Chemical characterization of as-deposited microcrystalline indium oxide films prepared by reactive dc magnetron sputtering

) films with a crystallite size of 20.6 nm and a thickness of 100–1600 nm were prepared by dc reactive magnetron sputtering onto Corning 7059 glass substrates in various mixtures of oxygen in argon at room temperature. In a previous article, we have shown that the conductivity of these films can change in a controllable and fully reversible manner by about six orders of magnitude between an insulating and a very conductive state by alternately exposing the films to ultraviolet light (hν≥3.5 eV) in vacuum and reoxidizing them in ozone. In the present article, we report on studies of the surface and depth composition of these films carried out by Auger electron spectroscopy (AES), combined with depth profiling analysis. Quantitative Auger and energy-dispersive X-ray analysis (EDX) were employed to determine the stoichiometry of the films. The effects of film thickness and oxygen content during the deposition on the stoichiometry were examined. Both AES and EDX analysis confirmed that the stoichiometry is invariant for these growth conditions. The depth profiling analysis showed that all films exhibit extremely good in-depth uniformity, regardless of their thickness.