Characterisation of reactive unbalanced magnetron sputtered chromium oxynitride thin films with air

The aim of this work is to study the stoichiometry of chromium oxynitride thin films deposited by reactive magnetron sputtering in presence of air with various relative humidities. Rutherford backscattering spectroscopy and resonant nuclear reaction (RNRA) were used to determine the thickness and the composition of the films. Hydrogen and nitrogen profiles were obtained by RNRA. The chemical bonds were investigated by X-ray photoemission spectroscopy and low energy electron induced X-ray spectroscopy. The chromium metallic and chromium compound concentrations were measured vs. the flow and relative humidity of the air. During sputtering in metallic mode, Cr2O3 stoichiometry is observed with low contents of CrN, CrO2 and (CrO2)3N, whereas in compound mode the CrO2 stoichiometry predominates.