Characterization of NiCrO<inf>x</inf> thin films deposited by reactive sputtering at different O<inf>2</inf> flow rate

NiCrO _x thin films were prepared by DC reactive magnetron sputtering from a NiCr metal target in Ar+O ₂ with the different O ₂ gas flow varied from 0 to 6 seem. The influence of the O ₂ flow rate on the deposition rate, film composition and optical properties were investigated. EDX detected a decrease in the Cr concentration with the increasing of oxygen flow rate due to the preferential oxidation of Cr to Cr ₂ O ₃ . The deposition rate decreases dramatically at oxygen flow of 2.6 seem, corresponding to the transition point from metal mode to compound mode on the target. Furthermore, an original numerical model, based on the standard Berg model was used to calculate the composition evaluation and deposition rate of NiCrO _x films. Results show a reasonable agreement between numerical and experimental data.