JP2001158687A - Seed chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the attachment and detachment of a slip-off stopping cap, and further to increase the number of the reusing of a seed chuck. SOLUTION: The tip end part of a wire-connecting shaft 14 integrally formed with a seed chuck body 10a is formed into a tapered state with 3 deg. cone angle. A steel ball 17a at the lower end of a wire 16 is inserted into a ball groove 15a, and thereafter the slip-off stopping cap 18 is outserted on the upper end part of the wire-connecting shaft 14. The cap 18 can fit to the shaft 14 without a gap because the inner surface of the cap 18 is expanded downward to form 3 deg. core angle. At the time, a positioning protrusion 18a is inserted into a wire- connecting groove 15 to position the wire 16 so as to have the same axis center as the chuck axis center. At the time of pulling, the cap 18 is firmly pressed on the shaft 14 by the thermal expansion. The cap 18 is readily separated from the shaft by cooling. The seizure of the cap is reduced, and the number of the reuse of the chuck is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a seed chuck,
More specifically, the present invention relates to a seed chuck used in a single crystal pulling apparatus for pulling and growing a single crystal by the Czochralski method.

[0002]

2. Description of the Related Art As a method of manufacturing single crystal silicon,
Melt the polycrystalline silicon in the crucible, contact the seed, which is a rod-shaped seed crystal, with this melt, and then pull it while slowly rotating it with a wire to pull up and grow single crystal silicon. The Czochralski method is known. In this method, a seed chuck is used as a jig for connecting a seed to a wire.

Hereinafter, a conventional seed chuck will be described with reference to FIG. FIG. 4 is a front view including a partial sectional view showing a use state of a seed chuck according to a conventional means. As shown in FIG. 4, the seed chuck 100 has a cylindrical chuck body 100a made of stainless steel. A seed mounting portion 101 is formed in a depressed form on the tip end surface (the lower end in FIG. 4) of the chuck main body 100a. In addition, the seed mounting section 101 includes a seed 1
The seed connecting member 103 to which the reference numeral 02 is fixed is mounted. On the other hand, a wire connection shaft 104 is integrally provided at the base (upper end in FIG. 4) of the chuck body 100a.

At the tip of the wire connecting shaft 104,
A wire connecting groove 105 extending from a part of the outer peripheral surface to the center of the shaft is engraved with its groove length direction coinciding with the chuck axis. Note that this wire connection groove 105
Is a ball groove 105a having a substantially spherical shape. In the wire connection groove 105, a caulking portion 107 in which the tip of the wire 106 is swaged is housed. A small-diameter steel ball 107a is integrally formed at the tip of the caulking portion 107. Further, a cap 108 for preventing the wire 106 from coming out of the wire connection groove 105 during the pull-up and growth of the single crystal silicon I is screwed into the tip of the wire connection shaft 104. Therefore, an external thread is engraved on the outer peripheral surface of the distal end portion of the wire connecting shaft 104, and an internal screw corresponding thereto is engraved on the inner peripheral surface of the retaining cap 108.

[0005]

However, in the conventional seed chuck 100, the retaining cap 108 is screwed to the distal end of the wire connecting shaft 104 as described above. In addition, since the seed chuck 100 is exposed to a high temperature of about 1000 ° C. during use, seizure occurs in the screw portion of the inner screw and the outer screw only by performing the pulling and growing of the single crystal several times. This has prevented the wire from coming off the seed chuck. As a result, there is a problem that the seed chuck 100 must be disposed of relatively frequently.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a seed chuck capable of increasing the number of times of reuse and facilitating attachment and detachment of a retaining cap to and from a wire connecting shaft. I have. Another object of the present invention is to provide a seed chuck that can prevent rattling of a wire during single crystal pulling growth. Further, the present invention provides a seed chuck in which a retaining cap is difficult to be removed from a wire connecting shaft during single crystal pulling growth.
That is the purpose.

[0007]

According to a first aspect of the present invention, there is provided a chuck main body, a seed mounting portion provided at one end of the chuck main body, to which a seed is removably mounted, and wherein the seed is seeded. A wire connection groove into which a wire for pulling a single crystal grown in the above is inserted is formed at the tip of the shaft, and a wire connection shaft provided at the other end of the chuck body; and a tip of the wire connection shaft. A detachable cap that is detachably attached to the portion from the outside to prevent the wire from detaching from the wire connection groove during single crystal pulling growth. Shape
By forming the outer peripheral surface into a tapered shape with a tapered surface, the inner peripheral surface of the retaining cap is formed into a tapered surface that matches the taper angle of the outer peripheral surface of the wire connection shaft.
This is a seed chuck in which the inner peripheral surface and the outer peripheral surface are in surface contact with each other, and the above-mentioned cap is detachably fitted to the distal end of the wire connecting shaft.

[0008] The kind of single crystal to be pulled is not limited. Examples include silicon and gallium arsenide.
The shape of the retaining cap is not limited. However, the cylindrical shape according to the third aspect is preferable because the amount of change in the cap due to thermal expansion increases. The taper angles of the mounting surfaces of the wire connecting shaft and the retaining cap are not limited. Usually, it is 2 ゜ to 4 ゜.

According to a second aspect of the present invention, a crimping portion is provided at a tip end of the wire inserted into the wire connection groove, and an inner peripheral surface of the cap is inserted into the wire connection groove. 2. The seed chuck according to claim 1, further comprising a positioning projection for positioning the caulked portion on the chuck axis. The shape, size,
The material and the like are not limited.

The invention according to claim 3 is the seed chuck according to claim 1 or 2, wherein the retaining cap is a cylindrical cap whose both end faces are open.

[0011]

According to the present invention, during the pulling growth of the single crystal,
Since the wire connecting shaft and the retaining cap attached to the distal end of the wire connecting shaft are exposed to a high-temperature atmosphere and thermally expanded, the retaining cap is firmly pressed to the wire connecting shaft. On the other hand, after use, both members return to their original dimensions as the seed chuck is released from the high-temperature atmosphere and cooled. As a result, the retaining cap easily comes off the wire connecting shaft. As described above, since the crimping method using thermal expansion is employed as the attachment method of the retaining cap, the cap is hardly seized during use.
As a result, the number of reuses of the seed chuck can be increased. In addition, since the retaining cap does not need to be twisted as in the related art, the operation of attaching and detaching the retaining cap to and from the wire connecting shaft becomes easy.

In particular, according to the second aspect of the present invention, when the retaining cap is attached to the wire connecting shaft,
The positioning protrusion formed on the retaining cap is inserted into the wire connection groove. As a result, the caulking portion of the wire is automatically positioned and fixed on the chuck axis by the positioning projection.

According to the third aspect of the present invention, the retaining cap is a cylindrical cap whose both end surfaces are open, so that the cap has a smaller shape than a container-like cap whose one surface is closed by an end plate. The amount of change of the cap due to thermal expansion increases. This makes it difficult for the retaining cap to come off from the wire connecting shaft during single crystal pulling growth.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a seed chuck according to one embodiment of the present invention will be described. FIG. 1 is a front view including a partial sectional view showing a use state of a seed chuck according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view of a retaining cap used in the seed chuck according to one embodiment of the present invention. FIG. 3 is an enlarged plan view of the retaining cap used in the seed chuck according to one embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a seed chuck incorporated in a single crystal pulling apparatus for pulling and growing single crystal silicon. The seed chuck 10 has a cylindrical chuck body 10a made of stainless steel. A seed mounting portion 11 is formed in a depressed shape on the distal end surface of the chuck body 10a. In addition, the seed mounting portion 11 is mounted with a seed connecting member 13 having a seed 12 fixed to a tip portion. On the other hand, the chuck body 10a
The wire connection shaft 14 is integrally provided at the base of the.

The tip of the wire connecting shaft 14 is slightly tapered. Note that the taper angle θ of the tapered portion
Is 3 ゜. The wire connecting shaft 14 is formed with a wire connecting groove 15 extending from a part of the outer peripheral surface to the center of the shaft so that the length direction of the groove matches the chuck axis. In addition, this wire connection groove 15
Is a ball groove portion 15a having a long hole shape in cross section. The tip of the wire 16 is swaged to form a caulking portion 17 having a small diameter steel ball 17a integrated at the tip. The caulking portion 17 is housed in the wire connection groove 15. The wire 16 is connected to the tip of the wire connecting shaft 14 during the pull-up growth of the single crystal silicon I.
A cap 18 for preventing the wire from being detached from the wire connection groove 15 is detachably fitted to the outside. The inner peripheral surface of the retaining cap 18 is
Is a taper surface having the same taper angle as the taper angle θ of the outer peripheral surface. Therefore, when the retaining cap 18 is attached, the retaining cap 18 is fitted to the wire connecting shaft 14 without rattling. On the small diameter side of the inner peripheral surface of the cap 18, a thick small piece-shaped positioning projection 18 a which is inserted into the wire connection groove 15 and positions the caulking portion 17 on the chuck axis is integrally formed. (See FIGS. 2 and 3).

Next, in using the seed chuck 10, first, the swaged portion 17 of the wire 16 is inserted into the wire connection groove 15 of the wire connection shaft 14. At this time, the steel ball 17a is arranged in the ball groove 15a. Next, the retaining cap 18 previously loosely inserted into the wire 16 is moved toward the seed chuck 10 and fitted into the tapered tip of the wire connecting shaft 14 from outside. At this time, the outer peripheral surface of the wire connecting shaft 14 and the inner peripheral surface of the retaining cap 18 have the same taper angle θ such that the surfaces come into contact with each other. As a result, the retaining cap 18 is fitted to the wire connecting shaft 14 without rattling. When the retaining cap 18 is fitted onto the wire connecting shaft 14, the positioning projections 1 formed on the cap 18 are removed.
8 a is inserted into the wire connection groove 15. Thereby, the caulking portion 17 is automatically formed by the positioning projection 18a.
Are positioned on the chuck axis. At this time, since the retaining cap 18 is a cylindrical cap whose both end surfaces are open, the change amount of the cap due to thermal expansion is larger than that of a conventional container-like cap whose one surface is closed by an end plate. Become. This makes it difficult for the retaining cap 18 to come off from the wire connecting shaft 14 during single crystal pull-up growth.

Thereafter, in a single crystal pulling apparatus (not shown), single crystal silicon is grown by the Czochralski method. That is, for example, polycrystalline silicon is melted by heating with a heater in a crucible in a high-temperature chamber filled with argon gas.
After the contact between the two, the wire 16 is pulled up while rotating slowly by the wire rotation pulling up means, whereby single crystal silicon is pulled up and grown. At this time, the wire connecting shaft 14 and the retaining cap 18 are exposed to a high-temperature atmosphere and thermally expand with each other. As a result, the cap 18 is firmly pressed on the wire connection shaft 14.

On the other hand, after use, the seed chuck 10 is released from the high-temperature atmosphere. Therefore, the temperature decreases, and the wire connecting shaft 14 and the retaining cap 18 which have been thermally expanded until then return to their original dimensions. As a result, the retaining cap 18 can be easily removed from the wire connecting shaft 14. As described above, since the crimping method utilizing thermal expansion is employed as the method of attaching the retaining cap 18, the seizure of the cap 18 is less likely to occur during use. Thereby, the number of times of reusing the seed chuck 10 can be increased.
Of course, when attaching / detaching the cap 18, the cap does not need to be twisted as in the conventional case, so that the attachment / detachment of the cap 18 to / from the wire connecting shaft 14 becomes easy.

[0020]

According to the present invention, as a method for attaching the retaining cap to the wire connecting shaft, the joining surface of the two members is a tapered surface (inclined surface) having the same taper angle, and the heat during the single crystal pulling growth is increased. Adopting the expansion-based crimping method, the retaining cap is firmly crimped to the wire connecting shaft during use, but after use, the seed chuck is released from the high-temperature atmosphere and cooled, allowing easy use. The cap can be removed. Moreover, the attachment and detachment of the retaining cap becomes easy.

In particular, according to the second aspect of the present invention, since the positioning projection is provided on the inner peripheral surface of the retaining cap, the caulking portion of the wire is automatically formed only by attaching the retaining cap to the wire connecting shaft. It can be positioned on the chuck axis.

According to the third aspect of the present invention, since the retaining cap is a cylindrical cap whose both end faces are open, compared with a container-like cap whose one face is closed by an end plate,
The amount of change of the cap due to thermal expansion increases. Thereby, it is possible to make it difficult for the retaining cap to come off from the wire connecting shaft during single crystal pulling growth.

[Brief description of the drawings]

FIG. 1 is a front view including a partial cross-sectional view showing a use state of a seed chuck according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a retaining cap used in a seed chuck according to one embodiment of the present invention.

FIG. 3 is an enlarged plan view of a retaining cap used in a seed chuck according to one embodiment of the present invention.

FIG. 4 is a front view including a partial cross-sectional view showing a use state of a seed chuck according to a conventional means.

[Explanation of symbols]

 Reference Signs List 10 seed chuck, 10a chuck main body, 11 seed mounting portion, 12 seed, 14 wire connection shaft, 15 wire connection groove, 16 wires, 17 caulking portion, 18 retaining cap, 18a positioning protrusion, θ taper angle.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroki Shirataki 1-5-1, Otemachi, Chiyoda-ku, Tokyo Within Mitsui Materials Silicon Co., Ltd. (72) Kunihiko Nagai 1-5, Otemachi, Chiyoda-ku, Tokyo No. 1 Inside Mitsubishi Materials Silicon Co., Ltd. (72) Inventor Ryusaku Nakajima 1-5-1, Otemachi, Chiyoda-ku, Tokyo F-term inside Mitsubishi Materials Silicon Co., Ltd. 4G077 AA02 BA04 CF10 EG11 EG12

Claims (3)

[Claims] 1. A chuck body, a seed mounting portion provided at one end of the chuck body, to which a seed is removably mounted, and a wire for pulling a single crystal grown using the seed as a seed A wire connection groove into which is inserted is formed at the tip of the shaft, and a wire connection shaft provided at the other end of the chuck body is detachably attached to the tip of the wire connection shaft from the outside. In a seed chuck having a retaining cap for preventing the wire from coming off the wire connecting groove during crystal pulling growth, the shape of the tip of the wire connecting shaft is tapered such that its outer peripheral surface is a tapered surface. By making the inner peripheral surface of the retaining cap a tapered surface that matches the taper angle of the outer peripheral surface of the wire connection shaft, The face and the outer peripheral surface by surface contact, the stopper seed chuck freely allowed fitted detachably to the cap to the distal end portion of the wire connecting shaft. 2. A caulking portion is provided at a tip portion of a wire inserted into the wire connection groove, and a caulking portion inserted into the wire connection groove is provided on an inner peripheral surface of the retaining cap with a chuck shaft. 2. The seed chuck according to claim 1, further comprising a positioning projection for positioning on a line. 3. The seed chuck according to claim 1, wherein the retaining cap is a cylindrical cap whose both end surfaces are open.