Apparent and steady-state etch rates in thin film etching and under-etching of microstructures: I. Modelling

Abstract

A general etch rate model is proposed that allows accurate etch rate calculations out of typical ex situ etch rate experiments. This model takes into account the influence of an incubation period during the initial stage of the etching process and the influence of a decreasing etch rate during the rinsing period. Expressions for the apparent etch rate and steady-state etch rate are proposed. This paper is the first part of a set of two. In part II, experimental etch data are obtained, confirming the proposed etch rate model in this work.