Synergy of experiment and model for reactive HiPIMS: effect of discharge parameters on WOx composition and deposition rate

Reactive high-power impulse magnetron sputtering of tungsten oxide films using metallic tungsten target (72 mm in diameter) in argon-oxygen atmosphere (total pressure of 0.75 Pa) was carried out. The effect of various discharge parameters on the deposition rate and film oxygen concentration was investigated. Moreover, a model combining a reactive high-power impulse magnetron sputtering model and a discharge plasma model for the ionization region was successfully used for deeper insight into the effect of particular discharge parameters such as voltage pulse length (from 100 -800 mu s), oxygen partial pressure (from 0.25-0.50 Pa) or the value of pulse-averaged target power density (from 2.5-500 W cm(-2)). The results of the presented model, most notably trends in the target- and substrate oxide fraction, composition of particle fluxes onto the substrate, degree of W atom ionization or degree of O-2 molecule dissociation are discussed and put into context with experimentally measured quantities.