JP2909945B2 - Seed bar cutting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a seed rod.

[0002]

2. Description of the Related Art When a single crystal having a certain crystal orientation is grown by using the Czochralski method or the floating zone method, a seed crystal is required. For the production of seed crystals, prepare a high-quality single crystal ingot, cut it according to its crystal orientation, and finish it with a chemical etching process etc. to obtain a clean surface without mechanical flaws etc. . At the time of cutting the single crystal ingot, the crystal orientation is adjusted by an optical image method.

[0003]

As means for detecting the crystal orientation of a single crystal ingot, an optical image method and an X-ray diffraction method are known. Since there is no suitable means for accurately adjusting the crystal orientation of a single crystal ingot, an optical image method has been conventionally used. However, in the optical image method, since a light spot is applied to an end face of a single crystal ingot and the crystal orientation is adjusted while visually confirming the reflected light image, the crystal orientation cannot always be adjusted accurately. The inclination of the crystal orientation of the cut seed rod may be large. And the inclination of the crystal orientation of the single crystal manufactured using such a seed rod also increases, and the irregularities on the outer periphery of the single crystal ingot also increase. Therefore, in the conventional cutting method using the optical image method, the yield rate of the seed bar is low. The present invention has been made in view of the above conventional problems, in order to obtain a good quality seed rod, to accurately detect the crystal orientation of the single crystal ingot that is the material of the seed crystal,
It is an object of the present invention to provide a seed bar cutting method that can accurately adjust the cutting direction based on this.

[0004]

In order to achieve the above object, a seed rod cutting method according to the present invention is characterized in that a crystal lattice plane spacing of a single crystal ingot is d, and an X-ray of wavelength λ is applied to the crystal lattice plane. When irradiated at an angle θ, sin θ = λ / 2d
A detector is provided at a position that satisfies the condition [Bragg's condition], and when the X-rays of wavelength λ are irradiated on the end face of the single crystal ingot, the single crystal ingot is maximized so that the intensity of the diffracted wave by the detector becomes maximum. After adjusting the direction of the axis, the first ingot is cut at a predetermined interval in a direction perpendicular to the crystal lattice plane, and the single crystal ingot is rotated by 90 ° about the axis of the ingot. X of wavelength λ
After irradiating a line, the direction of the axis of the single crystal ingot is adjusted so that the intensity of the diffracted wave by the detector is maximized, and the second ingot is cut at a predetermined interval in a direction perpendicular to the crystal lattice plane. By performing the process, a seed rod is obtained. In such a configuration, specifically, a jig 1 made of an angle plate, a bottom surface on which the jig 1 is placed, and opposing surfaces which stand vertically at both ends of the bottom surface A jig 2 composed of two adjusting bolts respectively arranged on the two facing surfaces, and an upper part on which the jig 2 is placed and fixed;
A jig 3 having a base compatible with the X-ray diffraction apparatus is prepared, and the outer periphery of a single crystal ingot is attached to two orthogonal surfaces of the jig 1, and the jig 2 is mounted and fixed on the jig 3. After placing the jig 1 on one side, the end face of the single crystal ingot is irradiated with X-rays. After adjusting the direction of the jig 1 by operating the adjusting bolts, the jig 2 is fixed to the reference surface of the cutting machine to perform the first ingot cutting, and the other surface of the jig 1 is turned down. X-rays are again applied to the end face of the single crystal ingot, and the jig is operated by operating the four adjustment bolts so as to maximize the intensity of the diffracted wave by the detector in the same manner as described above. After adjusting the direction of 1, the jig 2 is fixed to the reference plane of the cutting machine to perform the second ingot cutting.

[0005]

An X-ray having a wavelength λ that satisfies the Bragg condition represented by λ = 2d · sin θ is applied to the end face of the single crystal ingot having a distance d between the crystal lattice planes at an irradiation angle θ, and the rotation at the crystal lattice plane is performed. When the direction of the axis of the single crystal ingot is adjusted so that the bending angle becomes θ, the intensity of the diffracted wave becomes maximum. The present invention utilizes this phenomenon, and according to the above configuration, the outer periphery of a single crystal ingot serving as a material for a seed rod is attached and fixed to the jig 1 formed of an angle plate, and the jig 1 is fixed. The jig 1 was fixed to the jig 2 using an X-ray diffractometer in a direction that satisfies the Bragg condition. In this state, the jig 2 was attached to a cutting machine. It can be cut with high precision in the direction perpendicular to the crystal lattice plane. Then, by rotating the jig 1 by 90 ° and repeating the above operation, a very good quality seed rod can be obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a seed bar cutting method according to the present invention will be described below with reference to the drawings. In the present invention, the jig 1, the jig 2, and the jig 3 are used to detect the crystal orientation of a single crystal ingot (hereinafter, referred to as a raw material) as a raw material of a seed rod with high accuracy.
Is used. As shown in FIG. 1, the jig 1 has parallel surfaces 1a,
1b and an angle plate having surfaces 1c and 1d perpendicular to these surfaces. The jig 2 is a plate having a U-shaped cross section as shown in FIG. 2, and has two opposing surfaces 2a, 2a.
The spacing L2 of b is larger than the length L1 of the jig 1, and two adjusting bolts 2e are attached to the outer surfaces 2c and 2d parallel to the two surfaces 2a and 2b, respectively, near the bottom surface 2f. ing. The shape of the jig 3 is as shown in FIG. 3, and the distance L3 between the two opposing surfaces 3a and 3b is equal to the bottom length L of the jig 2.
The mounting bolt 3c is slightly larger than 4 and is attached to one surface 3a. The shape and dimensions of the base 3d of the jig 3 are manufactured so as to be compatible with the X-ray diffraction device.

Next, a procedure for cutting a seed rod will be described. (1) As shown in FIG. 4, a columnar material 4 is attached to the surfaces 1a and 1c of the jig 1 using an adhesive. (2) The jig 2 is placed on the jig 3, the jig 2 is fixed to the jig 3 with the mounting bolt 3c, and the jig 1 on which the material 4 is adhered is placed on the jig 2. At this time, for example, the surface 1b of the jig 1 shown in FIG. 1 is placed on the bottom surface 2f of the jig 2 shown in FIG. 2, and the adjusting bolt 2e of the jig 2 is loosened so that the jig 1 can be slightly moved. Keep it. (3) The jig 3 is attached to the X-ray diffraction device in the above state. At this time, as shown in FIG. 5, the mounting angle of the X-ray tube 5 and the detector 6 for detecting the diffracted wave of the X-ray is set to the reference plane A.
Is adjusted so as to be the Bragg angle θ of the material 4. (4) As shown in FIG. 6, the end face of the material 4 is irradiated with X-rays of wavelength λ from the X-ray tube 5 and the four adjustment bolts 2c are moved to the right or right so that the detection value of the detector 6 is maximized. Rotate to the left to adjust the direction of the jig 1. When the detection value of the detector 6 becomes the maximum, the crystal orientation of the raw material 4 coincides with the direction satisfying the Bragg condition, and the crystal lattice plane 4 a is parallel to the reference plane A. (5) After confirming that the jig 1 is fixed to the jig 2 by the four adjustment bolts 2c, the jig 2 is removed from the jig 3. (6) As shown in FIG. 7, the outer surface 2 c or 2 d of the jig 2 to which the jig 1 is fixed is attached to the cutting machine 7 in close contact with the reference surface 7 a of the cutting machine 7, and is attached to the jig 1. The cut material 4 is cut at predetermined intervals while leaving the slice base. (7) Remove the jig 2 from the cutting machine as shown in FIG.
Loosen the adjustment bolt 2e and remove the jig 1 from the jig 2.
The jig 2 is placed on the jig 3, and the jig 2 is fixed to the jig 3 by the mounting bolt 3c. (8) The jig 1 is rotated by 90 ° about the axis of the material 4 as a rotation axis, and the surface 1d is placed on the bottom surface 2f of the jig 2. (9) Repeat steps (3) to (7) described above. The end face of the seed rod cut out to a predetermined size in this manner is cut at right angles to the axis of the seed rod, and the seed rod cutting operation is completed. Further, the seed rod is completed by performing a chemical etching process or the like.

A seed rod was cut using the cutting method according to the present invention, and the crystal orientation deviation angle of the obtained seed rod was measured. The number of cut single crystal ingots was 26, and one seed rod was extracted from each ingot and the inclination angle of the crystal orientation was measured. As a result, the average value was 4.77 minutes, and the estimated standard deviation was 3.15.
Minutes. On the other hand, when the crystal orientation deviation angle of the seed rod cut using the conventional optical image method was measured by the same method as described above, the average value was 21.4 minutes, and the estimated value of the standard deviation was 1
At 6.73 minutes, the crystal orientation deviation accuracy was dramatically improved. In addition, the process capability index was improved more than five times.

[0009]

As described above, according to the present invention, the end face of a single crystal ingot, which is a seed crystal material, is irradiated with X-rays at a Bragg angle, and the single crystal ingot is so shaped as to maximize the diffraction wave intensity. Since the cutting is performed while maintaining the state after adjusting the direction of the axis, the cutting can be performed extremely accurately in the direction perpendicular to the crystal lattice plane. And
Since this procedure was performed in the x and y2 directions,
It is possible to obtain a seed rod having a crystal orientation deviation significantly smaller than that of the conventional optical imaging method. When such a very high quality seed rod is used, it becomes possible to produce a high-quality single crystal having a small crystal orientation deviation. Further, the yield of the seed bar cutting process can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a jig 1;

FIG. 2 is a perspective view of the jig 2;

FIG. 3 is a perspective view of the jig 3;

FIG. 4 is a front view showing a state in which the jig 2 is fixed to the jig 3 and a jig 1 on which a single crystal material is stuck is placed on the jig 2;

FIG. 5 is an explanatory diagram showing a positional relationship between an X-ray tube and a detector.

FIG. 6 is a top view showing a state where the direction of a crystal lattice plane of a single crystal material is adjusted.

FIG. 7 is a top view showing a state where the jig 2 is attached to a cutting machine.

FIG. 8 is a front view showing a state in which the cutting in one direction has been completed and the jig 2 has been removed from the cutting machine.

[Explanation of symbols]

 1, 2, 3 jig 1a, 1b, 1c, 1d, 2a, 2b, 3a, 3b surface 2e adjusting bolt 2f bottom surface 3d base 4 single crystal ingot (material) 4a crystal lattice surface 5 X-ray tube 6 detector 7 cutting Machine 7a Reference plane

Claims (2)

(57) [Claims] 1. The crystal lattice spacing of a single crystal ingot is d
When X-rays having a wavelength λ are irradiated at an angle θ with respect to the crystal lattice plane, a detector is provided at a position satisfying a condition (sin θ = λ / 2d) (Bragg condition), and the single crystal ingot is provided. The direction of the axis of the single crystal ingot is adjusted so that the intensity of the diffracted wave by the detector is maximized when the X-ray of wavelength λ is applied to the end face of the first crystal, and the first direction is perpendicular to the crystal lattice plane at a predetermined interval. After performing ingot cutting and rotating the single crystal ingot by 90 ° about the axis of the ingot, the end face of the ingot is irradiated with X-rays having a wavelength λ, and the intensity of the diffracted wave by the detector is maximized as described above. A seed rod cutting method characterized in that the seed rod is obtained by adjusting the direction of the axis of the single crystal ingot as described above and then performing a second ingot cutting at a predetermined interval in a direction perpendicular to the crystal lattice plane. 2. A jig 1 composed of an angle plate, a bottom surface on which the jig 1 is placed, opposing surfaces rising vertically at both ends of the bottom surface, and two jigs each disposed on the two opposing surfaces. And a jig 3 comprising an upper portion on which the jig 2 is mounted and fixed, and a base adapted to the X-ray diffraction apparatus. The outer periphery of the single crystal ingot is adhered to the two surfaces to be fixed, placed on a jig 3 and placed on a fixed jig 2 with one side of the jig 1 facing down, and then the end face of the single crystal ingot , And the direction of the jig 1 is adjusted by operating the four adjustment bolts so that the intensity of the diffracted wave by the detector of the X-ray diffractometer is maximized. The first ingot is cut and fixed on the reference surface of the jig 1, and is placed on the jig 2 with the other surface of the jig 1 facing down. The end face of the single crystal ingot is again irradiated with X-rays, and the direction of the jig 1 is adjusted by operating the four adjustment bolts so that the intensity of the diffracted wave by the detector is maximized as described above. 2. The seed rod cutting method according to claim 1, wherein the second ingot cutting is performed by fixing the tool 2 to a reference surface of the cutting machine.