Plasma Etching of ITO Thin Films Using a CH4/H2 Gas Mixture

Plasma etching of ITO (In2O3:Sn indium tin oxide) thin films has been performed using a CH4/H2 plasma. Etching occurs above a substrate temperature (T s) of 60°C and the etch rate increases with increasing T s, while amorphous like or polymer-like carbon deposits onto the ITO films below 60°C. The apparent activation energy of the etching is 4.12 kcal/mol (0.18 eV). This small activation energy suggests that the desorption of produced volatiles is the rate-limiting process. Fine ITO patterns (1.5 µmL/S) were obtained using this gas mixture.