JPH11255595A - Single crystal pulling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the single crystal to be stably pulled up, prevent the device from being increased its height and facilitate the maintenance of the device. SOLUTION: The pedestal 14 for lifting and lowering the single crystal is arranged in the crystal-receiving chamber 11 and the pedestal is equipped with a motor for rotating the crystal on the upper part at the center of the pedestal 14. The crystal-pulling shaft 17 is connected to the rotation shaft 15 of the crystal-rotating motor 15. Both right and left edges of the crystal-lifting and lowering pedestal are formed so that they may extend through outward from the crystal-rotating pedestal and are screwed with a couple of the crystal-lifting and lowering spindles 19L and 19R. The crystal-rotating motor 15 is rotated to rotate the crystal-pulling shaft 17 and the seed crystal 18. Simultaneously, the crystal-lifting and lowering motor 20 is rotated to lift the crystal-lifting and lowering pedestal 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pulling CZ (Czoc).
The present invention relates to a single crystal pulling apparatus for producing a dislocation-free single crystal of Si (silicon) by the hralski method.

[0002]

2. Description of the Related Art In general, in a single crystal manufacturing apparatus by the pulling CZ method, a high pressure-resistant airtight chamber is decompressed to about 10 torr and fresh Ar (argon) gas is flown, and a quartz crucible provided below the chamber is provided. The polycrystal in is melted by heating, and the seed crystal is immersed in the surface of this melt from above,
The seed crystal and the quartz crucible are rotated and moved up and down, and the seed crystal is pulled up to form a conical upper cone with the upper end protruding below the seed crystal, and a conical lower part with a cylindrical body and lower end protruding. It is configured to grow a single crystal (so-called ingot) composed of a cone portion.

Conventionally, in such an apparatus, as a member for pulling up the inside of the crystal accommodating chamber while rotating the single crystal in accordance with the growth of the single crystal, a wire method of winding up a wire longer than the single crystal and pulling it up, There is known a shaft method in which a rigid shaft is lifted while being moved upward. That is, both such wires and shafts require at least the length of the single crystal.

[0004]

However, in the wire method, since a mechanism for winding the wire and a mechanism for rotating the winding mechanism are arranged at the upper part of the crystal storage chamber, the height of the apparatus can be reduced. On the other hand, since the wire needs at least the length of the single crystal, there is a problem that elongation, blurring, and swaying of the wire are unfavorable for the growth of the crystal, and the stability is poor.

On the other hand, the shaft method does not have the above-mentioned problem, but similarly requires the shaft to be at least as long as the length of the single crystal. Since the device protrudes above the storage chamber, the height of the device is increased, the height of the building in which the device is installed is increased, and the maintenance cost of the clean room is also increased.

Japanese Patent Application Laid-Open Nos. 7-172981 and 9-2893 propose a method of adding a mechanism for holding a constriction of a single crystal or a body in addition to a wire and a shaft. However, since this gripping mechanism rises together with the single crystal, the height of the apparatus becomes high similarly to the shaft type. Also, JP-A-9-2893 and the like,
A method of arranging a telescopic bellows as a crystal storage chamber in a shaft type apparatus has been proposed,
A large-diameter bellows is not only expensive but also a safety problem because the bellows is heated to about 200 ° C. during the growth of the crystal, and a hole is easily formed in the bellows itself. Further, although maintenance is required to prevent dust from adhering inside the crystal storage chamber, it is difficult to clean the inside of the bellows due to its structure.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention provides a single crystal pulling apparatus capable of stably pulling a single crystal, preventing an increase in the height of the apparatus, and facilitating maintenance. The purpose is to provide.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a single crystal so that a shaft or a wire for pulling the single crystal in a crystal storage chamber does not need to be as long as the length of the single crystal. A motor for rotating a crystal is vertically movable in a crystal storage chamber. That is, according to the present invention, in a single crystal pulling apparatus that pulls a single crystal into a crystal storage chamber while rotating the single crystal in accordance with the growth of the single crystal, the single crystal pulling apparatus is supported so as to be able to move up and down in the crystal storage chamber, and drives the single crystal to rotate. A single crystal rotation drive unit, a single crystal pulling member having a seed crystal attachable to a tip thereof and the other end connected to the single crystal rotation drive unit, and the single crystal pulling by pulling up the single crystal rotation drive unit. A single crystal pulling apparatus characterized by comprising a single crystal pulling means for pulling up a member and thereby growing the single crystal while pulling the single crystal.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of a single crystal pulling apparatus according to the present invention, and FIG.
FIG. 3 is a left side view showing the crystal storage chamber of FIG. 1 along a horizontal sectional view along A ′.

1 to 3, a crystal storage chamber 1 is shown.
1 is formed in a substantially semi-cylindrical shape, and a front face thereof is provided with a door 11a which can be opened and closed to take out the Si single crystal 10 therein. The crystal storage chamber 11 is disposed above the lower chamber 12, and a quartz crucible for storing a single crystal raw material is disposed in the lower chamber 12, although not shown. The quartz crucible is supported by the carbon crucible so as to be rotatable around an axis and to be movable up and down, and a heater, a heat insulating material and the like are arranged around the carbon crucible. A gate house 13 is formed above the lower chamber 12, and the gate house 1 is formed.
A gate valve (not shown) for opening and closing the upper opening of the lower chamber 12 is disposed in the inside 3. Single crystal 10
During pulling up, argon gas is introduced from the argon gas inlet 11b of the crystal storage chamber 11 and the lower chamber 1
2 to the outside.

A crystal elevating pedestal 14 is arranged in the crystal housing chamber 11, and a crystal rotating motor 15 is mounted on the upper portion of the center of the crystal elevating pedestal 14. The crystal rotation motor 15 is stored in a motor housing 16. The rotating shaft of the crystal rotating motor 15 has a crystal pulling shaft 17.
Are connected so as to face downward from the crystal lifting pedestal 14, and a seed crystal 18 is attached to the tip of a crystal pulling shaft 17.

Both ends 14L, 14R of the crystal lifting pedestal 14
Is formed so as to penetrate outside the crystal storage chamber 11 through a pair of slits (not shown) formed in the crystal storage chamber 11 in a vertical direction as shown in FIG. Pair of crystal elevating spindles 19 fixed to extend vertically outside the
L, 19R. Crystal lifting spindle 19
A crystal elevating motor 20 is arranged at the upper end of L, 19R,
When the crystal elevating motor 20 rotates, the crystal elevating spindle 1
9L and 19R rotate, and the crystal elevating pedestal 14 moves up and down.

The slit of the crystal storage chamber 11 through which both ends 14L and 14R of the crystal elevating pedestal 14 pass is sealed (sealed) by a retractable shutter 21 and a shutter rail 22 as sealing means as shown in FIG. I have.
That is, an elastic seal (not shown) is mounted in the shutter rail 22 so that the inside of the crystal storage chamber 11 is kept airtight, and the elastic seal is in close contact with the side wall of the crystal storage chamber 11 to seal the slit. Stopped. The space between the shutter 21 and the shutter rail 22 is sealed, and both ends 14 L, 14
R penetrates the shutter 21 and both ends 14L, 1L
The space between the shutter 4R and the shutter 21 is sealed. When the crystal elevating pedestal 14 moves, for example, in the upward direction, the shutter 21 moves along the shutter rail 22 so that a portion above the crystal elevating pedestal 14 contracts, and a lower portion extends. Also,
The shutter 21 cools the crystal rotation motor 15 in the crystal storage chamber 11 and the like.
Water inlet and outlet 24 for supplying power to
Are formed. Note that, instead of the shutter that can be extended and retracted, a shutter member that can be wound up and used by continuously combining a large number of shutter pieces can be used as a sealing unit.

In such a configuration, when the single crystal 10 is pulled, the polycrystal in the quartz crucible provided below in the lower chamber 12 is heated and melted, and then the seed crystal is placed on the surface of the melt. The crystal elevating motor 20 is rotated so that 18 is immersed from above, and the crystal elevating pedestal 14 is lowered. Next, the crystal rotating motor 15 is rotated to rotate the crystal pulling shaft 17 and the seed crystal 18, and the crystal lifting motor 20 is rotated to raise the crystal lifting pedestal 14.

Here, the length of the crystal pulling shaft 17 does not need to be the same as the length of the single crystal as in the conventional shaft type. When the crystal lifting pedestal 14 is at the lowest position, the seed crystal 18 at the tip is The length may be such that it comes into contact with the melt in the quartz crucible. Further, the shaft 17 does not protrude from the upper part of the chamber 11 even when the pulling of the single crystal 10 is completed. The single crystal 10
In order to stably raise without swinging,
Although a shaft 17 that is more rigid than a wire is desirable, a wire may be used when the single crystal 10 is relatively lightweight.
Further, since this wire is not wound as in the conventional wire type, it does not require the length of the single crystal 10.

Next, a second embodiment will be described with reference to FIGS. In the second embodiment, the crystal elevating pedestal 14 does not penetrate the side wall of the crystal storage chamber 11 and is screwed with the crystal elevating spindles 19L and 19R arranged in the crystal storage chamber 11. Therefore, a mechanism for sealing the slit of the crystal storage chamber 11 is not provided unlike the first embodiment. However, the crystal raising / lowering spindles 19L and 19R are each provided with a bellows type spindle cover 23 to prevent the single crystal 10 from being contaminated.
L, 23R. Other configurations are the same as those of the first embodiment.

Here, the bellows type spindle cover 2
The 3L and 23R surround only the crystal elevating and lowering spindles 19L and 19R and do not surround the single crystal 10, so that they can be formed with a relatively small diameter. In addition, cleaning of the inside of the bellows is not so important and maintenance is easy. .

[0018]

As described above, according to the present invention, the single crystal is rotated so that the length of the shaft or wire for pulling up the single crystal in the crystal accommodating chamber does not require the length of the single crystal. Since the motor can be moved vertically in the crystal storage chamber, the single crystal can be stably pulled up, and the height of the apparatus can be prevented from being increased. Further, even if a mechanism for driving the motor for rotating the single crystal in the vertical direction is arranged in the crystal storage chamber, the maintenance can be simplified.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a single crystal pulling apparatus according to the present invention.

FIG. 2 is a horizontal sectional view taken along line A-A 'of FIG.

FIG. 3 is a left side view showing the crystal storage chamber of FIG. 1;

FIG. 4 is a side view showing a single crystal pulling apparatus according to a second embodiment.

FIG. 5 is a horizontal sectional view taken along line B-B ′ of FIG. 4;

[Explanation of symbols]

 Reference Signs List 11 crystal storage chamber 14 crystal lifting pedestal 15 crystal rotation motor (single crystal rotation drive unit) 16 motor housing 17 crystal pulling shaft (single crystal pulling member) 18 seed crystal 19L, 19R crystal lifting spindle 20 crystal lifting motor 21 shutter

Claims (8)

[Claims] 1. A single crystal pulling apparatus for pulling a single crystal into a crystal storage chamber while rotating the single crystal in accordance with the growth of the single crystal, wherein the single crystal is rotatably supported in the crystal storage chamber and drives the single crystal to rotate. A crystal rotation drive unit, a single crystal pulling member to which a seed crystal can be attached at the tip and the other end connected to the single crystal rotation drive unit, and a single crystal pulling member by pulling up the single crystal rotation drive unit. A single crystal pulling means for pulling the single crystal and thereby growing the single crystal while pulling the single crystal. 2. The single crystal pulling member is a rigid rod-shaped material to which a seed crystal can be attached at a tip and the other end is connected to the single crystal rotation drive unit.
The single crystal pulling apparatus as described in the above. 3. The single crystal rotation drive unit is mounted on a pedestal that can move up and down in the chamber, and the pedestal is linked to the single crystal pulling means outside the chamber to control the up and down movement. 3. The method according to claim 1, wherein
The single crystal pulling apparatus as described in the above. 4. The single crystal vertical drive means includes a spindle disposed outside the crystal storage chamber and a single crystal lifting motor for rotating the spindle, and supports the single crystal rotation motor in the crystal storage chamber. The single crystal pulling apparatus according to claim 1 or 2, wherein a part of the pedestal is vertically movable by screwing with the spindle through a side wall of the crystal storage chamber. 5. The single crystal, wherein the single crystal vertical driving means includes a spindle disposed inside the crystal storage chamber, and a single crystal lifting / lowering motor disposed outside the crystal storage chamber to rotate the spindle. The single crystal pulling apparatus according to claim 1 or 2, wherein a pedestal supporting a rotary motor is vertically movable by screwing with the spindle in the crystal storage chamber. 6. A side surface of the chamber is provided with a vertical slit, and penetrates the slit so that the pedestal or a member connected thereto can be moved up and down along the slit. A means for sealing an opening of the slit other than the pedestal passing through the slit or a member connected to the pedestal so as to be kept airtight, is provided. 4. The single crystal pulling apparatus according to any one of the above. 7. The single crystal pulling apparatus according to claim 6, wherein said means for sealing is a member that can expand and contract. 8. The single crystal pulling apparatus according to claim 6, wherein said sealing means is a shutter member which can be rolled up by continuously combining a large number of shutter pieces.