JP2950332B1 - Semiconductor crystal growing apparatus and growing method - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To uniformly distribute an impurity concentration in a grown semiconductor single crystal in a crystal pulling direction in a semiconductor single crystal growth by a Czochralski method to which a magnetic field and a current are applied. SOLUTION: In growing a semiconductor crystal by the Czochralski method to which a magnetic field and a current are applied, a current value is changed with a pulling length of the crystal under a fixed magnetic field strength. Alternatively, the current value is fixed, and the intensity of the applied magnetic field is changed with the pulling length of the crystal. Further, both the applied current value and the applied magnetic field strength are changed together with the crystal pulling length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for growing a semiconductor single crystal by the Czochralski method, and more particularly, to applying a perpendicular magnetic field and current to a semiconductor melt while rotating the semiconductor melt. The present invention relates to a semiconductor crystal growing apparatus and a growing method for growing crystals.

[0002]

2. Description of the Related Art A semiconductor single crystal wafer used as a substrate for an ultra-highly integrated electronic device is grown by a Czochralski method in which a semiconductor single crystal is pulled up from a rotating semiconductor melt while rotating in the opposite direction. The semiconductor melt held in the crucible receives heat from a cylindrical heater installed around the crucible. For this reason, the crucible is mechanically rotated in order to make the temperature distribution in the melt completely axisymmetric with respect to the crystal pulling axis. The rotation of the crucible changes the concentration of impurities taken into the crystal. The impurity concentration taken into the crystal changes with the growth time due to the segregation phenomenon at the interface between the growing crystal and the melt, and if not controlled, the concentration in the initial stage of crystal growth and the latter half of the crystal growth Will be significantly different. For this reason, control is performed such that the impurity concentration becomes uniform in one crystal by rotating the crystal and the crucible.

However, in a method of mechanically rotating a crystal and a crucible, it is becoming difficult to rotate the crystal with an increase in crystal diameter. In particular, in growing a silicon single crystal, since oxygen dissolved from quartz is mixed into the crystal due to the use of a quartz crucible, it is necessary to control the concentration together with dopant impurities. It is difficult to reduce the variation of these impurity concentrations in a single crystal in the growth direction of the crystal by 1% or less. In addition, it is becoming increasingly difficult to grow large crystals, for example, a large-scale apparatus is required to rotate a large-diameter crucible.

Therefore, in a semiconductor single crystal growing apparatus,
An apparatus for applying a magnetic field to the semiconductor melt during crystal growth, and an apparatus for applying a current perpendicular to the magnetic field to the semiconductor melt, an electrode penetrating into the semiconductor melt, and an electrode energizing the pulling crystal (Japanese Patent Application No. 9-343261) has been proposed.
In this technique, since the semiconductor melt is rotated by electromagnetic force, there is no need to mechanically rotate the crucible. Therefore, even when growing a large-diameter semiconductor single crystal having a diameter of 30 cm or more, the apparatus can be scaled up. Is minimized, and accurate control of the number of revolutions is enabled.

However, in the conventional method of rotating the semiconductor melt by applying a constant magnetic field and current,
It was difficult to make the impurity distribution in the growth direction in one crystal uniform with a variation of 1% or less. In particular, in the case of a silicon single crystal, it has been difficult to simultaneously and uniformly distribute both oxygen and dopant impurities.

[0006]

As described above, in the semiconductor crystal growing apparatus and method according to the prior art, it is difficult to control the impurity concentration in the crystal in the crystal pulling direction, and the growth of the impurity distribution in the semiconductor single crystal is difficult. It was difficult to improve the uniformity in the direction.

The present invention has been made in view of the above-mentioned problems, and is a technique for growing a semiconductor single crystal by the Czochralski method, wherein a magnetic field is applied to a semiconductor melt during crystal growth, and the magnetic field is orthogonal to the magnetic field. In a semiconductor single crystal growing apparatus and a growing method for applying a current to flow into a semiconductor melt, an object of the present invention is to provide an apparatus and a method capable of improving the uniformity of impurity concentration in a crystal growth direction in a semiconductor single crystal. And

[0008]

According to the present invention, there is provided an apparatus for growing a semiconductor crystal by a Czochralski method, comprising: an apparatus for applying a magnetic field and a current orthogonal to each other in a semiconductor melt. A semiconductor crystal growing apparatus provided with a magnetic field control unit for changing a magnetic field during crystal pulling and / or a current control unit for changing current during crystal pulling.

The present invention also provides a method for growing a semiconductor crystal by the Czochralski method, wherein a magnetic field and a current are applied to a semiconductor melt at right angles to each other, wherein the applied magnetic field and / or the applied current are changed during the crystal growth. A method for growing a semiconductor crystal is provided.

According to the present invention, an electric current is applied between a semiconductor melt held in a magnetic field and a growing semiconductor single crystal, and when a crystal is grown while rotating the semiconductor melt by electromagnetic force, By changing the applied magnetic field strength and current value according to the crystal growth time, the rotation speed of the melt changes according to the crystal growth time, that is, the crystal pulling length, and an impurity concentration corresponding to the rotation speed can be obtained. By obtaining the relationship between the number of rotations and the impurity concentration in advance, the change in the impurity concentration due to segregation during crystal growth is compensated for by the change in the number of rotations, and the impurity concentration distribution is made uniform throughout the growth direction of the semiconductor single crystal. Becomes possible.

In the present invention, during the crystal growth, the applied magnetic field and / or
Alternatively, it is appropriate to change the applied current. It is appropriate that the magnetic field signal parameter to be changed is a magnetic field strength, and the current signal parameter to be changed is a current value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. As Example 1-22, in order to verify that the impurities in the semiconductor crystal were uniformly distributed in the crystal pulling direction according to the present invention, 0.1 mm was placed in a quartz crucible having a diameter of 7.5 cm.
A 3 kg silicon melt was prepared, and the diameter was 4.0 c.
Crystal growth was performed for the m silicon single crystal when boron (B) was used as a dopant impurity and when phosphorus (P) was used as a dopant impurity. A silicon single crystal was used as an electrode for applying a current. Three electrodes were used, and the insertion position was set to an angle symmetric with respect to the crystal pulling axis. In addition, each electrode is 0.1 mm away from the crucible inner wall.
It was arranged at a position 7 cm inside.

In the case of boron doping, a crystal was grown by the method of the following Example 1-11, and the concentration of boron and oxygen in the grown crystal was measured in the crystal growth direction. Example 1
4, the applied magnetic field strength is set to 0.03T, 0.05T,
The current was changed along with the crystal pulling length while fixing at 0.1 T and 0.3 T. FIG. 1A shows the current change at this time. FIG. 1B shows the result of measuring the boron and oxygen concentrations along the pulling axis at the center of the grown crystal. 1A and 1B, the horizontal axis represents the crystal pulling length. Table 1 summarizes crystal growth conditions and changes in oxygen and boron concentrations.

[0014]

[Table 1]

In Example 5-8, the current value was 0.2 A,
At a fixed value of 0.5 A, 0.7 A and 1.0 A, the magnetic field strength was changed together with the pulling length of the crystal. FIG. 2A shows the magnetic field strength changed with respect to the crystal pulling length for each current value. FIG. 2B shows the concentrations of boron and oxygen measured along the pulling axis at the center of the grown crystal. 2A and 2B, the horizontal axis indicates the crystal pulling length. Crystal growth conditions,
Table 2 summarizes the oxygen and boron concentration fluctuations.

[0016]

[Table 2]

In Examples 9-11, both the applied current and the magnetic field intensity were changed along with the pulling length of the crystal. FIG. 3A shows the applied magnetic field intensity changed with the pulling time, and FIG. 3B shows the change in the current value. FIG.
(C) is the concentration of boron and oxygen measured along the pulling axis at the center of the grown crystal. FIG. 3 (a),
In (b) and (c), the horizontal axis indicates the crystal pulling length. Table 3 summarizes the crystal growth conditions and the oxygen and boron concentration fluctuations.

[0018]

[Table 3]

From the results of Examples 1-11, it was confirmed that the method according to the present invention can uniformly distribute the boron concentration and the oxygen concentration in the silicon single crystal with a fluctuation of 1% or less in the growth direction. .

Next, a case of growing a phosphorus-doped silicon single crystal will be described as Examples 12-22. In Examples 12 to 15, the applied magnetic field strength was 0.03 T,
The current was changed with the crystal pulling time while fixing at 0.05T, 0.1T, and 0.3T. FIG. 4A shows the current change at this time. FIG. 4B shows the result of measuring the phosphorus and oxygen concentrations along the pulling axis at the center of the grown crystal. 4A and 4B, the horizontal axis represents the crystal pulling length. Table 4 summarizes the crystal growth conditions and oxygen and boron concentration fluctuations.

[0021]

[Table 4]

As Embodiments 16-19, the current value was set to 0.2.
A, 0.5A, 0.7A, and 1.0A were fixed, and the magnetic field strength was changed with the pulling length of the crystal. FIG. 5 (a)
FIG. 7 shows the magnetic field strength changed with respect to the crystal pulling length for each fixed current value. FIG.
(B) is the concentration of phosphorus and oxygen measured along the pulling axis at the center of the grown crystal. FIG. 5 (a), (b)
In FIG. 7, the horizontal axis indicates the crystal pulling length. Table 5 summarizes the crystal growth conditions and changes in the concentrations of oxygen and phosphorus.

[0023]

[Table 5]

In Examples 20 to 22, both the applied current and the magnetic field strength were changed along with the crystal pulling length.
FIG. 6A shows the applied magnetic field strength changed with the pull-up length, and FIG. 6B shows the change in the current value. FIG. 6 (c)
Is the concentration of phosphorus and oxygen measured along the pulling axis at the center of the grown crystal. 6 (a), (b),
In (c), the horizontal axis indicates the crystal pulling length. Table 6 summarizes crystal growth conditions and changes in oxygen and phosphorus concentrations.

[0025]

[Table 6]

According to the results of Examples 12-22, the method of the present invention allows the concentration of phosphorus and oxygen in a silicon single crystal to be uniformly varied by 1% or less in the growth direction even when phosphorus is used as a dopant impurity. It has been confirmed that the impurities can be distributed, and that the method according to the present invention can uniformly distribute the impurities in the silicon single crystal regardless of the type of the dopant.

Next, the result of growing a crystal by the method according to the present invention by increasing the crystal diameter will be described. Example 23-3
As No. 1, a silicon single crystal having a crystal diameter of 20 cm was grown by doping with boron. The crystal was grown by preparing 200 kg of a silicon melt in a quartz crucible having a diameter of 60 cm. Three cylindrical single-crystal silicon having a diameter of 0.5 cm were used as electrodes for applying a current, and these were immersed in the melt at an angle so as to be arranged symmetrically with respect to the crystal pulling axis. . Also, these electrodes are 3c from the inner wall of the crucible.
m on the inner circumference.

In Examples 23 to 25, crystal growth was performed with the applied magnetic field strength fixed at 0.5 T, 0.1 T, and 0.3 T, and the current varied with the pulling length of the crystal. FIG. 7A shows the current change at this time. FIG. 7 (b)
Is the result of measuring the boron and oxygen concentrations along the pulling axis at the center of the grown crystal. FIGS. 7A and 7B
In FIG. 7, the horizontal axis indicates the crystal pulling length. Table 7 summarizes crystal growth conditions and changes in oxygen and boron concentrations.

[0029]

[Table 7]

In Examples 26-28, the current value was set to 0.2.
A, 0.5 A, and 1 A were fixed, and the applied magnetic field intensity was changed with the crystal pulling length. FIG. 8A shows the magnetic field strength changed with respect to the crystal pulling length for each fixed current value. FIG. 8B shows the concentrations of boron and oxygen measured along the pulling axis at the center of the grown crystal. 8A and 8B, the horizontal axis indicates the crystal pulling length. Crystal growth conditions,
Table 8 summarizes the oxygen and boron concentration fluctuations.

[0031]

[Table 8]

In Examples 29-31, both the current and the magnetic field strength were changed with the crystal pulling length.
FIG. 9A shows a change in the applied magnetic field strength changed with the pulling time, and FIG. 9B shows a change in the current value. FIG. 9C shows the concentrations of boron and oxygen measured along the pulling axis at the center of the grown crystal. FIG.
In (a), (b), and (c), the horizontal axis indicates the crystal pulling length. Table 9 summarizes the crystal growth conditions and oxygen and boron concentration fluctuations.

[0033]

[Table 9]

From the results of Examples 23-31, the boron concentration and the oxygen concentration in the crystal were set to 1% in the growth direction even in the case of a silicon single crystal having a diameter of 20 cm by the method of the present invention.
It was confirmed that the particles can be uniformly distributed with the following variations.

Further, the result of growing a crystal by the method according to the present invention for a silicon single crystal having a crystal diameter of 40 cm will be described. In Examples 32 to 40, a silicon single crystal having a crystal diameter of 40 cm was grown by doping with boron. The crystal is grown in a quartz crucible with a diameter of 120 cm by 400
kg of silicon melt was prepared. As the electrode for applying a current, three columnar silicon single crystals having a diameter of 1 cm were used, and these were immersed in the melt at an angle so as to be symmetrical with respect to the crystal pulling axis. These electrodes were arranged on a circumference 5 cm inside the crucible inner wall.

In Examples 32-34, the crystal growth was performed with the applied magnetic field strength fixed at 0.5 T, 0.1 T, and 0.3 T, and the current varied with the pulling length of the crystal. FIG. 10A shows the current change at this time. In this figure, the change in current is plotted against the pulling length of the crystal. FIG. 10B shows the result of measuring the boron and oxygen concentrations along the pulling axis at the center of the grown crystal. 10A and 10B, the horizontal axis indicates the crystal pulling length. Table 10 summarizes the crystal growth conditions and oxygen and boron concentration fluctuations.

[0037]

[Table 10]

In Examples 35-37, the current value was set to 0.2.
A, 0.5 A, and 1 A were fixed, and the applied magnetic field intensity was changed with the crystal pulling length. FIG. 11A shows the magnetic field strength changed with respect to the crystal pulling length for each fixed current value. FIG. 11B shows the concentrations of boron and oxygen measured along the pulling axis at the center of the grown crystal. 11A and 11B, the horizontal axis indicates the crystal pulling length. Table 11 summarizes the crystal growth conditions and the oxygen and boron concentration fluctuations.

[0039]

[Table 11]

In Examples 38-40, a method was employed in which both the current and the magnetic field strength were changed together with the crystal pulling length.
FIG. 12A shows the applied magnetic field strength changed with the pulling time, and FIG. 12B shows the change in the current value.
FIG. 12C shows the concentrations of boron and oxygen measured along the pulling axis at the center of the grown crystal. FIG.
In (a), (b), and (c), the horizontal axis indicates the crystal pulling length. Table 12 summarizes the crystal growth conditions and the oxygen and boron concentration fluctuations.

[0041]

[Table 12]

From the results of Examples 32 to 40, the method of the present invention shows that even in the case of growing a silicon single crystal having a diameter of 40 cm, the boron concentration and the oxygen concentration are uniformly distributed in the growth direction with a fluctuation of 1% or less. It was confirmed that it was possible.

As Comparative Example 1-10 of the present invention, crucibles were rotated by a conventional mechanical method to grow silicon single crystals having diameters of 20 cm and 40 cm. For crystal growth, in the case of a crystal having a diameter of 20 cm, 200 kg of a silicon melt is prepared in a quartz crucible having a diameter of 60 cm, and
The rotation was performed in the range of rpm. In addition, 40cm in diameter
In the case of a crystal of
kg of silicon melt was prepared, and the crucible was rotated at a rotation speed in the range of 1 to 20 rpm. These results are summarized in Table 13.

[0044]

[Table 13]

Further, as Comparative Examples 11-20, a magnetic field and a current of a constant intensity were applied to dope boron, and
A 0 cm silicon single crystal was grown. The crystal was grown by preparing 200 kg of a silicon melt in a quartz crucible having a diameter of 60 cm. Three cylindrical single-crystal silicon having a diameter of 0.5 cm were used as electrodes for applying a current, and these were immersed in the melt at an angle so as to be arranged symmetrically with respect to the crystal pulling axis. . These electrodes were arranged on the circumference 3 cm inside the crucible inner wall. Table 14 summarizes crystal growth conditions and oxygen and boron concentration fluctuations.

[0046]

[Table 14]

Further, as Comparative Examples 21 to 30, a magnetic field and a current of a constant intensity were applied to dope boron, and
A 0 cm silicon single crystal was grown. The crystal was grown by preparing 400 kg of silicon melt in a quartz crucible having a diameter of 120 cm. Three cylindrical single-crystal silicon having a diameter of 0.5 cm were used as electrodes for applying a current, and these were immersed in the melt at an angle so as to be arranged symmetrically with respect to the crystal pulling axis. . These electrodes were arranged on the circumference 3 cm inside the crucible inner wall. Table 15 summarizes the crystal growth conditions and oxygen and boron concentration fluctuations.

[0048]

[Table 15]

From the results of Comparative Example 11-30, when the crystal was grown by applying a magnetic field and current at a constant intensity, the distribution of the oxygen concentration and the dopant impurity concentration in the grown silicon single crystal in the growth direction was determined. It can be understood that the non-uniformity of 1% or more indicates that it is difficult to make the oxygen and dopant impurity concentrations uniform. Therefore, it was confirmed that by changing the magnetic field strength and the current value together with the change in the crystal pulling length as in the present invention, a crystal having a uniform impurity distribution can be grown even in a large-diameter crystal.

Next, in order to confirm that the present invention can be applied to the growth of a semiconductor single crystal other than silicon,
In Examples 41 to 43, a GaAs single crystal having a diameter of 15 cm was replaced with a p-BN (Pyrolytic-BornNitrid) having a diameter of 30 cm.
e) Raised from a crucible. As electrodes for applying a current, three GaAs single crystals having a diameter of 0.5 cm are used, and the concentric circles 1 cm inside the crucible inner wall are arranged at angular positions symmetrical with respect to the crystal pulling axis. Placed in position. At the time of crystal growth, an appropriate amount of silicon was added as a dopant so that the resistivity became 10 Ωcm.
In Example 41, the applied magnetic field was fixed at 0.05 T, and the current was changed with the pulling length of the crystal. In Example 42, the current value was fixed at 1.0 A, and the applied magnetic field strength was changed with the pulling length of the crystal. In Example 43, both the current and the magnetic field strength were changed along with the crystal pulling length. Table 16 summarizes the results of the crystal growth conditions and the concentration of silicon, which is a dopant impurity, measured in the pulling center direction of the crystal center in these examples.

[0051]

[Table 16]

Further, as Examples 44 to 46,
A 0 cm InP single crystal was grown from a 20 cm diameter p-BN crucible. Also in this case, the resistivity of the crystal is 10Ω.
An appropriate amount of antimony was added as a dopant so as to obtain a cm. As electrodes for applying a current, three InP single crystals having a diameter of 0.5 cm are used, and are placed on concentric circles 1 cm inside the crucible inner wall at an angular position symmetrical with respect to the crystal pulling axis. Placed in position. In Example 44, the applied magnetic field was fixed at 0.05 T, and the current was changed with the pulling length of the crystal. In Example 43,
The current value was fixed at 1.0 A, and the applied magnetic field strength was changed with the pulling length of the crystal. In Example 44, both the current and the magnetic field strength were changed along with the crystal pulling length. Table 17 summarizes the crystal growth conditions and the concentration of antimony, which is a dopant impurity, in these examples, which were measured in the axial direction by pulling up the crystal center.

[0053]

[Table 17]

From the above results, even in the case of growing a semiconductor single crystal other than silicon, according to the present invention, it is possible to grow a uniform semiconductor single crystal in which the impurity concentration distribution in the crystal pulling direction is 1% or less. It is confirmed.

In the present invention, the applied magnetic field strength and current value, and the amount of change with respect to each crystal pulling length are not limited to the above-described embodiments.
It includes all methods of changing the applied magnetic field strength and the current value with the crystal pulling length or the crystal pulling time.

[0056]

As described above, the present invention is directed to the growth of a semiconductor single crystal by the Czochralski method, wherein the growth is perpendicular to the growth interface between the growing semiconductor single crystal and the semiconductor melt and to the crystal pulling axis. In a method of applying a current between a growing semiconductor single crystal and a semiconductor melt in an axially symmetric magnetic field, by changing the applied magnetic field strength and the current value with the crystal pulling length or the crystal pulling time, The impurity concentration in the grown direction in the grown crystal can be made uniform.

[Brief description of the drawings]

FIG. 1 (a) shows a first embodiment of a method according to the present invention.
FIG. 4 is a diagram showing a change in an applied current value with respect to a change in a crystal pulling length in FIG. FIG. 1B is a diagram showing the results of measuring the boron and oxygen concentrations along the crystal pulling axis at the crystal center in the grown silicon single crystal in Example 1-4 of the method according to the present invention. .

FIG. 2 (a) shows Example 5 of the method according to the present invention.
FIG. 8 is a diagram showing a change in applied magnetic field strength with respect to a change in crystal pulling length in FIG. FIG. 2B is a diagram showing the results of measuring the boron and oxygen concentrations along the crystal pulling axis at the crystal center in the grown silicon single crystal in Example 5-8 of the method according to the present invention. .

FIG. 3 (a) shows an embodiment 9- of the method according to the present invention.
FIG. 11 is a diagram showing a change in the applied magnetic field strength with respect to a change in the crystal pulling length in No. 11. FIG. 3B is a diagram showing a change in applied current with respect to a change in crystal pulling length in Example 9-11 of the method according to the present invention. FIG. 3 (c) is a diagram showing the results of measuring the concentration of boron and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Example 9-11 of the method according to the present invention. .

FIG. 4 (a) shows a twelfth embodiment of the method according to the present invention.
FIG. 15 is a diagram illustrating a change in an applied current value with respect to a change in a crystal pulling length at −15. FIG. 4B is a diagram showing the results of measuring the concentrations of phosphorus and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Examples 12 to 15 of the method according to the present invention. .

FIG. 5 (a) shows a method according to a sixteenth embodiment of the present invention.
FIG. 21 is a diagram illustrating a change in the applied magnetic field strength with respect to a change in the crystal pulling length at −19. FIG. 5B is a diagram showing the results of measuring the concentrations of phosphorus and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Examples 16 to 19 of the method according to the present invention. .

FIG. 6 (a) shows an embodiment 20 of the method according to the present invention.
FIG. 23 is a diagram illustrating a change in the applied magnetic field strength with respect to a change in the crystal pulling length at −22. FIG. 6B is a diagram showing a change in applied current with respect to a change in crystal pulling length in Examples 20-22 of the method according to the present invention. FIG. 6C shows an embodiment 20-2 of the method according to the present invention.
FIG. 2 is a view showing a result of measuring phosphorus and oxygen concentrations along a crystal pulling axis at a crystal center in a grown silicon single crystal in No. 2.

FIG. 7 (a) shows an embodiment 23 of the method according to the present invention.
FIG. 21 is a diagram illustrating a change in an applied current value with respect to a change in a crystal pulling length at −25. FIG. 7B is a diagram showing the results of measuring the boron and oxygen concentrations along the crystal pulling axis at the crystal center in the grown silicon single crystal in Examples 23 to 25 of the method according to the present invention. .

FIG. 8 (a) shows an embodiment 26 of the method according to the present invention.
FIG. 14 is a diagram illustrating a change in the applied magnetic field strength with respect to a change in the crystal pulling length at −28. FIG. 8B is a view showing the results of measuring the concentrations of phosphorus and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Examples 26 to 28 of the method according to the present invention. .

FIG. 9 (a) shows an embodiment 29 of the method according to the present invention.
It is a figure which shows the change of the applied electric current and applied magnetic field intensity with respect to the change of the crystal pulling length in -31. FIG.
(B) is a diagram showing changes in applied current and applied magnetic field strength with respect to changes in crystal pulling length in Examples 29-31 of the method according to the present invention. FIG. 9C is a diagram showing the results of measuring the concentrations of phosphorus and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Examples 29 to 31 of the method according to the present invention. .

FIG. 10 (a) is a diagram illustrating a change in an applied current value with respect to a change in a crystal pulling length in Examples 32-34 of the method according to the present invention. FIG. 10 (b)
It is a figure which shows the result of having measured the phosphorus and oxygen concentration along the crystal pulling-up axis | shaft in the crystal center in the grown silicon single crystal in Example 32-34 of the method by this invention.

FIG. 11 (a) is a diagram showing a change in applied magnetic field strength with respect to a change in crystal pull-up length in Examples 35-37 of the method according to the present invention. FIG. 11B
FIG. 7 is a diagram showing the results of measuring the concentrations of boron and oxygen along the crystal pulling axis at the crystal center in a grown silicon single crystal in Examples 35 to 37 of the method according to the present invention.

FIG. 12 (a) is a diagram showing a change in applied magnetic field strength with respect to a change in crystal pull-up length in Example 38-40 of the method according to the present invention. FIG. 12 (b)
FIG. 10 is a diagram showing a change in applied current with respect to a change in crystal pulling length in Examples 38-40 of the method according to the present invention. FIG. 12 (c) is a diagram showing the results of measuring the concentration of boron and oxygen along the crystal pulling axis at the crystal center in the grown silicon single crystal in Example 38-40 of the method according to the present invention. .

Claims (11)

(57) [Claims] An apparatus for growing a semiconductor crystal by the Czochralski method, comprising a device for applying a magnetic field and a current orthogonal to each other in a semiconductor melt, wherein a magnetic field control unit for changing a magnetic field during crystal pulling is provided. An apparatus for growing a semiconductor crystal, comprising: 2. An apparatus for growing a semiconductor crystal by the Czochralski method, comprising a device for applying a magnetic field and a current orthogonal to each other in a semiconductor melt, wherein a current control unit for changing a current during crystal pulling is provided. An apparatus for growing a semiconductor crystal, comprising: 3. A method for growing a semiconductor crystal by the Czochralski method, wherein a magnetic field and a current orthogonal to each other are applied to a semiconductor melt, wherein the applied magnetic field is changed during the crystal growth. . 4. A method for growing a semiconductor crystal by the Czochralski method, wherein a magnetic field and a current orthogonal to each other are applied to a semiconductor melt, wherein the applied current is changed during the crystal growth. . 5. The method of growing a semiconductor crystal according to claim 3, wherein the applied magnetic field is changed according to the crystal pulling length during the crystal growth. 6. The method of growing a semiconductor crystal according to claim 3, wherein the applied magnetic field is changed according to the crystal pulling time during the crystal growth. 7. The method of growing a semiconductor crystal according to claim 4, wherein an applied current is changed according to a crystal pulling length during the crystal growth. 8. The method of growing a semiconductor crystal according to claim 4, wherein an applied current is changed according to a crystal pulling time during the crystal growth. 9. The method of growing a semiconductor crystal according to claim 3, wherein both the applied magnetic field and the applied current are changed during the crystal growth. 10. The method of growing a semiconductor crystal according to claim 3, wherein the magnetic field signal parameter to be changed is a magnetic field intensity. 11. The method according to claim 4, wherein the current signal parameter to be changed is a current value.