JPH11116376A - Pulling of silicon single crystal and apparatus for pulling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a method for pulling a silicon single crystal by which the silicon single crystal can stably be pulled with high reliability even when the pulling weight is increased by increasing the caliber and the length of a grown silicon single crystal ingot and an apparatus for pulling the silicon single crystal. SOLUTION: This method for pulling a silicon single crystal comprises dipping a seed crystal in a silicon melt, pulling the seed crystal, thereby growing a silicon single crystal ingot 9 at the rear end of the seed crystal, holding the silicon single crystal ingot 9 grown thereafter with a mechanical holding means and carrying out the pulling. In this case, the contact part of the means for performing the mechanical holding with the ingot 9 is a pillowy structure 17 deformable by an external force. Since the contact part is deformed along uneven parts on the surface of the ingot 9 when holding the ingot 9, the mechanical holding means can uniformly be brought into contact with the ingot 9 to uniformly disperse the applied pressing force throughout the whole contact part and hold the ingot 9 without causing trouble such as occurrence of a concentrated stress due to biased contact or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for pulling a silicon single crystal.
More specifically, the present invention relates to a pulling method and a pulling apparatus capable of stably and reliably pulling a silicon single crystal ingot to be grown even if the pulling weight increases due to an increase in diameter and length of the grown silicon single crystal ingot. is there.

[0002]

2. Description of the Related Art At present, silicon is a typical semiconductor that is widely used industrially as a device such as an integrated circuit (IC) and a large-scale integrated circuit (LSI).

A silicon single crystal used in the semiconductor industry or the like is a floating zone in which a polycrystalline material is used as a raw material to form a molten zone on a polycrystalline rod by induction heating and move the molten zone from a seed crystal side to grow a single crystal. Melting method (Floating Zone method,
Abbreviated as FZ method. ) Alternatively, a polycrystal is placed in a crucible and heated and melted, and the seed crystal is immersed in a melt and then pulled up to grow a single crystal ingot behind the seed crystal (abbreviated as Czochralski method or CZ method). ).

[0004] These production methods are selected depending on the use of the single crystal. The single crystal produced by the FZ method is used for high resistivity applications, and the single crystal produced by the CZ method is used for low to medium resistivity applications. However, recently, due to the progress of LSI manufacturing technology,
The number of circuits formed in a wafer in one process is increased by increasing the area of a single crystal wafer serving as a processing substrate while increasing the size of electronic circuits. The cost has been reduced.
For this reason, there is a constant demand for single crystal production technology to increase the diameter, and at the same time, a method of increasing the length of one single crystal ingot in order to increase productivity per hour during the production of a single crystal. Have been pursued.

[0005] The above-mentioned CZ method not only has an advantage that a large-diameter ingot can be easily obtained, but also has an advanced technology such as automatic diameter control and semi-continuous operation by recharging a raw material polycrystal, thereby reducing costs. The fact is that it surpasses the FZ method.

Conventionally, a pulling apparatus using the CZ method has a configuration in which a single crystal ingot grown behind a seed crystal is directly pulled up by lifting means such as a pulling wire for raising and lowering the seed crystal with respect to the melt surface. However, in this case, the weight of the single crystal ingot is received by the seed crystal or a small diameter portion called a dash's neck portion formed immediately below the seed crystal to prevent dislocation of the crystal. In particular, the dash neck has a diameter of about 3 to 4 mm and can withstand a weight of at most about 200 kg.

As described above, in the conventional lifting device, there is a limit in increasing the diameter and length of the ingot.

For this reason, the diameter of the single crystal ingot can be increased.
In order to cope with an increase in weight due to an increase in length, various improvements in a lifting mechanism have been proposed.

For example, in Japanese Unexamined Patent Publication No. Hei 5-270968, a cylindrical mold is provided which surrounds the above-mentioned dash neck portion when growing a single crystal, and the mold is made of a thermosetting resin such as a fluororesin or a silicone resin. Pour the resin and cure it,
A method of reinforcing the dashes neck is disclosed in Japanese Patent Laid-Open No. 5-27.
Japanese Patent Application Laid-Open No. 09-13808 discloses a method in which a reinforcing fiber such as carbon fiber is wound around a dashes neck portion to reinforce the dashes neck portion.
In Japanese Patent Publication No. 9-515, Japanese Patent Publication No. 7-515 discloses a method of cooling or heating a dash neck portion at the time of growing a single crystal to maintain the tensile strength of the portion at a maximum of about 600 to 800 ° C. In the so-called cone part, which expands to the desired diameter after dislocation by the dash neck part, temporarily reduces the diameter to form a cracked part, and hooks a nail-shaped locking member on this part to make the ingot A method is provided in which a single crystal is pulled by raising and lowering this gripping means separately.
In Japanese Patent No. 172981, the gripping means having a plurality of arms that can be opened and closed by a pneumatic cylinder is arranged so as to surround the single crystal ingot from the single crystal growth axis direction.
The pneumatic cylinder is actuated to grip the ingot by pressing the gripping portions provided at the distal ends of the plurality of arms against the straight body of the single crystal ingot, and the gripping means is moved up and down to lift the ingot. A method for pulling a crystal is disclosed.

[0010]

However, the reinforcement of the dashes neck portion with a thermosetting resin as disclosed in Japanese Patent Application Laid-Open No. Hei 5-270968 requires a very precise alignment for setting the formwork. And Japanese Patent Laid-Open No. 5-2
Reinforcement of a dashes neck portion by a reinforcing fiber as disclosed in JP-A-70976 is very complicated in terms of mechanism,
All of them lack operation reliability, and their reinforcing effect is not sufficient. Further, Japanese Patent Laid-Open No. 7-1
The method of controlling the temperature of the dashes neck portion disclosed in Japanese Patent No. 38089 is basically for holding the grown single crystal ingot by the strength of the dashes neck portion itself. Improvement in weight could not be expected. In addition, 7-51
In the technique disclosed in No. 5, it is necessary to form a crack portion for holding in a single crystal ingot, but there is a risk that dislocation occurs or polycrystallization occurs due to thermal stress when reducing the diameter. If these cracks are not formed uniformly in the radial direction, there is a possibility that the growth axis may be inclined when the claw-shaped locking member is engaged. Further, when a straight body of a single crystal ingot as shown in Japanese Patent Application Laid-Open No. 7-172981 is gripped by a gripping mechanism, a growth stripe step of about several millimeters is generally formed on the surface of the straight body of a silicon single crystal ingot. Since it inevitably occurs, the gripping reliability may be reduced due to one-sided contact of the gripping member contact surface during gripping, and the ingot may be damaged due to the application of concentrated stress to the ingot.

As described above, various methods have been conventionally proposed in order to cope with an increase in the weight of single crystal ingots due to the increase in diameter and length, but none of them has been satisfactory.

Accordingly, it is an object of the present invention to provide a novel silicon single crystal pulling method and a silicon single crystal pulling apparatus. The present invention also provides a silicon single crystal pulling method and a silicon single crystal pulling apparatus capable of stably and reliably pulling a silicon single crystal ingot to be stably and reliably even if the weight of the silicon single crystal ingot to be grown is increased due to an increase in diameter and length. It is an object to provide The present invention further provides a relatively simple operation and a simple mechanism, even if the lifting weight is increased.
An object of the present invention is to provide a silicon single crystal pulling method and a silicon single crystal pulling apparatus that can be pulled stably and with high reliability.

[0013]

Means for Solving the Problems The present inventor has conducted intensive studies in order to solve the above-mentioned problems, and as a result, mechanically grasps a silicon single crystal ingot to be grown separately from a seed crystal pulling mechanism. In the case of pulling up, the contact portion of the gripping mechanism with the silicon single crystal ingot is configured to be deformable by external force, so that the contact portion at the time of gripping the ingot is caused by the growth stripe step or the like as described above. The present invention has been found that the ingot can be stably and reliably held by being uniformly and highly adhesively gripped over the entire ingot by being deformed following the uneven shape of the surface of the ingot.

That is, the present invention for solving the above-mentioned problems has the following features:
(1) A seed crystal is immersed in a silicon melt, and the seed crystal is pulled up to grow a silicon single crystal ingot at the rear end of the seed crystal. Thereafter, the silicon single crystal ingot to be grown is mechanically gripped and pulled up. A method of pulling a silicon single crystal, wherein a contact portion of the means for performing mechanical gripping with the ingot is deformed by a pressing force applied during mechanical gripping, and is held in close contact with the surface of the silicon single crystal ingot. This is a method of pulling a silicon single crystal.

Further, (2) in a silicon single crystal pulling apparatus, there is provided a gripping means for mechanically gripping a silicon single crystal ingot to be grown, and a gripping means for growing the silicon single crystal ingot. Lifting means for raising and lowering the silicon single crystal along a silicon single crystal ingot, wherein a contact portion of the gripping means with the silicon single crystal ingot has a structure which can be compressed and deformed by an external force.

Further, in the present invention, it is preferable that (3) the abutting portion is constituted by a plurality of granules and a flexible surrounding body which covers the plurality of granules from outside.

Further, in the present invention, it is preferable that (4) the contact portion is made of a porous body or a bulky fiber assembly.

[0018]

In the present invention, the silicon single crystal ingot to be grown is gripped by a mechanical gripping mechanism during the operation of pulling up the silicon single crystal ingot, and the gripping mechanism contacts the silicon single crystal ingot. Is a structure that can be deformed by an external force. When the gripping mechanism is actuated and its abutment surface comes into contact with the silicon single crystal ingot, the pressing force provided by the gripping mechanism causes the abutting portion to be deformed according to the unevenness of the surface of the ingot, and is uniformly applied to the ingot. It is possible to uniformly distribute the applied pressing force to the entire contact portion and to grip the ingot without causing any troubles such as generation of concentrated stress due to one-sided contact. Stability and reliability are improved.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on specific embodiments.

A silicon single crystal pulling apparatus according to the present invention comprises a gripper for mechanically gripping a silicon single crystal ingot to be grown, and an elevating device for raising and lowering the gripper along a growth axis of the silicon single crystal to be grown. And a structure that can be deformed by an external force as a contact portion between the means and the silicon single crystal grown by the gripping means.

The gripping means in the pulling apparatus of the present invention may be a predetermined position below the dash neck portion of the silicon single crystal ingot to be grown, for example, a straight body, a cone, or a cone for gripping the same. In the special part formed in the ingot, if it can bend the outer periphery of the ingot and engage its abutment against the ingot surface, if it can grasp the silicon single crystal by pressing force, suspension force, etc. The structure itself is not particularly limited, and various modes can be adopted. Specifically, for example, the structure as illustrated in FIGS. 1 to 3 can be exemplified, but is not limited thereto. FIGS. 1 and 4 are schematic views showing the configuration of a gripping means in an embodiment of the silicon single crystal pulling apparatus according to the present invention in a use state, respectively. As described in detail below, the embodiment shown in FIG. In the embodiment shown in FIG. 4, the holding means has a configuration in which the straight body of the silicon single crystal ingot is held by a plurality of arms arranged around its outer periphery. In the embodiment shown in FIG. Immediately below the zneck part, the diameter is larger than this dash neck part,
In addition, a cylindrical portion (hereinafter, referred to as a mini straight body portion) having a diameter sufficiently smaller than a desired ingot diameter is provided, and the holding means uses the mini straight body with a structure similar to a so-called "collet chuck". It has a configuration for clamping.

Also, the arrangement of the contact portion of the gripping means in the radial cross section of the silicon single crystal ingot may be
It is sufficient that the ingot is gripped at least at two or more locations, and it is not necessary to make the ingot particularly wide as long as the contact area of each location can sufficiently withstand the weight of the ingot. However, in the present invention, a deformable pillow-like structure as described later is arranged at a contact portion of the gripping means with the silicon single crystal ingot, and the deformation causes the stability of holding the single crystal ingot. Therefore, it is desirable that the contact area of the contact portion with respect to the silicon single crystal be relatively large.

Further, it is desirable that the contact portion of the gripping means be configured so as to be easily detachable from the main body of the gripping means so that cleaning and replacement can be performed.

The structure which can be deformed by an external force, which is an abutting portion of the gripping means, is typically a pillow-like structure having a certain porosity and a certain filling material disposed in a predetermined volume. For example, it can be composed of a plurality of granules and a flexible sheet or foil-like surrounding body that covers the plurality of granules from the outside, a porous body, or a bulky fiber aggregate. . Even when a porous body or a fiber bulky aggregate is used, it is desirable to cover the outside with a flexible surrounding body.

As the granular material, for example, a spherical body is typical, but the shape is not particularly limited to a spherical body unless the shape is such that a chipped piece is easily generated due to contact between the granular bodies. Absent. Also, the size is not particularly limited, and can be appropriately selected according to the size of the irregularities generated on the surface of the silicon single crystal ingot to be manufactured. Those having a size of about 0.5 to 1.0 mm can be suitably used. The dimensional accuracy, sphericity and the like of the granular material represented by such a spherical body are not so required.

Also, by using two or more granular materials having different sizes in combination,
The filling rate can be improved, and a more stable gripping force can be expected.

It is desired that the material constituting such a granular material has sufficient heat resistance and strength. For example, ceramics such as SiC, Si ₃ N ₄ , Al ₂ O ₃ and ZrO ₂ , Heat-resistant metals such as Mo, Ti, Nb and W can be exemplified. Balls made of these materials are commercially available, for example, as balls for ball mills, balls for bearings, and the like, and these can be diverted.

Further, as a surrounding body for holding a plurality of such granular materials in a predetermined space, it is particularly preferable as long as it has sufficient flexibility, sufficient strength and heat resistance. Although not limited, for example, a highly ductile T
Examples thereof include a heat-resistant metal foil such as a, a heat-resistant metal fiber such as W, a net or a fabric woven with carbon fiber, or the like. In particular, a net or cloth made of a heat-resistant metal foil such as Ta or a heat-resistant metal fiber such as W is preferable because there is no risk of fluffing or dust generation. Further, as the thickness of the surrounding body, it is sufficient if it has sufficient flexibility while exhibiting sufficient strength,
Since it depends on the material, it cannot be unconditionally specified. For example, in the case of a metal foil, about 0.5 to 5.0 mm is appropriate.

Examples of the porous body that can be used for forming the pillow-like structure serving as an abutting portion of the gripping means include, for example, a metal sponge or the like as a sintered body. It is a "metal scourer" -shaped material in which a narrow band of fiber or metal foil is made bulky by processing such as shrinking or entanglement. For example, carbon fiber or heat-resistant metal foil such as Ta is used as a raw material. The one formed as is preferably exemplified.

When a porous body or a fibrous bulky aggregate is used as the pillow-like structure serving as the contact portion of the gripping means, the porous body or the fibrous bulky aggregate can be formed by a single use (gripping operation). Since a habit is easily formed and poor in restoring property, it may not be suitable for repeated use. Therefore, a configuration using a rigid granular material such as a spherical body is particularly desirable.

The material constituting the pillow-like structure serving as an abutting portion of such a gripping means needs to have a sufficient heat resistance as described above. It is desirable to have the above.

The porosity of such a pillow-like structure depends on the size of the irregularities formed on the surface of the silicon single crystal ingot to be gripped, and the granular material, porous material, and bulky fiber used. Although it depends on the type of packing such as the body, in an uncompressed state without applying external force,
It is desirable to be about 30 to 80%.

In the apparatus for pulling a silicon single crystal of the present invention, the material constituting the other part of the gripping means having the contact portion as described above is not particularly limited as long as it has sufficient heat resistance. It is not limited, and may be made of, for example, ceramics such as SiC, Si ₃ N ₄ , Al ₂ O ₃ and ZrO ₂ , heat-resistant metals such as Mo, Ti, Nb and W, carbon, silicon and the like.

Further, as a method of attaching the contact portion composed of the pillow-like structure to the main body of the gripping means,
There is no particular limitation, for example, such a pillow-like structure is locked with a screw or an adhesive, or a concave portion for fitting the pillow-like structure is formed on the main body side and is formed here. A method of fitting the pillow-like structure, a method of using these together, and the like can be adopted. However, by simply locking the pillow-like structure to the main body of the gripping means with a screw or the like, the pressing force applied when gripping the silicon single crystal ingot causes the pillow-like structure to move against the silicon single crystal ingot. Not only in the contact surface direction but also in the lateral direction (direction parallel to the ingot pulling direction), the pillow-like structure is unnecessarily deformed in the gripping state. If the pillow-like structure cannot support the load of the ingot if it cannot exhibit a certain degree of rigidity, it is preferable that the recess for fitting the pillow-like structure be provided on the main body side as described above. It is more desirable to form the pillow-like structure so as to restrict the deformation of the pillow-like structure in a direction other than the contact surface direction with the silicon single crystal ingot. In this case, when the concave portion for fitting the pillow-like structure in the main body portion is formed on the main body portion side, assuming that the depth of the concave portion is extremely deep, the wall surface of the main body portion is directly in the silicon single crystal ingot. Therefore, the depth should be set to an appropriate value according to the degree of deformation of the pillow-like structure which is influenced by, for example, the degree of filling of the granular material.

In the single crystal pulling apparatus of the present invention, the lifting means for raising and lowering the gripping means along the growth axis of the silicon single crystal to be grown may be used at least in the initial stage of silicon single crystal ingot growth (seed crystal melting). From the liquid immersion to the formation of a portion to be gripped by the gripping member on the silicon single crystal ingot))
The specific configuration is not particularly limited as long as it functions independently of the seed crystal raising / lowering mechanism, and a wire drive system including a hanging wire and its winding mechanism, a chain drive system, and a rack drive system. Any method such as a pinion drive method can be used.

Further, in the single crystal pulling apparatus according to the present invention, the structure other than the silicon single crystal ingot gripping means as described above, the pillow-like structure which is a contact portion of the gripping means, and the lifting / lowering means of the gripping means are as follows. At least in a chamber, a crucible for holding a silicon melt, a means for holding a seed crystal, and an elevating means for elevating and lowering the means for holding the seed crystal are arbitrary, and any conventionally known various types can be used. Can be adopted.

The single crystal pulling method of the present invention is carried out by using the single crystal pulling apparatus having the above-described structure. First, a multi-crystal is placed in a crucible disposed in the single crystal pulling apparatus according to a conventional method. A predetermined amount of crystalline silicon and a raw material such as a dopant to be added as needed are charged, and the raw material is melted by heating with a heater or the like to form a melt, and the melt is held by a seed crystal holding means. The seed crystal is immersed once, and then pulled up while rotating the seed crystal around an axis by an elevating means connected to the seed crystal holding means, to grow a single crystal at the lower end of the seed crystal. After reducing the diameter once to form a dashed neck part to eliminate dislocations, gradually increase the diameter to form a cone part, and after reaching the desired diameter, pull up speed to maintain the diameter, melt The straight body is formed by controlling the temperature and the like. In the cone portion, a mini straight body portion or the like is formed as necessary. In the steps so far, the holding means for the silicon single crystal ingot according to the present invention is held at a predetermined spatial position where it is not engaged with the ingot.

When the growth of the single crystal ingot progresses, a desired portion to be gripped is formed in the ingot, and when this portion rises to a desired position in the chamber, the gripping means is operated to contact the contact portion (pillow). (Like structure) is brought into contact with the ingot. The pillow-like structure is deformed in accordance with the unevenness (growth stripes) on the surface of the ingot due to the pressing force applied by the gripping means, and the gripping means abutment portion is evenly adhered to the surface of the ingot.

In this way, when the pillow-shaped structure, which is the contact portion of the gripping means, is deformed so as to uniformly grip the ingot surface, the single crystal is pulled up by the seed crystal elevating means. Switching to single crystal pulling by the lifting means connected to the gripping means is performed, and thereafter, single crystal growth is continued until the ingot has a desired length.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below more specifically based on embodiments.

FIG. 1 schematically shows a main part configuration of an embodiment of a silicon single crystal pulling apparatus according to the present invention in a used state.

In this embodiment, similarly to the conventional silicon single crystal pulling apparatus, a crucible 1 composed of a quartz crucible 1a and a graphite crucible 1b surrounding the quartz crucible 1a is provided at the center of the chamber by a rotating support shaft (not shown). is set up. On the other hand, on the upper part of the chamber, a crystal holding mechanism support plate 3 that is rotated around the chamber axis by a rotation motor 5 is provided, and a seed crystal pulling wire attached to a seed crystal pulling motor 4 installed on the support plate 5 is provided. 2 extends into the chamber along the axis of the chamber. A seed crystal holding unit (seed chuck) 6 is provided at the tip of the wire 2, and the seed crystal 7 attached thereto is driven by the seed crystal pulling motor 4 (and the rotation motor 5). Then, the single crystal ingot 9 is immersed in the silicon melt 8 formed in the crucible 1 and then pulled up while rotating.
Can be raised.

Thus, in this embodiment, the single crystal ingot gripping mechanism 10 disposed in the chamber has a through hole 11 at the center thereof through which the seed crystal holding portion 6 or the seed crystal pulling wire 7 can be inserted. A supporting rod 12 extending radially in the radial direction of the chamber, and a crystal holding arm 14 rotatably mounted at a fulcrum 13 at the tip thereof and extending substantially in the axial direction of the chamber. Note that four crystal holding arms exist at equal intervals (for example, every 90 °) around the axis of the chamber. At the lower end of the single crystal holding arm 14, a fulcrum 1
5 is provided with a single crystal contact portion attaching portion 16 which is rotatably and detachably attached and extends toward the center in the radial direction of the chamber. A pillow-like structure 17 is provided in a recess formed toward the center axis side of the chamber 16. On the other hand, a short horizontal abutment 18 extending toward the center of the chamber is provided at the upper end of the crystal holding arm 14, and the abutment 18 is fixed on the support rod 12. A tip end of a position adjusting screw 21 screwed to a screw mounting portion 20 provided on the support frame 19 is in contact with the supporting frame 19. The position adjusting screw 21 is rotated by a screw rotating mechanism (not shown), and the screw tip position abutting on the horizontal abutting portion 18 is displaced in the chamber radial direction.
3 and as a result, the pillow-like structure (single crystal contact portion) 17 provided at the lower end of the arm 14 is disengaged from the outer peripheral surface of the single crystal ingot 9 to be grown. It can be displaced between. The horizontal abutting portion 18 is bendable by a fulcrum 22 provided in the middle thereof, and the rotation of the arm 14 as described above causes the abutting position with the position adjusting screw 14 to shift. Is preventing that.

Then, this single crystal ingot holding mechanism 1
Reference numeral 0 denotes a plurality of single crystal gripping mechanism pulling wires 24a, 24b attached to the drive shaft of a single crystal gripping mechanism pulling motor 23 installed on the same support plate 3 as the one on which the seed crystal pulling motor 4 is mounted. , And can be moved up and down in the chamber independently of the seed crystal holding unit 6, and rotate around the axis in synchronization with the seed crystal holding unit.

FIG. 2A shows a single crystal ingot gripping mechanism 1 of the silicon single crystal pulling apparatus of the embodiment shown in FIG.
FIG. 3 is a cross-sectional view showing a contact portion structure of No. 0 in use.
(B) is the same longitudinal sectional view. As shown in FIGS. 2A and 2B, the pillow-like structure 17 includes a plurality of spherical bodies 17.
a and a surrounding body 17b made of metal foil that covers the plurality of spherical bodies 17a from the outside on the opening side of the concave portion provided in the single crystal contact part attaching portion 16. The surrounding body 17a is locked by a screw at a side surface of a concave portion provided in the single crystal contact portion attaching portion 16. In this embodiment, the surrounding body 17b is
Although present on the surface excluding the bottom surface of the concave portion provided in the single crystal contact portion attaching portion 16, it exists at least on the contact surface with the single crystal ingot 9, and the plurality of spherical bodies 17 a are positioned at predetermined positions. Any length can be used as long as it can be held. For example, the length of the side surface of the concave portion provided in the single crystal contact portion mounting portion 16 can be set to the minimum length necessary for mounting the concave portion. It is, of course, possible to form a complete bag covering the entire body 17a. In the present embodiment, the pillow-like structure 17 substantially prevents deformation in a direction other than the contact surface with the single crystal ingot 9 due to the wall surface of the concave portion provided in the single crystal contact portion attaching portion 16. The surface of the pillow-like structure 17 facing the ingot, which is the surface in contact with the ingot, which is in a regulated state, is closer to the end face of the single crystal contact portion attachment portion (gripping mechanism main body). 2 also protrudes toward the central axis, and FIG.
As shown in (a) and (b), even when the ingot is gripped, the single crystal contact portion mounting portion (grip mechanism main body) does not come into contact with the ingot.

As described above, the position adjusting screw 21 is rotated by a screw rotating mechanism (not shown), and the crystal holding arm 14 rotates about the fulcrum 13, and a pillow-like structure provided at the lower end of the arm 14. When the (single crystal contact portion) 17 comes into contact with the outer peripheral surface of the single crystal ingot 9 to be grown and is further pressed, as shown in FIGS. 2A and 2B, the ingot of the pillow-like structure 17 is formed. Is deformed so that the contact surface of the ingot 9 comes into close contact with the surface of the ingot 9 having irregularities.

FIG. 3 is a vertical sectional view showing a contact portion structure of a single crystal ingot gripping mechanism in another embodiment of the silicon single crystal pulling apparatus according to the present invention in a used state.

In this embodiment, the pillow-like structure 17 serving as the contact portion of the single crystal ingot gripping mechanism is composed of a fiber bulky aggregate 17c made of carbon fiber, and this fiber bulky aggregate 17c is connected to the single crystal abutment. 1 and 2, except that it comprises a surrounding body 17 b made of metal foil that covers the outside from the opening side of the concave portion provided in the mounting portion 16. In the apparatus of this embodiment, the pillow-like structure (single-crystal contact portion) 17 contacts the outer peripheral surface of the single-crystal ingot 9 to be grown, and is further pressed as shown in FIG. As shown in (1), the contact surface of the pillow-like structure 17 with the ingot is deformed so as to be in close contact with the surface of the ingot 9 having irregularities.

FIGS. 4 (a) and 4 (b) schematically show a main part configuration of another embodiment of the silicon single crystal pulling apparatus according to the present invention in use.

In this embodiment, the single crystal ingot gripping mechanism 40 is arranged around the axis of the chamber, and has a plurality of cuts on its peripheral surface along the axial direction at its lower end. And a cylindrical caulking tool 32 slidably fitted to the surface. The upper end of the collet 41 is extended to the outside of the chamber by a collet connecting cylinder 43 fixed to the outer peripheral surface of the collet. On the other hand, the cylindrical caulking tool 42 is similarly extended outside the chamber by a caulking tool connecting cylinder 44. Has been extended to The collet connecting cylinder 43 is coaxially arranged inside the caulking tool connecting cylinder 44, and both are displaced by an extendable cylinder mechanism 45 having a connection end on each outer peripheral surface. When the cylinder mechanism 45 is extended and contracted by a drive source (not shown), the relative position between the collet 41 and the caulking tool 42 connected to the lower end of the connecting cylinder is changed. The diameter of the part is scaled.

At the upper end of the collet connecting cylinder 43, three crystal holding portion pulling wires 46 (46a, 46b, 46c) are connected and suspended at equal intervals (every 120 °). Is attached to the drive shaft of a single crystal gripping mechanism pulling motor 47, and the single crystal ingot gripping mechanism 40 is independent of the seed crystal holding unit 36 connected to the seed crystal pulling motor 34 by the seed crystal pulling wire 32. By driving a rotation transmission mechanism 38 and a rotation motor 39 connected to the caulking tool connection cylinder 34, the rotation can be performed in the chamber in synchronization with the seed crystal holding unit. ing. In the drawing, reference numeral 50 indicates a seal portion between the chamber and the caulking tool connecting cylinder 34.

Also in this embodiment, the inner peripheral surface of the lower end of the collet 31, that is, the contact surface with the silicon single crystal ingot 39, is the same as that shown in FIGS. 2 (a) and 2 (b). The pillow-like structure 51 is disposed over the entire circumference, and when the mini-rect body portion 39a provided below the dashes neck portion of the single crystal ingot 379 is clamped by the collet 41, the pillow-like structure is formed on the clamping surface. The desired close gripping as described above due to the deformation of the structure 51 is performed.

[0053]

As described above, according to the present invention, when the silicon single crystal ingot to be grown is gripped by the mechanical gripping mechanism during the pulling operation of the silicon single crystal ingot, the silicon single crystal ingot of the gripping mechanism can be used. The contact part of the ingot has a structure that can be deformed by external force, and the contact surface deforms following the irregularities on the surface of the ingot. Without inconvenience such as the occurrence of concentrated stress, the applied pressing force can be evenly distributed throughout the abutting part and the ingot can be gripped, so that stability and reliability in gripping are improved. is there.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a main part configuration of an embodiment of a single crystal pulling apparatus according to the present invention in a use state;

2 (a) is a cross-sectional view schematically showing a further essential part of the embodiment of FIG. 1 in a use state, FIG. 2 (b) is a longitudinal sectional view of the same,

FIG. 3 is a longitudinal sectional view schematically showing a main part configuration of another embodiment of the single crystal pulling apparatus according to the present invention in a use state,

FIG. 4 (a) is a schematic view schematically showing a main part configuration of still another embodiment of the single crystal pulling apparatus according to the present invention in a use state, and FIG. 4 (b) is a cross-sectional view taken along line AA in FIG. FIG.

[Explanation of symbols]

 1a Quartz crucible 1b Graphite crucible 1 Crucible 2 Seed crystal pulling wire 3 Crystal holding mechanism support plate 4 Seed crystal pulling motor 5 Motor for rotating support plate 6 Seed crystal holding unit 7 Seed crystal 8 Silicon melt 9 Single crystal ingot 10 Single Crystal ingot gripping mechanism 11 Through hole 12 Support rod 13 Support point 14 Crystal holding arm 15 Support point 16 Single crystal contact part attaching part 17 Pillow-like structure 17a Spherical body, 17b Surrounding body, 17c Fiber bulky assembly 18 Horizontal abutting part DESCRIPTION OF SYMBOLS 19 Support frame 20 Screw attachment part 21 Position adjustment screw 22 Support 23 Single crystal gripping mechanism pulling motor 24 Single crystal gripping mechanism pulling wire 34 Seed crystal pulling motor 36 Seed crystal holding part 37 Seed crystal 39 Single crystal ingot 39a Mini straight body part 40 Single crystal ingot gripping mechanism 41 Tsu DOO 42 cylindrical caulking member 43 collet connecting cylinder 44 crimping tool coupling cylinder 45 cylinder mechanism 46 crystal holder pulling wire 47 single crystal gripping mechanism pulling motor 48 rotation transmission mechanism 49 rotates the motor 50 seal portion 51 pillow-like structure

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Morita 46-59 Nakahara, Toba-ku, Kitakyushu-shi, Fukuoka Prefecture Nippon Steel Plant Design Co., Ltd.

Claims (4)

[Claims] 1. A seed crystal is immersed in a silicon melt, and the seed crystal is pulled up to grow a silicon single crystal ingot at a rear end portion of the seed crystal. Thereafter, the grown silicon single crystal ingot is mechanically gripped. A method of pulling a silicon single crystal, wherein the contact portion of the means for performing mechanical gripping with the ingot is deformed by a pressing force applied at the time of mechanical gripping, and is brought into close contact with the surface of the silicon single crystal ingot. A method for pulling a silicon single crystal, characterized in that the silicon single crystal is pulled and held. 2. An apparatus for pulling a silicon single crystal, comprising: gripping means for mechanically gripping a silicon single crystal ingot to be grown; and elevating means for raising and lowering the gripping means along a growth axis of the silicon single crystal to be grown. And
A silicon single crystal pulling apparatus, wherein a contact portion of the gripping means with the silicon single crystal ingot has a structure deformable by an external force. 3. The pulling-up of a silicon single crystal according to claim 2, wherein the contact portion is constituted by a plurality of granular bodies and a flexible surrounding body covering the plurality of granular bodies from outside. apparatus. 4. The silicon single crystal pulling apparatus according to claim 2, wherein the contact portion is formed of a porous body or a bulky aggregate of fibers.