It is the purpose of this study to develop tough hinge material for the application of the torsional springs. Nitrogen-doped cobalt silicide (CoSixNy) film is sputtered from cobalt silicide (CoSi2) target in Ar/N-2 discharge. Stress and sheet resistance of CoSixNy film are two major properties to be evaluated. Taguchi method is practiced in reactive sputtering deposition of CoSixNy film. Process pressure is most critical to the CoSixNy film stress and the optimum condition of 1000 W, 0.8 Pa, and 20% N-2 flow ratio, indeed results in low tensile CoSixNy film stress, about 54. MPa. Reannealing process indicates that stability of CoSixNy film is attained after first annealing process. Stress hysteresis behaviors of CoSix and CoSixNy films resemble that of metal film with a complete elastic manner in the second stage of heating and cooling. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses suggest that toughness and strength of the film is achievable. It is concluded that CoSixNy film as a hinge material is feasible. (C) 2004 Elsevier B.V. All rights reserved.