Conductive nitride films are conventionally prepared by reactive sputtering using nitrogen as a reactive gas. Replacing nitrogen with air as a reactive gas allows the process to be conducted at high base pressures, i.e., low vacuum, which can reduce substantially the processing time. In this study, TiN films were selected as a model system for the investigation. As the air/Ar flow ratio reached 0.10-0.15, the films revealed the characteristic rock-salt structured TiN. The N/Ti of the films was 0.80-0.83 with 9-13 atom % of oxygen. The determined resistivities and hardnesses of the films were in the range of 110-130 mu Omega.cm and 26-27 GPa, respectively. All obtained data fulfill the characteristics of TiN films. Kinetic formation apparently prevails over thermodynamic predictions at low air/Ar ratios. In such plasma, the dissociation energy of nitrogen is much smaller than that of oxygen, leading to the high impingement rate of nitrogen. The dissolution of oxygen in the TiN films seems also to stabilize the nitride structure. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3571037] All rights reserved.