CHEMICAL CHARACTERIZATION OF AS-DEPOSITED MICROCRYSTALLINE INDIUM OXIDE-FILMS PREPARED BY REACTIVE DC MAGNETRON SPUTTERING

Microcrystalline indium oxide (InOx) films with a crystallite size of 20.6 nm and a thickness of 100-1600 nm were prepared by de reactive ma gnetron sputtering onto Coming 7059 glass substrates in various mixtur es of oxygen in argon at room temperature. In a previous article, we h ave shown that the conductivity of these films can change in a control lable and fully reversible manner by about six orders of magnitude bet ween an insulating and a very conductive state by alternately exposing the films to ultraviolet light (h nu greater than or equal to 3.5 eV) in vacuum and reoxidizing them in ozone. In the present article, we r eport on studies of the surface and depth composition of these films c arried out by Auger electron spectroscopy (AES), combined with depth p rofiling analysis. Quantitative Auger and energy-dispersive X-ray anal ysis (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 confirm ed that the stoichiometry is invariant for these growth conditions. Th e depth profiling analysis showed that all films exhibit extremely goo d in-depth uniformity, regardless of their thickness.