Annealing temperature effect on the properties of untreated and treated copper films with oxygen plasma

In this work, the copper films were deposited onquartz substrates by DC magnetron sputtering method andthen, the prepared films were annealed in air atmosphere atdifferent annealing temperatures. Before annealing, some ofthe copper films, treated by oxygen plasma, for comparison ofthe results. The structural and morphological properties of thefilms have been investigated using X-ray diffraction (XRD),atomic force microscopy, and four point probe techniques.XRDresults exhibited that the cuprous oxide phase changes tocupric oxide by enhancing of annealing temperatures. Also,oxygen plasma treatment can cause the better crystallinity forthe prepared copper oxide films. The results confirm thatoxygen plasma treatment, affected the crystal size, grain size,average roughness, sheet resistivity and strain of the films.Theoptical characteristics of the oxygen plasmatreated films, suchas refractive index, extinction coefficient and absorptioncoefficient were calculated by straight forward method proposedby Swanepoel using transmittance measurements.Moreover it was found that annealing temperature augmentationlead to decrease the optical band gap energy calculatedusing Tauc’s relation from 2.45 to 1.80 eV.