Growth of ZnO nano films on Sapphire/GaAs/ Si substrates

ZnO films of Nano dimensions 70-250 nm were obtained on different substrates namely Sapphire/GaAs. Metallic Zn films were deposited by thermal evaporation method at room temperature under vacuum ~ 10^-6 torr. These films were subsequently partially oxidized by chemical method followed by heat treatment at three different elevated temperatures 350degC,400degC, and 450degC in O2/air. These films were characterized by X-ray for phase analysis, Atomic Force Microscope (AFM) for surface related features . Surface steps flow mechanism drives the growth mode and ZnO nanoislands are well formed on c-axis sapphire due to less thermal mismatch between the film and the substrate.