JPH05194082A - Method for production single crystal and apparatus therefor - Google Patents

Abstract

PURPOSE:To provide a single crystal production apparatus enabling the rotation of a seed shaft at a high speed and the accurate detection of the weight with a load cell while keeping the total height comparable to that of the apparatus of a wire-winding method. CONSTITUTION:A freely rotatable seed housing 3 is placed above a chamber 1 interposing a bearing 2 and a seed guide part 11 vertically movable along a guide bar 9 is placed in the seed housing 3. A wire cable 19 for pulling up the seed guide part 11 is turned downward along the outer wall of the seed housing 3 with pulleys 13, 14. The seed shaft 10 fixed to the seed guide part 11 is rotated together with the seed housing 3. When a screw shaft 15 is rotated with a motor 17 to lower a load cell 20 with a seed-lift part 18, the wire cable 19 pulls up the seed shaft 10 and the grown single crystal 28 through the seed guide part 11. The weight of the single crystal is detected by the load cell 20 and fed back to a controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a single crystal by the Czochralski method and an apparatus therefor.

[0002]

2. Description of the Related Art In a Czochralski method single crystal manufacturing apparatus, when a single crystal is pulled by a seed axis, the wire cable 101 is wound while the wire cable is rotated as the single crystal 28 grows, as shown in FIG. A wire winding method or a shaft pulling method of pulling a grown single crystal while rotating the shaft 102 by raising the pulling shaft as shown in FIG. 4 is used.

[0003]

The wire winding method has an advantage that the total height of the apparatus does not change even if the length of the pulled crystal is long. However, on the other hand, since the pulling wire has a low torsional rigidity, the seed shaft cannot be rotated at a high speed, and therefore the pulling crystal cannot be rotated at a high speed. Further, the diameter of the crystal is directly measured by using a camera in order to control the diameter of the crystal during the crystal formation, but this method tends to cause a measurement error and the crystal diameter cannot be accurately controlled. On the other hand, the shaft pulling method enables high-speed rotation because the pulling shaft is a rigid body, and the crystal weight sensing method used to control the crystal diameter can accurately detect the degree of crystal growth. Therefore, the controllability of the crystal diameter is good. However, since the pulling shaft rises as the crystal is pulled, the total height of the single crystal manufacturing apparatus must be set sufficiently high in advance, and the height reaches about twice that of the wire winding method.

The present invention focuses on the above-mentioned conventional problems, and relates to a method for producing a single crystal by the Czochralski method and an apparatus therefor, and more specifically, to provide a method for pulling a single crystal in an apparatus for producing a single crystal and an apparatus therefor. To aim.

[0005]

In order to achieve the above object, the first invention of the method for producing a single crystal and the apparatus for producing the same according to the present invention is based on the Czochralski method in which the growth of the single crystal is pulled while rotating. In the single crystal manufacturing equipment,
When the single crystal is pulled up by the winding device, the wire itself is not rotated and the wire is pulled up in accordance with the growth of the single crystal, and at the same time, the seed housing part on which the winding device is mounted is rotated and the single crystal is grown while being rotated. Also,
In the second invention, a seed housing portion rotatably mounted via a bearing on an upper end of a chamber accommodating the crucible and the heater, and a rotating device portion for rotating the seed housing portion mounted on the outer periphery of the seed housing portion. ,
The seed housing includes a seed guide unit vertically moving along a guide bar vertically provided in the seed housing, and a winding device unit that winds the seed guide unit along with the growth of the single crystal along the guide bar. Further, in the third invention mainly based on the second invention, the seed housing drive motor rotates the seed housing to rotate the seed shaft with respect to the chamber, and the seed shaft is rotated by the rotation of the screw shaft driven by the sea drift motor. By lowering the drift portion and pushing down the load cell connected to the other end of the wire cable, the seed guide portion having the seed shaft fixed to the lower surface is raised through the wire cable and the pulley, and the load cell reduces the weight of the single crystal. measure.

[0006]

According to the above construction, since the seed housing which is rotated by the seed housing drive motor and the timing belt is provided at the upper end of the chamber, the seed shaft which moves up and down in the seed housing rotates with respect to the chamber and grows. The crystal can be given a rotational movement. At this time, since the twist due to the rotation is not applied to the wire cable for pulling up the seed shaft, it is not necessary to consider the low torsional rigidity of the wire cable, which has been a problem in the past. Further, the other end of the wire cable connected to the seed shaft via the seed guide part is connected to the load cell via a pulley, and the sea drift part that moves up and down by a screw shaft driven by a motor pushes down the load cell, Since the shaft is pulled up, the overall height of the single crystal manufacturing apparatus can be kept as low as the wire winding method. Further, since the weight of the single crystal is measured by the load cell, the diameter of the single crystal can be controlled with high accuracy.

[0007]

EXAMPLES Examples of a single crystal production apparatus according to the present invention will be described below with reference to the drawings. In FIG. 1, a seed housing portion 5 is rotatably mounted via a bearing on the upper end of a chamber that houses a crucible and a heater.
0, a rotating device unit 60 that rotates the seed housing unit 50 mounted on the outer periphery of the seed housing unit 50, and a seed guide unit 70 that moves up and down along a guide bar 9 vertically provided in the seed housing 3. , Guide bar 9
And a winding device unit 80 for winding the seed guide unit 70 along with the growth of the single crystal.

A seed housing portion 50 is provided above the chamber 1 via a bearing 2. The seed housing part 50 includes the seed housing 3 and the top plate 3 thereof.
a, a protruding portion 3b of the upper surface plate 3a, a plate 3c protruding from near the lower end of the seed housing 3, and a pulley cover 3d.

The rotating device section 60 drives the large pulley 4 fitted on the outer periphery of the lower end of the seed housing 3 and the absolute fixed side seed housing 3 provided on the base 5 fixed to the chamber 1. The motor 6, the small pulley 7 fitted on the output shaft of the drive motor 6, and the timing belt 8
And consists of. A timing belt 8 is wound between the large pulley 4 and the small pulley 7, and the seed housing portion 50 and the hoisting device portion 80 are relative to the crucible 24 in the chamber 1 by the rotation of the drive motor 6. The single crystal 28 is rotated by rotating the seed guide 70 together.

The seed guide portion 70 comprises a guide bar 9 vertically provided in the seed housing 3 and a seed guide member 11 which is inserted through the guide bar 9 and has a seed shaft 10 fixed to the lower surface thereof. Therefore, the seed guide member 11 can be prevented from swinging in the lateral direction by the guide bar 9 and can slide up and down along the guide bar 9.

The hoisting device 80 comprises a pulley 13 provided on the cover 12 above the guide bar 9 and a pulley 1 having a height substantially equal to that of the pulley 13 in the lateral direction of the pulley 13.
4 and the plate 3 protruding from the vicinity of the lower end of the seed housing 3
c and the projecting portion 3b, a screw shaft 15 and a lift guide bar 16, a sea drift motor 17 attached to the lower surface of the plate 3c, and a ball screw built into the fitting portion of the screw shaft 15. And a wire cable 19 having one end connected to the upper surface of the seed guide member 11. The screw shaft 15 is driven by a sea drift motor 17, and as the screw shaft 15 rotates, a sea drift part 18 having a ball screw in a fitting portion with the screw shaft 15 moves up and down along the lift guide bar 16.

The vertical movement of the sea-drift portion 18 passes through the hole of the sea-drift portion 18 and the hole of the projecting portion 3b, the pulley 13 and the pulley 14, and then the hole of the cover 12, and the upper surface of the seed guide member 11. The sea drift portion 18 is moved up and down by a wire cable 19 whose one end is connected to.

The wire cable 19 having one end connected to the upper surface of the seed guide member 11 passes through the hole of the cover 12, the pulley 13 and the pulley 14, and then the hole of the protruding portion 3b and the hole of the sea drift portion 18. The other end is connected to the load cell 20. In addition, the chamber 1
The joint between the seed housing 3 and the seed housing 3 and the joint between the upper surface plate 3a of the seed housing 3 and the pulley cover 3d are all sealed with a seal, packing or the like, and the lower surface of the protruding portion 3b and the sea drift portion 18 are sealed. Bellows 2 for enclosing and sealing the wire cable 19 between the upper surface and the upper surface
1 is attached.

In the above embodiment, the belt is used as the rotating device, but it may be directly driven by a chain, a gear or a motor. Further, the seed housing part may be an integral cylindrical type or a polygonal type. Further, although the winding device has a plurality of pulleys, it may be converted by one pulley and wound on the seed housing.

The operation of the above embodiment will be described below. In a single crystal manufacturing apparatus by the Czochralski method for pulling a single crystal growth while rotating, the screw guide 17 and the sea drift portion 1 are rotated by rotating the sea drift motor 17 of the winding device section 80.
8. The seed guide member 11 is pulled up along the guide bar 9 via the wire cable 19. At this time, the wire cable 19 is not rotated and the wire is pulled up in accordance with the growth of the single crystal. Further, the seed housing part 50 on which the hoisting device part 80 is mounted is rotated via the drive motor 6, the small pulley 7, the timing belt 8 and the large pulley 4 which rotate the seed housing 3 on the base 5 fixed to the chamber 1. Then, the single crystal grows while being rotated by the rotation of the seed housing part 50.

The process of growing a silicon single crystal using the above single crystal manufacturing apparatus will be described in more detail with reference to a system block diagram and FIG. (1) Seed rotation command signal V from the CZ controller 30
The SR and crucible rotation command signal VCR are transmitted to the seed housing drive motor 6 and the crucible rotation motor 22 via the I / O interface 31, power amplifiers 41 and 44, and are decelerated by deceleration mechanisms R1 and R4, for example, large and small pulleys. The seed housing 3 and the crucible rotation shaft 23 rotate. The rotation of the seed housing 3 causes the seed shaft 10 to rotate with respect to the crucible 24. In addition, the heater 25 is operated by the heater control command signal VH output from the CZ controller 30 via the I / O interface 31 and the power amplifier 45, the raw material of the silicon single crystal is melted, and the seed shaft 1
The growth of the silicon single crystal starts from the zero tip. (2) With the growth of the single crystal, the sea drift command signal VSL is sent from the CZ controller 30 to the I / O interface 3
1. The sea drift motor 17 via the power amplifier 42
Is transmitted to the screw shaft 15 via the speed reduction mechanism R2, and the sea drift portion 18 descends. Along with this, the seed guide member 11 is pulled upward through the wire cable 19. At the same time, the crucible lift command signal VCL is transmitted from the CZ controller 30 to the crucible lift motor 26 via the I / O interface 31 and the power amplifier 43, and the screw shaft 27 rotates via the reduction mechanism R3. The crucible 24 rises so that the melt surface maintains a predetermined height. (3) The weight of the silicon single crystal 28 pulled up along with the growth is measured by the load cell 20 connected to the end of the wire cable 19, and the signal output from the load cell 20 is a load cell feedback signal via the I / O interface 31. V
It is input to the CZ controller 30 as F. The CZ controller 30 controls each command signal based on the feedback signal VF.

[0017]

As described above, according to the present invention, the end of the wire cable for pulling up the seed axis as the single crystal grows is turned downward through a plurality of pulleys, and the end of this wire cable is changed. Connect the load cell to
Since the sea drift section that descends due to the rotation of the screw shaft pushes down the load cell to pull up the growing single crystal, the total height of the single crystal manufacturing apparatus can be kept as low as the conventional wire winding method, The diameter of the single crystal can be accurately controlled by detecting the weight of the single crystal with high accuracy. Further, since the single crystal pulling apparatus is housed in the seed housing and the seed housing is rotated by the timing belt, the problem of the torsional rigidity of the pulling wire can be solved, and the seed shaft is arranged along the guide bar. Since it rises vertically, it is possible to easily prevent the seed shaft from swinging due to the wire cable. Therefore, it is possible to realize a single crystal manufacturing apparatus capable of performing high-speed rotation and crystal diameter control equivalent to the shaft pulling-up method in an installation space similar to that of the wire winding-up method.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic structure of a single crystal manufacturing apparatus.

FIG. 2 is a system block diagram for controlling single crystal production.

FIG. 3 is an explanatory view showing a schematic structure of a conventional wire winding method of a single crystal manufacturing apparatus.

FIG. 4 is an explanatory view showing a schematic structure of a conventional shaft pulling method of a single crystal manufacturing apparatus.

[Explanation of symbols]

 1 Chamber 2 Bearing 3 Seed Housing 4 Large Pulley 6 Seed Housing Drive Motor 7 Small Pulley 8 Timing Belt 9 Guide Bar 10 Seed Shaft 11 Seed Guide Member 13, 14 Pulley 15, 27 Screw Shaft 16 Lift Guide Bar 17 Sea Drift Motor 18 See Drift part 19 Wire cable 20 Load cell 24 Crucible 25 Heater 28 Silicon single crystal 50 Seed housing part 60 Rotating device part 70 Seed guide part 80 Hoisting device part

Claims (3)

[Claims] 1. A single crystal manufacturing apparatus using the Czochralski method for pulling a single crystal growth while rotating, and when the single crystal is pulled by a winding device, the wire itself is not rotated and the wire is pulled in accordance with the growth of the single crystal. A method for producing a single crystal, which comprises rotating a seed housing part on which a winding device is mounted and growing the single crystal while rotating the single crystal. 2. A single crystal manufacturing apparatus using the Czochralski method, wherein a seed housing part is rotatably mounted via a bearing on the upper end of a chamber that houses a crucible and a heater, and is mounted on the outer periphery of the seed housing part. A rotating device part that rotates the seed housing part, a seed guide part that vertically moves along a guide bar vertically provided in the seed housing, and a seed guide part that winds up along the guide bar in accordance with the growth of a single crystal. An apparatus for producing a single crystal, comprising: a winding device section. 3. The seed housing drive motor rotates the seed housing to rotate the seed shaft with respect to the chamber, and the screw shaft driven by the seadrift motor rotates to lower the seadrift portion. By pushing down a load cell connected to the other end of the cable, a seed guide portion having a seed shaft fixed to the lower surface is raised via a wire cable and a pulley, and the weight of the single crystal is measured by the load cell. Item 1. The single crystal manufacturing apparatus according to Item 1.