JP2000233992A - Device for producing single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single crystal production device which enables the pulling-up of a single crystal without causing any inclination of a holding clamp or any break of a seed crystal even when an error in take-up of a holding wire is caused. SOLUTION: This device is provided with: pulley springs 20a and 20b each of which is used as an elastic member for supporting the corresponding one of holding wires 2a and 2b used for suspending a holding clamp 13, in the pulling-up direction; and a controller 19 for controlling the take-up rate of a main wire 1 by using a manipulated variable(s) of the growth rate of a single crystal 11 and also, controlling the take-up rate of each of the holding wires 2a and 2b by using the growth rate of the single crystal 1 and another manipulated variable(s) of the growth rate, which variable(s) is used for adjusting the tension of each of the holding wires 2a and 2b to a preset load sharing tension value of the single crystal 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripper for gripping a crooked portion on an upper portion of a single crystal, at least two gripping wires connected to the gripper, and a drum for winding each of the gripping wires. A single crystal manufacturing apparatus comprising
More specifically, the present invention relates to a single crystal manufacturing apparatus capable of pulling a single crystal without tilting a holding tool and without breaking a seed crystal even when a winding error of a holding wire occurs.

[0002]

2. Description of the Related Art Conventionally, as a single crystal manufacturing apparatus of this kind,
2. Description of the Related Art A pulling apparatus based on a CZ method (Czochralski method, pulling method) in which a seed crystal is brought into contact with a polycrystalline silicon melt and gradually pulled while rotating to grow a single crystal is known.

When a single crystal is produced by the CZ method, the diameter of the single crystal must be reduced in order to eliminate dislocations generated by heat shock when the seed crystal is brought into contact with the melt and remove the single crystal from the crystal surface. "Dashes neck processing" is adopted, which is narrow and narrow.

In an apparatus employing this dashes neck treatment, the weight of a single crystal is borne by a narrowed dashes neck portion, so that the weight of a manufactured single crystal is 2%.
The dashes neck was prevented from breaking, limited to a small weight of about 0 to 100 kg.

However, recently, there has been a demand for an increase in the diameter and length of a single crystal in order to increase the efficiency of semiconductor manufacturing. An apparatus capable of pulling a single crystal without breaking a dash's neck has been proposed.

As one example, for example, Japanese Patent Application Laid-Open No. 10-27338
Japanese Patent Publication No. 1 (hereinafter referred to as "prior art A") and Japanese Patent Application Laid-Open No. 10-81581 (hereinafter referred to as "prior art B"). Are disclosed. In these prior arts A and B, even if the weight of the single crystal to be pulled is increased, the load applied to the seed crystal is increased by using a “crawl holding portion” and a “holding mechanism” (hereinafter, these are referred to as “holding tools”). The configuration in which the load is suppressed and the remaining load load is borne on the gripping tool side prevents the dashes neck portion (hereinafter, referred to as a “seed crystal portion”) from breaking.

[0007]

By the way, in the pulling control of the prior art described above, the growth load of the single crystal borne by the seed crystal portion is made constant, and the load that increases with the growth of the single crystal is borne by the holding mechanism. I have to. Specifically, at every pulling time, the growth load of the single crystal and the load on the gripping wire are detected, and the load on the spindle that is set and stored in advance is subtracted from the detected growth load of the single crystal. Find the load of the gripping wire. Then, a deviation between the obtained burden load and the detected actually measured gripping wire burden load is determined, and based on the deviation, the tension control of the gripping wire is performed so as to protect the burden load on the design value. .

However, in such a tension control, the deviation between the actually measured growth load and the designed growth load tends to be large, whereby the winding wire winding control excessively responds. As a result, the gripping wire is overwound or underwound.

That is, conventionally, when the gripping wire is excessively wound or insufficiently wound, there are the following problems. In order to explain the problems caused by "overwinding" and "insufficient winding" at this time, a description will be given using a conceptual diagram of a winding operation in a normal state and an abnormal state shown in FIG. 12 (in this example, The spindle employs an ideal solid type, and it is assumed that abnormalities of “overwinding” and “insufficient winding” occur on the left gripping wire winding drum.)

When the former overwinding occurs, the gripping wire on the overwinding side is pulled upward with respect to the main shaft and other gripping wires. As a result, the gripper is tilted, the single crystal is shifted from the center of gravity, and a poor quality single crystal is produced. When the latter winding shortage occurs, the gripping wire on the winding shortage side lowers with respect to the main shaft and the other gripping wires, that is, the wire sags. As a result, the burden load on the slack gripping wire side moves to the main shaft, especially the seed crystal portion, and in the worst case, the seed crystal portion is broken by the moved burden load and the single crystal is lost. In addition, the device may be damaged by the drop of the single crystal.

Another cause of the occurrence of "overwinding" or "insufficient winding" is, for example, a case where uneven winding (such as cross winding) is performed on a winding drum of a holding wire. Conceivable.

As described above, in the above-described conventional apparatus, when a control winding error such as "overwinding" or "insufficient winding" of the gripping wire occurs, the gripping tool is tilted, thereby deteriorating the quality of the grown single crystal. In addition, there is a problem that a tension fluctuation occurs between the gripping wire and the main shaft, and in the worst case, the seed crystal is broken.

In view of the above, the present invention solves the above-mentioned problems, and makes it possible to pull up a single crystal without inclining the holding tool and breaking the seed crystal even when a winding error of the holding wire occurs. It is an object to provide a single crystal manufacturing apparatus.

[0014]

In order to achieve the above object, the invention according to claim 1 comprises a gripper for gripping a crooked portion on an upper portion of a single crystal, and at least two grippers connected to the gripper. In a single crystal manufacturing apparatus having a holding wire and a drum for winding each of the holding wires, an elastic member for supporting a holding wire for suspending the holding tool in a pulling direction is provided.

According to a second aspect of the present invention, a seed crystal connected to a main wire is immersed in a polycrystal melt, and the main wire is wound by a drum to grow a single crystal under the seed crystal. In a single crystal manufacturing apparatus having a gripper for gripping a crack portion on the upper part of the single crystal, at least two gripping wires connected to the gripper, and a drum for winding each of the gripping wires, An elastic member that supports each gripping wire that suspends the gripper in the lifting direction,
Elastic member elongation detection means for detecting the elongation of the elastic member, growth weight detection means for detecting the growth weight of the single crystal, and the winding speed of the main wire using the manipulated variable of the growth rate of the single crystal. In addition to controlling, the winding speed of each of the holding wires is controlled by using the operation amount of the speed for adjusting the growth speed of the single crystal and the tension of each of the holding wires to a preset load sharing tension value of the single crystal. And control means for performing the control.

According to a third aspect of the present invention, in the second aspect of the present invention, the control means controls the operation amount of the speed for adjusting the tension of each of the holding wires to a preset load sharing tension value of the single crystal. The present invention is characterized in that an operation amount of a speed for applying a tension corresponding to a design value of a tension of each gripping wire to the elastic member is used.

According to a fourth aspect of the present invention, in the third aspect, a value in which a relationship between a growth length of the single crystal and a growth rate of the single crystal according to the growth length is set is stored in advance. First storage means, a growth length detection means for detecting the growth length of the single crystal, and fitting the growth length detected by the growth length detection means to the relationship stored by the first storage means. A growth rate determining means for determining a growth rate of the single crystal, and a value in which a value in which a relationship between a growth weight of the single crystal and a load sharing tension value of the holding wire according to the growth weight is set is stored in advance. 2 storage means,
Setting means for setting a control section of the gripping wire winding speed when calculating an operation amount of a speed for applying a tension corresponding to a design value of the gripping wire tension to the elastic member; The change amount of the weight detected by the growth weight detecting means in the control section was applied to the relationship stored in the second storage means, and the change amount of the load sharing tension on the design value of the gripping wire was determined. A design elongation change amount calculating means for calculating an elongation change amount on the design value of the elastic member using the load sharing tension value change amount and the elastic coefficient of the gripping wire; and calculating the calculated elongation change amount on the design value. Operating amount calculating means for converting an amount of speed using the time of the control section to calculate an operating amount for operating the growth rate of the single crystal determined by the growth rate determining means. .

According to a fifth aspect of the present invention, in the second aspect of the present invention, the control means includes an operation amount of a speed for adjusting the tension of the holding wire to a preset load sharing tension value of the single crystal. And comparing a measured tension value of the gripping wire with a design tension value, and using a manipulated variable of a speed for giving a negative feedback amount for adjusting the measured tension value to the design tension value.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the control means compares the measured tension value of the gripping wire with a design tension value and adjusts the measured tension value to the design tension value. When calculating the manipulated variable of the speed for giving the negative feedback amount to be incorporated, the weight detected by the growth weight detecting means is applied to the relation value stored in the second storage means, and the load sharing on the design value of the gripping wire is performed. Design elongation calculating means for calculating the tension, calculating the elongation of the elastic member at a design value by using the obtained load sharing tension and the elastic coefficient of the elastic member, and calculating the elongation at the calculated design value and the elasticity. Error elongation calculating means for comparing the actual elongation detected by the member elongation detecting means and calculating the error elongation between the current design value and the actually measured value, and using the calculated error elongation as the time of the control section. Change to speed And having a control input calculation means for calculating a manipulated variable to manipulate the growth rate of the single crystal is determined by the growth rate determining means is.

Further, according to the invention of claim 7, a shaft holding portion for holding a shaft connected to the seed crystal, a seed crystal connected to the shaft is immersed in a polycrystal melt, and the shaft is pulled up to remove the shaft. A shaft pulling portion for growing a single crystal under a seed crystal, a gripper for gripping a crack portion on the upper portion of the single crystal, at least two gripping wires connected to the gripper, and a shaft together with the shaft. In a single crystal manufacturing apparatus having a drum held by a holding unit and winding up each of the gripping wires, an elastic member that supports each gripping wire that suspends the gripping tool in a pulling direction, and an elastic member that detects elongation of the elastic member Elongation detection means, growth weight detection means for detecting the growth weight of the single crystal, and a pulling speed of the shaft using an operation amount of the growth speed of the single crystal. Control means for controlling the winding speed of each gripping wire by using an operation amount of a speed for adjusting the tension of each gripping wire to a preset load sharing tension value of the single crystal. It is characterized by doing.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the control means includes an operation amount of a speed for adjusting the tension of the holding wire to a preset load sharing tension value of the single crystal. And an operation amount of a speed for applying a tension corresponding to a design value of the gripping wire tension to the elastic member is used.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, a value in which a relationship between a growth length of the single crystal and a growth rate of the single crystal according to the growth length is set is stored in advance. First storage means, a growth length detection means for detecting the growth length of the single crystal, and fitting the growth length detected by the growth length detection means to the relationship stored by the first storage means. A growth rate determining means for determining a growth rate of the single crystal, and a value in which a value in which a relationship between a growth weight of the single crystal and a load sharing tension value of the holding wire according to the growth weight is set is stored in advance. 2 storage means,
Setting means for setting a control section of the gripping wire winding speed when calculating an operation amount of a speed for applying a tension corresponding to a design value of the gripping wire tension to the elastic member; The change amount of the weight detected by the growth weight detecting means in the control section was applied to the relationship stored in the second storage means, and the change amount of the load sharing tension on the design value of the gripping wire was determined. A design elongation change amount calculating means for calculating an elongation change amount on the design value of the elastic member using the load sharing tension value change amount and the elastic coefficient of the gripping wire; and calculating the calculated elongation change amount on the design value. Operating amount calculating means for converting an amount of operation of the winding speed of the gripping wire by converting the amount into a speed amount using the time of the control section.

According to a tenth aspect of the present invention, in the seventh aspect of the present invention, the control means includes an operation amount of a speed for adjusting the tension of the holding wire to a preset load sharing tension value of the single crystal. And comparing a measured tension value of the gripping wire with a design tension value, and using a manipulated variable of a speed for giving a negative feedback amount for adjusting the measured tension value to the design tension value.

According to an eleventh aspect of the present invention, in the tenth aspect, the control means compares the measured tension value of the gripping wire with a design tension value to adjust the measured tension value to the design tension value. When calculating the manipulated variable of the speed for giving the negative feedback amount to be incorporated, the weight detected by the growth weight detecting means is applied to the relation value stored in the second storage means, and the load sharing on the design value of the gripping wire is performed. Design elongation calculating means for calculating the tension, calculating the elongation of the elastic member at a design value by using the obtained load sharing tension and the elastic coefficient of the elastic member, and calculating the elongation at the calculated design value and the elasticity. Error elongation calculating means for comparing the actual elongation detected by the member elongation detecting means and calculating the error elongation between the current design value and the actually measured value, and using the calculated error elongation as the time of the control section. Speed Wherein the conversion to and an operation amount calculating means for calculating an operation amount of the take-up speed of the gripping wires.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a single crystal manufacturing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of a single crystal manufacturing apparatus according to an embodiment of the present invention. In this example, a spindle wire method in which a seed crystal (10) is raised and lowered using a wire (1) is employed. And growing single crystal (11)
The gripper (13) for gripping the crack portion (11a) of
The apparatus configuration in the case of lifting and lowering using the gripping wires (2a, 2b) is shown.

The rotation of the crystal not directly related to the present invention,
The structure for raising and lowering and rotating the crucible has been omitted to clarify the configuration requirements.

As shown in the figure, in the single crystal manufacturing apparatus of this embodiment, the holding wires a and b (2a and 2b) for hanging the holding tool (13) of the conventional apparatus are connected to pulleys a and b (8a and 8).
b), the gripping wire winding drums a, b (5a,
5b) In addition to the winding configuration, the pulleys a and b (8
a, 8b) are replaced by pulley springs a, b (20a,
20b) and the pulley springs a, b (5
a, a linear sensor 21a for detecting the amount of elongation of 5b),
21b is provided. Further, the control device 19 controls the growth weight GW [n] of the single crystal detected by the load cell (7).
And elongation of the pulley springs a, b (20a, 20b) at a design value using the elastic modulus of the pulley springs a, b (20a, 20b). Means for controlling the winding speed of the gripping wires a, b (2a, 2b) accordingly.

Here, the pulley springs (20a, 20b)
Even when a winding error ("overwinding" or "insufficient winding") of the gripping wires a, b (2a, 2b) due to the disturbance as described in the above-described prior art occurs, the gripper (13).
And a function of suppressing the load weight of the gripping wire from moving to the seed crystal (10).

In order to make the suppression function easy to understand, a description will be given with reference to a conceptual diagram of a winding operation in a normal state and an abnormal state shown in FIG. 2 (in this example, the spindle is an ideal solid state). The formula is adopted, and it is assumed that abnormalities of “overwinding” and “insufficient winding” occur on the left gripping wire winding drum side.) As shown in FIG. 2, the left-hand drawing shows that the gripping tool is horizontal, and unnecessary tension fluctuation does not occur between the main wire and the gripping wire, that is, “overwinding” and “insufficient winding” on the gripping wire side. This shows a case where no winding error has occurred. On the other hand, the figure on the right side shows an abnormal state when an unexpected disturbance causes a winding error of the gripping wire. Here, in the abnormal state shown in the figure on the right side, "overwinding" will be described first. Conventionally, if the gripping wire is overwound,
The gripping wire is pulled upward by the overwinding, and the gripping tool is tilted. In this embodiment, however, the pulley spring is provided, and the tension due to the overwinding is caused by the elasticity (absorbing action) of the pulley spring. The pulley spring is extended downward by the amount of the change, thereby suppressing the gripper from tilting. next,
The “insufficient winding” will be described. Conventionally, when the winding of the gripping wire is insufficient, the gripping wire is loosened due to the insufficient winding, and as a result, the load tension of the gripping wire moves to the seed crystal portion. Due to the (absorbing action), the pulley spring contracts upward by an amount corresponding to the tension fluctuation due to insufficient winding, thereby suppressing the movement of the load tension from the holding wire to the seed crystal due to the slack.

The absorptance of the pulley spring is determined by the elastic coefficient of the pulley spring and the gripping wire. Needless to say, in order to sufficiently obtain the characteristics of the above-described example, the pulley spring has to have a sufficient absorption characteristic. It is desirable that the elongation length is several times larger than the elongation length of the gripping wire, and one that can eliminate the disadvantages of the above-described conventional technique is used.

Also, linear sensors (21a, 21b)
Measures the amount of elongation of the pulley springs a, b (20a, 20b) at a certain point during single crystal pulling. The value of the amount of extension of the pulley spring measured at this time is output to the control device 19.

That is, according to this configuration, even if a winding error of the gripping wire occurs due to a disturbance, the tilting of the gripping tool can be suppressed by the absorbing action of the pulley spring supporting the gripping wire. It is possible to manufacture a single crystal of higher quality by pulling it at a constant level. In addition, the load acting on the holding wire can be prevented from moving to the seed crystal by the absorbing action of the pulley spring, so that the seed crystal can be prevented from breaking, and the single crystal can be safely pulled up.

According to this configuration, when the gripping wire is wound up faster than the main wire and gripped, the pulley spring expands, so that a force is slowly applied to the single crystal and no vibration is applied to the single crystal.

It is desirable that the gripper (not shown) of the gripper grips at the same time. However, even if the timing is shifted, the spring constant of the pulley spring is larger than that of the gripping wire (spring constant). Becomes smaller.

Here, the calculation timing relating to the control in this embodiment will be described. FIG. 3 is a conceptual diagram showing a relationship between a contact and a section serving as a reference for calculation timing. As shown in FIG. 3, a contact n becomes a contact 0, a contact 1,. -1, contact n, contact n + 1,
... indicates the calculation timing on the time axis. on the other hand,
The section i-1 indicates an interval between the contact point n-1 and the contact point n, and is counted as time t elapses, similarly to the contact point. The intervals at which the contacts and sections are counted are set to desired timing (for example, 1 second, 60 seconds).

Next, the drum rotation angle values (θ, θa, θ
Regarding the detection method of b), the main wire winding drive mechanism (4) and the gripping wire winding drive mechanism a shown in FIG.
The configuration of b (6a, 6b) will be described. FIG.
Since the configurations of the main wire winding drive mechanism (4) and the gripping wire winding drive mechanisms a and b (6a, 6b) are basically the same, here, the configuration of the wire winding drive mechanism is one. Only one is shown. As shown in FIG. 4, the rotation angle values (θ, θa, θ) of the main wire winding drum 3 and the gripping wire winding drums a, b (5a, 5b).
The detection of b) is performed by a rotary encoder (RE) that generates a pulse according to the rotation speed of the main wire winding drum 3 and the gripping wire winding drums a and b (5a and 5b).
(63) and the rotary encoder (RE) (6)
3) A pulse counter (P
C) and (65). FIG. 5 is a conceptual diagram showing the concept of the drum rotation angle θ. As shown in FIG. 5, the drum rotation angle θ [i-1] is different from that of the main wire winding drum 3 during the section i-1. And the angle at which the gripping wire winding drums a, b (5a, 5b) are rotated.

At this time, the drum rotation angle (θ, θ
The detection operation of a, θb) is expressed by the following equation. (In the above equation (0), θ [i−1]: interval i
-1, the drum rotation angle of the main wire winding drum (3), t [n]: time of contact n, t [n-1]: contact n-
Time 1 indicates ω (t): the rotational angular velocity of the main wire winding drum (3). ) (In the above equation (1), θa [i-1]: the drum rotation angle of the gripping wire winding drum a (5a) in the section i-1, t [n]: the time of the contact n, t [n− 1]: time of contact point n−1, ωa (t): rotational angular velocity of gripping wire winding drum a (5a).) (In the above equation (2), θb [i-1]: the drum rotation angle of the gripping wire winding drum b (5b) in the section i-1, t [n]: the time of the contact n, t [n− 1]: time of contact n−1, ωb (t): rotation angular velocity of gripping wire winding drum b (5b). FIG. 6 shows control device 19 according to the present embodiment shown in FIG. FIG. 2 is a block diagram illustrating an entire configuration, and illustrates a peripheral portion illustrated in FIG. 1 (a main wire winding drum 4, a gripping wire winding drive mechanism 6a, a gripping wire winding drive mechanism 6b, a load cell 7, a diameter sensor 15, an actual measurement diameter calculation section). 16, liquid level sensor 17, liquid level change amount calculation unit 18, linear sensor 2
1a and the configuration of the linear sensor 21b). In this control device 19, only the components related to the winding control of the main wire (1) and the holding wires a and b (2a and 2b) are shown.

Here, the main wire mechanical winding length calculating section 191 calculates the main wire mechanical winding length based on θ obtained from the main wire winding driving mechanism 4.

The TS [n] calculating section 192 calculates the crystal weight GW [n] measured by the load cell 7 and the THa calculated by the THa [n] calculating section 197 described later.
[N] (load tension of gripping wire a (2a)) and TH
The load tension (TS [n]) applied to the main wire (1) is calculated using THb [n] (load tension of the gripping wire b (2b)) calculated by the b [n] calculation unit 199. The arithmetic expressions used at this time are shown below.

[0040] (Where, GW [n]: crystal weight measured by the load cell 7 at the contact n, THa [n]: load tension value of the gripping wire a (2a) at the contact n, THb [n]: at the contact n (The load tension value of the gripping wire b (2b)) Further, the main wire elongation correction unit 193 detects the main wire winding drum 3 detected by the main wire winding drive mechanism 4.
Using the rotation angle θ, the TS [n] calculated by the TS [n] calculation unit 192, and various design values, the main wire elongation in the control section and the main wire taking the elongation into consideration. Of operation (SLCw
[N]) is calculated. The calculation method at this time will be specifically described using an arithmetic expression.

First, a case where the amount of elongation of the main wire in a certain control section is obtained will be described. In order to determine the amount of elongation of the wire, the amount of change in the elongation at the portion wound on the drum and the amount of change in the elongation at the portion hanging down from the drum may be determined.

Therefore, first, when calculating the amount of change in the elongation length at the portion of the main wire wound on the drum, the following equation is used. (Where (delta) SLWELW [i-1]: section i
-1, change in elongation length at the main wire winding drum (3), rd: radius of the main wire winding drum (3), r
w: radius of main wire (1), φ: traverse angle of main wire (1) wound on main wire winding drum (3), θ [i-1]: main wire winding drum in section i-1 (3) drum rotation angle, ε (TS [n]): contact point n
TS [n]: Load tension applied to the main wire (1) at the contact n, ε (TS [n-1]): Elongation at the contact n-1, TS [n-1]: Contact n- 1 main wire (1)
Load tension applied to) (Here, SLWELW [n]: extension length of the contact n at the main wire winding drum (3), (delta) SLWEL
W [k]: change amount of elongation length at the main wire winding drum (3) in section k).

When the amount of change in the extension length in the hanging part hanging down from the main wire winding drum (3) is determined, the following equation is used. (Where, SLWELS [n]: extension length of the hanging part of the contact n, rd: radius of the main wire winding drum (3), r
w: radius of main wire (1), φ: traverse angle of main wire (1) wound on main wire winding drum (3), θ [k]: main wire winding drum (3) in section k
Rotation angle, SLWEW [n]: extension length of the contact n at the main wire winding drum (3), ε (TS [n]):
Elongation rate of contact n, TS [n]: load tension applied to main wire (1) of contact n), (Where (delta) SLWELS [i-1]: section i
−1, SLWELS [n]: hanging length of contact n, SLWELS [n−1]: contact n−
1 hanging part extension length).

As described above, the actual growth length of the single crystal can be obtained more accurately by obtaining the amount of extension of the main wire (1) in a certain control section.

Next, using the obtained amount of elongation, an operation amount (SLCw) for controlling the winding speed of the main wire is used.
[N]) will be described.

When calculating the manipulated variable (SLCw [n]), the following equation is used: (Where, SLCw [n]: main wire of contact n (1)
Manipulated variable to correct the elongation of (Delta) SLWELW [i
-1]: Elongation change amount of winding portion in section i-1, (Delta) SLWELS [i-1]: Elongation change amount of hanging part in section i-1, (Delta) t [i-1]: Section i-1) is calculated.

With the calculated operation amount, it is possible to correct a control deviation due to the extension of the main wire (1).

The GR [n] calculating section 194 calculates the main wire winding length calculated by the main wire mechanic winding length calculating section 191 based on θ obtained from the main wire winding driving mechanism 4 and the main wire winding length. Actual growth of the single crystal obtained from the elongation amount of the main wire calculated by the wire elongation correction unit 193 and the liquid level change amount ((delta) MP) calculated by the liquid level sensor 17 and the liquid level change amount calculating unit 18. Length (GL
[N]), the growth rate (GR) of the single crystal is determined. That is, GR [n] is a base of the wire winding speed. Specifically, the relationship between the growth length (GL [n]) of the single crystal and the growth rate (GR [n]) of the single crystal according to the growth length (GL [n]) was set. A table for storing values in advance is provided.
The corresponding GR [n] is determined according to [n].

The target diameter calculating section 195 calculates the target diameter using the actual growth length (GL [n]) of the single crystal. Specifically, the target diameter calculation section 195 specifically calculates the actual growth length of the single crystal. (G
L [n]) and a table that stores in advance a value in which a relationship between the target diameter of the single crystal according to the actual growth length (GL [n]) is stored, and according to the input GL [n]. The target diameter value of the corresponding single crystal is calculated.

The diameter control manipulated variable calculator 196 (PI
D control or the like) is based on the target diameter value calculated by the target diameter calculation unit 195 and the actually measured diameter value GD of the single crystal calculated using the diameter sensor 15 and the actually measured diameter calculation unit 16.
Based on the deviation from [n], an operation amount (SLC (FB) [n]) for protecting the diameter of the single crystal is calculated.

The THa [n] calculating section 197 calculates the pulley spring a (20) measured by the linear sensor 21a.
a) (LSa [n] -LSa [0]) and the pulley spring a (20) stored in a design value storage unit 205 described later.
Using the elastic modulus (spring constant [mm / kg]) ksa of a), the load tension (T
Ha [n]) is calculated. The arithmetic expressions used at this time are shown below.

[0052] (Here, LSa [n] -LSa [0]: pulley spring a (20) measured by the linear sensor 21a at the contact n.
a) elongation, ksa: elastic modulus of the pulley spring) The gripping wire a elongation correction unit 198 rotates the gripping wire winding drum a (5a) detected by the gripping wire winding drive mechanism a (6a). Using the angle θa, THa [n] calculated by the THa [n] calculation unit 197, and various design values, the amount of extension of the gripping wire a (2a) in the control section and the amount of extension are considered. Holding wire a (2a)
Is calculated (HLaCw [n]). The calculation method at this time will be specifically described using an arithmetic expression.

First, the gripping wire a in a certain control section
The case of obtaining the elongation amount of (2a) will be described. To determine the amount of elongation of the wire, in the same way as for the main wire described above, the amount of change in elongation at the part wound on the drum and the change in elongation at the part hanging down from the drum What is necessary is just to obtain the amount.

Therefore, first, when calculating the amount of change in the extension length at the portion of the gripping wire a (2a) wound on the drum, the following equation is used. (Here, (Delta) HLaWELW [i-1]: the amount of change in the extension length at the gripping wire winding drum a (5a) in section i-1, rda: gripping wire winding drum a
(5a) radius, rwa: radius of gripping wire a (2a), φa: traverse angle of gripping wire a (2a) wound on gripping wire winding drum a (5a), θa
[I-1]: gripping wire winding drum a in section i-1
(5a) drum rotation angle, εa (THa [n]): elongation percentage of contact n, THa [n]: gripping wire a of contact n
The load tension applied to (2a), εa (THa [n−
1]): Elongation percentage of contact n-1, THa [n-1]: Load tension applied to gripping wire a (2a) of contact n-1)
When, (Here, HLaWELW [n]: extension length of the contact n at the gripping wire winding drum a (5a), (delta) H
LaWELW [k]: the amount of change in the extension length at the gripping wire winding drum a (5a) in section k).

When the amount of change in the extension length of the gripping wire a (2a) in the hanging part hanging down from the drum is calculated, the following equation is used. (Here, HLaWELS [n]: the length of the hanging portion of the contact n, WILa: the length of the gripping wire a (2a) hanging from the gripping wire winding drum a (5a) when gripping is started (contacted) , “Wire initial hanging length”), rda: radius of gripping wire winding drum a,
rwa: radius of gripping wire a (2a), φa: traverse angle of gripping wire a (2a) wound on gripping wire winding drum a (5a), θa [k]: gripping wire winding drum a in section k Rotation angle, HLaWELW
[N]: gripping wire winding drum a (5a) for contact n
Elongation length at the part, εa (THa [n]): elongation rate of contact n, THa [n]: load tension applied to gripping wire a (2a) of contact n), (Here, (Delta) HLaWELS [i-1]: the amount of change in the extension of the hanging portion in the section i-1, HLaWELS [n]:
This is calculated by executing the hanging extension length of the contact n, HLaWELS [n-1]: the hanging extension length of the contact n-1.

Thus, the amount of extension of the gripping wire 2 (2a) in a certain control section is obtained.

Next, a description will be given of a case where the operation amount (HLaCw [n]) for operating the winding speed of the gripping wire 2 (2a) is calculated by using the obtained amount of elongation.

When calculating the manipulated variable (HLaCw [n]), the following equation is used: (HLaCw [n]: gripping wire a for contact n (2a)
Manipulated variable to correct the elongation of (Delta) HLaWELS
[I-1]: change in elongation of the winding portion in section i-1; (delta) HLaWELS [i-1]: change in elongation of the hanging part in section i-1; (delta) t [i-1] : Time in section i-1).

Based on the calculated operation amount, it is possible to correct a control deviation due to the extension of the gripping wire a (2a).

The THb [n] calculation unit 199 calculates the pulley spring b (20) measured by the linear sensor 21b.
b) (LSb [n] −LSb [0]) and the pulley spring b (20) stored in a design value storage unit 205 described later.
Using the elastic modulus (spring constant [mm / kg]) ksb of b), the load tension (T) applied to the gripping wire a (2a)
Hb [n]). The arithmetic expressions used at this time are shown below.

[0061] (Here, LSb [n] -LSb [0]: pulley spring b (20) measured by the linear sensor 21b at the contact n
b) elongation, ksb: elastic coefficient of the pulley spring) The gripping wire b elongation correction unit 200 rotates the gripping wire winding drum b (5b) detected by the gripping wire winding drive mechanism b (6b). The angle θb and the above TH
THb [n] calculated by b [n] calculation unit 199,
Using various design values, gripping wire b in control section
(2b) and the winding speed of the gripping wire b (2b) in consideration of the amount of extension (that is, the GR
[N]) is calculated (HLbCw [n]). The calculation method at this time will be specifically described using an arithmetic expression.

First, the gripping wire b in a certain control section
The case of obtaining the amount of elongation of (2b) will be described. In order to obtain the amount of elongation of the wire, the amount of change in the elongation at the part wound on the drum and the amount of change in the elongation at the part hanging down from the drum may be obtained.

Therefore, first, when obtaining the amount of change in the extension length at the portion of the gripping wire b (2b) wound on the drum, the following equation is used. (Here, (delta) HLbWELW [i-1]: the amount of change in elongation length at the gripping wire winding drum b (5b) portion in section i-1, rdb: gripping wire winding drum b
(5b) radius, rwb: radius of gripping wire b (2b), φb: traverse angle of gripping wire b (2b) wound on gripping wire winding drum b (5b), θb
[I-1]: gripping wire winding drum b in section i-1
(5b) Drum rotation angle, εb (THb [n]): elongation percentage of contact n, THb [n]: gripping wire b of contact n
The load tension applied to (2b), εb (THb [n−
1]): Elongation percentage of contact n-1, THb [n-1]: Load tension applied to gripping wire b (2b) of contact n-1)
When, (Here, (Delta) HLbWELW [n]: Extension length of the contact n at the gripping wire winding drum b (5b) portion,
(Delta) HLbWELW [k]: change amount of the extension length at the gripping wire winding drum b (5b) in section k).

When the amount of change in the length of extension of the gripping wire b (2b) in the hanging part hanging down from the drum is calculated, the following equation is used. (Here, HLbWELS [n]: the length of the hanging portion of the contact n, WILb: the length of the gripping wire b (2b) hanging from the gripping wire winding drum b (5b) when gripping is started (contacted) , “Wire initial hanging length”), rdb: radius of gripping wire winding drum b,
rwb: radius of gripping wire b (2b), φb: traverse angle of gripping wire b (2b) wound on gripping wire winding drum b (5b), θb [k]: gripping wire winding drum b in section k Rotation angle of HLbWELW
[N]: Winding drum b (5b) for gripping wire at contact point n
Elongation length at the part, εb (THb [n]): elongation percentage of contact n, THb [n]: load tension applied to gripping wire b (2b) of contact n), (Where (delta) HLbWELS [i-1]: the amount of change in the extension of the hanging portion in section i-1, HLbWELS [n]:
It is calculated by executing the hanging length of the contact n, HLbWELS [n-1]: the hanging length of the contact n-1.

Thus, the amount of extension of the gripping wire 2 (2b) in a certain control section is obtained.

Next, a description will be given of a case where the operation amount (HLbCw [n]) for operating the winding speed of the gripping wire 2 (2b) is calculated using the obtained elongation amount.

When calculating the manipulated variable (HLbCw [n]), the following arithmetic expression is used. (HLbCw [n]: gripping wire b of contact n (2b)
Manipulated variable to correct the elongation of (Delta) HLbWELS
[I-1]: change in elongation of the winding portion in section i-1; (delta) HLbWELS [i-1]: change in elongation of hanging part in section i-1; (delta) t [i-1] : Time in section i-1).

With the calculated operation amount, it is possible to correct a control deviation due to the extension of the gripping wire b (2b).

The pulley spring a elongation correction unit 201 calculates the growth weight GW [n] of the single crystal (11) detected by the load cell 7 and the growth weight of the single crystal stored in the design value storage unit 205 in advance. Using the load sharing tension value information (see FIG. 7) indicating the relationship with the load sharing tension value of the corresponding holding wire a (2a) and the elastic coefficient (ksa) of the pulley spring a (2a), the holding wire suspension. An operation amount (HLaCs) for winding the gripping wire b (2b) by an amount corresponding to the elongation of the pulley spring a (20a) based on the design value (THP) of the tension.
[N]) is calculated. This operation amount has two meanings, and as a first meaning, by adjusting the pulley spring a (20a) to the elongation by the design value (THP) of the gripping wire suspension tension, as shown in FIG. Gripping wire a
(2a) Load sharing, that is, tension control. As a second meaning, the length of the pulley a (8a) lowered cancels out, that is, the pulley spring a (20a) is extended by the stretched weight of the pulley spring a (20a) along with the growth weight of the single crystal.
Is to wind up.

Specifically, the crystal weight (GW [n]) of a single crystal in a certain control section detected by the load cell 7,
(GW [n-1]) is applied to the load sharing tension value information (see FIG. 7) to determine the amount of change in the load tension of the gripping wire on the design value. And this value is doubled and the pulley spring a
(20a) is converted into the amount of change in tension, and this value is used as the pulley spring a
The elongation change amount of the pulley spring a (20a) on the design value is predicted by multiplying the elastic coefficient (ksa) of (20a). Then, the amount of change in elongation is divided by the time displacement (delta) t [i-1] of the control section to convert the amount into a speed amount. And finally, this value is doubled. This is because, when correcting the elongation (height) of the pulley spring a (2a), the elongation (height) can be corrected by taking up twice the elongation (height) with the winding drum.

The calculation method will be specifically described using an arithmetic expression.

When calculating the manipulated variable (HLaCs [n]), the following arithmetic expression is used. (Here, HLaCs [n]: single crystal of contact n (11)
A manipulated variable for correcting the extension of the pulley spring (20a) due to the growth weight of THP (GW [n]): single crystal of contact n (1
1) Load tension of gripping wire on design value based on growth weight, THP (GW [n-1]): Load tension of gripping wire on design value by growth weight of single crystal (11) at contact point n-1, ksa: elastic modulus of the pulley spring a (20a),
(Delta) t [i-1]: time in section i-1).

Further, the pulley spring b elongation correction unit 202 operates similarly to the above-described pulley spring a elongation correction unit 201 to calculate the growth weight G of the single crystal (11) detected by the load cell 7.
Load sharing tension value information (see FIG. 7) indicating the relationship between W [n] and the load sharing tension value of the gripping wire according to the single crystal growth weight stored in advance in the design value storage unit 205; pulley spring b based on the design value (THP) of the gripping wire suspension tension using the elastic modulus (ksb) of b (2b)
(20b) of the gripping wire b (2
b) Calculate the operation amount (HLbCs [n]) for involving. This operation amount has two meanings.
By adjusting the pulley spring b (20b) to the elongation by the design value (THP) of the gripping wire suspension tension, load sharing of the gripping wire b (2b) as shown in FIG. Is to do. Also, the second
Means that the length of the pulley b (8b) lowered cancels out, that is, the pulley spring b (20) increases with the growth weight of the single crystal.
b) winds up the gripping wire b (2b) by the amount of extension.

Specifically, the crystal weight (GW [n]) of a single crystal in a certain control section detected by the load cell 7;
(GW [n-1]) is applied to the load sharing tension value information (see FIG. 7) to determine the amount of change in the load tension of the gripping wire on the design value. Then, this value is doubled and the pulley spring b
(20b) and the pulley spring b
The elongation change amount of the pulley spring b (20b) on the design value is predicted by multiplying the elastic coefficient (ksb) of (20b). Then, the amount of change in elongation is divided by the time displacement (delta) t [i-1] of the control section to convert the amount into a speed amount. And finally, this value is doubled. This is because, when correcting the elongation (height) of the pulley spring b (2b), the elongation (height) can be corrected by taking up twice the elongation (height) with the winding drum.

The calculation method will be specifically described using an arithmetic expression.

When calculating the manipulated variable (HLbCs [n]), the following arithmetic expression is used. (Here, HLbCs [n]: single crystal of contact n (11)
A manipulated variable for correcting the extension of the pulley spring b (20b) due to the growth weight of THP (GW [n]): single crystal of contact n (1
1) Load tension of gripping wire on design value based on growth weight, THP (GW [n-1]): Load tension of gripping wire on design value by growth weight of single crystal (11) at contact point n-1, ksb: elastic modulus of the pulley spring b (20b),
(Delta) t [i-1]: time in section i-1).

The pulley spring a extension error correction unit 203
Is the growth weight (GW [n]) of the single crystal detected by the load cell (7) and the load sharing tension value of the gripping wire according to the single crystal growth weight stored in the design value storage unit 205 in advance. Load sharing tension value information indicating the relationship (see FIG. 7)
And the elastic modulus (ksa) of the pulley spring a (20a) and the pulley spring a measured by the linear sensor a (21a)
The measured elongation length of (20a) (LSa [n] -LSa
[0]), the error elongation between the actual measured elongation and the designed elongation of the pulley spring a (2a) at the present time is obtained, and the gripping wire a is obtained from the obtained error elongation. (2
An operation amount (HLaCsd) for operating the winding speed of a) (that is, the above GR [n]) is calculated. In addition, the meaning of this operation amount is the gripping wire a due to each disturbance factor.
This is for performing negative feedback control on the load tension error of (2a).

More specifically, the weight of the single crystal (GW [n]) detected at a certain point in time by the load cell 7 is applied to the load sharing tension value information (see FIG. 7) to obtain a grip on the design value. Find the load tension of the wire. Then, this value is doubled and converted into the amount of change in tension of the pulley spring a (20a), and this value is converted into the elastic coefficient (ks) of the pulley spring a (20a).
By multiplying by a), the amount of elongation of the pulley spring a (20a) at the design value is predicted. Then, this value is converted to the pulley spring a (20) measured by the linear sensor a (21a).
Actual elongation of a) (LSa [n] -LSa [0])
From the actual value of the pulley spring a (20a) at the present time and the designed value to calculate the error elongation. Then, this value is converted into a speed amount by dividing the value by the time of the control section. And finally, this value is doubled. This is because, when correcting the elongation (height) of the pulley spring a (2a), the elongation (height) can be corrected by taking up twice the elongation (height) with the winding drum.

The calculation method will be specifically described using an arithmetic expression.

When calculating the manipulated variable (HLaCsd), the following equation is used: (Here, HLaCsd: an operation amount for correcting a winding error of the gripping wire a (2a) due to a disturbance at the contact point n, LS
a [n]: length of the measured pulley spring a (20a) at the contact n, LSa [0]: measured pulley spring a at the contact 0
(20a) length, THP (GW [n]): tension value of gripping wire on design value based on growth weight of single crystal (11) at contact point n, ksa: elastic modulus of pulley spring a (20a), (Delta) t [i-1]: time in section i-1).

The pulley spring b extension error correction unit 204
Is the growth weight (GW [n]) of the single crystal detected by the load cell (7) and the load sharing tension value of the gripping wire according to the single crystal growth weight stored in the design value storage unit 205 in advance. Load sharing tension value information indicating the relationship (see FIG. 7)
And the elastic modulus (ksb) of the pulley spring b (20b) and the pulley spring b measured by the linear sensor b (21b)
(20b) measured elongation length (LSb [n] -LSb
[0]), the error elongation between the actual measured elongation and the designed elongation of the pulley spring b (2b) at this time is obtained, and the gripping wire b is obtained from the obtained error elongation. (2
An operation amount (HLbCsd) for operating the winding speed of b) (that is, the above GR [n]) is calculated. The meaning of this operation amount is the gripping wire b caused by each disturbance factor.
This is for performing negative feedback control on the error of the load tension of (2b).

More specifically, the crystal weight (GW [n]) of the single crystal at a certain point in time detected by the load cell 7 is applied to the load sharing tension value information (see FIG. 7) to obtain a grip on the design value. Find the load tension of the wire. Then, this value is doubled and converted into the amount of change in the tension of the pulley spring b (20b), and the elastic coefficient (ks) of the pulley spring b (20b) is converted into this value.
By multiplying by b), the amount of elongation of the pulley spring b (20b) at the design value is predicted. Then, this value is used as the pulley spring b (20) measured by the linear sensor b (21b).
b) Actual elongation of b) (LSb [n] -LSb [0])
From the actual value of the pulley spring b (20b) at the present time and the designed value to calculate the error elongation. Then, this value is converted into a speed amount by dividing the value by the time of the control section. And finally, this value is doubled. This is because, when correcting the elongation (height) of the pulley spring b (2b), the elongation (height) can be corrected by taking up twice the elongation (height) with the winding drum.

The calculation method will be specifically described using an arithmetic expression.

When calculating the manipulated variable (HLbCsd), the following equation is used: (Here, HLbCsd: an operation amount for correcting a winding error of the gripping wire b (2b) due to a disturbance at the contact point n, LS
b [n]: length of the measured pulley spring b (20b) at the contact n, LSb [0]: measured pulley spring b at the contact 0
(20b) length, THP (GW [n]): tension value of gripping wire on design value by growth weight of single crystal (11) at contact point n, ksb: elastic modulus of pulley spring b (20b),
(Delta) t [i-1]: time in section i-1).

Note that the design value storage unit 205 stores data such as rd, rw, φ, WIL, ksa, and ksb used in the above arithmetic expressions.

As described above, by performing the above processing,
The operation amount of the winding speed of the main wire (1) is expressed by the following relational expression. Is defined by Then, this SL becomes a winding speed setting signal for the main wire (1) and is output to the main wire winding driving mechanism 4. As a result, the main wire winding drive mechanism 4 uses the main wire winding drum 3 based on the SL.
Adjust the rotation speed of the.

The operation amount of the winding speed of the gripping wire a (2a) is expressed by the following relational expression. Is defined by And this HLa is the gripping wire a
It becomes the winding speed setting signal of (2a), and the gripping wire a
It is output to the winding drive mechanism 6a. Thus, the gripping wire a winding drive mechanism 6a adjusts the rotation speed of the gripping wire winding drum a (5a) based on the HLa.

The operation amount of the winding speed of the gripping wire b (2b) is expressed by the following relational expression. Is defined by And this HLb is the gripping wire b
It becomes the winding speed setting signal of (2b), and the gripping wire b
It is output to the winding drive mechanism 6b. Thus, the gripping wire b winding drive mechanism 6b adjusts the rotation speed of the gripping wire winding drum b (5b) based on the HLb.

The pulley spring a extension error correction unit 20
2 is subtracted from the operation amount (HLaCsd) and the operation amount (HLbCsd) calculated by the pulley spring b extension error correction unit 204, that is, the reason why the operation amount has a negative sign is shown in FIG.
This will be described with reference to FIG. As shown in FIG. 2, when a winding error of the gripping wire occurs, for example, when the wire is overwound, the pulley spring expands due to the absorbing action, and the position of the pulley decreases. In other words, to correct this error in winding control,
Reverse winding, that is, the operation of sending out the gripping wire,
That is, an operation of reducing the winding speed of the gripping wire must be performed. When the winding is insufficient, the pulley spring contracts due to the absorbing action, and the position of the pulley is raised. Therefore, in order to correct the error in the winding control, it is necessary to perform a forward winding, that is, an operation of winding more gripping wires, that is, an operation of increasing the winding speed of the gripping wires. Therefore, in order to realize this control, the operation amount obtained by subtracting the expansion amount on the design value from the actual expansion amount is subtracted from the winding speed of the gripping wire, that is, the operation amount has a negative sign. There is a need.

By controlling the winding of the gripping wire described above, unexpected disturbances are corrected while correcting the elongation of the pulley springs a and b (20a, 20b) accompanying the growth weight of the single crystal (11). The single crystal can be pulled up while correcting the winding error due to. That is, the problem caused by the provision of the pulley springs a and b (20a, 20b) shown in FIG. 1 is eliminated, and the pulling speed of the gripping wire generated by each negative factor, that is, the actual crystal growth speed (GR)
Since the gripping wire can be wound up while correcting the deviation from the above, a more accurate pulling control can be realized and a high-quality single crystal can be manufactured.

In this embodiment, both the load cell 7 and the diameter sensor 15 are used. Instead of the SLC (FB) [n] based on the diameter sensor signal, the SLC (FB) [n] based on the load cell signal is replaced with the SLC (FB) [n] based on the load cell signal. It is also possible to use a configuration that performs calculations and does not use an optical sensor. Instead of the crystal weight GW [n] measured by the load cell 7, the actual growth length GL [n] of the single crystal and the diameter value GD [n] based on the optical sensor signal or the target diameter obtained from the target diameter calculator 195. It is also possible to calculate the crystal weight by using, and to use a configuration without using a load cell.

In the above-described single crystal manufacturing apparatus, when the liquid level movement control is performed, the following equation is used. (Where, Vmp: manipulated variable of crucible speed for liquid level movement at crystal length La-Lb, MPb-MPa: crystal length L
A pull-up condition for changing the liquid level from MPa to MPb between a and Lb, Tab (t): changing the crystal length from La to Lb
(The time required to grow the liquid), the operation amount Vmp of the crucible speed for the liquid level movement is calculated.

Then, the calculated amount of operation is divided into the amount of operation of the winding speed of the main wire defined by the above-mentioned relational expression (22) and the gripping wire a ( The operation amount of the winding speed of 2a) and the operation amount of the winding speed of the gripping wire b (2b) defined by the above-mentioned relational expression (24) are added. At this time, the calculated operation amount is also added to the operation amount of the crucible lifting speed which is not directly related to the present invention.

Thus, the winding control in consideration of the liquid level movement control can be executed.

FIGS. 7 to 9 are graphs of various design value information stored in the set value storage unit 205 shown in FIG. In this embodiment, 500 kg of the polycrystalline silicon melt is charged into the crucible 14 shown in FIG. 1, and it is possible to pull up a maximum of 450 kg of a single crystal, and to manufacture a single crystal when there are two gripping wires. This shows the design value information of the device.

FIG. 7 is a characteristic graph showing the ratio of the load tension value of the main wire (1) and the holding wires a, b (2a, 2b) according to the growth weight GW of the single crystal. in this case,
The main wire was supported until the crystal growth weight (GW) reached 100 kg.
3) is lowered. Then, after gripping the cracked portion (11a) of the single crystal (11) shown in FIG. 1 with the gripping tool (13), for example, at the first plot point, a load tension of 20 kg is applied to the main wire (1) side, Gripping wires a, b
A load tension of 40 kg is applied to each of the (2a, 2b) sides, and increases at this rate in the following.

FIG. 8 shows pulley springs a and b (20
a, 20b) is a characteristic graph showing characteristics of a load tension value and a crystal weight (GW) according to 20b). As can be seen from the figure, the load tension value applied to the pulley springs a, b (20a, 20b) is twice as large as the load tension applied to the gripping wires a, b (2a, 2b).

FIG. 9 shows pulley springs a and b (20
a, 20b) is a characteristic graph showing characteristics of an elongation value and a pulley spring tension value, that is, pulley springs a, b (20).
a, 20b) of the elastic coefficient (spring constant [mm / kg]). It is desirable that this value be prepared for each pulley spring to be used.

FIG. 10 is a numerical representation of data at an arbitrary plot point in FIGS. 7 to 9.

Next, as another modification of the single crystal manufacturing apparatus shown in FIG. 1, a case in which a pulling mechanism using a solid shaft is adopted as a main shaft will be described.

FIG. 11 is a diagram showing a schematic configuration of a main part of a single crystal manufacturing apparatus in a case where a pulling mechanism using a solid shaft is adopted as a main shaft. The same reference numerals are used for the same components as those shown in FIG. This will be described with reference to FIG.

As shown in FIG. 11, in this single crystal manufacturing apparatus, the holding wire winding drums a and b (FIG. 11) are mounted on the shaft holding portion (32) for holding the shaft (31) connected to the seed crystal (10). 5a, 5b) and the gripping wire winding drive mechanisms a, b (6a, 6b) are integrally held.

In the configuration in which the main shaft is a solid shaft, the winding speed SL of the main wire (1) is
Changed to the shaft lifting speed, the following relational expression Is defined by Then, this SL becomes a setting signal of the shaft lifting speed and is output to the shaft lifting portion. As a result, the shaft lifting section adjusts the shaft lifting speed based on the SL.

The winding speed of the gripping wire a (2a) is expressed by the following relational expression. Is defined by And this HLa is the gripping wire a
It becomes the winding speed setting signal of (2a), and the gripping wire a
It is output to the winding drive mechanism 6a. Thus, the gripping wire a winding drive mechanism 6a adjusts the rotation speed of the gripping wire winding drum a (5a) based on the HLa.

The winding speed of the gripping wire b (2b) is expressed by the following relational expression. Is defined by And this HLb is the gripping wire b
It becomes the winding speed setting signal of (2b), and the gripping wire b
It is output to the winding drive mechanism 6b. Thus, the gripping wire b winding drive mechanism 6b adjusts the rotation speed of the gripping wire winding drum b (5b) based on the HLb.

That is, in this configuration, the shaft holding portion (32) for holding the solid shaft (31) of the main shaft is
Since the gripping wire winding drums a and b (5a and 5b) and the gripping wire winding drive mechanisms a and b (6a and 6b) are integrated and held, the operation amount of the speed at which the solid shaft of the main shaft is pulled up is reduced. GR [n] and SLC
(FB) [n], the manipulated variables for the winding speed of the gripping wire include the GR [n] and the SLC
(FB) [n] becomes unnecessary. Also in this case, when the liquid level movement control is performed, if Vmp is added to the main shaft, the operation amount of the winding speed on the grip side becomes unnecessary.
Needless to say, since the main shaft is a solid shaft, the operation amount of the pulling speed of the main shaft does not require the operation amount of the wire elongation correction.

[0107]

As described above, according to the present invention,
An elastic member is provided for supporting the gripping wire for suspending the gripping tool in the lifting direction. Therefore, even when a winding error of the gripping wire occurs, the gripping tool is prevented from tilting due to the absorbing action of the elastic member, and the gripping wire is prevented. Can be suppressed from moving to the seed crystal portion, thereby making it possible to pull up the single crystal while keeping the crystal growth axis constant. Of the seed crystal portion caused by the movement of the single crystal can be prevented, and damage to the apparatus due to loss of the single crystal and falling of the single crystal can be prevented.

Further, according to the present invention, an elastic member for supporting each gripping wire for suspending the gripping tool in the lifting direction, an elastic member elongation detecting means for detecting the elongation of the elastic member,
Growth weight detecting means for detecting the growth weight of the single crystal, and controlling the winding speed of the main wire using the manipulated variable of the growth speed of the single crystal, and controlling the winding speed of each gripping wire to the single crystal. Control means for controlling the growth rate and the tension of each gripping wire using an operation amount of a speed that is adjusted to a preset load-sharing tension value of the single crystal. Compared with the control, the part necessary for tension control is minimized, and more stable single crystal pulling control is possible,
Since the problem caused by the provision of the elastic member can be eliminated, and the gripping wire can be wound up while correcting the lifting speed of the gripping wire caused by each negative factor, that is, the deviation from the actual crystal growth speed (GR). ,
Higher-precision pulling control can be realized to produce a high-quality single crystal.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a single crystal manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 shows a state in which a gripping wire is normally wound in a single crystal manufacturing apparatus according to an embodiment of the present invention;
FIG. 4 is a conceptual diagram illustrating a state in which a winding error has occurred.

FIG. 3 is a conceptual diagram illustrating a relationship between a contact point and a section serving as a reference for calculation timing.

4 shows a gripping wire winding drive mechanism 6a shown in FIG.
The figure which shows the whole structure of 6b.

FIG. 5 is a conceptual diagram showing a concept of a drum rotation angle θ.

FIG. 6 is a block diagram showing a detailed configuration of a control device 19 shown in FIG. 1 according to the present embodiment.

FIG. 7 is a characteristic graph showing a ratio of a load tension value of a main wire (1) and gripping wires a, b (2a, 2b) according to a growth weight GW of a single crystal.

FIG. 8 shows pulley springs a and b (20a and 20b) on design values.
Is a characteristic graph showing characteristics of a load tension value and a crystal weight (GW) according to the present invention.

FIG. 9 shows pulley springs a and b (20a and 20b) on design values.
5 is a characteristic graph showing characteristics of an elongation value and a pulley spring tension value.

FIG. 10 is a table showing various kinds of design value information at predetermined points on the characteristic graphs shown in FIGS. 7 to 9;

FIG. 11 is a diagram showing a schematic configuration of a main part of a single crystal manufacturing apparatus when a pulling mechanism using a solid shaft is adopted as a main shaft.

FIG. 12 is a conceptual diagram showing a state in which the gripping wire in the conventional device is normally wound, and a state in which a winding error occurs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main wire 2a ... Holding wire a 2b ... Holding wire b 3 ... Main wire winding drum 4 ... Main wire winding drive mechanism 5a ... Holding wire winding drum a 5b ... Holding wire winding drum b 6a ... Holding wire winding Take-up drive mechanism a 6b gripping wire take-up drive mechanism b 61 motor 62 gear 63 rotary encoder 64 motor amplifier 65 pulse counter 7 load cell 8a pulley a 8b pulley b 9 seed crystal holding unit 10 Seed crystal 11 ... Single crystal 11a ... Crack portion 12 ... Polycrystalline silicon melt 13 ... Gripping tool 14 ... Crucible 15 ... Diameter sensor 16 ... Measured diameter calculation unit 17 ... Liquid level sensor 18 ... Liquid level change amount calculation unit 19 ... Control Device 191: Main wire winding length calculation unit 192: TS [n] calculation unit 193: Main wire extension And correction section 194 GR [n] calculation section 195 target diameter calculation section 196 diameter control operation amount calculation section (PID) 197 THa [n] calculation section 198 gripping wire a elongation correction section 199 THb [n] Calculation unit 200: gripping wire b extension correction unit 201: pulley spring a extension correction unit 202: pulley spring b extension correction unit 203: pulley spring a extension error correction unit 204: pulley spring b extension error correction unit 205: design value storage unit 206 Vmp calculation unit 20a Pulley spring a 20b Pulley spring b 21a Linear sensor a 21b Linear sensor b 31 Solid shaft 32 Shaft holding unit 33 Load cell 34 Shaft holding unit pull-up unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Kumagai 2612 Shinomiya, Hiratsuka-shi, Kanagawa Prefecture, Komatsu Electronic Metals Co., Ltd. (Reference) 4G077 AA02 BA04 CF10 EG12 EG27 EH10 PG01

Claims (11)

[Claims] An apparatus for producing a single crystal, comprising: a gripper for gripping a crooked portion on an upper portion of a single crystal; at least two gripping wires connected to the gripper; and a drum for winding each gripping wire. The single crystal manufacturing apparatus according to any one of claims 1 to 3, further comprising an elastic member that supports a holding wire that suspends the holding tool in a pulling direction. 2. A seed crystal connected to a main wire is immersed in a polycrystal melt, and the main wire is wound by a drum to grow a single crystal under the seed crystal. In a single crystal manufacturing apparatus having a gripper for gripping a certain crack portion, at least two gripping wires connected to the gripper, and a drum for winding each gripping wire, each gripping wire for hanging the gripping tool An elastic member that supports the elastic member in the pulling direction; an elastic member elongation detecting unit that detects the elongation of the elastic member; a growing weight detecting unit that detects the growing weight of the single crystal; While controlling using the manipulated variable of the crystal growth speed, the winding speed of each gripping wire was set in advance for the growth speed of the single crystal and the tension of each gripping wire. Serial single crystal manufacturing apparatus characterized by comprising a control means for controlling by using the operation amount of the speed is intended to adjust the load sharing tension value of a single crystal. 3. The control means corresponds to a design value of the tension of each gripping wire as an operation amount of a speed for adjusting the tension of each gripping wire to a preset load sharing tension value of the single crystal. 3. The single crystal manufacturing apparatus according to claim 2, wherein an operation amount of a speed for applying a tension to the elastic member is used. 4. A first storage means for storing in advance a value which sets a relationship between a growth length of the single crystal and a growth rate of the single crystal according to the growth length, and a growth length of the single crystal. And a growth rate determining unit that determines a growth rate of the single crystal by applying the growth length detected by the growth length detecting unit to the relationship stored in the first storage unit. Means, and a second storage means for storing in advance a value that sets a relationship between a growth weight of the single crystal and a load sharing tension value of the gripping wire according to the growth weight, wherein the control means Setting means for setting a control section of the gripping wire winding speed when calculating an operation amount of a speed for applying a tension corresponding to a design value of the gripping wire tension to the elastic member; and a growth weight detecting means. Weight detected The amount of change in the control section is applied to the relationship stored by the second storage means to determine the amount of change in the load-sharing tension on the design value of the gripping wire. A design elongation change amount calculating means for calculating an elongation change amount on a design value of the elastic member using an elastic coefficient of a gripping wire; and using the calculated elongation change amount on the design value, using a time of the control section. 4. An operation amount calculating means for calculating an operation amount for converting the single crystal growth rate determined by the growth rate determining means into a speed amount.
The single crystal manufacturing apparatus according to the above. 5. The control means compares the measured tension value of the gripping wire with a design tension value as an operation amount of a speed for adjusting the tension of the gripping wire to a preset load sharing tension value of the single crystal. 3. The apparatus for producing a single crystal according to claim 2, wherein an operation amount of a speed for giving a negative feedback amount for adjusting the measured tension value to the design tension value is used. 6. The control means compares the measured tension value of the gripping wire with a design tension value to calculate an operation amount of a speed for giving a negative feedback amount that matches the measured tension value with the design tension value. By applying the weight detected by the growth weight detecting means to the relation value stored in the second storage means, a load sharing tension on a design value of the gripping wire is obtained, and the obtained load sharing tension and the elastic member are obtained. A design elongation calculating means for calculating elongation at a design value of the elastic member using the elastic coefficient of the elastic member; and estimating the calculated elongation at the design value and the measured elongation detected by the elastic member elongation detecting means. An error elongation calculating means for comparing and calculating an error elongation between a current design value and an actually measured value; and converting the calculated error elongation into a speed amount using the time of the control section and determining by the growth speed determining means. Simple Single crystal manufacturing apparatus according to claim 5, characterized in that it comprises a control input calculation means for calculating a manipulated variable to manipulate the growth rate of the crystal. 7. A shaft holding part for holding a shaft connected to a seed crystal, and a seed crystal connected to the shaft is immersed in a polycrystal melt, and the shaft is pulled up to form a single crystal under the seed crystal. A shaft pulling part for growing a, a gripper for gripping a crack portion on the upper part of the single crystal,
In a single crystal manufacturing apparatus having at least two gripping wires connected to the gripping tool and a drum that is held by a shaft holding unit together with the shaft and winds each gripping wire, each gripping wire for hanging the gripping tool is provided. An elastic member supporting in the pulling direction; an elastic member elongation detecting means for detecting elongation of the elastic member; a growth weight detecting means for detecting a growth weight of the single crystal; While controlling using the operation amount of the speed, the winding speed of each of the holding wires is controlled using the operation amount of the speed for adjusting the tension of each of the holding wires to a preset load sharing tension value of the single crystal. A single crystal manufacturing apparatus, comprising: 8. The control means, as an operation amount of a speed for adjusting a tension of the holding wire to a preset load sharing tension value of the single crystal, a tension corresponding to a design value of the holding wire tension, 8. The single crystal manufacturing apparatus according to claim 7, wherein an operation amount of a speed applied to the elastic member is used. 9. A first storage means for storing in advance a value which sets a relationship between a growth length of the single crystal and a growth rate of the single crystal according to the growth length, and a growth length of the single crystal. And a growth rate determining unit that determines a growth rate of the single crystal by applying the growth length detected by the growth length detecting unit to the relationship stored in the first storage unit. Means, and a second storage means for storing in advance a value that sets a relationship between a growth weight of the single crystal and a load sharing tension value of the gripping wire according to the growth weight, wherein the control means Setting means for setting a control section of the gripping wire winding speed when calculating an operation amount of a speed for applying a tension corresponding to a design value of the gripping wire tension to the elastic member; and a growth weight detecting means. Weight detected The amount of change in the control section is applied to the relationship stored in the second storage means to determine the amount of change in the load-sharing tension on the design value of the gripping wire. A design elongation change amount calculating means for calculating an elongation change amount on a design value of the elastic member using an elastic coefficient of a gripping wire; and using the calculated elongation change amount on the design value, using a time of the control section. The single crystal manufacturing apparatus according to claim 8, further comprising an operation amount calculation unit configured to calculate an operation amount of the winding speed of the gripping wire by converting the operation amount into a speed amount. 10. The control means compares an actually measured tension value of the gripping wire with a design tension value as an operation amount of a speed for adjusting the tension of the gripping wire to a preset load sharing tension value of the single crystal. 8. The single crystal manufacturing apparatus according to claim 7, wherein a manipulated variable of a speed for giving a negative feedback amount for adjusting the measured tension value to the design tension value is used. 11. The control means compares the measured tension value of the gripping wire with a design tension value to calculate an operation amount of a speed for giving a negative feedback amount that matches the measured tension value with the design tension value. By applying the weight detected by the growth weight detecting means to the relation value stored in the second storage means, a load sharing tension on a design value of the gripping wire is obtained, and the obtained load sharing tension and the elastic member are obtained. A design elongation calculating means for calculating elongation at a design value of the elastic member using the elastic coefficient of the elastic member; and estimating the calculated elongation at the design value and the measured elongation detected by the elastic member elongation detecting means. Error elongation calculating means for comparing and calculating the error elongation between the current design value and the actually measured value; and converting the calculated error elongation into a speed amount using the time of the control section to wind up the gripping wire. Manipulated variable Single crystal manufacturing apparatus according to claim 10, characterized in that it comprises a control input calculation means for calculating for.