In this article, nitrogen doped ZnO thin films with various nitrogen concentrations were obtained by thermal processing of zinc oxynitride alloy films prepared by radio frequency reactive magnetron sputtering. X-ray photoelectron spectroscopy study shows that varying the annealing temperature can modulate the concentration of nitrogen in ZnO. X-ray diffraction and Raman scattering measurements were employed to investigate the structural changes of ZnO films induced by the introduction of nitrogen. The results of the temperature-dependent photoluminescence measurements suggest that the optical properties of ZnO thin films are strongly influenced by nitrogen incorporation. With this technique, the binding energy of the nitrogen acceptor is also estimated. (C) 2004 American Vacuum Society.