JPH0691633A - Cutting state monitoring device for inner peripheral blade - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the quality of a semiconductor wafer cut by an inner blade. A cutting state monitoring device for an inner peripheral blade provided in a wafer cutting device for cutting a semiconductor wafer from a silicon ingot 8 using the inner peripheral blade 1, wherein the cutting resistance is monitored by a piezoelectric cutting dynamometer 7. Along with
It is assumed that the cutting resistance alarm value can be arbitrarily set by the cutting resistance alarm setter 12, and the set value and the measured value of the piezoelectric cutting dynamometer 7 are compared by the cutting resistance measured value comparison section 11 to measure the set value. When the value exceeds the value, the operation stop command 16 is output, and it is assumed that it is the optimum time for dressing the inner peripheral blade 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for cutting a semiconductor wafer from an ingot, and more particularly to a technique effective for constantly monitoring the cutting state when the semiconductor wafer is cut by an inner blade.

[0002]

2. Description of the Related Art When a large number of semiconductor wafers (hereinafter referred to as wafers) are cut out from a silicon ingot (hereinafter referred to as "ingot") at a constant thickness, the ingot is usually placed inside a circular inner blade. The inner peripheral blade is disposed at a high speed while the ingot is horizontally moved, and cutting is performed by the blade provided on the inner periphery.

By the way, in the slicing process, it is required to reduce the warp amount and thickness variation of the cut wafer. As a countermeasure against this, as a cutting state monitoring means that has been conventionally performed, a waviness (displacement) of the inner peripheral blade during cutting is monitored by using a non-contact type displacement sensor, and the cutting resistance (inner peripheral blade) is thereby detected. It is known to indirectly control the situation of resistance received by the sharpness of the blade).

[0004]

According to the study of the present inventor, the cutting state monitoring technique for monitoring the waviness of the inner peripheral blade during cutting is such that the dressing for controlling the waviness can be made, but the blade It is difficult to perform proper dressing in consideration of sharpness, and conversely, there is a problem that variations in the thickness of the wafer and variations in the amount of warpage occur due to variations in the dressing method.

In order to reduce the warp amount and thickness variation of the cut-out wafer, it is not enough to control the waviness of the inner peripheral blade during cutting, and the sharpness of the blade is also controlled at the same time. It is desirable to maintain the sharpness by performing appropriate dressing in.

Therefore, an object of the present invention is to provide a technique capable of improving the quality of a wafer cut out by an inner peripheral blade.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0008]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, a cutting state monitoring device for an inner peripheral blade provided with a wafer cutting device for cutting a wafer from a silicon ingot using the inner peripheral blade,
Piezoelectric cutting dynamometer that monitors cutting resistance, and cutting resistance alarm setter that can set cutting resistance alarm value arbitrarily,
A cutting resistance measurement value comparison unit that outputs an operation stop command when the measurement value of the piezoelectric cutting dynamometer exceeds the setting value of the cutting resistance alarm setter is provided.

[0010]

According to the above-mentioned means, the cutting resistance measurement value measured by the piezoelectric cutting dynamometer is compared with the value set by the cutting resistance alarm setting device to monitor the sharpness of the inner peripheral blade and When the value exceeds the set value, it is regarded as the proper timing for dressing, the automatic operation stop command is sent, and the inner peripheral blade can be dressed at the optimum time. Therefore, it is possible to reduce the variation in the thickness of the inner peripheral blade and reduce the amount of warpage.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the cutting condition monitoring device for an inner peripheral blade according to the present invention.

The inner peripheral blade 1 is mounted horizontally on a chuck body 2, and a main shaft 3 is mounted on the center of rotation of the chuck body 2 (only the chuck body 2 and the inner peripheral blade 1 are shown in cross section). Has been. Spindle 3
Is configured to be connected (or interlocked) to a rotary shaft of a motor (not shown) installed in the gantry 4 directly or via a transmission mechanism. A cutting feed table 5 is further installed on the gantry 4. This cutting feed table 5
Of the indexing portion 6 for determining the thickness of the wafer, the piezoelectric cutting dynamometer 7 for measuring the cutting resistance, and the ingot holder 9 for holding the ingot 8 while the piezoelectric cutting dynamometer 7 is attached. Each is installed. An amplifier 10 is connected to the piezoelectric cutting dynamometer 7, and its output is input to the cutting resistance measurement value comparison unit 11. The cutting resistance measurement value comparison unit 11 includes a cutting resistance alarm setter 12
Is connected and the setting value is input. A cutting resistance recorder 13 and an inner blade cutting device controller 14 are connected to the cutting resistance measurement value comparison unit 11. The base material 15 is applied to the side surface of the ingot 8 in order to stably cut the wafer.

In the above structure, when cutting, the thickness of the wafer to be cut out is determined in advance by the indexing section 6.
Attach the ingot 8 vertically to the ingot holder 9,
The ingot 8 is set at a fixed position inside the inner peripheral blade 1. In this state, the cutting feed table 5 is horizontally moved in the direction of the arrow at a constant speed and the chuck body 2 is rotated. While the cutting feed table 5 moves, the ingot 8 is gradually cut by the blade provided on the inner circumference of the inner circumference blade 1. When one wafer is cut out, the cutting feed table 5 is returned to the home position,
The ingot holder 9 moves down by the thickness of one wafer. After that, the second wafer is cut out by the procedure described above. After that, cutting out up to the Nth sheet is repeated.

On the other hand, the displacement sensor provided conventionally measures the blade displacement of the inner peripheral blade, and the piezoelectric cutting dynamometer 7 measures the cutting resistance during cutting, and the X and Y components thereof are measured. And the resistance value of each Z component during cutting is applied to the amplifier 10 and amplified, and the amplified output is compared with the setting output by the cutting resistance alarm setter 12 by the cutting resistance measurement value comparison unit 11. When the resistance value during cutting exceeds the value set by the cutting resistance alarm setting device 12, dressing is performed to restore the sharpness of the inner peripheral blade 1, so that the inner peripheral blade cutting device controller 14 is automatically stopped. A command 16 (automatic dressing start command if an automatic dressing device is provided) is output to stop the device at an appropriate timing.

Further, the cutting resistance recorder 13 outputs data for recording the cutting resistance value, and the cutting resistance value is recorded.

As a result, the conventional inner peripheral blade 1
The sharpness of the inner peripheral blade 1 can be maintained and managed by the monitoring function by the above and the cutting state monitoring function by the present invention, and the quality in the inner peripheral blade cutting (reduction in thickness variation, reduction in warpage, etc.) can be improved. Can be improved. As described above, since the sharpness of the inner peripheral blade can be constantly monitored, proper dressing can be performed on the blade at proper timing, and the amount of wafer warp and the variation in thickness can be reduced.

An alarm is issued when the value measured by the piezoelectric cutting dynamometer 7 exceeds the cutting resistance alarm set value set by the cutting resistance alarm setter 12, and the operator is alerted to the caution.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the gist thereof. Needless to say.

For example, instead of the piezoelectric cutting dynamometer 7, X,
The vibrometers in the Y and Z directions may be set, and an alarm may be sent to the inner blade cutting device controller 14 depending on the magnitude of each vibration value.

[0020]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

That is, a cutting state monitoring device for an inner peripheral blade provided in a wafer cutting device for cutting a wafer from a silicon ingot using the inner peripheral blade,
Piezoelectric cutting dynamometer that monitors cutting resistance, and cutting resistance alarm setter that can set cutting resistance alarm value arbitrarily,
Since a cutting resistance measurement value comparison unit that outputs an operation stop command when the measurement value of the piezoelectric cutting dynamometer exceeds the setting value by the cutting resistance alarm setter, the thickness of the inner peripheral blade is set. It is possible to reduce unevenness in thickness and warp amount.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a cutting state monitoring device for an inner peripheral blade according to the present invention.

[Explanation of symbols]

 1 Inner peripheral blade 2 Chuck body 3 Spindle 4 Stand 5 Cutting feed table 6 Indexing section 7 Piezoelectric cutting dynamometer 8 Ingot 9 Ingot holder 10 Amplifier 11 Cutting resistance measurement value comparison section 12 Cutting resistance alarm setter 13 Cutting resistance recording Total 14 Inner peripheral blade cutting device controller 15 Base material 16 Automatic operation stop command

Claims (3)

[Claims] 1. A wafer cutting device for cutting a wafer from a silicon ingot using an inner peripheral blade,
Piezoelectric cutting dynamometer that monitors cutting resistance, and cutting resistance alarm setter that can set cutting resistance alarm value arbitrarily,
A cutting resistance measurement value comparison unit that outputs an operation stop command when the measurement value of the piezoelectric cutting dynamometer exceeds the setting value by the cutting resistance alarm setter. Disconnection status monitoring device. 2. A cutting state monitoring device for an inner peripheral blade according to claim 1, further comprising control means for stopping the cutting by the inner peripheral blade based on the operation stop command. 3. The cutting condition monitoring device for an inner peripheral blade according to claim 1, further comprising a cutting resistance recorder for recording a cutting resistance measurement value by the piezoelectric cutting dynamometer.