JPH10338598A - Single crystal holding apparatus and single crystal holding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to hold sections having good reproducibility of shapes and sizes and to deal with the degradation in holding force accompanying the shrinkage of a single crystal at the time of pulling up the single crystal of a large weight. SOLUTION: Polygonal link bodies 14 which are connected with plural equilateral links 14a and are deformable within a horizontal plane by moving the positions of link pins 14b are connected to the bottom ends of two holding rods 11 of the signal crystal holder which moves vertically and rotates in synchronization with a single crystal pulling up wire. The polygonal link bodies 14 enclosing the single crystal 9 are installed in the prescribed positions and thereafter, the holding rods 11 are moved in a horizontal direction to deform the polygonal link bodies 14 to a rhombic shape from a square shape to hold the straight drum part of the single crystal 9. When the single crystal 9 is shrunk by cooling and the holding force of the polygonal link bodies 14 is degraded, the holding force is restored by further moving the holding rods 11. The mounting direction of a seed crystal is so selected as to avoid the contact of the polygonal link bodies 14 with the ridge lies of the single crystal 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal holding apparatus and a single crystal holding method which are mounted on a single crystal manufacturing apparatus by the CZ method and are particularly suitable for manufacturing 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, the polycrystalline silicon is heated and melted by a heater provided around the quartz crucible, and the seed crystal attached to the seed holder is melted. Immerse in liquid. Then, while rotating the seed holder and the quartz crucible in the same or opposite directions, the seed holder is pulled up 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 prevent the dislocation from propagating to the single crystal, a neck portion having a diameter of about several 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, as the diameter and length of a single crystal have increased, their weight has increased, and the strength of the neck has approached its limit. 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, in the diameter expanding step after dislocation-free by the dash neck method, the diameter of the single crystal is once narrowed to form a constricted portion, and a holding tool is held at the constricted portion to hold the single crystal. Something has been devised. 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 holder can prevent the single crystal from falling.

[0005] For example, the single crystal growing apparatus disclosed in Japanese Patent Publication No. 5-65477 has an openable / closable clamp arm which suspends the single crystal by hanging it on a constricted portion formed in the single crystal. Further, the crystal pulling device disclosed in Japanese Patent Publication No. 7-515 is provided with a plurality of claws that stop at a fixed angle at the lower end of a vertically movable gripping holder, and these claws are provided in a constricted portion of a single crystal. The single crystal is suspended by being hung. In addition, Tokuho 7-103000
The crystal pulling apparatus disclosed in Japanese Patent Application Publication No. H10-146556 has a plurality of gripping levers each having a claw hooked on a constricted portion of a single crystal, opening and closing by winding or unwinding a wire, and a ring for preventing the gripping lever from opening. Are used to suspend the single crystal. In addition, JP-A-9-2893, JP-A-5-270934, and the like are disclosed.

[0006]

However, when the constricted portion formed on the single crystal is held by various holders, there are the following problems. (1) When forming a constricted portion, it is difficult to form the target shape with good reproducibility because the shape is controlled by adjusting the crystal pulling speed and the melt temperature. Each time it is different. (2) When a single crystal is held by applying mechanical pressure to the holder, the holding force decreases due to shrinkage due to cooling of the single crystal,
Although the single crystal cannot be held reliably, no measure has been established to solve this problem. (3) Generally, a habit line (ridge line) depending on the crystal orientation is generated on the outer peripheral surface of the single crystal, and the ridge line protrudes from the outer peripheral surface of the single crystal. For this reason, when the holder holding the single crystal abuts on the ridge and a holding force is applied, the ridge may be chipped. When the missing single crystal fragments fall into the melt, the single crystal being grown is dislocated. Also,
It is possible that the single crystal is broken at the site where the ridge line is missing as a fracture starting point, and the single crystal is dropped into the melt. Therefore, it is necessary to control the holder so that the ridge line of the single crystal does not coincide with that of the single crystal. However, a single crystal holding method that clarifies this point is not disclosed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. When a single crystal having a large weight is held, a portion having good reproducibility in shape and dimensions is held, and the cooling of the single crystal is performed. It is possible to cope with a decrease in holding force due to shrinkage, and
It is an object of the present invention to provide a single crystal holding device and a single crystal holding method capable of controlling a holding portion so as not to coincide with a ridge line of a single crystal.

[0008]

In order to achieve the above object, a single crystal holding device according to the present invention comprises a plurality of links connected to each other, and can be deformed in a horizontal plane by moving the position of a link pin. Polygonal link body, means for deforming the polygonal link body to sandwich the single crystal, means for rotating and lifting the polygonal link body in synchronization with the crystal pulling wire, and detecting the load applied to the crystal pulling wire A load cell for pulling wire, a load cell for total load detecting a total load of a load applied to the crystal pulling wire and a load applied to the polygonal link body, and a control device for controlling each of the above means. Features.
The single crystal holding device of the present invention is to hold a single crystal by deforming a polygonal link body disposed so as to surround the single crystal. According to the above configuration, since the interval between the links located at the opposing positions is reduced due to the deformation of the polygonal link body, the single crystal can be sandwiched between the links. Since the polygonal link rotates and moves up and down in synchronization with the crystal pulling wire, no friction occurs due to a difference in rotation speed or a difference in the rising speed between the crystal pulling wire and the polygonal link when the single crystal is sandwiched. The crystal pulling speed after sandwiching the single crystal by the polygonal link body is the same as the pulling speed by only the crystal pulling wire. In addition, the load applied to the crystal pulling wire, that is, the load applied to the neck portion is detected by the load cell for the pulling wire, and the load applied to the polygonal link body is determined as the difference between the detected value of the load cell for the total load and the detected value of the load cell for the pulling wire. The controller detects the detected values and controls the growth of the single crystal and the load distribution based on these values.

In the single crystal holding apparatus, a crystal pulling wire winding mechanism, a load cell for a pulling wire, and a polygonal link body driving mechanism are housed in a vacuum vessel provided at an upper part of the single crystal manufacturing apparatus. And a load cell for a total load for detecting a load applied to the vacuum vessel, and a vacuum vessel rotating mechanism mounted on a carriage capable of moving up and down. According to the above configuration, since the crystal pulling wire take-up mechanism, the polygonal link driving mechanism and the two types of load cells are mounted on the vertically movable carriage, the single crystal can be pulled up by winding the crystal pulling wire and raising the carriage. It becomes possible by any of the above.

The first of the polygonal link body driving mechanisms in the single crystal holding device of the present invention is a motor or a fluid pressure actuator, which is vertically held in the single crystal manufacturing device, and is horizontally moved by the motor or the fluid pressure actuator. A polygonal link body driving mechanism including two moving holding rods is provided, and a link pin at a position facing the polygonal link body is connected to a lower end of the holding rod.
According to the above configuration, since the holding rod moves in the horizontal direction while maintaining the vertical posture, the polygonal link body connected to the lower end of the holding rod is deformed to hold the single crystal.

The second of the polygon link driving mechanism in the single crystal holding device of the present invention is that two wire winding drums, two polygon link driving wires hanging from the wire winding drum, A polygonal link body drive mechanism comprising a plurality of pulleys installed at the lower end of the vacuum vessel and a guide plate for moving the link pins of the polygonal link body in the horizontal direction as the polygonal link body drive wire is wound. And a link pin at a position facing the polygonal link body is connected to a lower end of the wire. If a polygon link drive wire is connected to each of the link pins located at the opposite positions of the polygon link, and these wires are wound by a wire winding mechanism, the link pins move in the lateral direction. The polygonal link deforms and holds the single crystal.

Further, the single crystal holding device of the present invention has a function of recovering the holding force when the single crystal shrinks due to cooling and the holding force of the single crystal holding device is reduced. It is characterized in that the holding force is maintained until it is removed from the device. When the single crystal shrinks, the load applied to the crystal pulling wire abnormally increases, and the load applied to the single crystal holding device decreases. When the detected value of the pull-up wire load cell exceeds a predetermined set load, the holding rod is further moved or the polygonal link driving wire is further wound by the command signal of the control device, so that the polygonal link is simply used. The crystal holding power is restored, and the state can be constantly maintained.

Further, in the single crystal holding device of the present invention, a holding member having an arc-shaped cross section for holding a constricted portion of the single crystal is attached to an inner surface of a link constituting a polygonal link body. It is characterized by. If a holding member surrounding the constricted portion of the single crystal is attached to the polygonal link body, it is possible to hold not only the straight body portion of the single crystal but also the constricted portion. In this case, since the holding member having the arc-shaped cross section supports the conical surface near the constricted portion and does not tighten the constricted portion, damage and destruction of the constricted portion are prevented.

Next, in the method for holding a single crystal according to the present invention, after the polygonal link surrounding the single crystal is lowered to a predetermined position, the holding rod is moved in the horizontal direction or the polygonal link drive wire is wound up. It is characterized in that the polygonal link body is deformed to hold the single crystal straight body. According to the above structure, the single crystal can be held by deforming the polygonal link body to sandwich the straight body of the single crystal and tightening it with a predetermined force.

As another method for holding a single crystal,
A constricted portion formed between the neck portion and a shoulder portion of the single crystal or a constricted portion formed on a straight body portion of the single crystal is held by a holding member attached to the inner surface of the polygonal link body. I do. After deforming the polygonal link body and surrounding the constriction of the single crystal with the holding member, raise the polygonal link slightly to abut the constriction, holding the single crystal without tightening the constriction can do.

The method for holding a single crystal according to the present invention is characterized in that a seed crystal or a single crystal holding device is provided so that the position where the polygonal link body contacts the single crystal does not coincide with the ridge line of the single crystal. . Although the generation position and the number of the ridge lines vary depending on the crystal orientation, according to the above configuration, even if the single crystal is tightened by the polygonal link, the crush of the ridge line is avoided, and the single crystal during growth is not adversely affected.

Further, in the single crystal holding method of the present invention, a part or all of the weight of the single crystal is borne by the single crystal holding device during the growth of the single crystal. It is characterized in that the neck portion bears the weight that does not break. According to the above configuration, the weight to be applied to the single crystal holding device and the neck portion is determined in advance, and the control device controls the weight distribution based on the detection signals of the pulling wire load cell and the total load load cell. Even when pulling a heavy single crystal, breakage of the neck does not occur.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a single crystal holding apparatus and a single crystal holding method according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view showing a schematic structure of a first embodiment of a single crystal holding device. The vacuum vessel 2 installed at the upper end of the single crystal manufacturing apparatus 1 includes a support plate 2a,
A wire winding drum 4 for winding the crystal pulling wire 3 on the support plate 2b, and a load cell 5 for a pulling wire for detecting a load applied to the crystal pulling wire 3 are provided on the support plate 2b. The crystal pulling wire 3 hangs down from the center of the single crystal manufacturing apparatus 1 and a seed holder 6 is supported at the lower end thereof, and a neck portion 8 is formed at a lower end of the seed crystal 7 attached to the seed holder 6 by a dash neck method. After that, a single crystal 9 is grown.

On the support plate 2a, a holding rod drive motor 12 for horizontally moving two columnar holding rods 11, which are constituent members of the single crystal holding device 10, is provided. A motor shaft 13 projecting horizontally from both left and right ends of the holding rod drive motor 12 has a ball screw that rotates synchronously, and an upper end of the holding rod 11 is screwed to the motor shaft 13. The holding rod 11 is a single crystal manufacturing apparatus 1
And a polygonal link body 14 is attached to a lower end thereof. Note that a hydraulic cylinder or a pneumatic cylinder that expands and contracts in both left and right directions may be used as a driving unit of the holding rod 11.

A pulley 15 is attached to a lower portion of the vacuum vessel 2, and a support plate 2b is carried by a total load cell 16 installed on the pulley 15. The total load load cell 16 detects the total load of the load applied to the crystal pulling wire 3 and the load applied to the single crystal holding device 10 and inputs the detected load to a control device (not shown). The control device calculates the load borne by the single crystal holding device 10 based on the total load detection value and the detection value of the pull-up wire load cell 5. The vacuum container 2 is mounted on a carriage 18 via a vacuum seal 17, and is rotated by a rotation motor 19 installed on the carriage 18. The pulley 15 is supported on a support cylinder 20 mounted on a carriage 18 via a thrust bearing 21. The carriage 1
Numeral 8 denotes a lifting means (not shown), for example, which can be raised and lowered by rotation of a ball screw shaft.
Goes up and down. Further, the carriage 18 and the gate chamber 2
2 is connected to the main chamber (not shown) through a top chamber 24 at the lower end of the gate chamber 22.

FIG. 2 is a perspective view of the polygonal link body. The polygonal link body 14 is formed by connecting four equal-side links 14a to each other with link pins 14b, and the lower end of the holding rod 11 is connected to each of two diagonal link pins. When the two holding rods 11 move to the center side, the polygonal link body 14 becomes square, and the holding rod 11
Is moved outward, the polygonal link 14 is transformed into a rhombus and sandwiches the single crystal 9. The holding rod 11, the equilateral link 14a, and the link pin 14b are manufactured using a heat-resistant metal such as molybdenum. The polygonal link 14 may be deformed into a rhombus when the holding rod 11 moves toward the center.

In order to increase the holding capacity of the polygonal link for holding the single crystal, irregularities 14c may be provided on the inner surface of the equilateral link 14a as shown in FIG. A portion 14d may be provided.

Hereinafter, a method for holding a single crystal will be described. When the seed crystal 7 shown in FIG. 1 is mounted on the seed holder 6, the mounting direction of the seed crystal is selected so that the polygonal link body 14 does not abut on the ridge generated on the single crystal 9. The drawing process, the formation of the shoulder portion, and the growth up to the middle of the straight body portion are performed by controlling the winding of the crystal pulling wire 3. The single crystal growth at this time is controlled by a control device (not shown) based on the detection value of the pull-up wire load cell 5. After the single crystal 9 has grown to a position suitable for holding, the alignment between the polygonal link body 14 of the single crystal holding device 10 and the single crystal 9 is performed. As a first single crystal holding method, the polygonal link body 14 is made to stand by at an optimum position for holding, and the growth of the single crystal 9 is waited. When the single crystal 9 grows to the optimum position, the crystal pulling wire 3 is wound. The carriage 18 is stopped, and the carriage 18 starts to rise at the winding speed of the crystal pulling wire 3 immediately before the stop. Crystal pulling wire 3 to carriage 1
The transition to 8 is instantaneous. Since the diameter of the single crystal 9 is controlled by the detected values of the load cell 5 for the pulling wire and the load cell 16 for the total load, the transition from the crystal pulling wire 3 to the carriage 18 can be performed smoothly. The single crystal growth after the shift is controlled by feeding back the weight detection signal to the ascending speed of the carriage 18 by the control device.

When the polygonal link body 14 is in the standby position, the quadrilateral formed by the four equilateral links 14a is a square as shown in FIG. A certain gap is secured between the outer peripheral surface of the trunk 9a and the inner surface of each equilateral link 14a. When shifting from the crystal pulling wire 3 to the carriage 18, the holding rod drive motor 12 shown in FIG.
Move 1 outward. Thereby, the polygonal link body 14
Is deformed into a rhombus, and the straight body portion 9a is sandwiched and clamped by the equilateral links 14a as shown in FIG. 5B. When the polygonal link member 14 is deformed and comes into contact with the straight body portion 9a, the control device holds the single crystal so as not to vibrate or shock it, and to prevent excessive surface pressure from being generated in the single crystal by tightening. The rotation speed and torque of the rod drive motor 12 are controlled.

As a second method for holding the single crystal, for example, the polygon link 14 is engaged with the single crystal 9 at an arbitrary position above the lower end of the bellows 23 shown in FIG. Is increased at the speed Va (mm / min), the winding speed of the crystal pulling wire 3 commanded by the control device based on the detection signal of the pulling wire load cell 5 is Vb (mm / min), and the wire winding is performed. The speed is controlled to Vb-Va (mm / min).
Conversely, the polygonal link 14 is moved at the speed Va (mm /
min), the wire winding speed is V
b + Va (mm / min).

As described above, by moving the polygonal link body 14 relatively to the single crystal, the straight body can be sandwiched at an arbitrary position. The temperature profile of the single crystal in the furnace is grasped in advance, and the holding position with respect to the temperature can be controlled, for example, by holding the single crystal in a temperature zone where silicon is stable mechanically and preventing contamination. After the polygonal link body 14 is engaged with the single crystal, the crystal pulling wire 3 is rewound to transfer a part of the single crystal weight to the single crystal holding device side. For example, a load of about 5 kg is left on the crystal pulling wire side to prevent the crystal pulling wire 3 from coming off from the wire winding drum 4 due to slackness. In order to increase the pullable weight, it is advantageous to carry out the pulling while leaving a load on the crystal pulling wire such that the neck 8 is not broken. Therefore, the load applied to the crystal pulling wire 3 is monitored by the load cell for pulling wire 5, and when the detected load exceeds the set load, the crystal pulling wire 3 is fed back to the wire winding drum 4 to rewind the crystal pulling wire 3 and always keep a constant load. Is applied to the neck portion 8.

When the single crystal cools and contracts, the engagement between the single crystal holding device and the single crystal is loosened, and the load moves to the crystal pulling wire side. In FIG. 1, the value detected by the pull-up wire load cell 5 is
Is exceeded, the holding rod drive motor 12 is rotated by the command signal of the control device, the holding rod 11 is further moved outward, and the polygonal link body 14 is further flattened. At this time, the torque of the holding rod drive motor 12 is
It is provided in such a size that single crystal 9 is not lost. The function of retightening the polygonal link body 14 against the shrinkage of the single crystal is not only during the growth of the single crystal, but also in the cooling step, the temperature in the chamber is lowered to a temperature at which the chamber can be disassembled, and the single crystal is held in the unloading device. It is continuously maintained until

FIG. 6 is a schematic diagram showing the lower structure of the second embodiment of the single crystal holding device. This single crystal holding device is shown in FIG.
The holding rod driving motor and a pair of motor shafts and holding rods are added by being shifted by 90 ° above the holding rod driving motor 12 and the motor shaft 13 shown in FIG. Hold at 14 and 25. Thereby, the single crystal holding ability can be increased.

FIG. 7 is an explanatory view of a lower structure of a single crystal holding device for holding a narrow portion formed at the upper end of a single crystal shoulder as a third embodiment of the single crystal holding device, and FIG. 8B is a top view of the polygonal link body shown in FIG.
It is an AA sectional view of (a). In this single crystal holding device, four equilateral links 1
An arc-shaped holding member 14e is attached to the inner surface of 4a, so that the outer peripheral surface in the vicinity of the constricted portion 9b having poor shape reproducibility can be held at a plurality of locations.

Unlike the straight body holding described above, when holding the constricted portion 9b, the inner diameter of the portion surrounded by the four holding members 14e is an arbitrary value between the maximum diameter and the minimum diameter of the constricted portion. It is sufficient that the polygonal link body 14 is deformed so as to have the following value, and it is not necessary to tighten the constricted portion. Therefore, in this single crystal holding device, two holding rods 11 are connected by an opening prevention plate 26, and a guide pin 27 attached to the holding rod 11 is connected to a guide groove 2 provided in the opening prevention plate 26.
6a, the amount of movement of the holding rod 11 is restricted. When the guide pin 27 comes into contact with both ends of the guide groove 26a, the interval between the two holding rods 11 becomes maximum, and the inner diameter of the holding member 14e becomes a predetermined value between the maximum diameter and the minimum diameter of the constricted portion. The opening prevention plate 26 is provided with the holding member 1.
4e is prevented from crushing the constricted portion 9b, and the rigidity of the polygonal link body 14 when the constricted portion 7b is held is ensured.

When the polygonal link 14 is engaged with the constricted portion 9b, the polygonal link 14 is moved at a speed Va (mm).
/ Min) to reduce the wire winding speed to Vb + V
a (mm / min) to maintain the crystal pulling speed Vb (mm / min) commanded by the controller. Then, the polygonal link body 14 is aligned with the position of the minimum diameter of the constricted portion 9b, and the holding rod 11 is driven outward to hold the holding member 1
After setting the inner diameter of 4e to a predetermined value D, the single crystal holding device is raised relatively to the single crystal. As a result, the holding member 14e comes into contact with the upper conical surface of the constricted portion 9b. The speed operation at this time is the same as in the first embodiment. When the desired load is applied to the crystal pulling wire, the control of the single crystal growth rate is instantaneously switched to the carriage raising means.

FIGS. 9 and 10 are explanatory views showing another embodiment of the single crystal holding method using the single crystal holding apparatus according to the present invention. FIG. 9 shows a single crystal growing process in which an enlarged diameter portion 9c is formed at the lower end of the neck portion 8, a straight body portion 9d having a smaller diameter than the enlarged diameter portion 9c is formed, and then a single diameter enlarged to a predetermined diameter. A method of holding the straight body 9d with the polygonal link body 14 in the production of the crystal will be described. FIG. 10 shows the neck portion 8.
After forming a straight body 9d having a smaller diameter than a straight body of a predetermined dimension at the lower end of the single crystal, in the production of a single crystal expanding to a predetermined diameter,
A method of holding the straight body portion 9d with a polygonal link body 14 is shown. In any case, since the method is a method of holding the straight body portion with good reproducibility of the shape and the size, the dimensional control of the straight body portion 9d is easy, and the single crystal can be reliably held. Further, in the case of the single crystal holding device shown in FIGS. 9 and 10, the polygonal link can be reduced in size.

FIG. 11 shows a fourth embodiment of a single crystal holding device, in which a drive motor independent for each holding rod is used, and a plan view of a holding rod driving mechanism in a single crystal holding device in which two sets of upper and lower polygonal links are mounted. FIG. 12 is a Z view of FIG. Four holding rod drive motors 28, which rotate synchronously according to a command signal of the control device, are attached to the outside of the vacuum vessel 2 at a 90 ° pitch via a vacuum seal 29, and ball screws attached to each holding rod drive motor 28 The shaft 30 is screwed to the slide block 31. The slide block 31 slides on the support plate 2a while being constrained by a slide guide 32 laid on the support plate 2a as shown in FIG. The upper end of the holding rod 11 is connected to the slide block 31 and moves outward or inward in a notch 2c provided in the support plate 2a. One polygonal link body is connected to the lower end of a pair of holding rods connected to two opposing slide blocks, and a pair of holding rods connected to the other two opposing slide blocks. Another polygonal link body is connected to the lower end. Holding rod drive motor 28 and holding rod 1
It is also possible to provide only one pair of 1 at opposite positions of the vacuum vessel 2 and connect only one polygonal link to the lower end of the holding rod.

FIG. 13 is a schematic longitudinal sectional view showing a fifth embodiment of a single crystal holding device, FIG. 14 is a Z view of FIG. 13, and FIG. 15 is a plan view of a guide plate. In this configuration, the body is deformed by operating a wire to hold a single crystal. As shown in FIG. 13, a motor 34 is installed in a vacuum vessel 2 above a wire winding drum 4 for winding the crystal pulling wire 3, and wire winding drums 35 are provided on both sides of the motor 34. Has been attached. Further, on the left and right sides of the lower surface of the vacuum vessel 2, FIG.
As shown in FIG. 14, pulley holding plates 36 are attached, and three right and left pulleys 3 are sandwiched between these pulley holding plates 36.
7, 38, 39 are attached. The wire 40 wound around the wire take-up drum 35 hangs down in the vacuum container 2, and passes through blocks 41 via pulleys 37, 38 and 39.
The block 41 is connected to a link pin extension shaft 42.
Through the link pin 14b of the polygonal link body 14. A moving shaft 43 that projects horizontally in the left-right direction is attached to the block 41.

Two guide plates 44 are attached to the outside of the pulley holding plate 36. As shown in FIG. 15, the guide plate 44 has a guide groove 44 at the center.
a. This guide groove 44a is shown in FIGS.
When the polygonal link body 14 is in the standby posture, the movable shaft 43 is in the guide groove 44a.
Is stationary at the position A within. The structure of this single crystal holding device other than the above is the same as that of the single crystal holding device shown in FIG. 1, and the same components are denoted by the same reference numerals as in FIG.

When the polygonal link 14 of the single crystal holding device is engaged with the single crystal, the motor 34 is rotated by a command signal of the control device, and the wire 40 is wound by a predetermined amount.
The block 41 is pulled in the direction of the pulley 39. At this time, the moving shaft 43 is connected to the guide groove 44 of the guide plate 44.
a is slid from the position A to the position B, and the link pin extension shaft 42 and the link pin 14b move outward together with the block 41, so that the polygonal link body 14 is transformed from a square to a rhombus to hold a single crystal.

In the single crystal holding apparatus of the fifth embodiment, the polygonal link body is driven by using a wire instead of the holding rod in the single crystal holding apparatus of the first embodiment.
The weight of the single crystal holding device can be reduced.

[0038]

As described above, according to the single crystal holding device and the holding method of the present invention, the following effects can be obtained. (1) Unlike a conventional single crystal holding device, a narrow portion having poor shape and dimensional reproducibility is not held, and a single crystal straight body is sandwiched and held by a polygonal link body. The state is constant, and a heavy single crystal can be held more reliably. Further, the vertical position adjustment of the holding device is extremely easy as compared with the case of holding the constricted portion. (2) When the single crystal is held, by controlling the deformation speed of the polygonal link body, it is possible to hold the single crystal smoothly without giving any vibration or impact at the time of contact with the single crystal. (3) By controlling the torque of the motor driving the polygonal link or the fluid pressure of the fluid pressure actuator,
The single crystal can always be held with the desired clamping force,
Does not damage single crystals. (4) The load applied to the neck portion and the load applied to the polygonal link body are distributed based on the detected value of the load cell, and the neck portion load is controlled within an allowable range, so that the neck portion is reliably broken. Is prevented. In addition, since the neck load can be arbitrarily set within an allowable range, by setting the load distribution between the two while considering the allowable load of the single crystal holding device, the weight of the single crystal that can be pulled is increased. It is possible. (5) Since the crystal pulling wire and the polygonal link are rotated by the same motor, the rotational speeds of the two are exactly the same. Therefore, when the single crystal is held by the polygonal link, friction between the single crystal and the polygonal link caused by a slight difference in rotation speed cannot occur, and the single crystal can be held smoothly and safely. (6) In single crystal pulling using both a crystal pulling wire and a single crystal holding device, the single crystal is held while controlling the growth rate of the single crystal to a desired value, as in the case of single crystal pulling using only the crystal pulling wire. Therefore, a conventional high-precision crystal growth technique can be easily applied. (7) When the seed crystal is mounted on the seed holder, the mounting direction is selected so that the polygonal link body does not abut on the ridge line of the single crystal. Does not adversely affect the single crystal. (8) When the holding force is reduced due to the shrinkage of the single crystal, the holding force can be recovered, so that there is no danger of the single crystal falling and the safety is high. (9) If a holding member is attached to the polygonal link body as an attachment, it is possible to maintain the constricted portion even with variations in shape and dimensions.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a schematic structure of a first embodiment of a single crystal holding device.

FIG. 2 is a perspective view of a polygonal link body.

FIG. 3 is an explanatory diagram showing an example of an inner surface shape of an equilateral link forming a polygonal link body.

FIG. 4 is an explanatory diagram showing another example of the inner surface shape of the equilateral link forming the polygon link body.

FIG. 5 is an explanatory diagram showing a deformed state of a polygonal link body;
(A) shows the state before holding the single crystal, and (b) shows the state after holding the single crystal.

FIG. 6 is a schematic diagram showing a lower structure of a second embodiment of the single crystal holding device.

FIG. 7 is an explanatory view showing a lower structure of a third embodiment of the single crystal holding device.

FIGS. 8A and 8B show a polygonal link attached to the single crystal holding device of the third embodiment, wherein FIG. 8A is a top view and FIG.
It is -A sectional drawing.

FIG. 9 is an explanatory view showing another embodiment of a single crystal holding method using the single crystal holding device of the present invention.

FIG. 10 is an explanatory view showing another embodiment of a single crystal holding method using the single crystal holding device of the present invention.

FIG. 11 is a plan view showing an upper structure of a fourth embodiment of the single crystal holding device.

FIG. 12 is a Z view of FIG.

FIG. 13 is a schematic longitudinal sectional view showing a schematic structure of a fifth embodiment of the single crystal holding device.

FIG. 14 is a Z view of FIG.

FIG. 15 is a plan view of a positioning plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Single crystal manufacturing apparatus, 2 ... Vacuum container, 3 ... Crystal pulling wire, 4, 35 ... Wire winding drum, 5 ... Load cell for pulling wire, 7 ... Seed crystal, 8 ... Neck, 9
... Single crystal, 9a, 9d ... Straight body, 9b ... Constriction, 10
... single crystal holding device, 11 ... holding rod, 12, 28 ... holding rod drive motor, 14, 25 ... polygonal link body, 1
4a: equilateral link, 14b: link pin, 14e: holding member, 16: load cell for total load, 18: carriage, 26: opening prevention plate, 37, 38, 39: pulley, 40
... Polygon link body drive wire, 44 ... Guide plate.

Claims (10)

[Claims] 1. A polygonal link formed by connecting a plurality of links and being deformable in a horizontal plane by moving the position of a link pin, and means for deforming the polygonal link to sandwich a single crystal Means for rotating and raising and lowering the polygonal link in synchronization with the crystal pulling wire, a load cell for a pulling wire for detecting a load applied to the crystal pulling wire, a load applied to the crystal pulling wire and a load applied to the polygonal link A load cell for total load for detecting the total load of the above, and a control device for controlling each of the above means. 2. A crystal pulling wire take-up mechanism, a pull wire load cell, and a polygonal link body driving mechanism are housed in a vacuum container provided at an upper part of a single crystal manufacturing apparatus.
The single crystal holding device according to claim 1, wherein the vacuum container, a load cell for total load for detecting a load applied to the vacuum container, and a vacuum container rotating mechanism are mounted on a vertically movable carriage. 3. A motor or fluid pressure actuator,
A polygonal link drive mechanism consisting of two holding rods vertically held in the single crystal manufacturing apparatus and horizontally moved by the motor or the fluid pressure actuator,
2. The single crystal holding device according to claim 1, wherein a link pin located at a position facing the polygonal link body is connected to a lower end of the holding rod. 4. A polygonal link body comprising: two wire winding drums; two polygonal link body driving wires hanging from the wire winding drum; a plurality of pulleys installed at a lower end of the vacuum vessel; And a guide plate for moving a link pin of the polygonal link body in a lateral direction with the winding of the drive wire. The polygonal link body driving mechanism is provided at a lower end of the wire at a position facing the polygonal link body. 2. The single crystal holding device according to claim 1, wherein link pins are connected. 5. A single crystal shrinks by cooling, and has a holding force recovery function when the holding force of the single crystal holding device is reduced,
2. The single crystal holding device according to claim 1, wherein the holding force is maintained until the pulled single crystal is taken out of the single crystal manufacturing device. 6. A holding member having an arc-shaped cross section for holding a constricted portion of a single crystal is attached to an inner surface of a link constituting a polygonal link body. Single crystal holding device. 7. After lowering the polygonal link surrounding the single crystal to a predetermined position, the polygonal link is deformed by moving the holding rod in the horizontal direction or winding up the polygonal link drive wire to form the single crystal. A method for holding a single crystal, comprising clamping a straight body. 8. A constricted portion formed between a neck portion and a shoulder portion of a single crystal or a constricted portion formed on a straight body portion of a single crystal is held by a holding member attached to an inner surface of a polygonal link body. The method for holding a single crystal according to claim 7, wherein: 9. The single crystal according to claim 7, wherein a seed crystal or a single crystal holding device is installed so that a position where the polygonal link body contacts the single crystal does not coincide with a ridge line of the single crystal. Retention method. 10. During the growth of a single crystal, a part or all of the weight of the single crystal is borne by the single crystal holding device, and when a part of the weight is borne, the weight that does not break the neck portion is borne by the neck portion. The method for producing a crystal according to claim 7, wherein: