JPH05148071A - Holding tool for polycrystalline silicon rod - Google Patents

Abstract

PURPOSE:To enable a polycrystalline silicon rod to be held effectively by ensuring a threaded hole and press screw both providing the holding function for a polycrystalline silicon rod to be avoided from the heat from the silicon rod at elevated temperatures. CONSTITUTION:The upper end of a polycrystalline silicon rod P is put into an internal adapter 26, and on engaging a press screw 46 with a threaded hole 44, a press arm 38 is rotated with a pin 42 as support so that the press part 48 at the lower end of the arm pushes inwardly the extended part 34 at the lower end of an elastic vertical wall 32a. Thus, the press force of this arm 38 moves the extended part 34 inwardly and grips the upper end of the rod P. In this way, the rod P is held with a holding tool 22, being partly heated and melted using a high-frequency induction heating coil in a high-frequency induction heating chamber, and the melt zone is moved, thus carrying out silicon single crystal growth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a FZ method semiconductor single crystal for growing a silicon single crystal by partially melting a raw material silicon polycrystalline rod by using a high frequency induction heating coil and moving the melting zone. The present invention relates to a crystal manufacturing apparatus, and more particularly to a silicon polycrystal rod holder capable of effectively holding a polycrystal silicon rod.

[0002]

2. Description of the Related Art Conventionally, when a silicon single crystal is manufactured by the FZ method, a polycrystalline holder attached to the lower end of an upper drive shaft having a vertical movement function and located in a chamber, and a lower portion having a vertical movement function. Using a device having a seed crystal holder attached to the upper end of the drive shaft and located in the chamber, and a high frequency induction heating coil provided in the middle part of the chamber, the polycrystalline silicon holder is made of a raw silicon Hold the crystal rod and hold the seed of the silicon single crystal in the seed crystal holder, melt one end of the silicon polycrystal rod by the high-frequency induction heating coil, fuse it to the seed crystal, and seed it, and then perform the high-frequency induction heating. By rotating the coil and the polycrystalline silicon rod relatively and moving them relative to each other in the axial direction, the polycrystalline silicon rod is melted in the axial direction one by one while the silicon single bond It is being carried out to produce the bar.

As shown in FIG. 2, the polycrystalline rod holder 2 described above is used.
The structure of is a cylindrical adapter (usually made of stainless steel) 8 fixed to the lower end of the upper drive shaft 4 by a screw 6 and opening downward, and a plurality of perforated holes around the lower end of the adapter. Plural pieces (usually 6-8 pieces) that are screwed into the screw holes 10 and have a heat-resistant pad 14 attached to the tip.
It is configured to be held by the contact plate 14 by screwing the screw 12 inward. As the material of the contact plate 14, molybdenum having a melting point higher than that of silicon is usually used.

[0004]

When the silicon single crystal is grown by the FZ method semiconductor single crystal manufacturing apparatus having the conventional silicon polycrystalline rod holder 2 shown in FIG. 2, the following problems occur. Since the silicon polycrystal rod P held by the silicon polycrystal rod holder 2 becomes high temperature (1000 ° C. or higher), the screw structure of the screw hole 10 and the holding screw 12 of the stainless steel adapter becomes unusable at one time. It is necessary to replace with a new silicon polycrystalline rod holder 2 each time. It is difficult to balance the tightening method of the holding screw 12 located on the diagonal line, and when the silicon polycrystalline rod is held and then rotated, a center (core) of the silicon polycrystalline rod draws a locus of a circle having a radius. .. The FZ method in this state is extremely difficult and causes, for example, instability of the quality of a single crystal. Near the end of the FZ process, since the molten heating state is located near the silicon polycrystalline rod holder 2, the polycrystalline rod near the holder reaches a high temperature, sometimes 1000 ° C. or higher, and the radiant heat mainly causes the holder 2 to reach a high temperature. Is entirely heated, and as a result, the tightening force of the polycrystalline rod of the cap screw 12 is reduced by thermal expansion, and the polycrystalline rod P falls off the holder 2.

The present invention has been made in view of the above-mentioned prior art, and it is possible to avoid as much as possible the heat from the silicon polycrystalline rod which becomes a high temperature in the screw hole and the holding screw for holding the silicon polycrystalline rod. In this way, the durability of the holding function is improved, and when the silicon polycrystalline rod is rotated by uniformly pressing and pinching the polycrystalline silicon rod from the surroundings, the center of the circular polycrystalline rod is not drawn. In addition, it is an object of the present invention to provide a silicon polycrystal rod holder capable of preventing the silicon polycrystal rod from falling out of the holder in the latter half of the FZ step.

[0006]

In order to solve the above-mentioned problems, in the silicon polycrystalline rod holder of the present invention, a cylindrical internal adapter fixed to the lower end of the upper drive shaft and opening downward, A cylindrical external adapter that is provided on the outer surface side of the internal adapter and is similarly fixed to the lower end portion of the upper drive shaft and opens downward, and the circumferential side wall of the internal adapter is a plurality of elastic hanging walls. And a lower end portion thereof is extended from the lower end of the circumferential side wall of the external adapter to form a lower end extension portion, and is longer than the circumferential side wall of the external adapter. A plurality of pressing arms are rotatably and pivotally attached to the outer surface of the peripheral side wall, and the lower end pressing portion of the pressing arm is urged outward so that the lower end pressing portion of the pressing arm is elastically suspended from the elastic hanging wall of the internal adapter. Inward with bottom extension Pressure, is obtained so as to hold the upper end of the polysilicon rod to be accommodated in the internal adapter.

It is preferable that a plurality of pairs of the elastic hanging walls are provided, and that every other lower end extending portion of the elastic hanging wall is pressed inward by the holding arm. Although the number of the elastic hanging walls is an even number, it is preferable that the number is, for example, about 6, 8, or 10.

[0008]

In the silicon polycrystalline rod holder of the present invention,
When the upper end of the silicon polycrystalline rod is put into the internal adapter and the cap screw is screwed into the threaded hole, the press arm pushes the bottom extension part of the elastic hanging wall inward with the pin as a fulcrum. To rotate. The lower end extending portion is displaced inward by the pressing force of the pressing arm, and presses and holds the upper end of the silicon polycrystalline rod. Further, when the elastic hanging walls are made of a high-melting-point metal material having good heat resistance, since the elastic hanging walls are formed in a strip shape in the vertical direction, the F
Even at the end of the Z process, the elastic hanging wall itself cannot receive induction heating due to the approach of the coil.

An embodiment of the present invention will be described below with reference to the accompanying drawings.
It will be described with reference to FIG. In FIG. 1, the same members as those in FIG. 2 showing the conventional apparatus are designated by the same reference numerals.

In FIG. 1, reference numeral 22 denotes a silicon polycrystalline rod holder according to the present invention, which is used in an FZ method semiconductor single crystal manufacturing apparatus. The silicon polycrystalline rod holder 22 has a cylindrical internal adapter 26 fixed to the lower end of the upper drive shaft 4 by a screw 24 and opening downward. Reference numeral 28 denotes an external adapter, which is provided on the outer surface side of the internal adapter 26 and is similarly fixed to the lower end portion of the upper drive shaft 4 by a screw 30 and has a cylindrical shape opening downward.

The circumferential side wall 32 of the inner adapter 26 is formed of a plurality of elastic hanging walls 32a, and the lower end portion thereof extends downward from the lower end of the circumferential side wall of the outer adapter to form a lower end extending portion 34. Therefore, it is longer than the circumferential side wall 36 of the external adapter 28.

A plurality of pressing arms 38 are rotatably pivoted on the outer surface of the circumferential side wall 36 of the external adapter 28 via pins 42 provided on a projecting portion 40. A screw hole 44 is opened at the upper end of the pressing arm 38, and
A cap screw 46 is screwed into the unit 4.

The upper end of the holding arm 38 is biased outward by screwing the holding screw 46, and the lower end holding portion 48 of the holding arm 38 extends the lower end of the elastic hanging wall 32a of the internal adapter 26. The portion 34 is pressed inward to hold the upper end portion of the silicon polycrystalline rod P housed in the inner adapter 26.

A plurality of pairs of the elastic hanging walls 32a are provided,
Every other one of the lower end extending portions 34 of the elastic hanging wall 32a is configured to be pressed inward by the lower end pressing portion 48 of the pressing arm 38. The number of the elastic hanging walls 32a is an even number, but for example, about 6, 8, or 10 pairs are preferable.

Reference numeral 50 denotes a heat-resistant pad plate provided on the inner surface side of the lower end extension portion 34 of the elastic hanging wall 32a. It is necessary to use a material having a melting point higher than that of silicon as the material of the pad plate 50, and molybdenum is suitable.

With such a structure, the upper end of the silicon polycrystalline rod P is put in the internal adapter 26 and the cap screw 46 is inserted.
Is screwed into the screw hole 44, the holding arm 38 moves the pin 4
2 is a fulcrum, and the lower end pressing portion 48 has an elastic hanging wall 32a.
The lower end extending portion 34 of the above is rotated so as to be pushed inward. The lower end extension 34 is displaced inward by the pressing force of the pressing arm 38, and presses and holds the upper end of the silicon polycrystalline rod P.

In this way, the silicon single crystal rod P is held by the holder 22, and the high frequency induction heating coil is used in the chamber to partially heat and melt and move the melting zone to grow the silicon single crystal. If this is done, the temperature of the polycrystalline silicon P becomes high, but its heat is shielded by the presence of the internal adapter 26 and the external adapter 28, and the screw holes 44 and the pressing screw 46 of the pressing arm 38 heat the polycrystalline silicon rod P at high temperature. 1 is much less than that of the conventional holder shown in FIG. 1, and the life of the screw hole 44 and the holding screw 46 of the holding arm 38 is extended accordingly.

In order to hold the silicon polycrystalline rod P, the lower end extending portion 34 of the elastic hanging wall 32a is pressed and displaced by the lower end holding portion 48 of the holding arm 38 by screwing the holding screw 46 into the silicon located inside. Since the upper end of the polycrystalline rod P is held, the silicon polycrystalline rod P
As compared with the conventional structure in which the side surface of the silicon polycrystalline rod is directly pressed and held by the pressing screw as in the conventional case, the force is evenly applied from the surroundings, and even if the silicon polycrystalline rod P is rotated. It no longer draws a circular orbit whose center has a radius.

Further, a plurality of pairs of elastic hanging walls 32a (6
Pairs, about 8 pairs, about 10 pairs), and every other one of the lower end extending portions 34 of the elastic hanging wall 32a is pressed inward by the lower end pressing portion 48 of the pressing arm 38 to move the silicon polycrystalline rod P. If held, the silicon polycrystalline rod P will be formed in the latter half of the FZ process.
Becomes high temperature (1000 ° C. or higher), and the radiant heat causes the holder 2 to thermally expand, and even if a force due to the outward expansion is applied to the lower end extending portion 34 of the elastic hanging wall 32a that is displaced inwardly. Since the elastic hanging wall 32a itself has a spring action, its pressure holding force does not weaken,
An accident such as the silicon polycrystalline rod P sliding down does not occur. Further, at this time, the spring action of the elastic hanging wall not pressed by the pressing arm 38 is caused by the pressing arm 38.
Since it is not limited by the holding arm 38, it contributes to the maintenance and strengthening of the holding force when the silicon polycrystalline rod P expands larger than the elastic hanging wall 32a which is pressed and displaced by the holding arm 38.

[0020]

As described above, according to the present invention, the screw hole for performing the holding function of the silicon polycrystalline rod and the holding screw can avoid the heat from the high temperature silicon polycrystalline rod as much as possible. The durability of the polycrystalline silicon rod is improved and the polycrystalline silicon rod can be evenly clamped and held from the surroundings. The quality is stable. Further, the spring effect of the elastic hanging wall achieves a great effect that it is possible to prevent the silicon polycrystalline rod from falling off the holder in the latter half of the FZ process.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional explanatory view showing an embodiment of a silicon polycrystalline rod holder of the present invention.

FIG. 2 is a cross-sectional schematic explanatory view showing an example of a conventional silicon polycrystalline rod holder.

[Explanation of symbols]

 2 Conventional silicon polycrystalline rod holder 4 Upper drive shaft 22 Silicon polycrystalline rod holder of the present invention 26 Internal adapter 28 External adapter 32a Elastic hanging wall 34 Lower extension part 38 Holding arm 42 Pin 44 Screw hole 46 Holding screw 48 Lower end holding part P Silicon polycrystalline bar

Claims (2)

[Claims] 1. A chamber, an upper drive shaft provided at an upper part of the chamber, a lower drive shaft provided at a lower part of the chamber, and a high frequency induction heating coil provided at an intermediate portion in the chamber. A silicon polycrystalline rod, which is provided with a lower end portion of the upper drive shaft via a holder, is partially heated and melted by using a high frequency induction heating coil, and the melting zone is moved to grow a silicon single crystal. A silicon polycrystalline rod holder in an FZ method semiconductor single crystal manufacturing apparatus for performing, which is a cylindrical internal adapter fixed to the lower end of the upper drive shaft and opening downward, and provided on the outer surface side of the internal adapter. A cylindrical outer adapter similarly fixed to the lower end of the upper drive shaft and opening downward, the circumferential side wall of the inner adapter being formed of a plurality of elastic hanging walls. And the lower end portion is made longer than the circumferential side wall of the external adapter so as to extend downward from the lower end of the circumferential side wall of the external adapter to form a lower end extension portion. A plurality of presser arms are rotatably pivotally attached to the outer surface of the presser arm, and the lower end presser part of the presser arm extends toward the lower end of the elastic hanging wall of the internal adapter by urging the upper end part of the presser arm outward. A tool for holding a polycrystalline silicon rod, characterized in that the protruding portion is pressed inward to hold an upper end portion of the polycrystalline silicon rod housed in the internal adapter. 2. A plurality of pairs of the elastic hanging walls are provided, and every other lower end extending portion of the elastic hanging wall is pressed inward by the holding arm. Silicon polycrystalline rod holder.