Tantalum nitride films were deposited on silicon wafer and steel substrates by cathodic vacuum arc in N-2/Ar gas mixtures. The chemical composition, crystalline microstructure and morphology of the films were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. According to the results, film composition and microstructure depends strongly on the N-2 partial pressure and the applied negative bias (V-s). (c) 2006 Elsevier B.V. All rights reserved.