Influence of postdeposition annealing on the properties of Ga2O3 films on SiO2 substrates

We have investigated the structural and optical properties of annealed gallium oxide (Ga2O3) film in the range of 750-1050 °C, which had been grown on SiO2 substrates by the metal organic chemical vapor deposition (MOCVD) technique. We revealed that postdeposition annealing of amorphous Ga2O3 generated grains in β-Ga2O3 phase. While photoluminescence spectra of as-deposited Ga2O3 films showed strong blue-green (BG) and ultraviolet (UV) emission, postdeposition annealing at high temperatures resulted in appearance of a longer wavelength UV band and a new green band.