A study of suppression effect of oxygen contamination by bias voltage in reactively sputtered ZrN films

► The importance of minimizing oxygen contamination during film growth is stressed. ► We outline reliable methods for an efficient minimization of oxygen contamination. ► Nearly stoichiometric ZrN films are obtained, with a very low oxygen contamination. ► Bias voltage is suitably chosen to allow preferential sputtering of absorbed oxygen. ► Optimal bias is higher than nitrogen sputtering threshold and lower than argon one.