JP2011037667A - Apparatus for producing single crystal and method for producing single crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing a single crystal by which a single crystal controlled in quality more highly precisely can be produced by correctly controlling the rotation speed of the single crystal. <P>SOLUTION: The apparatus 10 for producing a single crystal includes: a seed crystal holder 18 holding a seed crystal 17 for growing a single crystal 16 by bringing the seed crystal into contact with a melt 13 of the raw material substance in a crucible 12; a wire rope 19 to which the seed crystal holder 18 is attached; and a winding mechanism 20 that winds up the wire rope 19 while rotating and pulls the seed crystal and the single crystal grown on the seed crystal while rotating. The apparatus further includes: a single crystal rotation speed measuring means 22 that measures the actual rotation speed of the single crystal 16 to be pulled; and a control means 23 that controls the winding mechanism 20 in such a manner that the rotation speed of the single crystal reaches a target rotation speed by using the actual rotation speed of the single crystal measured by the single crystal rotation speed measuring means 22. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a single crystal manufacturing apparatus and a single crystal manufacturing method capable of controlling the quality of a single crystal to be grown with high accuracy when a single crystal is manufactured by the Czochralski method, in particular, a magnetic field application type Czochralski method. It is about the method.

  Conventionally, the production of a single crystal by the Czochralski method (CZ method, MCZ method) is performed, for example, by bringing a seed crystal attached to the tip of a wire rope into contact with a melt of a raw material in a crucible and rotating the seed crystal. It is done by pulling up.

  Specifically, the production of a single crystal by the Czochralski method is carried out by a seed chuck (seed crystal holder) 82 attached to the tip of a wire rope 81 in, for example, a general single crystal production apparatus 80 shown in FIG. The seed crystal 83 is brought into contact with the raw material melt 86 in the crucible 85 heated by the heater 84, and then the crucible 85 is rotated by the crucible rotating mechanism 87, and the wire rope 81 is moved by the winding mechanism 88. The seed crystal 83 and the single crystal 89 are pulled up while being rotated in the direction opposite to the crucible 85 to pull up the seed crystal 83 and the single crystal 89.

  Here, in general, when producing a single crystal by the Czochralski method, the rotation speed of the seed crystal (single crystal) and the ratio of the rotation speed of the seed crystal (single crystal) to the rotation speed of the crucible (that is, the crucible) It is known that the relative rotation speed of the single crystal with respect to the crystal has an influence on the quality of the grown crystal (defect incorporation, oxygen in-plane distribution, etc.). Therefore, when pulling a single crystal in the production of a single crystal by the Czochralski method, it is necessary to control the rotation speed of the seed crystal (single crystal) and the ratio of the rotation speed of the single crystal to the rotation speed of the crucible.

  On the other hand, as a method of controlling the rotation speed of the single crystal and the rotation speed of the single crystal relative to the crucible, the speed of rotating the wire rope with the winding mechanism is regarded as the actual rotation speed of the single crystal, and the winding mechanism A method for controlling the rotation speed of a single crystal based on the rotation speed is known.

  Here, in recent years, establishment of a method for controlling the quality of the grown crystal with higher accuracy has been demanded. Therefore, when the present inventor examined the single crystal rotation speed that affects the crystal quality and the control of the single crystal (seed crystal) rotation speed relative to the crucible, the actual single crystal rotation speed is The rotational speed of the winding mechanism is not the same as the rotational speed of the winding mechanism due to the influence of twisting back of the wire rope accompanying the increase in weight and the viscosity of the raw material melt. In the conventional control method that is considered to be, there is a problem that the rotation speed of the single crystal and the ratio of the rotation speed of the single crystal to the rotation speed of the crucible cannot be accurately controlled (the crystal quality cannot be controlled with high accuracy). It became clear. It has also been clarified that the difference between the rotation speed of the single crystal and the rotation speed of the winding mechanism is particularly large when the single crystal is produced by the magnetic field application type Czochralski method.

  Therefore, a single crystal manufacturing apparatus and a single crystal manufacturing method that can accurately control the rotation speed of the single crystal and the rotation speed of the single crystal with respect to the crucible and can control the quality with higher precision are developed. There was a need.

  An object of the present invention is to advantageously solve the above-described problems, and a single crystal manufacturing apparatus according to the present invention is a seed crystal for growing a single crystal in contact with a raw material melt in a crucible. A seed crystal holder that holds the seed crystal, a wire rope to which the seed crystal holder is attached, and the seed crystal and a single crystal grown on the seed crystal by rotating the wire rope while rotating the wire rope. A single-crystal manufacturing apparatus comprising a winding mechanism for pulling up, while measuring a single-crystal rotational speed measuring means for measuring an actual rotational speed of the single crystal to be pulled up, and an actual single-crystal rotation measured by the single-crystal rotational speed measuring means And a control means for controlling the winding mechanism so that the single crystal rotation speed becomes the target rotation speed by using the speed. Thus, if the actual rotation speed of the single crystal being pulled is measured by the single crystal rotation speed measuring means, and the winding mechanism is controlled based on the actual single crystal rotation speed, the rotation speed of the single crystal is accurately controlled. Thus, it is possible to manufacture a single crystal whose quality is controlled with higher accuracy.

  The single crystal production apparatus of the present invention includes a crucible, a crucible rotating mechanism for rotating the crucible, and a seed for holding a seed crystal for growing the single crystal in contact with the melt of the raw material in the crucible. A crystal holder, a wire rope to which the seed crystal holder is attached, and winding the wire rope in a direction opposite to the direction of rotation of the crucible to grow on the seed crystal and the seed crystal A single crystal manufacturing apparatus comprising a winding mechanism for pulling up the single crystal while rotating the single crystal, a single crystal rotational speed measuring means for measuring an actual rotational speed of the single crystal to be pulled up, and a crucible for measuring the rotational speed of the crucible. Using the rotational speed measuring means, the actual single crystal rotational speed measured by the single crystal rotational speed measuring means, and the crucible rotational speed measured by the crucible rotational speed measuring means, a single crystal Rolling speed and the ratio of the crucible rotation speed (rotational speed ratio) and a controlling means for controlling at least one of the winding mechanism and the crucible rotation mechanism such that the target revolution speed ratio. Thus, if the actual rotation speed of the single crystal being pulled is measured by the single crystal rotation speed measuring means, and the winding mechanism and the crucible rotation mechanism are controlled based on the actual single crystal rotation speed and the crucible rotation speed, the crucible is Thus, it is possible to manufacture a single crystal having a controlled quality with higher accuracy by accurately controlling the rotation speed of the single crystal.

  Here, in the single crystal manufacturing apparatus of the present invention, the control means controls the winding mechanism to change the single crystal rotation speed, thereby changing the ratio of the single crystal rotation speed to the crucible rotation speed (rotational speed ratio). ) May be a means for achieving a target rotational speed ratio. This is because the target rotational speed ratio can be easily achieved by controlling only the winding mechanism.

  Further, in the single crystal production apparatus of the present invention, the control means controls the crucible rotation mechanism to change the crucible rotation speed, so that the ratio (rotational speed ratio) with the crucible rotation speed taking the single crystal rotation speed is It may be a means for achieving a target rotational speed ratio. This is because it is possible to easily achieve the target rotational speed ratio by controlling only the crucible rotating mechanism.

  Furthermore, the single crystal production apparatus of the present invention is a means for measuring the actual rotational speed of the single crystal by measuring the rotational speed of the seed crystal holder using a laser. There may be. This is because if the rotational speed of the seed crystal holder is measured using a laser, contamination in the single crystal device can be prevented.

  In the single crystal production apparatus of the present invention, the single crystal rotation speed measuring means is a means for measuring the actual rotation speed of the single crystal by measuring the rotation speed of the single crystal using image processing. May be. This is because the actual rotation speed of the single crystal can be measured at a low cost using a simple and easy-to-install apparatus.

  And it is preferable that the single crystal manufacturing apparatus of this invention is further equipped with the magnetic field applicator which applies a magnetic field to the melt of the raw material in the said crucible. When a crystal is produced by the magnetic field application type Czochralski method (MCZ method), the seed crystal holder and the wire rope are affected by the magnetic field, and the difference between the actual rotation speed of the single crystal and the rotation speed of the winding mechanism is This is because the single crystal production apparatus of the present invention can accurately control the rotation speed of the single crystal and the rotation speed of the single crystal relative to the crucible even under such conditions.

  Moreover, the single crystal production method of the present invention is such that the seed crystal held in the seed crystal holder attached to the tip of the wire rope is brought into contact with the raw material melt in the crucible and the wire rope is rotated. In the method of winding and winding the seed crystal and the single crystal grown on the seed crystal while rotating the single crystal, the actual rotational speed of the single crystal to be pulled is measured by the single crystal rotational speed measuring means, Using the actual single crystal rotation speed measured by the single crystal rotation speed measuring means, the single crystal rotation speed is controlled so that the single crystal rotation speed becomes the target rotation speed. Thus, if the actual rotation speed of the single crystal being pulled is measured by the single crystal rotation speed measuring means and the single crystal rotation speed is controlled based on the actual single crystal rotation speed, the single crystal rotation speed can be accurately determined. It is possible to manufacture a single crystal whose quality is controlled with higher accuracy.

  Furthermore, in the method for producing a single crystal of the present invention, the seed crystal held in the seed crystal holder attached to the tip of the wire rope is brought into contact with the melt of the raw material in the crucible, and the crucible is rotated. In the method for producing a single crystal by winding the wire rope while rotating it in a direction opposite to the direction of rotation of the crucible and pulling up the seed crystal and the single crystal grown on the seed crystal, the single crystal to be pulled up The actual rotation speed of the crucible is measured with a single crystal rotation speed measurement means, the rotation speed of the crucible is measured with a crucible rotation speed measurement means, and the actual single crystal rotation speed measured with the single crystal rotation speed measurement means, Using the crucible rotation speed measured by the crucible rotation speed measuring means, the ratio of the single crystal rotation speed to the crucible rotation speed (rotational speed ratio) becomes the target rotation speed ratio. And controlling at least one of speed and crucible rotation rates. Thus, if the actual rotational speed of the single crystal being pulled is measured by the single crystal rotational speed measuring means, and the rotational speed ratio is controlled based on the actual single crystal rotational speed and the crucible rotational speed, the single crystal relative to the crucible can be controlled. It is possible to manufacture a single crystal in which the rotation speed is accurately controlled and the quality is controlled with higher accuracy.

  Here, in the method for producing a single crystal of the present invention, the single crystal rotation speed may be controlled so that the ratio (rotation speed ratio) between the single crystal rotation speed and the crucible rotation speed becomes the target rotation speed ratio. This is because the target rotational speed ratio can be easily achieved by controlling only the single crystal rotational speed.

  In the method for producing a single crystal of the present invention, the crucible rotation speed may be controlled so that the ratio (rotation speed ratio) between the single crystal rotation speed and the crucible rotation speed becomes the target rotation speed ratio. This is because the target rotational speed ratio can be easily achieved by controlling only the crucible rotational speed.

  Furthermore, in the method for producing a single crystal of the present invention, it is preferable to pull up the seed crystal and the single crystal while applying a magnetic field to the raw material melt in the crucible. When a crystal is produced by the magnetic field application type Czochralski method, the seed crystal holder and the wire rope are affected by the magnetic field, and the difference between the actual rotation speed of the single crystal and the rotation speed of the winding mechanism increases. This is because the single crystal production method of the present invention can accurately control the rotation speed of the single crystal and the rotation speed of the single crystal relative to the crucible even under such conditions.

  According to the single-crystal manufacturing apparatus and single-crystal manufacturing method of the present invention, the single crystal with high-precision control can be manufactured by accurately controlling the rotation speed of the single crystal and the rotation speed of the single crystal relative to the crucible. Can do.

It is explanatory drawing which shows the structure of an example of the single crystal manufacturing apparatus of this invention. It is a top view which shows the shape of the seed crystal holder of the single crystal manufacturing apparatus shown in FIG. It is a graph which shows the time change of the intensity | strength of the laser beam which the laser type rotational speed sensor of the single crystal manufacturing apparatus shown in FIG. 1 detected. It is explanatory drawing which shows the other example of the method of measuring a single-crystal rotational speed in the single-crystal manufacturing apparatus of this invention. It is a flowchart explaining the control method (1st control method) of the single-crystal rotational speed at the time of manufacturing a single crystal using an example of the single-crystal manufacturing method of this invention. It is a flowchart explaining the control method (2nd control method) of the crucible rotational speed at the time of manufacturing a single crystal using the other example of the single crystal manufacturing method of this invention. It is a graph which shows the time change of the crystal rotation speed when manufacturing a single crystal by controlling the single crystal rotation speed according to the single crystal manufacturing method of the example of the present invention and the comparative example. It is explanatory drawing which shows the structure of the conventional common single crystal manufacturing apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a single crystal manufacturing apparatus 10 as an example of the single crystal manufacturing apparatus of the present invention shown in FIG. 1 is an apparatus for manufacturing, for example, single crystal silicon by a magnetic field application type Czochralski method.

  In this single crystal manufacturing apparatus 10, a crucible 12 for containing polycrystalline silicon as a raw material material for single crystal silicon in a chamber 11 and a raw material material in the crucible 12 are heated to form a melt 13. Heater 14, a crucible rotating mechanism 15 for rotating the crucible 12 provided at the lower part of the crucible 12 in the circumferential direction (clockwise as viewed from above the apparatus in FIG. 1), and a seed crystal for growing the single crystal 16. 17, a wire rope 19 having a seed crystal holder (seed chuck) 18 attached to the tip thereof, and a direction opposite to the direction of rotation of the crucible 12 (in FIG. A winding mechanism 20 that winds the single crystal 16, the seed crystal 17, and the seed crystal holder 18 while rotating it while rotating it clockwise.

  Further, in the single crystal manufacturing apparatus 10, a magnetic field applicator 21 for applying a magnetic field of, for example, 0.3 T (3000 gauss) to the melt 13 in the crucible 12 surrounds the chamber 11 outside the lower portion of the chamber 11. In addition, a laser-type rotational speed sensor 22 for measuring the rotational speed of the single crystal 16 is disposed in the upper part of the chamber 11. Furthermore, the single crystal manufacturing apparatus 10 also has a controller 23 for controlling the winding mechanism 20 and the crucible rotating mechanism 15.

  Here, the crucible rotating mechanism 15 is a known device that rotates the crucible, and rotates at the same rotational speed as the crucible. Therefore, the actual rotational speed of the crucible can be obtained by measuring the rotational speed of the crucible rotating mechanism 15 with a sensor (not shown) such as an encoder. At this time, a sensor such as an encoder functions as a means for measuring the rotational speed of the crucible.

  The seed crystal holder 18 is cylindrical and has a structure for holding a seed crystal. As shown in FIG. 2, a plurality of slits 24 are provided at equal intervals on the upper surface. The laser-type rotational speed sensor 22 includes a light projecting unit 25 that irradiates laser light on the same circumferential line L that passes through the slit 24 on the upper surface of the rotating seed crystal holder 18, and the upper surface of the seed crystal holder 18 ( And a light receiving portion 26 that detects the laser light reflected by the portion where the slit 24 is not provided. In the laser rotation speed sensor 22, a rectangular wave as shown in FIG. 3 is obtained as the seed crystal holder 18 rotates. For example, the number of times the light receiving unit 26 detects the laser light per unit time. By dividing (the number of rectangular waves) by the number of portions on the same circumferential line L where the slits 24 are not provided, the rotational speed of the seed crystal holder 18 can be measured. Since the seed crystal holder 18 rotates integrally with the seed crystal 17 and the single crystal 16, the rotation speed of the seed crystal holder 18 is equal to the actual rotation speed of the single crystal 16. Therefore, in the single crystal manufacturing apparatus 10, the laser rotational speed sensor 22 and the slit 24 function as a single crystal rotational speed measuring means.

  Here, as another embodiment of the single crystal manufacturing apparatus of the present invention, measurement of the rotational speed of the seed crystal holder 18 (that is, the rotational speed of the single crystal 16) using the laser rotational speed sensor 22 is shown in FIG. As shown in FIG. 2, a mirror 27 is installed in the chamber 11, and laser light is irradiated to the upper surface of the seed crystal holder 18 from the laser type rotational speed sensor 22 in which the light projecting unit and the light receiving unit are integrated. The laser light reflected by the upper surface of the seed crystal holder 18 may be received by the laser rotational speed sensor 22 via the mirror 27.

  Further, as another embodiment of the single crystal manufacturing apparatus of the present invention, a camera is installed instead of the laser-type rotational speed sensor 22 and the slit 24, and, for example, the shape of the single crystal (the position of the ridge line) is obtained by image processing by the camera. Alternatively, the rotational speed of the single crystal may be measured.

  Based on the actual rotation speed of the single crystal 16 measured by the laser-type rotation speed sensor 22 and the rotation speed of the crucible 12 measured by a sensor such as an encoder, the controller 23 compares the ratio of the single crystal rotation speed and the crucible rotation speed (rotation). (Speed ratio) controls at least one of the rotational speed of the crucible rotating mechanism 15 and the speed at which the winding mechanism 20 rotates the wire rope 19 so that the target rotational speed ratio is determined in advance. The target rotation speed ratio can be determined as appropriate according to the desired crystal quality.

  Here, the control of the crucible rotating mechanism 15 and / or the winding mechanism 20 in the controller 23 is performed by controlling either the crucible rotating mechanism 15 or the winding mechanism 20 from the viewpoint of simplicity of control. For example, it can be carried out as follows.

First, as a first control method, as shown in FIG.
(1) Determine whether the single crystal 16 is rotating (whether the winding mechanism 20 is operating) (S51),
(2) When the single crystal 16 is rotating, the actual rotational speed N of the single crystal 16 is acquired from the laser rotational speed sensor 22 (S52),
(3) Difference X (= N′−N) between the target rotational speed N ′ of the single crystal obtained from the predetermined target rotational speed ratio and the rotational speed of the crucible measured by an encoder or the like and the actual rotational speed N To determine whether the absolute value of X is greater than 0.2 (S53),
(4) When the absolute value of X is determined to be greater than 0.2 in S53, the speed at which the winding mechanism 20 rotates the wire rope is N ′ + βX (β is a fine adjustment term, for example, 0 ≦ the winding mechanism 20 is controlled so as to satisfy (β ≦ 1) (S54),
(5) When the absolute value of X is determined to be 0.2 or less (−0.2 ≦ X ≦ 0.2) in S53, or after the control of S54, the pulling of the single crystal 16 is completed. If the pulling of the single crystal 16 has not been completed, the process returns to S52, and if the pulling of the single crystal 16 has been completed, the control is terminated to thereby complete the winding mechanism. There is a method of controlling the speed at which the wire rope 19 is rotated by 20 so that the ratio (rotational speed ratio) between the single crystal rotational speed and the crucible rotational speed becomes a predetermined target rotational speed ratio. It should be noted that the criterion for determining the absolute value of X and β can be any value determined according to the length of the pulled single crystal.

As a second control method, as shown in FIG.
(1) Determine whether the single crystal 16 is rotating (whether the winding mechanism 20 is operating) (S61),
(2) When the single crystal 16 is rotating, the actual rotational speed N of the single crystal 16 is acquired from the laser rotational speed sensor 22 (S62),
(3) The target rotational speed N ′ obtained from a predetermined target rotational speed ratio Y ′ (= N ′ / C) and the rotational speed C of the crucible measured by the encoder, and the actual rotational speed N The difference X (= N′−N) is calculated to determine whether the absolute value of X is greater than 0.2 (S63),
(4) If the absolute value of X is determined to be greater than 0.2 in S63, the crucible rotation mechanism so that the speed at which the crucible rotation mechanism 15 rotates the crucible is C + β '(N / Y'-C). 15 (S64),
(5) When the absolute value of X is determined to be 0.2 or less (−0.2 ≦ X ≦ 0.2) in S63, or after performing the control of S64, the pulling of the single crystal 16 is completed. (S65), if the pulling of the single crystal 16 has not been completed, the process returns to S62, and if the pulling of the single crystal 16 has been completed, the control is terminated, whereby the crucible rotating mechanism There is a method of controlling the speed at which the 15 rotates the crucible 12 so that the ratio (rotational speed ratio) between the single crystal rotational speed and the crucible rotational speed becomes a predetermined target rotational speed ratio. When this control is performed, the rotational speed of the crucible is controlled with high accuracy using an encoder. Further, the above-mentioned criteria for determining the absolute value of X and β ′ (where 0 ≦ β ′ ≦ 1) can be any values determined according to the length of the pulled single crystal.

  Incidentally, when controlling the rotational speed of the crucible according to the second control method described above, an upper limit and a lower limit of the amount of change in the crucible rotational speed may be defined from the viewpoint of maintaining the quality of the single crystal. Specifically, when the absolute value of X is determined to be greater than 0.2 (S64), the value of β ′ (N / Y′−C) is changed based on the crystal length. When the amount is larger than the maximum value or smaller than the minimum amount of change, the crucible rotation speed may be controlled so that the amount of change in the crucible rotation speed becomes the maximum value or the minimum value.

  Then, in the single crystal manufacturing apparatus 10, the ratio (rotational speed ratio) between the single crystal rotational speed taken by the controller 23 and the crucible rotational speed as described above based on the rotational speed of the single crystal 16 measured by the laser rotational speed sensor 22. The single crystal 16 can be manufactured while controlling the above. Specifically, the seed crystal held in the seed crystal holder 18 attached to the tip of the wire rope 19 with respect to the raw material melt in the crucible 12 subjected to a magnetic field of 0.3 T by the magnetic field applicator 21. 17, the crucible 12 is rotated by the crucible rotating mechanism 15, and the wire rope 19 is rotated by the winding mechanism 20 while rotating in the direction opposite to the rotating direction of the crucible 12. The single crystal 16 grown on the crystal 17 can be pulled up while rotating to produce the single crystal 16.

  Here, since the single crystal manufacturing apparatus 10 measures the actual rotation speed of the single crystal 16 and controls the single crystal rotation speed and the crucible rotation speed, the single crystal manufacturing apparatus 10 accurately controls the rotation speed of the single crystal with respect to the crucible, For example, a defect-free single crystal having a controlled quality can be produced.

  In addition, the single crystal manufacturing apparatus of this invention is not limited to the said example, A change can be added suitably. Specifically, the single crystal manufacturing apparatus of the present invention may not include a magnetic field applicator. Moreover, the number of slits provided in the seed crystal holder can be an arbitrary number. Further, the seed crystal holder may be provided with an uneven portion instead of the slit, and the single crystal rotational speed may be measured with a laser rotational speed sensor.

  Further, the controller 23 is based on the actual rotational speed of the single crystal 16 measured by the laser rotational speed sensor 22 and does not take into account the rotational speed of the crucible and follows the flowchart according to the flowchart shown in FIG. The winding mechanism 20 may control the speed at which the wire rope 19 is rotated so that the speed becomes a predetermined target rotational speed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to the following Example.

(Example)
A single crystal produced using the single crystal production apparatus shown in FIG. 1 according to the method for producing a single crystal of the present invention by controlling the rotation speed of the single crystal so as to achieve the target rotation speed shown in FIG. The actual rotation speed was measured. The time change of the single crystal rotation speed is shown in FIG.

(Comparative example)
The single crystal manufacturing apparatus shown in FIG. 8 is provided with the same magnetic field applicator and laser type rotational speed sensor as the single crystal manufacturing apparatus shown in FIG. 7 (according to the conventional single crystal production method), the actual rotation speed of the single crystal when the single crystal is produced by controlling the rotation speed of the single crystal so as to achieve the target rotation speed shown in FIG. Was measured. The time change of the single crystal rotation speed is shown in FIG.

  FIG. 7 shows that according to the method for producing a single crystal of the present invention, it is possible to produce a single crystal whose quality is controlled with high accuracy by accurately controlling the rotation speed of the single crystal.

  According to the single-crystal manufacturing apparatus and single-crystal manufacturing method of the present invention, the single crystal with high-precision control can be manufactured by accurately controlling the rotation speed of the single crystal and the rotation speed of the single crystal relative to the crucible. Can do.

DESCRIPTION OF SYMBOLS 10 Single crystal manufacturing apparatus 11 Chamber 12 Crucible 13 Melt 14 Heater 15 Crucible rotation mechanism 16 Single crystal 17 Seed crystal 18 Seed crystal holder 19 Wire rope 20 Winding mechanism 21 Magnetic field applicator 22 Laser type rotational speed sensor 23 Controller 24 Slit 25 Light Emitting Unit 26 Light Receiving Unit 27 Mirror 80 Single Crystal Manufacturing Device 81 Wire Rope 82 Seed Chuck 83 Seed Crystal 84 Heater 85 Crucible 86 Melt 87 Crucible Rotating Mechanism 88 Seed Crystal 89 Single Crystal

Claims (12)

A seed crystal holder for holding a seed crystal for growing a single crystal in contact with a melt of a raw material in a crucible, a wire rope to which the seed crystal holder is attached, and rotating the wire rope A single crystal manufacturing apparatus comprising: a winding mechanism that pulls up while rotating the seed crystal and the single crystal grown on the seed crystal while rotating,
A single crystal rotation speed measuring means for measuring the actual rotation speed of the single crystal to be pulled up;
Control means for controlling the winding mechanism so that the single crystal rotation speed becomes the target rotation speed using the actual single crystal rotation speed measured by the single crystal rotation speed measurement means;
An apparatus for producing a single crystal, comprising: A crucible, a crucible rotating mechanism for rotating the crucible, a seed crystal holder for holding a seed crystal for growing a single crystal in contact with the raw material melt in the crucible, and the seed crystal holder An attached wire rope, and a winding mechanism for winding the wire rope while rotating it in a direction opposite to the direction of rotation of the crucible and pulling up the seed crystal and the single crystal grown on the seed crystal while rotating A single crystal manufacturing apparatus comprising:
A single crystal rotation speed measuring means for measuring the actual rotation speed of the single crystal to be pulled up;
Crucible rotation speed measuring means for measuring the rotation speed of the crucible;
Using the actual single crystal rotation speed measured by the single crystal rotation speed measurement means and the crucible rotation speed measured by the crucible rotation speed measurement means, the ratio between the single crystal rotation speed and the crucible rotation speed is the target rotation speed. Control means for controlling at least one of the winding mechanism and the crucible rotating mechanism so as to have a ratio;
An apparatus for producing a single crystal, comprising:   The control means is means for controlling the winding mechanism to change the single crystal rotation speed so that a ratio between the single crystal rotation speed and the crucible rotation speed becomes a target rotation speed ratio. The single crystal manufacturing apparatus according to claim 2.   The control means is means for controlling the crucible rotation mechanism to change the crucible rotation speed so that the ratio of the single crystal rotation speed to the crucible rotation speed becomes a target rotation speed ratio. The single crystal manufacturing apparatus according to claim 2.   The single crystal rotation speed measuring means is a means for measuring an actual rotation speed of the single crystal by measuring a rotation speed of the seed crystal holder using a laser. 4. The single crystal production apparatus according to any one of 4 above.   The single crystal rotation speed measuring means is a means for measuring the actual rotation speed of the single crystal by measuring the rotation speed of the single crystal using image processing. The single-crystal manufacturing apparatus in any one of.   The single crystal manufacturing apparatus according to any one of claims 1 to 6, further comprising a magnetic field applicator for applying a magnetic field to the melt of the raw material in the crucible. The seed crystal held in the seed crystal holder attached to the tip of the wire rope is brought into contact with the melt of the raw material in the crucible, and the wire crystal is wound while being rotated to wind the seed crystal and the seed crystal on the seed crystal. In a method for producing a single crystal by pulling up the single crystal grown on
Measure the actual rotation speed of the single crystal to be pulled up with the single crystal rotation speed measuring means,
Using the actual single crystal rotation speed measured by the single crystal rotation speed measuring means, the single crystal rotation speed is controlled so that the single crystal rotation speed becomes the target rotation speed.
A method for producing a single crystal. The seed crystal held in the seed crystal holder attached to the tip of the wire rope is brought into contact with the raw material melt in the crucible, the crucible is rotated, and the wire rope is opposite to the direction of rotation of the crucible. In the method of producing a single crystal by winding up while rotating in the direction and pulling up the seed crystal and the single crystal grown on the seed crystal while rotating,
Measure the actual rotation speed of the single crystal to be pulled up with the single crystal rotation speed measuring means,
Measure the rotational speed of the crucible with a crucible rotational speed measuring means,
Using the actual single crystal rotation speed measured by the single crystal rotation speed measurement means and the crucible rotation speed measured by the crucible rotation speed measurement means, the ratio between the single crystal rotation speed and the crucible rotation speed is the target rotation speed. Controlling at least one of the single crystal rotation speed and the crucible rotation speed to be a ratio,
A method for producing a single crystal.   The method for producing a single crystal according to claim 9, wherein the single crystal rotation speed is controlled so that a ratio between the single crystal rotation speed and the crucible rotation speed becomes a target rotation speed ratio.   The method for producing a single crystal according to claim 9, wherein the crucible rotation speed is controlled so that a ratio between the single crystal rotation speed and the crucible rotation speed becomes a target rotation speed ratio.   The method for producing a single crystal according to any one of claims 8 to 11, wherein the seed crystal and the single crystal are pulled up while applying a magnetic field to a melt of the raw material in the crucible.

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