Kinetics characterization of the oxidation of Cu thin films at low temperature by using sheet resistance measurement

Film sheet resistance measurement was developed to obtain the oxidation kinetics of Cu thin films in the nanometer range. Cu thin films with smooth and homogenous surfaces were prepared by vacuum evaporation. Oxidation behaviour of Cu thin films at low temperatures from 180 °C to 260 °C in dry air has been studied. The results show that oxidation of Cu thin film follows a parabolic rate law with a considerable low activation energy of 0.57 eV, which is much lower than that reported for bulk Cu and the thick film. The observed rapid oxidation phenomenon may be attributed to the fast diffusion mechanism dominated by the defect-related grain boundary diffusion in thin films. PACS 07.50.-e; 73.61.-r; 82.65.+r