Effect of silicon surface states on the properties of epitaxial Al2O3 films

Abstract Epitaxial γ-Al 2 O 3 films were grown on a chemically oxidized Si(111) substrate by ionized beam deposition. The effects of an oxidized Si surface on the film properties were examined and compared with the results of the Al 2 O 3 films grown on a clean Si surface. Al 2 O 3 films grown on an oxidized Si surface showed higher crystalline quality, a flatter surface, and a more abrupt interface than those of the films grown on a clean Si substrate. Temperature dependence of Al 2 O 3 films on the crystallinity and surface morphology was estimated by reflection high-energy electron diffraction and atomic force microscopy. Chemical composition and interface state of the films were evaluated by X-ray photoelectron spectroscopy and Rutherford backscattering spectroscopy.