Influence of Cadmium Composition on CH_(4)-H_(2)-Based Inductively Coupled Plasma Etching of Hg_(1-x)Cd_(x)Te

摘要

In this paper, inductively coupled plasma etching of Hg_(1-x)Cd_(x)Te in CH_(4)-H_(2)-based chemistry is studied. This work is focused on the effects of substrate temperature, ion energy, and alloy composition on etch rate and surface composition. A strong influence of substrate temperature is shown. The etch rate is multiplied by more than a factor of 3 when the temperature is increased from 5 deg C to 35 deg C. A purely physical Cd removal mechanism is ruled out using x-ray photoelectron spectroscopy data from samples etched at different temperatures. Under the conditions of very low ion energy, an etching mechanism limited by the supply of active species from the plasma predicts an Hg_(1-x)Cd_(x)Te etch rate evolution that fits very well with our data.