PREPARATION OF C-AXIS ORIENTED ZNO FILMS BY LOW-PRESSURE ORGANOMETALLIC CHEMICAL-VAPOR-DEPOSITION

ZnO films have been deposited on sapphire (0001) substrates at 370 degrees C at a H2O partial pressure of 2.7 X 10(-2) to 2.7 X 10(-3) Pa, using zinc acetate as a precursor. All of the resultant ZnO films are insulators at room temperature. ZnO film with a smooth surface has been prepared at a H2O partial pressure of 6.7 X 10(-3) Pa, and its X-ray diffraction pattern is not affected by annealing at 500 degrees C for 10 h in air. In photoluminescence spectra at 77 K, an intense broad band is observed in near-UV region (3.3-3.4 eV) for as-deposited ZnO films, whereas the emission in the near-UV region is significantly diminished by the annealing.