Magnetron sputtering growth and characterization of high quality single crystal ZnO thin films on sapphire substrates

Abstract

ZnO films were grown on sapphire substrates by rf magnetron sputtering and their structural and optical properties were characterized in detail. It was observed that high quality single crystal ZnO films are obtained when grown at high temperature (>600 °C) and low plasma power in oxygen-rich ambient. Films grown at 800 °C and 75 W in pure O2 showed sharp and intense photoluminescence (PL) and high resolution x-ray diffraction (XRD) peaks, with full-width-at-half-maximum values of 155 meV (room temperature PL), 23 meV (12 K PL) and 280 arcsec (XRD), which is comparable with previously reported values from ZnO films grown by more sophisticated techniques such as metal-organic chemical vapour deposition.