JPH1174234A - Wire-saw cutting method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a large number of wafers to be cut off from an ingot at the same time, the crystal orientations of the wafers being arranged with high precision. SOLUTION: A sampling wafer 24 is cut off from the end of an ingot 9 with a wire 22 of a sample slicing machine 20 which runs in parallel to a multiwire 5 of a wire saw body. The crystal orientation of the cut-off sampling wafer 24 is measured, a set angle of the orientation of the ingot 9 which is fixed to a holder 10 of the wire saw body is readjusted, based on the measurements and then a plurality of wafers are cut off from the ingot 9 with the multiwire 5 of the wire saw body. Thereby, since the set angle of the orientation of the ingot 9 and an attached position and angle of the ingot 9 to the holder 10 are readjusted with high precision, the wafer products are cut off with high productivity, in which the crystal orientations are arranged with an object orientation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw cutting method and apparatus for cutting a wafer having a crystal orientation set with high precision from an ingot.

[0002]

2. Description of the Related Art An ingot manufactured by a pulling method or the like is cut into a top and a tail, and then sliced into a wafer having a predetermined thickness through processes such as outer diameter grinding and orientation flat processing. As the slicing, a slicer having an inner peripheral blade is known, but recently, cutting with a wire saw such as a piano wire has been adopted as the diameter of a wafer increases. The wire saw cutting device generally has three groove rollers 1 to 3 as shown in FIG.
, One of which is connected to the drive motor 4. The multi-wire 5 configured by making the groove rollers 1 to 3 make multiple turns is unwound from one wire reel 6 and wound up on the other wire reel 7. A tension is applied to the multi-wire 5 by the tensioner 8 so as to go around the rollers 1 to 3 in a pulled state.

An ingot 9 to be sliced is mounted on a holder 10 via an adhesive jig, disposed between the groove rollers 1 and 2, and sliced into a plurality of wafers by a multi-wire 5. At this time, the slurry 11 is supplied to the multi-wire 5 in order to smoothly perform the slicing operation. The slurry 11 is supplied from the slurry tank 12 to the multi-wire 5 from the nozzle 14 via the supply pipe 13, then collected by the pan 15 and returned to the slurry tank 12. In order to cool the slurry 11, the slurry 11 is circulated between the heat exchanger 16 and the slurry tank 12.

[0004]

In the ingot 9, the normal of the (100) crystal plane often does not coincide with the central axis determined by the outer diameter. Further, the ingot 9 is fixed to the holder 10 via an adhesive jig at the time of slicing, but a cut surface set to a specific crystal orientation of the ingot 9 may not be obtained due to a positional relationship between the jig and the wire saw. Therefore, it is necessary to set the crystal orientation of the ingot prior to slicing. The setting of the crystal orientation is roughly classified into an inner setup method and an outer setup method. In the internal setup method,
The inclination of the temporarily fixed ingot in the wire saw device main body is adjusted, and the cut surface is adjusted to a predetermined crystal orientation. In the external setup method, the crystal orientation of the ingot is set by adjusting the relative angle to the ingot bonding jig outside the wire saw device body.

However, if there is an error in the crystal orientation angle of the ingot 9 set in advance and the position or angle at which the ingot 9 is mounted on the holder 10 exceeding an allowable range, the wire saw cutting for simultaneously cutting a large number of wafers from the ingot 9 requires the ingot 9. There is a possibility that the total number of wafers cut out of the standard may be out of specification. The present invention has been devised in order to solve such a problem, and cuts out a crystal orientation measurement sample from an end of an ingot prior to ordinary wire saw cutting, and based on the measurement result of the sample, a wire saw body. By adjusting the azimuth setting angle again, it is an object to cut out a large number of wafers having crystal orientations extremely precisely and surely matching the target value by wire saw cutting.

[0006]

In order to achieve the object, a wire saw cutting method of the present invention achieves the object by using a wire of a sampling and cutting device running in a direction parallel to a multi-wire of a wire saw main body. The crystal orientation of the obtained sample wafer is measured, the orientation setting angle of the ingot fixed to the holder of the wire saw body is readjusted based on the measurement result, and then a plurality of wafers from the ingot are multi-wired by the wire saw body. It is characterized by cutting out. The apparatus used for this wire saw cutting method includes a wire saw body having a holder for fixing an ingot with a central axis substantially orthogonal to a traveling direction of a multi-wire circling a plurality of groove rollers, and a portion contacting an end of the ingot. It consists of a sampling cutting device with a wire running parallel to the running direction of the multi-wire, and after cutting out a sample wafer of a predetermined thickness from the end of the ingot, the sampling cutting device is used when cutting the ingot by the multi-wire. It is possible to retreat to the standby position.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A wire saw cutting device according to the present invention
As shown in FIG.
Separately from the wire saw main body to be rotated around 3, a sampling cutting device 20 for cutting out a sample wafer is provided. The sampling and cutting device 20 is attached to a pair of frames, and the entire frame moves in the Y and X directions by a moving mechanism provided inside the wire saw main body. As a driving means for moving the frame itself, a motor, a hydraulic cylinder having a long stroke, or the like is employed.

In the sampling cutting device 20, a wire 22 is wound once around single groove pulleys 21, 21,. The wire 22 travels in one direction or in a reciprocating manner on an endless track by power from a drive motor 23. In a portion in contact with the ingot 9 to cut out the sample wafer 24 from the end of the ingot 9, the wire 22 travels along a locus parallel to the multi-wire 5 of the wire saw body. The sampling cutting device 20 slides in a direction (Y direction) parallel to the axis of the ingot 9 and is fixed at an arbitrary position. Then, the wire 22 travels while moving the sampling and cutting device 20 in the cutting and feeding direction (Z direction) of the ingot 9.
Thus, a sample wafer 24 having a constant thickness of about 1 mm is cut out from the end surface of the ingot 9 having various lengths. After cutting out the sample wafer 24, the sampling and cutting device 20 moves to the end in the Y direction and waits at a position where it does not hinder the cutting operation by the wire saw body.

In order to establish the facing relationship between the obtained sampling wafer 24 and the product wafer cut out from the ingot 9 by the main cutting, the traveling trajectory of the wire 22 that cuts out the sampling wafer 24 from the ingot 9 and the multi-wire 5 Not to break the parallel relationship of
It is necessary to move the sampling and cutting device 20 parallel to the wire saw body. Then, the sampling cutting device 20 is moved by the moving mechanism 30 shown in FIG.
The moving mechanism 30 includes a linear guide 31 with a built-in bearing that is attached to a frame of the wire saw main body and extends in the Z direction. By adjusting the position, angle, and the like of the linear guide 31 with respect to the wire saw main body, the correspondence between the wire 22 and the multi-wire 5 is adjusted. A linear guide 32 movable in the Z direction is attached to the linear guide 31 at right angles. The linear guide 32 has a built-in bearing, and the parallel relationship between the wire 22 and the multi-wire 5 does not change by moving the left and right in synchronization.

Further, a frame 33 on which the sample cutting device 20 is mounted is attached to the linear guide 32 in parallel. Since the frame 33 moves integrally in the Y direction, the parallel relationship between the wire 22 and the multi-wire 5 does not change. By such a moving mechanism 30, the sampling cutting device 20 is moved in the Z direction and the Y direction between the cutting operation position and the standby position shown in FIG. 2 without changing the parallel relation of the wire 22 to the multi-wire 5. be able to. Therefore, the ingot 9 is
The information obtained from the sample wafer 24 cut out from the end of the sample can be used for the main cutting. In FIG. 2, the sample wafer 24 is cut out from the ingot 9 by moving the sampling cutting device 20 in the Z direction. However, instead of moving the sampling and cutting device 20 in the Z direction, the sample wafer 24 can be cut out while moving the ingot 9 in the Z direction by the cutting and feeding mechanism of the wire saw main body as shown in FIG. in this case,
After the position of the sampling and cutting device 20 is adjusted by sliding in the Y direction, the sampling and cutting device 20 is fixed in the Z direction.

Further, in order to adapt to ingots 9 having various lengths, multi-groove rollers 23, 23 as shown in FIG.
.. can also be used. In this case, ingot 9
, And an appropriate groove of the multi-groove rollers 23, 23... Is selected, and the wire 22 is wound once in the selected groove. Then, the ingot 9 is moved in the Z direction by the cutting and feeding mechanism of the wire saw main body, or the sampling and cutting device 20 is moved in the Z direction while running the wire 22 by the power from the drive motor 23, thereby the end of the ingot 9 is moved. The sample wafer 24 is cut out from the portion. In this method, the sample wafer 24 having a predetermined thickness is cut from the ingot 9 having various lengths without moving the sampling and cutting device 20 in the Y direction. In the above example, the sample wafer 24 is cut out from the end face of the ingot 9 using the wire 22 welded in a loop shape. However, the present invention is not limited to this. Instead of the loop-shaped wire 22, a wire 27 having a start end and an end fixed to a capstan 26 may be used.

For example, as shown in FIG. 6, one wire 27 whose starting end is fixed to a capstan 26 is routed around single groove pulleys 21, 21,.
After winding by a length of about 30 m, the end of the wire 27 is fixed to the capstan 26. Alternatively, as shown in FIG. 7, one wire 27 having a starting end fixed to the capstan 26 is wound around the multi-groove rollers 25, 25,... And wound around the capstan 26 by a length of 10 to 30 m. ,
The end of the wire 27 is fixed to the capstan 26. The sample wafer 24 is cut out from the end of the ingot 9 by causing the wire 27 thus wound to reciprocate in a short cycle. Sample wafer 24 cut out
And the crystal orientation is measured according to a conventional method. Based on the measurement result, the azimuth setting angle of the ingot 9 fixed to the holder 10 is readjusted by moving the holder 10 or the bonding jig of the wire saw body in the X to Y directions or tilting the X and Y axes around the X axis and the Z axis. You. The readjusted ingot 9 is cut by the multi-wire 5, and a large number of wafers are cut out at the same time.

Since the cut wafer reflects the measurement result of the crystal orientation using the sample wafer 24, the product is aligned with the target crystal orientation with extremely high accuracy. Further, it is possible to sufficiently cope with the recent tendency that the standard of the crystal orientation is strict, and the crystal orientation is uniform within a range of the target value ± 5 minutes. It is expected that it will take about the same time as cutting the main body of the ingot 9 to obtain the sample wafer 24. However, since the sample wafer 24 is cut out from the end of the ingot 9, it is possible to greatly reduce the time by adopting a special condition applied only to the end face cutting. Such conditions include the feed speed of the wire 22, the cutting feed speed of the sampling and cutting device 20 or the wire saw main body, the use of abrasive grains having the optimum diameter, the use of an electrodeposited diamond wire and the like. Therefore, a decrease in productivity due to the cutting operation of the sample wafer 24 is reduced.

[0014]

As described above, according to the present invention, a sample wafer is cut out from the end of the ingot, and the crystal orientation of the sample wafer is measured. The direction setting angle has been readjusted. Since a large number of wafers are cut out from the ingot that has been readjusted in this way, the problem of losing the entire ingot due to out of specification of the crystal orientation after the completion of cutting as in the conventional wire saw cutting is eliminated, and the target crystal orientation can be extremely accurately adjusted. An aligned product wafer can be obtained with high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a conventional wire saw cutting device.

FIG. 2 is a perspective view of a main part of a wire saw cutting device provided with a sampling cutting device according to the present invention.

FIG. 3 is a diagram illustrating a moving mechanism of the sampling and cutting device.

FIG. 4 is a perspective view of a main part of a wire saw cutting device provided with a sampling cutting device capable of adjusting a position in a Y direction.

FIG. 5 is a perspective view of a main part of a wire saw cutting device provided with a sampling cutting device using a multi-groove roller.

FIG. 6 is a perspective view of a main part of a wire saw cutting device provided with a sampling cutting device in which a wire whose start and end are fixed to a capstan is drawn around a single groove pulley.

FIG. 7 is a perspective view of a main part of a wire saw cutting device provided with a sampling cutting device in which a wire having a start end and an end fixed to a capstan is routed to a multi-groove roller.

[Explanation of symbols]

1-3: Groove roller 4: Drive motor 5: Wire 6, 7: Wire reel 8: Tensioner
9: Ingot 10: Holder 11: Slurry 12: Slurry tank 13: Supply pipe 1
4: Nozzle 15: Pan 16: Heat exchanger 20: Sampling cutting device 21: Single groove pulley
22: loop-shaped wire 23: drive motor 24: sample wafer 2
5: Multi-groove roller 26: Capstan 27: Wire with start and end fixed to capstan 30: Moving mechanism 31, 32: Linear guide 3
3: Frame

Claims (2)

[Claims] 1. A sample wafer is cut out from an end of an ingot by a wire of a sampling and cutting device running in a direction parallel to a multi-wire of a wire saw main body, and a crystal orientation of the obtained sample wafer is measured. A wire saw cutting method, comprising: re-adjusting an azimuth setting angle of an ingot fixed to a holder of a wire saw main body based on the plurality of wafers; 2. A wire saw body having a holder for fixing an ingot with a center axis substantially perpendicular to a traveling direction of a multi-wire circling a plurality of groove rollers, and a multi-wire traveling at a position where it contacts an end of the ingot. It consists of a sampling and cutting device equipped with a wire running parallel to the direction.The sampling and cutting device cuts out a wafer for a sample having a predetermined thickness from an end of the ingot, and then moves to a standby position when cutting the ingot with a multi-wire. Wire saw cutting device that can be retracted.