[sup 29]Si-Nuclear Magnetic Resonance on the Etching Products of Silicon in Potassium Hydroxide Solutions

Abstract

We present results of Si-29-nuclear magnetic resonance experiments on a large number of KOH solutions in which silicon has been dissolved. The goal of the experiments is to clarify the chemical composition of concentrated alkaline solutions after etching of silicon. It is confirmed that the initial etching product of wet-chemical etching of silicon in KOH is a silicate monomer. Increasing the silicon content of the solution gives rise to silicate polymerization products. The often reported aging of etching solutions is due to silica in the etchant. (C) 2000 The Electrochemical Society. S0013-4651(99)10-074-0. All rights reserved.