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

ZnO thin films have been grown on thin Si3N4 membranes and (001) sapphire s ubstrates by an ultraviolet-assisted pulsed laser deposition (UVPLD) techni que. 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 degrees C. For deposition temperatures higher than 400 degrees C, ZnO films grown o n sapphire substrates were found to be epitaxial by Ruther-ford backscatter ing (RBS) and X-ray diffraction measurements. The minimum yield of channeli ng RES spectra recorded from films deposited at 550 degrees C was around 2% and the FWHM of the rocking curve for the (002) diffraction peak was 0.17 degrees; these values are similar to those recorded from ZnO layers grown b y conventional PLD at 750 degrees C.