CHARACTERIZATION OF ZNO FILMS PREPARED BY DE REACTIVE MAGNETRON SPUTTERING AT DIFFERENT OXYGEN PARTIAL PRESSURES

ZnO films have been deposited on the glass substrates by de reactive m agnetron sputtering method at different oxygen partial pressures (5 x 10(-4) to 3 x 10(-3) mbar). The deposited films have been characterize d by X-ray diffraction (XRD), scanning electron microscopy (SEM), opti cal transmittance and reflectance, respectively. XRD results show that all the films are oriented with the c-axis perpendicular to the subst rate. As oxygen partial pressure is increased, the grain size and diff raction peak intensify decrease. SEM results show that the films have columnar structure and the average crystallite dimension in the direct ion perpendicular to the c-axis decreases as oxygen partial pressure i s increased. The film transmittance increases as oxygen partial pressu re is increased. By comparing the diffuse transmittance and reflectanc e spectra of the films it has been found that the light loss in the fi lm is mainly due to Rayleigh type scattering and the scattering decrea se as the oxygen partial pressure is increased.