Deposition and characterization of copper oxide thin films

In the present work we study thin films of copper oxide that were deposited by oxidation of copper thin films on silicon substrates in temperatures varying from 150 °C up to 450 °C. Copper films were deposited by vacuum evaporation and their thickness was estimated from the evaporated mass. X-rays diffraction (XRD) patterns showed that in the copper oxide films coexist two phases: CuO and Cu₂O their proportion varying with oxidation temperature. At temperatures up to 225 °C Cu and Cu₂O is formed while above this temperature CuO forms. Pure Cu₂O was obtained at 225 °C while pure CuO above 350 °C. FTIR transmittance spectra confirmed the results from the XRD. The index of diffraction was calculated from spectroscopic ellipsometry measurements within the energy range 1 to 3 eV, which were analysed using the Forouhi-Bloomer model.