JP2000281485A - Apparatus for pulling single crystal and pulling of single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for speed control when moving the load of a single crystal from a neck part to a holding means and prevent the height of an apparatus for pulling from increasing when a seed crystal and a constricted part under a large-diameter part together by a wire method. SOLUTION: This apparatus for pulling a single crystal 2 is capable of rotating a main drum 8 by a main motor 9 in order to lift and lower a main wire 7 having a seed crystal 14 attached to the tip thereof, arranging auxiliary drums 27a and 27b coaxially with the main drum 8 and integrally rotating the auxiliary drums 27a and 27b with the main drum 8 by the main motor 9 or selectively rotating the auxiliary drum 27a and 27b independently of the main drum 8 by an auxiliary motor 21 in order to lift and lower auxiliary wires 20a and 20b having parts 30 for engaging with a constricted part 2c of the single crystal 2 capable of engaging with the constricted part 2c and supporting the constricted part 2c and attached to the tips thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pulling CZ (Cz
The present invention relates to a single crystal pulling apparatus and a single crystal pulling method for producing a dislocation-free single crystal of Si (silicon) by the ochralski method, and particularly to a mechanism for locking a large diameter portion and pulling the single crystal, and a method using the same. About.

[0002]

2. Description of the Related Art In general, in a single crystal manufacturing apparatus using 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 the melt is heated and melted, the seed crystal is immersed from above in the surface of the melt, and the seed crystal and the quartz crucible are rotated, and the seed crystal is pulled up while moving up and down, so that the upper end is below the seed crystal. It is configured to grow a single crystal (a so-called ingot) composed of a conical upper cone portion protruding, a cylindrical body portion and a conical lower cone portion protruding at a lower end.

[0003]

In such an apparatus, as a mechanism for supporting a seed crystal and vertically pulling the single crystal while rotating it around a vertical axis, a method using a wire and a method using a shaft are known. ing. The shaft method has a problem that the height of the apparatus increases because the shaft moves upward as the single crystal is pulled up. In addition, the clean room becomes large and the cost increases. On the other hand, in the wire method, the wire can be wound by a drum as the single crystal is pulled up, so that the height of the apparatus does not increase.

[0004] In recent years, the diameter of a single crystal has been increased and the weight has also increased, and the dash neck cannot withstand the weight only by pulling up the seed crystal. A portion (enlarged diameter portion) "and a" small diameter portion "formed thereunder to form an" annular constriction ", and this" annular constriction "is connected to another locking member (hereinafter referred to as a constriction member). There is known a method of locking up with a stop member and pulling up. Similarly, the mechanism for raising the constriction locking member does not increase the height of the device in the wire system.

[0005] However, in a mechanism for pulling up both the seed crystal and the constriction below the large-diameter portion by a wire method, there is a problem that if the two drums are arranged vertically, the height of the apparatus is correspondingly increased. Also, since the drum for winding the wire is similarly rotated to rotate the single crystal around a vertical axis corresponding to the pulling direction, when the wire is wound in the axial direction by winding the wire around the drum surface, Since the horizontal hanging position of the wire suspended in the vertical direction moves, and the pulling direction is not vertical, it must be prevented.

As another conventional example, Japanese Patent Application Laid-Open No. 5-27
Japanese Patent Application Laid-Open Nos. 0974, 5-270975 and 5-301793 disclose a pulling mechanism for the seed crystal and a pulling mechanism for the holding device, which are formed of different driving sources. There is no disclosure or suggestion on how to operate them synchronously.

Further, in Japanese Patent Application Laid-Open No. 9-2893,
The lifting mechanism of the seed crystal and the lifting mechanism of the gripping device are composed of different driving sources, and there is a disclosure that these are operated synchronously or independently.However, in the case of synchronous operation, the control process is complicated, and The required equipment is also complex and expensive. Further, in Japanese Patent Publication No. Hei 7-515, a vertical movement mechanism for engaging the gripping device with the constriction of the single crystal is provided on a shaft forming a pulling mechanism of the seed crystal,
Although a configuration in which the gripping device is pulled up in synchronization with the seed crystal only by controlling the pulling mechanism of the seed crystal after engagement is disclosed, disclosure or suggestion of an effective means for stopping the engagement portion is disclosed. No, it has to be said that it is not feasible.
Further, in the technique disclosed in Japanese Patent Publication No. 7-515, since the single crystal pulling mechanism has a shaft, there is a problem that the height of the pulling device is increased. Further, according to the technology disclosed in the publication, the lifting mechanism of the gripping device, that is, the mechanical drive unit where the metals come into contact with each other is located in the high-temperature lifting chamber, so that it is difficult to take heat-resistant measures or the mechanical mechanism is sufficiently high at high temperatures. There is a defect that the single crystal may not function, and the dislocation of the single crystal may be caused by the influence of particles generated at the mechanical contact portion of the lifting mechanism.

The synchronous control of the pulling speed of the seed crystal and the pulling speed of the holding mechanism in the above-mentioned Japanese Patent Application Laid-Open No. 9-2893 relates to a pulling drive in which a wire drum for winding a wire for pulling the seed crystal and a holding means are connected. Are realized by adjusting the two lifting speeds to each other, the control mechanism and the control process are complicated, the cost of designing and manufacturing the device is high, and it is difficult to easily perform maintenance. There is.

In view of the above-mentioned conventional problems, the present invention does not require speed control when the load of the single crystal is transferred from the neck to the gripping means, and when pulling the single crystal, the weight of the crystal is constricted from the neck. Can be moved smoothly and softly to the gripping position of the device, avoiding the effects of high temperature and the problem of particle mixing, and also using the wire method to pull up both the seed crystal and the constriction below the large diameter part by wire. It is an object of the present invention to provide a single crystal pulling apparatus capable of preventing the height from increasing.

[0010]

According to the present invention, in order to achieve the above object, a drum for pulling a seed crystal and a drum for pulling a constriction below a large diameter portion are coaxially provided outside a single crystal pulling chamber. They are arranged so as to be selectively rotatable integrally or independently.

That is, according to the present invention, a first drum rotatable by a first motor for raising and lowering a first wire to which a seed crystal is attached at a tip with respect to a crucible in a chamber; The first motor is provided coaxially with the drum of the first drum, and a locking member that locks and supports the constriction below the single crystal is moved up and down by the first motor to raise and lower a second wire attached to the tip. A second drum integrally rotatable independently of the first drum by a second motor, wherein the first drum and the second drum combine the crucible and the single crystal; A single crystal pulling apparatus configured to be located outside a housing chamber is provided.

According to the present invention, a first drum rotatable by a first motor for raising and lowering a first wire on which a seed crystal is attached at a tip with respect to a crucible in a chamber; The first wire is arranged coaxially with the drum of FIG. 1 and is provided with a locking member that locks and supports the constriction below the single crystal to raise and lower the second wire attached to the tip.
Motor and the first drum, and the second drum
And a second drum rotatable independently of the first drum by the first motor, wherein the first drum and the second drum
A single crystal pulling method using a single crystal pulling apparatus configured such that the drum is located outside a chamber storing the crucible and the single crystal, wherein the first motor is used to rotate the first drum. While raising the seed crystal, rotating the second drum by the first motor in a state where the second motor is stopped until a constriction is formed by growing a single crystal on the seed crystal, Raising the locking member, then rotating the second drum by the second motor to lower the locking member below the large diameter portion, and then using the second motor to Rotating a second drum to raise the locking member until it comes into contact with the large-diameter portion; and then stopping the second motor while the first motor is stopped. A step of raising the locking member is rotated more the second drum, the single crystal pulling method with is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a main part of a first embodiment of a single crystal pulling apparatus according to the present invention. FIG. 2 is a side cross-sectional view showing a sub motor slide mechanism taken along line AA ′ in FIG. FIG. 3 is an explanatory view showing a pulling operation of the single crystal pulling apparatus of FIG.

In FIG. 1, a quartz crucible containing a raw material (not shown) is arranged in a substantially cylindrical crystal storage chamber 1, and a heater is arranged around the quartz crucible. Is provided with a heat insulating material and the like. Above the crystal storage chamber 1 and outside the crystal storage chamber 1, a housing 3 for housing a mechanism for pulling up a semiconductor crystal (single crystal) 2 is arranged, and the housing 3 is formed below the housing 3. The pulley chamber 3a is configured to be rotatable around a vertical axis, that is, about the pulling direction, by a crystal rotating table 4, a crystal rotating motor 5 and a belt 6.

In the housing 3, a main drum 8 for winding the main wire 7 for raising and lowering the seed crystal is disposed so as to be rotatable around a horizontal shaft 22. In this case, the main drum 8 is rotatable around a shaft (sub-drum connecting rod) 22 by a main motor 9, a main motor connecting rod 10, a main motor connecting gear 11a, and a main drum rotating gear 11b. 7 is supported by the main drum feed mechanism 12 so as to be movable in the horizontal direction so that the horizontal hanging position is always constant. The tip of the main wire 7 is attached with a seed crystal 14 via a crystal holder 13 and is suspended in the crystal storage chamber 1.

The inside of the main drum 8 is formed hollow, and on the inner wall thereof, a sub motor 21 for winding up a pair of sub wires 20a and 20b for raising and lowering a constriction locking portion 30 described later is provided together with the main drum 8. The sub motor casing 21a, the casing support 21b, the sub motor slide guide 21c, and the sub motor slide rail 21d rotate in the horizontal direction (axial direction) as shown in detail in FIG.
Are movably arranged. That is, the sub motor 21
Is provided in the internal space of the main drum 8 and is movable in the horizontal direction, but is fixed to the main drum 8 in the rotation direction. The shaft of the sub-motor 21 is constituted by a sub-drum connecting rod 22 for connecting two sub-drums 27a and 27b to be described later. When the sub-motor 21 is not energized, the sub-drum connecting rod 22 is moved to the sub-motor casing 21a by a brake mechanism. It is configured so that it does not rotate. The sub-drum connecting rod 22 is configured so that both ends thereof are outside the main drum 8 and protrude into the housing 3.

A sub-drum feed gear 23 is fixed to the sub-drum connecting rod 22 in the main drum 8 (that is, rotatably disposed together with the sub-drum connecting rod 22). So that the horizontal hanging position of the main drum 8 is always constant.
Are supported movably in the horizontal direction by a sub-drum feed mechanism 24 provided on the inner wall of the. Wiring 2 of sub motor 21
5 is taken out of the housing 3 via the slip ring 26 so as not to be twisted during rotation.

At both ends of the sub-drum connecting rod 22, sub-drums 27a and 27b for winding the sub-wires 20a and 20b are attached, respectively. Secondary wire 20
The tips of a and 20b are suspended in the crystal storage chamber 1 via sub-wire positioning pulleys 28a and 28b and crystal weight detection mechanisms (load cell units) 29a and 29b, respectively. With the configuration described above, the rotation shaft of the sub-motor 21 and the rotation shafts of the sub-drums 27a and 27b are connected so as to be able to transmit the rotational force and to be movable in the axial direction of the sub-drums 27a and 27b. become. Also,
The rotating shafts of the sub-drums 27a, 27b are connected in a manner that can transmit the rotational force and can be moved in the axial direction of the sub-drums 27a, 27b.

The main drum 8 and the sub drums 27a, 27
The respective wire grooves b are inclined in the same direction with respect to the axis, and the winding directions of the wires of the main drum 8 and the sub drums 27a and 27b are the same. Further, since the wire winding diameters of the main drum 8 and the sub-drums 27a and 27b are set to be the same, the pulling speed of the crystal coincides with the rising speed of the gripping means described later. Further, means for regulating the hanging position of one or both of the wire of the main drum 8 and the wire of the sub-drum is provided, and the means for regulating the hanging position includes the main drum 8 or the sub-drum 27a, 27
Weight detecting means for detecting the weight of the single crystal according to b can be provided. Further, the main drum 8 and the sub drums 27a,
Weight detection means for detecting the weight of the single crystal on the main drum 8 or the sub-drums 27a, 27b can be provided on one or both of the drums 7b or one or both of the rotating shafts of these drums.

At the distal ends of the sub-wires 20a and 20b, a constriction locking portion 30 as a gripping means is attached, and the constriction locking portion 30 is provided with two or more locking claws 31a and 31b. The locking claws 31a, 31b are configured to be rotatable,
Also, they are supported by stoppers 32a and 32b so as not to rotate below the horizontal locked state. Here, when manufacturing the semiconductor crystal 2, a dash neck portion 2a is formed below the seed crystal 14, a large-diameter portion 2b is formed below the dash neck portion 2a, and a constriction is formed below the large-diameter portion 2b. 2c is formed. Here, a portion below the large-diameter portion 2b, that is, a portion where the diameter is reduced, is referred to as a constriction 2c for convenience. When the locking claws 31a, 31b are lowered from above the large-diameter portion 2b, the locking claws 31a, 31b abut on the large-diameter portion 2b and open upward, and then the locking claws 31a, 31b are moved to the large-diameter portion 2b. Is passed over, the stopper 32a, 32b horizontally supports the constriction 2c and the large-diameter portion 2b above the constriction 2c.
Can be supported.

Next, the lifting operation will be described with reference to FIG. First, as shown in FIG. 3 (a), the main motor 9 is rotated in the downward direction from the state where the seed crystal 14 and the constriction locking portion 30 are on standby above the melt 2 'which is the raw material of the semiconductor crystal 2 (the When the motor 21 is stopped), the main drum 8 rotates in the descending direction and the main wire 7 descends. At this time, the main wire 7 is moved horizontally (rightward) so that the horizontal hanging position of the main wire 7 is always constant. Go to). Further, since the sub-drum connecting rod 22 does not rotate with respect to the sub-motor casing 21a when the sub-motor 21 is not energized, the sub-motor 21 and the sub-motor casing 21a rotate together with the main drum 8 to lower the sub-wires 20a and 20b. Further, at this time, the sub wires 20a and 20b are moved in the horizontal direction (right direction) so that the horizontal hanging position is always constant. Therefore, the seed crystal 14 and the constriction locking portion 30 descend at the same speed. Then, as shown in FIG. 3 (b), when the seed crystal 14 is immersed in the melt 2 ', the main motor 9 is stopped (the sub motor 21).
Also stop).

Next, when the main motor 9 is rotated in the ascending direction (the sub-motor 21 is stopped), the above structure causes the main motor 9 to rotate as shown in FIG.
The seed crystal 14 and the constriction locking portion 30 rise as shown in FIG. Then, the dash neck portion 2a is formed below the seed crystal 14 by controlling the rising speed to form a large diameter portion 2b below the dash neck portion 2a, and a constriction 2c is formed below the large diameter portion 2b. Form. FIG. 3 (c),
(D), (e), (f) and up to the final stroke, since the main motor 9 is always rotated in the ascending direction, no particular description will be given. 2A to 2F and the final stroke, the housing 3 is always rotated around the vertical axis by the crystal rotation motor 5.

Next, as shown in FIG.
To the auxiliary drum connecting rod 22, the auxiliary drum 27a,
When 27b is rotated in the downward direction, the auxiliary wires 20a, 20
b, the constriction locking part 30 descends. Then, the constricted locking portion 30 is gradually lowered, and the locking claws 31a, 31b are opened upward by the rising large-diameter portion 2b.
a, 31b get over the large diameter portion 2b and stop 32a,
32b supports it horizontally. And the locking claw 3
When 1a and 31b descend below the constriction 2c, FIG.
As shown in (e), the locking claws 31a, 31b are raised,
Then, the contact with the constriction 2c is detected by the crystal weight detection mechanism 2
When 9a and 29b are detected, the ascent is stopped. And
In this state, the main motor 9 is rotated in the ascending direction (the sub motor 21).
Is stopped), the large-diameter portion 2b as shown in FIG.
The lower part 2c is supported by the locking claws 31a, 31b, and the semiconductor crystal 2 rises.

<Second Embodiment> FIG. 4 is a structural view showing a main part of a second embodiment, and FIG. 5 is a side sectional view showing a sub motor slide mechanism taken along line BB 'in FIG. is there. In the first embodiment, the sub motor casing 21a is configured to be movable in the main drum 8 in the horizontal direction. However, in the second embodiment, as shown in detail in FIG.
The sub motor casing 21a is fixed to the inner wall of the main drum 8 via the sub motor support 21b. The auxiliary motor casing 21a is connected to the auxiliary motor rotating shaft 21 so that the auxiliary drum connecting rod 22 is configured to be movable in the horizontal direction.
e, and is connected to the sub-drum connecting rod 22 via
The gap between the auxiliary motor rotation shaft 21e and the auxiliary drum connection rod 22 is restricted in the rotation direction, but the slide groove 21e-1 and the slide groove are respectively formed in the auxiliary motor rotation shaft 21e and the auxiliary drum connection rod 22 so as not to be restricted in the horizontal direction. Rail 22-
1 is formed.

In the second embodiment, the locking pawl 31
The crystal weight detection mechanisms 29a and 29b for detecting that the a and 31b are raised and abutted on the constriction 2c are omitted, and the torque sensor unit 9 is attached to the shaft of the main motor 9 instead.
a is provided. According to such a configuration, FIG.
As shown in (d), the locking claws 31a and 31b are narrowed 2c.
After descending further below, as shown in FIG.
1a, 31b is raised to abut the constriction 2c, the load on the main wire 7 is reduced and the torque is reduced. This is detected by the torque sensor unit 9a and
Stop 1 Note that the torque sensor unit 9a may be provided on the sub motor 21 side instead of the main motor 9 side to detect an increase in torque on the sub wire 20 side.

<Third Embodiment> FIG. 6 is a structural view showing a main part of a third embodiment, and FIG. 7 is a side sectional view showing a sub motor slide mechanism taken along line CC 'in FIG. is there. The auxiliary motor 21 is coaxially fixed outside the main drum 8, and when the power is not supplied, the auxiliary drum connecting rod 22 is connected to the auxiliary motor 2.
It is configured not to rotate with respect to 1. The sub-drum 27 is configured to be movable in the horizontal direction with respect to the housing 3 when rotated by the sub-drum feed mechanism 41.
As shown in detail, the space between the sub-drum 27 and the sub-drum connecting rod 22 is restricted in the rotation direction, but is not restricted in the horizontal direction.
Slide groove 27-1, slide rail 22-
1 (sub-drum slide mechanism 42) is formed.

[0027]

As described above, according to the present invention, a drum for pulling a seed crystal and a drum for pulling a large-diameter portion or a constriction are coaxially arranged outside a single crystal pulling chamber to be integrated or integrated. Since it is configured to be selectively and independently rotatable, speed control when transferring the load of the single crystal from the neck portion to the holding means is unnecessary, and both the seed crystal and the large diameter portion or the constriction are pulled up by a wire method. In this case, the height of the apparatus can be effectively prevented from increasing, and the effects of high temperature and the problem of particle mixing can be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of a first embodiment of a single crystal pulling apparatus according to the present invention.

FIG. 2 is a side sectional view showing the sub motor slide mechanism as seen from a line AA ′ in FIG. 1;

FIG. 3 is an explanatory view showing a pulling operation of the single crystal pulling apparatus of FIG. 1;

FIG. 4 is a configuration diagram illustrating a main part of a second embodiment.

FIG. 5 is a side sectional view showing the sub motor slide mechanism as viewed from line BB ′ in FIG. 4;

FIG. 6 is a configuration diagram illustrating a main part of a third embodiment.

FIG. 7 is a side cross-sectional view showing the sub motor slide mechanism as seen from line CC ′ in FIG. 6;

[Explanation of symbols]

Reference Signs List 2 semiconductor crystal (single crystal) 2a dash neck portion 2b large-diameter portion 2c constriction 7 main wire (first wire) 8 main drum (first drum) 9 main motor (first motor) 12 main drum feed mechanism 14 Seed crystal 20a, 20b Sub-wire (second wire) 21 Sub-motor (second motor) 22 Sub-drum connecting rod (sub-motor shaft) 23 Sub-drum feed gear 27, 27a, 27b Sub-drum (second drum) 29a, 29b Crystal weight detection mechanism (load cell unit) 30 Neck locking part

Claims (15)

[Claims] 1. A first drum rotatable by a first motor for raising and lowering a first wire to which a seed crystal is attached at a tip with respect to a crucible in a chamber, and coaxially with the first drum. A locking member for locking and supporting the lower neck of the single crystal is arranged integrally with the first drum by the first motor to raise and lower a second wire attached to the tip, and further includes a A second drum rotatable independently of the first drum by a second motor, wherein the first drum and the second drum are outside a chamber in which the crucible and the single crystal are stored. A single crystal pulling apparatus configured to be located at: 2. The single crystal pulling apparatus according to claim 1, wherein the second motor is provided in an internal space of the first drum. 3. The single crystal pulling apparatus according to claim 1, wherein the first drum and the second drum are attached to a unit that rotates about the first wire. 4. The first drum, the first motor,
The single crystal pulling apparatus according to any one of claims 1 to 3, wherein the second drum and the second motor are arranged in a housing outside the chamber. 5. The apparatus according to claim 1, wherein the first and second drums are movable in a horizontal direction so that the horizontal hanging positions of the first and second wires are always constant during rotation. The single crystal pulling apparatus according to claim 1. 6. The second motor is arranged in the first drum so as to be fixed in a rotating direction and to be movable in an axial direction, and the second motor is not energized when the second motor is de-energized.
The single crystal pulling apparatus according to any one of claims 1 to 5, wherein a portion between a rotating shaft connected to the drum and the second motor is fixed. 7. The motor according to claim 1, wherein the second motor is fixed to the first drum via a guide rail movable in an axial direction of the second motor. The single crystal pulling apparatus according to the above. 8. A rotating shaft of the second motor and a rotating shaft of the second drum are connected in a manner capable of transmitting a rotating force and moving in an axial direction of the second drum. The single crystal pulling apparatus according to any one of claims 1 to 7, wherein: 9. The second drum and a rotating shaft of the second drum are connected so as to be able to transmit a rotating force and to be movable in an axial direction of the second drum. The single crystal pulling apparatus according to any one of claims 1 to 8, wherein 10. The winding of wires of the first and second drums, wherein respective wire grooves of the first and second drums are inclined in the same direction with respect to an axis. The single crystal pulling apparatus according to any one of claims 1 to 9, wherein the taking directions are the same. 11. The single crystal pulling apparatus according to claim 1, wherein a wire winding diameter of each of the first drum and the second drum is the same. 12. The wire of the first drum and the second drum
The single crystal pulling apparatus according to any one of claims 1 to 11, further comprising means for regulating one or both hanging positions of the wire of the drum. 13. The apparatus according to claim 12, wherein the means for regulating the hanging position is provided with a weight detecting means for detecting a weight of the single crystal applied to the first drum or the second drum. Single crystal pulling device. 14. A weight of a single crystal applied to the first drum or the second drum on one or both of the first drum and the second drum or one or both of rotation axes of these drums. 13. The single crystal pulling apparatus according to claim 1, further comprising a weight detecting means for detecting the weight of the single crystal. 15. A first drum rotatable by a first motor for raising and lowering a first wire to which a seed crystal is attached at a tip with respect to a crucible in a chamber, and coaxially with the first drum. A locking member for locking and supporting the lower neck of the single crystal is arranged integrally with the first drum by the first motor to raise and lower a second wire attached to the tip, and further includes a A second drum rotatable independently of the first drum by a second motor, wherein the first drum and the second drum are outside a chamber in which the crucible and the single crystal are stored. A single crystal pulling method using a single crystal pulling apparatus configured to be located at a position where the first crystal is rotated by rotating the first drum by the first motor, and the single crystal is placed on the seed crystal. Rotating the second drum by the first motor in a state where the second motor is stopped until the constriction is formed by growing and raising the locking member; Rotating the second drum by a motor to lower the locking member below the large-diameter portion; and rotating the second drum by the second motor to release the locking member. E. Raising the locking member until it comes into contact with the large-diameter portion, and then rotating the second drum by the first motor while the second motor is stopped, A single crystal pulling method.