JPH10273388A - Apparatus for pulling single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a single crystal during pulling from dropping when holding the single crystal during the pulling with a holding tool. SOLUTION: This apparatus for pulling a single crystal comprises the first two or more holding arms 12 for holding a constricted part 6 under an enlarged diameter part 5 for supporting and the second two or more holding arms 13 for holding a body part 7, connected through connecting arms 14 thereto and arranged around a wire 1. When the enlarged diameter part 5 and the body part 7 are lifted to the tip positions of the arms 12 and 13 during the pulling, the arms 12 and 13 are driven so as to close the tips thereof and the constricted part 6 and the body part 7 are respectively held therewith. A power is fed from an uninterruptible power source device (UPS) 15 to driving motors.

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 hermetic chamber is decompressed to about 10 torr to flow fresh Ar (argon) gas, 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 to raise the seed crystal, thereby forming 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.

[0003] In addition, as a growth method, in order to remove dislocations generated in the seed crystal by thermal shock when the seed crystal is immersed in the surface of the melt (to eliminate dislocations), the seed crystal is placed on the surface of the melt. After immersion, a dash (Dash) method is known in which the upper cone is started to be pulled after a neck portion having a diameter smaller than that of the seed crystal, for example, 3 to 4 mm, is formed by making the pulling speed relatively high. I have.

Further, through the small diameter neck portion,
Since a single crystal having a large diameter and a large weight (150 to 200 kg or more) cannot be pulled, for example, Japanese Patent Publication No. 5-654.
As shown in Japanese Patent No. 77, after forming a small diameter neck portion by the Dash method, the pulling speed is relatively slow to form a large diameter, and then the pulling speed is relatively high to form a small diameter. A method has been proposed in which a "neck" is formed, and a large crystal having a large diameter and a large weight is pulled by gripping a neck below the large diameter portion with a gripping tool. Further, as a conventional device for gripping the constriction, for example, there are devices disclosed in Japanese Patent Publication No. 7-103000 and Japanese Patent Publication No. 7-515, in addition to the above publications.

[0005] Further, as another conventional example, as described in, for example, JP-A-5-270974 and JP-A-7-172981, a method of holding the body portion without forming the above-mentioned "constriction", JP-A-63-252
No. 991, JP-A-5-270975, an "annular portion" having a larger diameter than the body portion is formed between the upper cone portion and the body portion instead of the "constriction". A method has been proposed for gripping under a "section".

[0006]

However, a gripper for gripping the above-mentioned "constriction" during pulling of a single crystal,
Since it is used repeatedly, there is a problem that the single crystal falls when it is broken by fatigue. Also, gripping tools are usually
Since it is driven by a motor, the gripping force is reduced during a power failure and the single crystal falls, and the method of gripping the “constriction” has a problem that if the “constriction” breaks, the single crystal falls. In addition, when the single crystal falls, dislocations are generated and the single crystal does not become a product, and in the worst case, the quartz crucible is damaged and cooling water inside the crucible shaft for rotating and moving the quartz crucible up and down In such a case, the high-temperature melt reacts to cause a steam explosion.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a single crystal pulling apparatus capable of preventing a single crystal being pulled from falling when the single crystal being pulled is gripped by a gripping tool. With the goal.

[0008]

According to the present invention, in order to achieve the above object, a single crystal is gripped by using two types of gripping tools which are gripped at different positions of the single crystal. That is, according to the present invention, a seed crystal pulling means for pulling up while rotating a seed crystal holder supporting a seed crystal, and a first grip of a single crystal formed under the seed crystal by the pulling by the seed crystal pulling means A single crystal having first gripping means for gripping a position and second gripping means for gripping a second gripping position of a single crystal formed below the seed crystal by pulling by the seed crystal pulling means; A lifting device is provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of a single crystal pulling apparatus according to the present invention and a pulling step thereof.

In FIG. 1, a seed crystal holder 2 is attached to the tip of a wire 1 (which may be a shaft), and a seed crystal 3 is attached to the seed crystal holder 2. The wire 1 is configured to be wound up by a wire winding drum and a wire winding motor (not shown), and the wire winding drum and the wire winding motor are rotatable by a drum rotation motor (not shown). Have been. Then, after immersing the seed crystal 3 in the Si melt 11 in the quartz crucible 10, the seed crystal 3 is pulled up.
Below, a neck portion 4, an enlarged diameter portion 5 for support, a constricted portion 6,
A crystal main body (body) 7 is formed.

Around the wire 1, two or more first gripping arms 12 for gripping the constricted portion 6 below the enlarged diameter portion 5 and two or more second gripping arms 12 for gripping the body portion 7.
Are connected to each other via a connecting arm 14. The gripping arms 12 and 13 can be opened and closed by an arm opening / closing motor (not shown) for gripping the constricted portion 6 and the body portion 7, and not shown for raising the constricted portion 6 and the body portion 7 in a gripped state. And a rotatable motor together with the wire 1 by a drum rotation motor. These motors are all configured so that power can be supplied from an emergency uninterruptible power supply (UPS) 15. The emergency uninterruptible power supply 15 is a device capable of continuously supplying power even during a power failure, and prevents sudden rotation stop of the seed crystal holder 2 and disappearance of the gripping force of the gripping arms 12 and 13. Is what you do.

In such a configuration, when manufacturing the single crystal body 7, the pressure inside the chamber (not shown) is reduced to about 10 torr and fresh Ar (argon) gas is flown.
The polycrystal in the quartz crucible 10 provided below in the chamber is heated and melted, and the wire 1 is pulled down as shown in FIG.
i. Dipped into the surface of the melt 11 and allowed to blend in. At this time, the arms 12 and 13 stand by at a position where the tips do not contact the Si melt 11, and the tips of the arms 12 and 13
It is opened so as not to contact the enlarged diameter portion 5 and the body portion 7 during the pulling. Next, after a lapse of a predetermined time, FIG.
The wire 1 is pulled up in the direction of arrow M1 to pull up the seed crystal 3.

Next, as shown in FIG.
Is pulled up in the direction of arrow M2 at a relatively high speed to form a small-diameter neck portion 4 having a diameter of 3 to 4 mm under the seed crystal 3, and then, at a relatively low pulling speed, to form a neck portion 4 under the neck portion 4. After forming the enlarged diameter portion 5, the pulling speed is relatively increased to form a constricted portion 6 below the enlarged diameter portion 5,
Next, the formation of the body 7 is started.

During the pulling up, as shown in FIG.
When the diameter-enlarging portion 5 and the body portion 7 rise to the tip positions of the arms 12 and 13, the arms 12, 13 as shown in FIG.
13 moves in the directions indicated by arrows M3, M4, M5, and M6, that is, in a radially inward direction with respect to the axis of the single crystal, and is driven to close to grip the constricted portion 6 and the body portion 7, respectively. I do. When the gripping is completed, the wire 1 and the arms 12 and 13 are lifted up as shown by the arrow M7 while rotating integrally. Opening and closing of the arms 12 and 13
After the tip of the arm 12 is closed, the tip of the arm 13 may be closed. That is, the arms 12 and 13 do not always need to be closed at the same time.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, the body portion 7 is formed below the neck portion 4 without forming the enlarged diameter portion 5 for supporting a single crystal and the constricted portion 6 as in the first embodiment, and the first and second portions are formed. The two gripping arms 12 and 13 are configured to grip the body 7 together. Also, the arms 12, 1
3 is connected via a rotating shaft 16.

In such a configuration, when a single crystal body is manufactured, the wire 1 is pulled down and the seed crystal 3 is immersed in the surface of the Si melt 11 in the quartz crucible 10 as shown in FIG. Let it blend in. At this time, arm 1
Reference numerals 2 and 13 stand by at positions where the tips do not contact the Si melt 11, and the tips of the arms 12 and 13 are open so as not to contact the body part 7 being pulled up. Next, after a lapse of a predetermined time, the wire 1 is pulled up in the direction shown by the arrow M1 from the state of FIG.
As shown in FIG. 2B, the seed crystal 3 is pulled up at a relatively high speed in the direction of the arrow M2 to form a small-diameter neck portion 4 having a diameter of 3 to 4 mm below the seed crystal 3 and then pulled up. The speed is gradually reduced to form a cone below the neck 4. Next, by making the pulling speed constant, formation of the body portion 7 under the cone portion is started.

During this pulling up, as shown in FIG.
When the body part 7 moves up to the tip positions of the arms 12 and 13, the tips of the arms 12 and 13 move in the directions indicated by arrows M3, M4, M5 and M6, ie, in the axis of the single crystal, as shown in FIG. On the other hand, it moves in a radially inward direction and is driven to close to grip the body part 7 together. When the gripping is completed, the wire 1 and the arms 12 and 13 are lifted up as shown by the arrow M7 while rotating together. Arms 12, 1
3 is opened and closed after the tip of the arm 12 is closed.
3 may be closed. That is, the arms 12 and 13 do not always need to be closed at the same time.

[0018]

As described above, according to the present invention, since the gripping tool has a safe double structure and is configured to grip different positions of the single crystal, the gripping tool and the single crystal being pulled are damaged. Can prevent the single crystal from falling,
In addition, by supplying power from the uninterruptible power supply to the driving device of the gripper, it is possible to prevent the single crystal from dropping during a power failure. Further, by configuring the seed crystal pulling means so as to be able to supply power from the uninterruptible power supply, it is possible to prevent the rotation of the single crystal from suddenly stopping and the seed crystal from breaking at the time of power failure.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a single crystal pulling apparatus according to the present invention and a pulling step thereof.

FIG. 2 is an explanatory view showing a single crystal pulling apparatus according to a second embodiment and a pulling step thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire 2 seed crystal holder 3 seed crystal 5 Enlarged diameter part for support 6 Constriction part 7 Single crystal main body (body part) 10 Quartz crucible 11 Si melt 12, 13 Gripping arm 15 Uninterruptible power supply (UPS)

Claims (7)

[Claims] 1. A seed crystal pulling means for pulling up while rotating a seed crystal holder supporting a seed crystal; and a first gripping position of a single crystal formed below the seed crystal by the pulling by the seed crystal pulling means. First to grip
Holding means for holding a second holding position of a single crystal formed under the seed crystal by pulling by the seed crystal pulling means.
A single crystal pulling apparatus comprising: 2. The method according to claim 1, wherein the first gripping means grips a constricted part below a diameter-enlarging part formed below the seed crystal, and the second gripping means is formed below the constricted part. The single crystal pulling apparatus according to claim 1, wherein the single crystal pulling apparatus is configured to grip a body portion. 3. The single crystal pulling apparatus according to claim 1, wherein both the first and second gripping means are configured to grip a body formed below the seed crystal. 4. The apparatus according to claim 1, wherein one of said first and second holding means is attached to said seed crystal holder.
4. The single crystal pulling apparatus according to any one of items 1 to 3. 5. The method according to claim 1, wherein said second gripping means is attached to said first gripping means, or said first gripping means is attached to said second gripping means. The single crystal pulling apparatus according to any one of the above. 6. The apparatus according to claim 1, wherein at least one of said first and second gripping means is drivable by power supply from an uninterruptible power supply. Single crystal pulling equipment. 7. The single crystal pulling apparatus according to claim 1, wherein the seed crystal pulling means is drivable by power supply from an uninterruptible power supply.