Characterization of rf sputtered TiOySz thin films

Different titanium oxysulfide thin films were prepared by rf magnetron sputtering using two types of targets in a pure argon or mixed oxygen/argon atmosphere with a total pressure of 1 or 0.2 Pa. We have studied the influence of the sputtering conditions (target, total pressure, oxygen partial pressure) on the composition, the morphology and the local and electronic structure of our thin films. A set of complementary techniques (scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS)) was used to characterize the thin films. Two types of films have been obtained: thin films prepared from TiS2 target having a composition and a local structure close to TiS3 and thin films obtained from TiS2/TiS3 target characterized by a composition and a local structure close to TiS2. The complementary use of XPS and sulfur K-edge XAS spectroscopies has allowed us to evidence the coexistence of different microdomains into the thin films corresponding respectively to a pure sulfur, a pure oxygen or a mixed sulfur/oxygen environment.