Browse Prior Art Database

Polishing Technique for GaAs

IP.com Disclosure Number: IPCOM000077492D
Original Publication Date: 1972-Aug-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Rideout, VL: AUTHOR

Abstract

An improvement in the polishing technique for gallium arsenide wafers shown in U.S. Patent 3,342,652, issued September 19, 1967 in the names of A. Reisman et al is disclosed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 86% of the total text.

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Polishing Technique for GaAs

An improvement in the polishing technique for gallium arsenide wafers shown in U.S. Patent 3,342,652, issued September 19, 1967 in the names of A. Reisman et al is disclosed.

In the patent, a wafer plate which carries gallium arsenide wafers to be polished is allowed to rotate freely about a ball-joint socket. The rotation is caused by the friction between the wafers and the liquid layer between the wafers and the cloth used in the process.

To provide wafers with improved surface quality, namely, enhanced flatness and decreased edge rounding, the wafer disk of the patent is motor driven in the present method in the same direction and at a speed slightly higher than the natural speed of rotation due to friction alone.

Under the following conditions, improved wafers were obtained:

a) Motor speed of 12 inch diameter plate - 60 rpm. In addition

to the Pellon PAN-W cloth recommended in the patent, a Politex

PS Supreme cloth by Geoscience Co. may be used.

b) Motor speed of a 4 inch diameter glass disk used as a wafer

plate, with three or more gallium arsenide wafers held

therein - 30 rpm. The center of the disk is disposed 3 inches

from the

center of the polishing plate. In addition, the motor driving

the glass disk or wafer plate is restrained by a stop, which

prevents any downward force from being applied to the disk.

c) Polishing solution is 20:1 H(2)O : NaOCl (Fisher Reagent

grade). Application rated is 4 ml of solution every 30 seconds...