Low-temperature growth of epitaxial ZnO films on (001) sapphire by ultraviolet- assisted pulsed laser deposition

Abstract. ZnO thin films have been grown on thin Si3N4 membranes and (001) sapphire substrates by an ultraviolet-assisted pulsed laser deposition (UVPLD) technique. The microstructure of the films grown on Si3N4 membranes, investigated by transmission electron microscopy, showed that crystalline and textured films can be grown by UVPLD at a substrate temperature of only 100 °C. For deposition temperatures higher than 400 °C, ZnO films grown on sapphire substrates were found to be epitaxial by Rutherford backscattering (RBS) and X-ray diffraction measurements. The minimum yield of channeling RBS spectra recorded from films deposited at 550 °C was around 2% and the FWHM of the rocking curve for the (002) diffraction peak was 0.17°; these values are similar to those recorded from ZnO layers grown by conventional PLD at 750 °C.