Characteristics of Indium-Tin Oxide Thin Film Etched by Reactive Ion Etching

Indium-tin oxide (ITO) films coated on glass have been etched by reactive ion etching (RIE) with a gas mixture of Ar and Cl2. The etching rates of ITO films depend strongly on power density, gas pressure, the composition of reactive gases, and the total flow rate of etchants. According to the results from the study, we can postulate that the ITO films' etching follows the ion-assisted chemical etching. A high etching rate above 100 Å/min can be achieved, and an etching mechanism will be proposed. The selectivity of ITO films to glass reaches 35 with a 30 line/mm pattern. After exposure of ITO films to an Ar/Cl2 mixed gas plasma discharge, their sheet resistance does not markedly change. The residue of Cl atoms exists only in the region near the surface. By means of parameter control, we can obtain good pattern images of ITO films measured by scanning electron microscopy (SEM).