The effects of barrier layers and annealing temperature on texture variation, grain growth and void forming of nanocrystalline Cu films were investigated by X-ray diffraction, transmission electron microscope and scanning electron microscope (SEM). The variation in texture and grain size of Cu films with annealing temperature is different for Cu/Ti and Cu/Ta. The activation energies of grain growth of Cu films on Ti and Ta. respectively, are 19.7 and 23.4 kJ mol(-1), which are much closer to that of grain boundary diffusion of Cu. The average diameter of about 400 nm for surface voids of Cu/Ti is larger than that of Cu/Ta structure. Furthermore, both the electrical resistivity measurement and SEM observation imply that Cu/Ti rather than Cu/Ta structure tend to fail easier as annealing temperature exceed 400 degrees C. (C) 2009 Elsevier B.V. All rights reserved.