JPH11217293A - Single crystal manufacturing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A holder for holding a constricted portion formed in a single crystal is not exposed to a high temperature, and there is no danger that the growing single crystal becomes dislocated due to vibration caused by a nail closing operation of the holder. Be able to open closed claws, if necessary. A single crystal holder (10) includes a plurality of first wire units (1) for raising and lowering a holder body (13).
7) and a plurality of second wire units (18) for opening and closing a plurality of claws (16) swingably attached to the holder body (13), and the second wire unit (18) is After holding the constricted portion (9b) by the single crystal holder (10), it functions as a crystal pulling shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal manufacturing apparatus used for manufacturing a semiconductor single crystal by the CZ method, and particularly suitable for pulling a heavy single crystal.

[0002]

2. Description of the Related Art Single crystal silicon is generally manufactured by the CZ method. In the CZ method, polycrystalline silicon is filled in a quartz crucible installed in a single crystal manufacturing apparatus, and the polycrystalline silicon is heated and melted by a heater provided around the quartz crucible to form a melt. Then, the seed crystal attached to the seed holder is immersed in the melt, and the seed holder is pulled up while rotating the seed holder and the quartz crucible in the same or opposite directions to grow single crystal silicon to a predetermined diameter and length. .

In a seed crystal, dislocations are generated by thermal shock when immersed in a melt. In order to remove the dislocation, a neck portion having a diameter of about 3 to 4 mm is formed below the seed crystal by using a dash neck method, and the dislocation is released to the surface of the neck portion. Then, after the dislocation-free state is confirmed, the shoulder is formed to enlarge the single crystal to a predetermined diameter, and then the process shifts to the formation of a straight body.

In recent years, the weight of single crystals has increased with the increase in the diameter or the axial length of single crystals for the purpose of improving the efficiency of semiconductor device production, improving the yield, etc., and the strength of the neck portion has reached the limit. I have. Therefore, the neck portion may be broken by the conventional crystal pulling method, and a safe single crystal growth cannot be performed. As a countermeasure, an apparatus or method for transferring the load from the neck to the holder during the growth of the single crystal has been proposed. According to such an apparatus and method, since most of the weight of the single crystal is supported by the holder, breakage of the neck portion is prevented, and even when the neck portion is broken, the single crystal can be prevented from falling by the holder. .

[0005] Among the various types of single crystal pulling apparatuses using the single crystal holder, the crystal pulling apparatus disclosed in Japanese Patent Publication No. 7-103000 suspends a plurality of gripping levers with wires and raises and lowers the wires. The structure is such that the grip lever is opened and closed to hold the narrow portion of the single crystal. Further, as the grip lever closes, the slide ring descends by its own weight, preventing the grip lever from opening. On the other hand, in the single crystal pulling apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 5-270975, when an elevating ring provided above a seed holder pushes up an upper hook, the lower hook closes in conjunction with this to hold the single crystal. It has a structure.

[0006]

However, each of the above-mentioned single crystal pulling apparatuses has the following problems. (1) The crystal pulling device according to Japanese Patent Publication No. 7-103000
Since the seed holder also serves as a positioning function of the holder, the holder cannot arbitrarily select a position in the furnace, and must be moved up and down following the seed holder.
Therefore, when the seed crystal is immersed in the melt, the lower end of the grip lever is close to the melt and is exposed to a high temperature.
The growing single crystal may be contaminated. Further, when the dimension from the lower end of the seed holder to the constricted portion deviates from the target value, the predetermined holding operation cannot be performed. Furthermore,
When the holding operation starts, the slide ring descends,
The gripping lever cannot be opened again in the furnace. Therefore, when the dislocation occurs in the single crystal during the growth, the single crystal cannot be removed from the holder and redissolved, and there is no other way but to take it out of the furnace. (2) In the single crystal pulling apparatus according to JP-A-5-270975, the operation of closing the lower hook depends on the tension of the spring. For this reason, when the elevating ring pushes up the upper hook, the lower hook moves instantaneously to the final position, and the single crystal being grown may be dislocated due to the vibration generated at this time. Further, the lower hook moved to the holding position cannot be opened in the furnace, similarly to the crystal pulling apparatus according to Japanese Patent Publication No. 7-103000.

The present invention has been made in view of the above-mentioned conventional problems, and a holder for holding a constricted portion formed in a single crystal is not exposed to a high temperature, and the holder is being grown by vibration caused by a nail closing operation of the holder. It is an object of the present invention to provide a single crystal manufacturing apparatus provided with a single crystal holder that can open a closed claw as needed without a risk of dislocation of the single crystal.

[0008]

In order to achieve the above object, a single crystal manufacturing apparatus according to the present invention is provided with a single crystal having a single crystal holder for pulling up a single crystal while holding a narrow portion formed in the single crystal. In the manufacturing apparatus, a plurality of first wire units for elevating and lowering the holder main body of the single crystal holder and a plurality of second wire units for opening and closing a plurality of claws swingably attached to the holder main body are provided. The second wire unit is characterized in that it functions as a crystal pulling shaft after holding the constricted portion by the single crystal holder. According to the above configuration, since the holder main body of the single crystal holder that holds the constricted portion formed in the single crystal is moved up and down by the plurality of first wire units, the single crystal holder is independent regardless of the elevation of the seed holder. It is possible to move up and down. Therefore,
Until the constricted portion is formed in the single crystal and the straight body grows to a predetermined length, the single crystal holder can be kept at a high position away from the melt surface. Further, by operating the plurality of second wire units, the claws of the single crystal holder can be opened and closed at any time, and the claws can be freely engaged with the constricted portions. After holding the constricted portion by the single crystal holder, the second wire unit is wound up at a predetermined speed to continue the growth of the single crystal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a single crystal manufacturing apparatus according to the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view schematically showing a single crystal manufacturing apparatus according to a first embodiment of the present invention. This single crystal manufacturing apparatus includes a vacuum vessel 1 above a pull chamber (not shown), a crystal pulling wire winding apparatus 2, a plurality of wire winding apparatuses 11 for raising and lowering a single crystal holder 10, and a vacuum chamber 1. A wire winding device 12 is provided. A seed holder 5 having a seed crystal 4 attached thereto is connected to the lower end of the crystal pulling wire 3 hanging down from the crystal pulling wire winding device 2 to the center of the furnace body.
A crucible 7 for storing the melt 6 is installed in a main chamber (not shown) so as to rotate and move up and down.

The single crystal holder 10 includes a holder body 13 formed of a ring-shaped plate, and a plurality of links rotatably attached at one ends to a plurality of support members 14 protruding from the lower surface of the holder body 13. 15, and a pawl 16 swingably attached to the other end of each link 15. The claw 16 is manufactured such that the inner portion, that is, the outer portion is heavier than the portion on the furnace body center side with respect to the swing center. The holder main body 13 is supported by a plurality of first wire units 17 hanging from the wire winding device 11, and a plurality of second wire units 18 hanging from the wire winding device 12 are provided on an upper surface of an outer portion of the claw 16. Are connected at the lower end.

The operation of the single crystal holder 10 of the first embodiment is as follows. The crystal pulling wire 3 is rewound in the same manner as in the normal single crystal pulling, and the seed crystal 4 mounted on the seed holder 5 is immersed in the melt 6 to be blended. Is formed. Further, after forming the enlarged diameter portion 9a and the constricted portion 9b of the single crystal 9, the process shifts to the formation of the shoulder portion 9c and the straight body portion 9d.
During this time, the single crystal holder 10 is supported on the upper part of the main chamber by the first wire unit 17 and rotates in the same direction as the crystal pulling wire 3 at the same rotation speed.
Since the second wire unit 18 is loosened, the outer part of the claw 16 is lowered and the inner part is kept open as shown in FIG. Therefore, the enlarged diameter portion 9a can pass without touching the inner tip of the claw 16.

When the growing single crystal 9 is grown to a preset length, the wire winding device 11 and the wire winding device 12 are driven to rewind the first wire unit 17 and the second wire unit 18. Then, the single crystal holder 10 descends. After the inner tip of the claw 16 has passed through the enlarged diameter portion 9a,
The drive of the wire winding device 11 is stopped, and the wire winding device 12 is driven to the winding side so that the second wire unit 18
Is wound up. As a result, the outer end of the claw 16 is pulled up, and the other end of the link 15, that is, the connection portion with the claw 16 is displaced upward. As shown in FIG. It is pushed out and the nail is closed. The claw 16 is fixed at a position where the upper surface of the outer portion is in contact with the lower surface of the support member 14, and when the second wire unit 18 is further wound, the entire single crystal holder 10 is raised. First wire unit 17 and second wire unit 1
8 is wound at a higher speed than the crystal pulling wire 3,
The inner tip of the closed claw 16 contacts the lower conical surface of the enlarged diameter portion 9a to hold the single crystal 9. After holding the single crystal 9 with the single crystal holder 10, the first wire unit 17 and the second wire unit 18 are wound at the same rising speed as the crystal pulling wire 3.

After the single crystal 9 is held by the single crystal holder 10, most of the weight of the single crystal 9 is held by the second wire unit 18 and a part of the single crystal 9 is held by the crystal pulling wire 3. Continue training. The load sharing ratio between the two is arbitrarily determined.

FIG. 3 is a schematic diagram illustrating a single crystal holder in a single crystal manufacturing apparatus according to a second embodiment of the present invention. The left side of the center line shows a state where the nail is opened, and the right side shows a state where the nail is closed. This shows a state where a single crystal is held. The single crystal holder 20 is swingably attached to the holder body 21 formed of a ring-shaped plate, a plurality of support members 22 and stoppers 23 projecting from the lower surface of the holder body 21, and the support member 22. And a plurality of claws 24. As in the case of the first embodiment, the holder main body 21 is supported by a first wire unit 17 hanging from a plurality of wire winding devices (not shown) installed in the vacuum vessel 1. The lower end of the second wire unit 18 hanging from the plurality of wire winding devices is connected to the upper surface of the intermediate portion between the swing center of the claw 24 and the tip.

Next, the operation of the single crystal holder 20 of the second embodiment will be described. As in the case of the first embodiment, a portion of the enlarged diameter portion 9a, the constricted portion 9b, the shoulder portion 9c, and a part of the straight body portion 9d are formed following the neck portion 8. The single crystal holder 20 is supported on the upper part of the main chamber by the first wire unit 17 and rotates in the same direction as the crystal pulling wire 3 at the same rotation speed. Since the second wire unit 18 is loosened, the tip of the claw 24 faces downward, and does not come into contact with the enlarged diameter portion 9a when it passes therethrough.

When the growing single crystal 9 is grown to a preset length, the first wire unit 17 and the second wire unit 18 are rewound, and the single crystal holder 20 is lowered. After the tip of the claw 24 has passed through the enlarged diameter portion 9a, the first
The rewinding of the wire unit 17 and the second wire unit 18 is stopped, and the second wire unit 18 is wound. As a result, the tip of the claw 24 is pulled inward, and after the side surface of the claw 24 contacts the stopper 23, the entire single crystal holder 20 is raised. Thus, the tip of the closed claw 24 abuts on the lower conical surface of the enlarged diameter portion 9a to hold the single crystal 9. Thereafter, since the first wire unit 17 and the second wire unit 18 are wound at the same speed as the crystal pulling wire 3, the single crystal 9 is pulled by the single crystal holder 20. Most of the weight of the single crystal 9 is the single crystal holder 2
Held by 0.

In the first and second embodiments,
The crystal pulling wire winding device 2 and the wire winding device 12 are placed on a load sensor, and the driving torque of the crystal pulling wire winding device 2 and the wire winding device 12 is controlled based on the detected load value. For example, the crystal pulling wire 3 and the single crystal holder 10
(Or the single crystal holder 20) can be controlled to have a desired ratio of load distribution.

Although the first and second embodiments have described the single crystal manufacturing apparatus of the wire type, the present invention is also applicable to a single crystal manufacturing apparatus of the shaft type.

[0019]

As described above, according to the present invention, the following effects can be obtained. (1) Since the single crystal holder can be freely moved to an arbitrary position in the furnace, it is possible to select an optimal holding timing in consideration of the temperature and weight of the single crystal being grown, and the holder can be used. No exposure to high temperatures. (2) The claw closing operation of the single crystal holder and the pulling operation after holding the single crystal are performed by the same lifting mechanism, and a dedicated wire winding device is installed. can do. In addition, no vibration is generated due to the nail closing operation, and there is no possibility that the single crystal being grown is dislocated. (3) Even after the single crystal is held by the single crystal holder, the closed claws can be opened. If the single crystal held by the single crystal holder is dislocated, the dislocation is placed in the crucible. It is easy to return, open the nails and redissolve.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a single crystal manufacturing apparatus according to a first embodiment of the present invention, showing a state where a claw of a single crystal holder is opened.

FIG. 2 is a schematic diagram showing a state where a single crystal is held by the single crystal holder of FIG.

FIG. 3 is a schematic view showing the open / closed state of a nail in the single crystal holder of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Crystal pulling wire winding device 3 Crystal pulling wire 9 Single crystal 9a Enlarged diameter part 9b Constriction part 10, 20 Single crystal holder 11,12 Wire winding device 13,21 Holder body 15 Link 16, 24 Claw 17 First wire unit 18 Second wire unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junsuke Tomioka 2612 Yonomiya, Hiratsuka-shi, Kanagawa Prefecture, Komatsu Electronic Metals Co., Ltd. Inventor Akihiro Yoshimoto 23 Kotsu Koki, Komatsu-shi, Ishikawa Pref. Komatsu Koki Co., Ltd. (72) Inventor Narutoshi Oshi 1200, Manda, Hiratsuka-shi, Kanagawa Pref. Komatsu Seisakusho Co., Ltd. 1200 Manda, Hiratsuka-shi, Japan Inside Komatsu Seisakusho Research Laboratory Co., Ltd. (72) Inventor Hiroshi Kadota 1200 Manda, Hiratsuka-shi, Kanagawa Prefecture Inside Komatsu Seisakusho Research Laboratories Co., Ltd. (72) Inventor Kenji Okamura 1200 Manda, Hiratsuka-shi, Kanagawa Prefecture Komatsu Ltd.

Claims (1)

[Claims] An apparatus for manufacturing a single crystal comprising a single crystal holder (10) for pulling up a single crystal (9) while holding a constricted portion (9b) formed in the single crystal (9), comprising: A plurality of first wire units (17) for raising and lowering the holder body (13) of 10) and a plurality of claws (16) for opening and closing the plurality of claws (16) swingably attached to the holder body (13). Having a second wire unit (18), the second wire unit (18) holding the constricted portion (9b) by the single crystal holder (10),
An apparatus for producing a single crystal, which functions as a crystal pulling shaft.