Improving dielectric properties of epitaxial Gd2O3 thin films on silicon by nitrogen doping

Abstract

We report about the effect of nitrogen doping on the electrical properties of epitaxial Gd2O3 thin films. Epitaxial Gd2O3:N thin films were grown on Si (111) substrates by solid source molecular beam epitaxy using nitrous oxide as the nitridation agent. Substitutional nitrogen incorporation into the dielectric layer was confirmed by secondary ion mass spectroscopy and X-ray photoelectron spectroscopy analysis. Substantial reduction of the leakage current density and disappearance of hysteresis in capacitance-voltage characteristics observed in the Gd2O3:N layers indicate that nitrogen incorporation in Gd2O3 effectively eliminates the adverse effects of the oxygen vacancy induced defects in the oxide layer.