Investigation of transparent and conductive undoped Zn2In2O5-x films deposited on n-type GaN layers

Transparent, conductive, multicomponent oxide films composed of undoped Zn2In2O5-x were deposited on n-type GaN layer using rf sputtering. We investigated the dependence of the surface, electrical, and optical properties on the sputtering parameters, including rf power, total pressure, and the post-deposition annealing process. We obtained high transparency (>80% in the visible and near-infrared ranges) and low electrical resistivity (2.58x10(-4) Omega cm). Atomic force microscopy and optical transmittance measurements of Zn2In2O5-x films were used to investigate the mechanisms of resistivity variation in the films. The ohmic performances of Zn2In2O5-x contacts to the n-type GaN layer are also demonstrated. (C) 2002 American Institute of Physics.