Copper nitride thin films were deposited on Si ( 1 0 0) wafers by reactive magnetron sputtering at various H-2/N-2 ratios. X-ray diffraction measurements show that the films are composed of Cu3N crystallites with anti-ReO3 structure and exhibit preferred orientation of [ 1 0 0] direction. Although the relative composition of the films has obviously changes with the H-2/N-2 ratios, the orientations of the films keep almost no changes. However, the grain size, lattice parameter and composition of the films are strongly dependent on the H-2/N-2 ratios. The copper nitride films prepared at 10% H-2/N-2 ratios show poor stability and large weight gain compared to the copper nitride films prepared at 0% H-2/N-2 ratios. (C) 2008 Elsevier B.V. All rights reserved.