Preparation of transparent and conductive In2O3–ZnO films by radio frequency magnetron sputtering

Abstract

Highly transparent and conductive In2O3–ZnO films have been prepared by rf magnetron sputtering using targets composed of In2O3 and ZnO. Polycrystalline Zn2In2O5 films were deposited at a substrate temperature of 350 °C using targets with a Zn content [Zn/(Zn+In)] of about 10–60 at. %. A uniform spatial resistivity distribution on the substrate surface was obtained even in Zn2In2O5 films deposited at room temperature. A resistivity of 3.4×10−4 Ω cm was obtained in Sn-doped Zn2In2O5 films deposited at 350 °C. A sheet resistance of 400 Ω/sq and an average transmittance above 90% in the visible range were obtained for an undoped Zn2In2O5 film with a thickness of about 20 nm. The etching rate of In2O3–ZnO films when using HCl as the etchant could be controlled by the Zn content in the films.