Epitaxial ZnO films grown on sapphire (001) by ultraviolet-assisted pulsed laser deposition

ZnO thin films were grown on Si(100) and sapphire (001) substrates by an in situ ultraviolet-assisted pulsed laser deposition technique. Using this technique, highly textured ZnO films were grown on Si substrates even at 100°C. Films grown on sapphire (001) at temperatures higher than 400°C, were found to be epitaxial by Rutherford backscattering (RBS) and X-ray pole figure measurements, with [001]_ZnO ∥ [001]_sap and [100]_ZnO ∥ [110]_sap. The minimum yield of the channeling RBS spectra recorded from films deposited at 550°C was around 2%, while the full width at half maximum of the rocking curve on the (002) diffraction peak was only 0.168°. Such values, characteristic for high quality epitaxial ZnO films, are identical with those previously reported for films grown by conventional pulsed laser deposition at 750-800°C substrate temperatures.