Oxidation behaviour of a nano-scale copper film at 140 ℃ was investigated in this paper. Nano-scale copper films were prepared on glass substrate by vacuum deposition at different depositing rates. Atomic force microscope (AFM) was applied to characterization of the surface morphology of these thin films to choose suitable samples. Kinetics of the oxidation process of the copper films in the thickness range of 16～22 nm at 140 ℃ was studied by using transmission spectrum and sheet resistance methods. The crystal structures and compositions of the oxidation products were analyzed with X-ray diffraction (XRD). The results show that the copper was oxidized to form Cu₂O following a cubic rate law at 140 ℃.

Key words: Cu thin film, oxidation, kinetics characterization, sheet resistance, transmission spectrum