US 5,494,862 A · Method of making semiconductor wafers

Abstract

A method for a flatter semiconductor wafer free of ORP-observed irregularity and particles generated in handling on the back side of the wafer, in which an alkaline etching is adopted to utilize its advantage and a slight polishing step is combined to a conventional method of this kind. A deficiency of alkaline etching which brings about rougher surface irregularities on the surface of a wafer is eliminated by the use of the step of slight polishing on the back surface after the etching step and the inherent advantage stands without a loss, so that particle generation from the back surface of a semiconductor wafer in handling is much reduced and what's more a flatter semiconductor wafer is realized and a yield of an electronic device fabrication is increased.

Claims6

Dependent claims

A method of making a semiconductor wafer comprising the steps, in sequence, of:

slicing a monocrystalline semiconductor ingot to obtain at least one semiconductor wafer,
chamfering a periphery of said wafer,
flattening surfaces of said wafer by lapping,
etching surfaces of said wafer in an alkaline etching solution,
partly removing surface irregularities on a first surface of said wafer by removing less than 3.0 .mu.m of a portion of wafer surface by a polishing process,
polishing a second surface of said wafer to be mirror-polished, and
cleaning said wafer.

4 more elements

Dependencies are inferred from the claim text.

Method of making semiconductor wafers

Life of this patent

Method of making semiconductor wafers

Life of this patent

Abstract

Claims6