JP2001223188A - Graphite-slicing stand for cutting semiconductor ingot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a graphite-slicing stand for cutting single crystals for positively insulating the graphite slice stand from fixing fitting in a wire saw device for cutting and machining a semiconductor ingot such as silicon into wafers. SOLUTION: One surface of a graphite slice stand is formed in a recessed surface, and the recessed surface is formed in a recessed surface that can stick to the side surface of the semiconductor ingot such as cylindrical silicon. The other surface that opposes the recessed surface is fixed while being in contact with the mounting fixing fitting of a wire saw device. In this case, an insulation resin sheet with woven cloth such as the plain weave of ceramic fiber such as glass fiber, the non-woven cloth of paper, felt, or the like, and short fiber as filling reinforcing materials is applied to a recessed surface for plating the semiconductor ingots or a plane at the side of the fixing fitting for fixing before insulation treatment in this graphite-slicing stand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw for cutting a semiconductor ingot such as silicon into a wafer.
The present invention relates to an insulated graphite slicing table for fixedly supporting a semiconductor ingot.

[0002]

2. Description of the Related Art A method of cutting a semiconductor ingot such as silicon into a wafer is performed by an inner peripheral blade grinding machine in which abrasive grains such as diamond are bonded to the inner periphery of a donut-shaped thin plate, and a thin ring-shaped steel strip. Or a wire source that cuts with a loose abrasive while continuously moving a thin piano wire.
There is a cutting method.

Recently, as the wafer diameter has increased, the product yield has shifted to a wire saw device.

[0004] A wire saw device is used for cutting a wire during a cutting process.
(Japanese Patent Application Laid-Open No. HEI 8-112748) has been developed in which electric power is supplied to the power supply to detect the cutting state.

To detect the cutting state in the apparatus, two types of electrodes are embedded in advance in a graphite slicing table that supports a workpiece, and the graphite slicing table is connected to a control unit through a fixture that is fixed to the graphite slicing table. .

Specifically, when the wire contacts the workpiece, a current flowing from the wire to one electrode attached to the graphite slicing table is detected.

[0007] Next, the other electrode, which is insulated on the surface attached to the graphite slicing table so as to be joined to the bottom surface of the workpiece, is connected to a wire to cut the workpiece, and the insulating coating on the surface of the electrode is cut off. When the wire breaks, the current from the wire is detected as a signal indicating the end of the cutting.

[0008] In this manner, each electrode receives the current flowing through the wire, and the disconnection state is identified in the form of a connection signal to the control unit through the fixture.

For this reason, in order to prevent erroneous operation without leaking the signal current, the graphite slicing table and the fixture are insulated by interposing an insulating plate such as a glass plate.

In addition to the above-mentioned method, there is a method for detecting the presence or absence of a break in a wire, and a method in which a load applied to the wire is detected by a tension meter.
A current is passed between the apparatus and the graphite slicing table for detection.

In any case, it is necessary to secure insulation by interposing an insulating plate such as a glass plate between the fixture and the graphite slicing table. As the insulating method, Japanese Patent Application Laid-Open No. 9-3
[0034] Japanese Patent Application Laid-Open No. 2000-6138 has been proposed.

Japanese Patent Application Laid-Open No. 9-300344 discloses an electrically insulating ceramic artificial wood in place of a conductive graphite slice table, and it is feasible if there is no problem such as workability and contamination of semiconductors. is there.

Japanese Patent Application Laid-Open No. 2000-6138 discloses a method in which an insulating polymer film having a thickness of 1 to 100 μm is applied to a surface of a graphite slice table which is in contact with a fixing bracket. Was an issue.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the graphite slicing table, and is directed to a wire saw apparatus for cutting a semiconductor ingot such as silicon into a wafer. Provided is a graphite slicing table for cutting a semiconductor single crystal, which can reliably insulate the semiconductor.

[0015]

One surface of a graphite slice table is formed as a concave surface, and the concave surface is formed as a concave surface that can be fixed to a side surface of a semiconductor ingot such as a cylindrical silicon.

The other surface opposed to the concave surface is in contact with and fixed to the mounting fixture of the wire saw device. The concave surface of the semiconductor ingot loading or the flat surface of the fixture is provided with a plain weave of ceramic fiber such as glass fiber. A non-woven fabric such as cloth, paper, felt, or the like, and an insulating resin sheet using short fibers as a filling reinforcing material are adhered and fixed, and a graphite slice table is insulated.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A graphite slice table is made of a resin sheet adhered and fixed to a graphite base. Since a resin sheet having no filler and having no filler is poor in dimensional stability and wrinkles, a prepreg sheet in which glass cloth is impregnated with an epoxy resin is used. The graphite substrate is not particularly limited as long as it has good workability.

A preferred embodiment will be described below. The graphite substrate shaped into a graphite slice table is washed with methanol, an epoxy-based adhesive is applied to the resin sheet bonding surface, the resin sheet is bonded, and air is removed from the bonding surface. And heat-curing at 150 ° C. for 2 hours. Deburring after cooling.

[0019]

The present invention is configured as described above.
Insulation can be stably obtained between the graphite slicing table and the wire saw device, and malfunction of the device can be prevented.

Continued on the front page (72) Inventor Mitsunobu Sato 50 Royal Amenity 209, Nakane-cho, Soka City, Saitama Prefecture (72) Inventor Toshio Shimada 1-13-23 Shinmachi, Obanazawa-shi, Yamagata F-term (reference) 3C069 AA01 BA06 CA04 CB01 DA01 DA03 EA02

Claims (1)

[Claims] 1. A wire source for cutting a semiconductor ingot.
In the apparatus, the loading surface of the graphite slicing table on which the semiconductor ingot is placed and supported or the flat surface on the fixture side is filled with a woven fabric such as a cloth of ceramic fiber such as glass fiber, a non-woven fabric such as paper or felt, or a short fiber. Insulating resin screen
A graphite slice table, which has been fixed by sticking.