided into the growth axis direction and the distribution in the cross section. The two growth methods are compared with respect to the growth axis distribution.

In the CZ method, when the silicon melt is solidified into a solid silicon single crystal, segregation of the dopant substance occurs, the dopant concentration of the silicon melt gradually increases, and the electrical resistivity decreases as it grows. The degree of non-uniformity of the electrical resistivity distribution in the growth axis direction is large.

On the other hand, in the FZ method, since the silicon melt corresponding to crystallization is constantly supplied from above for a small melt volume, the dopant concentration in the growth axis direction is more macroscopic than that in the CZ method. The electric resistivity distribution becomes uniform.

However, in the FZ method, since the melt volume is small, convection fluctuations in the melt cause the dopants to be irregularly taken in microscopically and the cross-sectional distribution to increase.

For example, as described later, a diameter of 100 mm
In the silicon wafer having a thickness of 300 μm, a silicon single crystal ingot having a growth orientation of <111> (rotational speed, 6 revolutions per minute) was measured for the electrical resistance in the diametrical direction, and the change rate of the electrical resistivity was measured. From the graph arranged and plotted in A, it can be seen that the variation of the change rate A is large (FIG. 3).

However, when the maximum value of the measured electrical resistivity R is Rmax, the minimum value is Rmin, and the average of the electrical resistivity R in the wafer surface is Rave, the rate of change in electrical resistivity A
A = [(R-Rave) / Rave] × 100 (%) ... (1) Further, the cross-sectional variation rate a of the electrical resistivity is a = [(Rmax-Rmin) / Rmin]. × 100 (%) ・ ・ ・ (2) is defined.

Here, instead of simply plotting the electric resistivity R, the electric resistance change rate A value is treated so that the electric resistance change rate apparently increases as the electric resistance R increases. This is to avoid being visible.
Further, the variation of the electrical resistivity R is expressed as a single numerical value by the variation rate a in the cross section, whereby the electrical resistivity distributions can be compared and evaluated with each other.

FIG. 3 is a distribution diagram of the electrical resistivity change rate A in the cross section of the silicon single crystal ingot, and it can be seen that the electrical resistivity decreases near the center of the wafer and is non-uniform.
Further, the value of the variation rate a in the cross section is 22.1%.

In the production of individual semiconductors, the value of the variation coefficient a in the cross section is required to be as small as possible, and a strict device may be required to be 3% or less. In such a case, after growing a silicon single crystal rod by the FZ method without doping impurities, the single crystal rod is inserted into the reactor and neutron irradiation is performed to change ³⁰ Si into ³¹ P by a nuclear reaction. A method of doping with the selected dopant is known.

However, this neutron irradiation doping method has a drawback that a nuclear reactor is required and the cost of silicon production is significantly increased, and the value of the cross-section variation rate a is industrially low without neutron irradiation. A method for growing a silicon single crystal ingot is required.

Comparing the silicon melt capacities of the FZ method and the CZ method, the former is approximately 1/100 to 1000 of the latter.
It is said that the FZ method is difficult to artificially control the convection state in the silicon melt like the CZ method.

Therefore, it has been considered that the non-uniform distribution of the dopant concentration in the cross section in the diametrical direction in the silicon single crystal ingot by the FZ method and the non-uniform distribution of the electrical resistivity cannot be eliminated.

Here, considering the flow of the silicon melt in the melting zone of the FZ method, the forced convection due to the rotation of the seed crystal, the natural convection caused by the heating of the high frequency coil, and the volume of the melt. There is surface tension convection due to the surface tension induced by the much larger proportion of the melt free surface.

Here, as a method of reducing the velocity of natural convection, it is conceivable to cause the forced convection so as to face these flows. However, since the FZ method has a small melting volume, the forced convection is weak. Almost no effect can be obtained.

It is also possible to intensify the forced convection by rotating the growing silicon single crystal ingot at a higher speed, but the weight of the crystal ingot is supported by the narrowed portion formed at the lower end of the single crystal ingot. Therefore, the growing single crystal rod collapses without being able to endure such high speed rotation, and this means is not practical.

As a method for solving such a problem, F
The method of applying a magnetic field to the silicon melt of the Z method parallel to the growth direction is described in N. De. Leon et al. (N. De. Leo
n, J. Gulburg and J. Sallin
g; Cryst. Growth, 55 (198
1) 406-408), diameter 42
It is reported that a magnetic field of 180 gauss or less was applied in the growth axis direction during the growth of a silicon single crystal ingot having a thickness of mm to reduce the fluctuation of the electrical resistivity in the cross section.

For the growth of a silicon single crystal ingot having a large diameter, that is, a diameter of 75 mm or more, 180 to 60 in the growth axis direction of the silicon single crystal ingot as in Leon et al.
The inventors of the present invention have proposed a method of applying a 0 Gauss magnetic field (vertical magnetic field) to reduce fluctuations in electrical resistivity in a cross section (Japanese Patent Application No. 3-307127).

[0022]

However, as represented by the neutron-irradiated silicon single crystal, the present FZ is present.
The demand for uniformity in the cross-sectional resistivity distribution of industrial wafers by the method is even more rigorous, and the application of the previously proposed perpendicular magnetic field cannot sufficiently meet the requirements.

According to the present invention, when a silicon single crystal ingot having a large diameter, that is, a diameter of 75 mm or more is grown by the FZ method,
The purpose of the present invention is to supplement the above-mentioned inadequacies of the prior art, and to obtain a silicon single crystal ingot having an electric resistivity distribution which falls into the neutron-irradiated silicon single-crystal ingot without neutron irradiation.

[0024]

In order to solve the above-mentioned problems, the method of the present invention is a method of growing a large-diameter silicon single crystal rod by the FZ method, which is formed in the growth axis direction of the silicon single crystal rod. The present invention is characterized in that a vertical magnetic field and a horizontal magnetic field formed by intersecting the vertical magnetic field are simultaneously applied to the melting zone of the silicon single crystal ingot.

The magnetic field strength of the vertical magnetic field is 150 to 700.
It is set between Gauss and the magnetic field strength of the horizontal magnetic field is 10
It is preferably set between 0 and 800 gauss.

It is more preferable to rotate the single crystal ingot while applying a magnetic field to the silicon single crystal ingot.

The number of rotations of the silicon single crystal ingot is as follows.
It is preferable to set from 0.5 to 8 revolutions per minute.

Further, the apparatus of the present invention is provided with vertical magnetic field forming means so as to surround the silicon single crystal rod at a position above and / or below the melting zone of the silicon single crystal rod in the growth axis direction, and A horizontal magnetic field forming means orthogonal to the growth axis direction of the silicon single crystal ingot is provided so that the above-mentioned vertical magnetic field and horizontal magnetic field can be simultaneously applied to the melt.

It is preferable that the vertical and horizontal magnetic field forming means is a solenoid coil, and a direct current is supplied to the solenoid coil, and the ripple rate of the direct current is suppressed to 15% or less.

[0030]

In the present invention, a large diameter, for example, a diameter of 70 m
In the FZ growth method for a silicon single crystal ingot having a length of m or more, nonuniformity of the dopant in the cross section of the single crystal ingot can be eliminated without significantly increasing the lower axis rotation speed.

It has been confirmed by experiments by the inventors that increasing the rotational speed of the lower shaft causes reverse convection to prevent surface tension convection, but at most 8 revolutions / minute, this type of effect is obtained. There is no.

Further, although the lower shaft rotation causes the above-mentioned forced convection and the forced stirring of the melt, the rotating peripheral velocity which is the factor of the forced convection at the center of the rotation is zero, and the dopant due to stirring is There is no mixing effect, and the central portion exhibits a low electrical resistivity due to flat facet growth at the growth interface.

However, a magnetic field forming means is arranged around the grown single crystal rod or the raw material polycrystalline rod at a position slightly above or below the growth axis of the melt, and in addition to this, the above-mentioned silicon is used. By arranging magnetic field forming means perpendicular to the growth direction of the single crystal, and supplying a direct current to them to form a vertical direct current magnetic field in the growth axis direction including the melted portion, and a horizontal direct current magnetic field in a direction intersecting this direction. , Not only the flow perpendicular to the growth direction but also the flow parallel to it are suppressed, and therefore melt surface tension convection, natural convection, and forced convection are suppressed.

Further, when a direct current is supplied to a solenoid coil as a magnetic field forming means to apply a magnetic field, if the direct current contains ripples, the ripples generate an induced eddy current in the silicon melt. It is considered that the temperature distribution and the non-uniform distribution of the flow in the cross section of the melting zone are induced, and the dopant concentration distribution in the cross section is deteriorated.

Therefore, it is necessary that the upper limit of the ripple rate is suppressed to such a degree that the induced nonuniform distribution is practically recognized.

[0036]

EXAMPLES Examples of the apparatus of the present invention will be illustratively described in detail below with reference to FIGS. 1, 2, 11, and 12 in the accompanying drawings, and experimental examples using these apparatuses will also be described. explain. The dimensions, materials, shapes, relative positions, etc., and various experimental conditions of the structural parts described in the examples and experimental examples are not intended to limit the scope of the present invention thereto but merely mere explanatory examples. Absent. Note that FIG. 1, FIG.
11 and 12, members that are the same as or similar to those in FIG. 14 will be described using the same symbols.

FIG. 1 is a schematic explanatory view showing the overall structure of an embodiment of a silicon single crystal growth apparatus 22a by the FZ method according to the present invention. The FZ method growth apparatus 22a has a chamber 24, and an upper shaft 26 and a lower shaft 28 are provided in the chamber 24.

A raw material rod 30 of silicon polycrystal having a predetermined diameter is attached to the upper shaft 26, and a seed crystal 32 is attached to the lower shaft 28. The raw material rod 30 is connected to the high frequency coil 3
After melting in 4, the seed crystal 32 was fused and made dislocation-free by the diaphragm 36, the raw material rod 30 was lowered at a slow speed while rotating both shafts, the melting zone 38 was moved to the upper end of the raw material, and the FZ A single crystal 40 can be obtained by the method.

The chamber wall 24a forming the chamber 24 is narrowed below the high frequency coil 34 to form a narrowed step portion 42. A first solenoid coil 44 is arranged on the narrowed step portion 42. The distance between the high frequency coil 34 and the solenoid coil 44 is 175
It is preferable that they are separated by about mm.

Further, a second solenoid coil 48 is provided outside the chamber 24 so as to surround an imaginary axis 46 which is orthogonal to the growth axis direction of the silicon single crystal ingot 40. The silicon single crystal rod 4
It is preferable to arrange such that the distance between the rotation center shaft 50 of 0 and the second solenoid coil 48 is about 225 mm.

The size of the first solenoid coil 44 is
The inner diameter is 210 mm, the outer wall is 500 mm, and the height is 130 mm.
00 mm, outer wall 500 mm, height 115 mm Fig. 1
The following experiment was conducted using the FZ method silicon single crystal ingot growth apparatus 22a shown in FIG.

Experimental Example 1 Phosphine as a dopant was flown into the chamber 24 to dope phosphorus to grow an n-type silicon single crystal rod having a growth direction <111>.

A direct current with a ripple rate of 15% is applied to the first solenoid coil 44 and the second solenoid coil 48, and the measured values at the center of the growth interface are both changed to a magnetic force of 0 to 1000 gauss. Let

The rotation speed of the upper shaft 26 is constant at 0.4 rotations per minute, and the rotation of the lower shaft 28 is 0.5 to 1 per minute in the same direction.
The forced convection in the silicon melt 38 was changed by changing it to 0 revolutions.

The obtained silicon single crystal ingot is placed in the chamber 2
After taking out from No. 4, a silicon wafer having a thickness of 300 μm was cut out from a predetermined position with a diamond saw to obtain a sample for measuring electric resistivity. The electrical resistivity R of the cut-out wafer was measured by the 4-probe measuring method.

In the present experimental example, the rotation speed of the upper shaft 26 is 0.4 rpm and the rotation speed of the lower shaft 28 is 6 rpm.
The electrical resistivity R was measured for a wafer cut out from a silicon single crystal rod (growth direction <111>, phosphorus-doped n-type crystal) having a diameter of 100 mm grown by rotation.

Using the measured electrical resistivity R, the electrical resistivity change rate A was calculated based on the equation (1) described above, and the value was plotted with respect to the distance from the center of the wafer. In the case where no magnetic field is applied to the melting zone for growing the single crystal rod), FIG.
FIG. 5 (when Gauss is applied only in the growth direction) and FIG. 5 (when a vertical magnetic field having an intensity of 300 Gauss is applied to the melting zone in the growth direction and when a horizontal magnetic field of 400 Gauss is applied in a direction intersecting the growth direction) ) Is shown as a graph.

At the same time, the in-section variation rate a of the electrical resistivity was determined from the measured value of the electrical resistivity R based on the above-mentioned equation (2). As shown in each figure, 22.1 each
%, 9.7%, and 4.0%, and it was found that a uniform distribution of the electrical resistivity in the cross section was obtained by applying the magnetic field in the two directions.

Experimental Example 2 The upper shaft rotation speed was 0.4 rpm, and the lower shaft rotation speed fluctuated within the range of 0.5 to 10 rpm, and the ripple rate was 3%.
The intensity of the magnetic field due to the direct current is applied in the range of 0 to 1000 gauss, and the in-section variation coefficient a of the electrical resistivity of the sample wafers cut out from the grown silicon single crystal rods with different diameters is measured. , Fig. 6 (Diameter 75
mm), FIG. 7 (diameter 100 mm), FIG. 8 (diameter 125 m
m) and FIG. 9 (diameter 150 mm).

The lower axis rotation speed and the magnetic field strength, which are suitable growth conditions, are read out from Tables 6 to 9 where the in-section variation rate a of the electrical resistivity is small, and the rotation speed is determined. Is 1 to 8 revolutions / minute, a magnetic field in the growth axis direction (vertical magnetic field)
Was 150 to 700 gauss, and the magnetic field in the direction intersecting the growth axis direction (horizontal magnetic field) was 100 to 800 gauss.

Further, when the optimum condition that the variation coefficient a in the cross section is the minimum value is shown for each diameter of each silicon single crystal, it is as follows.

In the case of a silicon single crystal having a diameter of 75 mm, the lower axis rotation speed is 7 rotations / minute and the strength of the magnetic field applied is 50.
0 gauss (vertical magnetic field) and 600 gauss (horizontal magnetic field).

For a silicon single crystal having a diameter of 100 mm, it is 300 gauss (vertical magnetic field) and 400 gauss (horizontal magnetic field) at 6 revolutions / minute.

At a diameter of 150 mm, the rotational speed is 150 gauss (vertical magnetic field) and 200 gauss (horizontal magnetic field) at 2 revolutions / minute.

From the above results, the reason why good results cannot be obtained unless the lower-axis rotation speed is decreased and the magnetic field strength is decreased as the diameter of the wafer increases is as follows.
As described in the section of the above action, it is considered that the uneven distribution of the thickness of the boundary diffusion layer is improved on the delicate balance between the centrifugal force due to the lower axis rotation in the silicon melting zone and the force acting by the magnetic field. Be done.

Experimental Example 3 With respect to single crystal rods having various diameters, the ripple rate contained in the direct current under the above optimum conditions was changed to 3 to 20%, and the in-section variation rate a of the electrical resistivity was determined, 10
It was shown to. It can be seen from FIG. 10 that the range of the ripple rate in which the value of the in-section variation rate a is as small as is allowable is 15% or less.

In the embodiment shown in FIG. 1, the first solenoid coil 44 and the second solenoid coil 48 are provided one by one, but a plurality of these may be provided. ..

For example, the device 2 shown in FIGS. 11 and 12.
2c, a second solenoid coil 48 for generating a magnetic field in a direction perpendicular to the growth direction of the silicon single crystal ingot may be arranged in 90 degrees in four directions in a horizontal plane so as to surround the silicon melting zone. Yes (Figs. 11 and 12).

Experimental Example 4 Using the apparatus shown in FIGS. 11 and 12, a diameter of 100 m
m silicon single crystal ingot is grown (upper axis rotation speed: 0.
4 rotations / minute, lower shaft rotation speed: 6 rotations / minute, growth axis direction,
That is, the vertical magnetic field: 300 gauss, the horizontal direction to the growth axis direction, that is, the horizontal magnetic field: each solenoid coil 80 gauss), and the electrical resistivity distribution in the cross section of the silicon single crystal is shown in FIG.
Shown in 3. Separately, the cross-sectional variation rate a of the electrical resistivity was calculated from the measured value and found to be 4.6%.

It has been found that even if the second solenoid coil 48 for generating the magnetic field (horizontal magnetic field) in the direction intersecting the growth direction is arranged in four directions, the same effect as in the case of one direction can be obtained. Needless to say, the number of the second solenoid coils 48 provided is also effective in a few directions.

On the other hand, in FIG. 2, two step portions 4 are formed in the vertical direction of the melting zone 38 so as to surround the silicon single crystal ingot.
2 and 42 are provided, and the device 22b in which the first solenoid coils 44 and 44 are arranged on the respective step portions is shown, but even when the two first solenoid coils are arranged in this manner, the first solenoid coil Of course, the same effect can be obtained as in the case where there is only one lower position (FIG. 1).

Needless to say, the same effect as described above can be obtained when one first solenoid coil 44 is provided only at the upper position.

[0063]

As described above, according to the present invention, when a silicon single crystal ingot having a large diameter, that is, a diameter of 75 mm or more is grown by the FZ method, the electrical energy of the neutron-irradiated silicon single-crystal ingot is reduced without neutron irradiation. A silicon single crystal ingot having a resistivity distribution can be obtained, and the dopant distribution in the diametrical cross section of the silicon single crystal ingot can be made microscopically uniform.

Further, according to the present invention, since the step of doping by thermal neutron irradiation is not included in the step of the FZ method, the silicon single crystal ingot can be grown at a desired cost.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional explanatory view showing the overall structure of an embodiment of a silicon single crystal growth apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional explanatory view showing the overall structure of another embodiment of the silicon single crystal growth apparatus according to the present invention.

FIG. 3 is a graph showing the relationship between the rate of change in electrical resistivity A and the distance from the wafer center in the cross section of a silicon single crystal in the case where no magnetic field is applied in Experimental Example 1.

FIG. 4 shows the change rate A of electrical resistivity in the cross section of the silicon single crystal in the case where the first solenoid coil is disposed only in the lower position of the melting zone and the vertical magnetic field is applied in Experimental Example 1 and the wafer center. It is a graph which shows the relation with the distance of.

FIG. 5 shows that in Experimental Example 1, the first solenoid coil is arranged only in the lower position of the melting zone to apply the vertical magnetic field, and at the same time, the second solenoid coil arranged in the horizontal position in the horizontal direction of the melting zone makes it horizontal. It is a graph which shows the relationship of the electrical resistivity change rate A in the cross section of a silicon single crystal injecting a magnetic field, and the distance from the wafer center.

FIG. 6 is a variation in electrical resistivity cross section in the single crystal ingot when the lower axis rotation speed and the strength of the applied magnetic field were changed within appropriate ranges in the growth of a silicon single crystal ingot having a diameter of 75 mm in Experimental Example 2. It is a table figure which shows the change of the value of the rate a.

FIG. 7 is a variation in electric resistivity cross section in the single crystal rod when the lower axis rotation speed and the strength of the applied magnetic field are changed within appropriate ranges in the growth of a silicon single crystal rod having a diameter of 100 mm in Experimental Example 2. It is a table figure which shows the change of the value of the rate a.

FIG. 8: Variation in electric resistivity cross section in the single crystal ingot when the lower axis rotation speed and the strength of the applied magnetic field were changed within appropriate ranges in the growth of a silicon single crystal ingot having a diameter of 125 mm in Experimental Example 2. It is a table figure which shows the change of the value of the rate a.

9 is a variation in electrical resistivity cross section in the single crystal ingot when the rotation speed of the lower axis and the strength of the applied magnetic field were changed within appropriate ranges in the growth of a silicon single crystal ingot having a diameter of 150 mm in Experimental Example 2. FIG. It is a table figure which shows the change of the value of the rate a.

FIG. 10 is a table showing a variation rate a in the electrical resistivity cross section of the single crystal rod when the ripple rate contained in the direct current forming the applied magnetic field is changed in Experimental Example 3.

FIG. 11 is a vertical cross-sectional schematic explanatory view showing the overall structure of another embodiment of the silicon single crystal growth apparatus according to the present invention.

FIG. 12 is a horizontal cross-sectional schematic explanatory view showing the entire structure of another embodiment of the silicon single crystal growth apparatus according to the present invention.

FIG. 13 is a table showing a change in the value of the variation rate a in the electrical resistivity cross section of the single crystal ingot obtained in Experimental Example 4.

FIG. 14 is a schematic explanatory view showing the overall structure of a conventional FZ method silicon single crystal growth apparatus.

[Explanation of symbols]

 22 FZ Method Silicon Single Crystal Rod Growth Device 24 Chamber 26 Upper Axis 28 Lower Axis 30 Silicon Polycrystalline Rod 32 Seed Crystal 34 High Frequency Coil 36 Drawing 38 Melting Zone 40 Silicon Single Crystal Rod 44 First Solenoid Coil 48 Second Solenoid Coil

Claims (8)

[Claims] 1. A method of growing a large-diameter silicon single crystal ingot by the FZ method, wherein a vertical magnetic field formed in the growth axis direction of the silicon single crystal ingot and a horizontal magnetic field formed intersecting with the vertical magnetic field are used. A method for growing an FZ method silicon single crystal ingot, characterized in that the voltage is simultaneously applied to the melting zone of the silicon single crystal ingot. 2. The magnetic field strength of the vertical magnetic field is 150 to 70.
It is set between 0 Gauss and the magnetic field strength of the horizontal magnetic field is 1
The FZ method silicon single crystal ingot growing method according to claim 1, wherein the FZ method silicon single crystal ingot is set between 0 and 800 Gauss. 3. The method for growing an FZ method silicon single crystal ingot according to claim 1, wherein the magnetic field is formed by a direct current having a ripple rate of 15% or less. 4. The method for growing an FZ method silicon single crystal ingot according to claim 1, 2 or 3, wherein the single crystal ingot is rotated while applying a magnetic field to the silicon single crystal ingot. 5. The method for growing an FZ method silicon single crystal ingot according to claim 4, wherein the rotation speed of the silicon single crystal ingot is set to 0.5 to 8 revolutions per minute. 6. An apparatus for carrying out the method according to any one of claims 1 to 5, wherein a large-diameter silicon single crystal ingot is grown by the FZ method, the position being above the melting zone of the silicon single crystal ingot in the growth axis direction and / or Alternatively, a vertical magnetic field forming means is provided at a lower position so as to surround the silicon single crystal rod, and a horizontal magnetic field forming means orthogonal to the growth axis direction of the silicon single crystal rod is provided. Single crystal rod growth equipment. 7. The apparatus for growing an FZ method silicon single crystal ingot according to claim 6, wherein the vertical and horizontal magnetic field forming means are solenoid coils and supply a direct current to the solenoid coils. 8. The FZ method silicon single crystal ingot growth apparatus according to claim 7, wherein the ripple rate of the direct current is suppressed to 15% or less.