Electrical and structural properties of annealed epitaxial CeO<inf>2</inf> films on Si(111) substrates

Abstract

Epitaxial CeO2 films were grown on Si(111) substrates by laser ablation of CeO2 targets under UHV conditions. The as-grown films were found to have poor electrical properties due to the presence of a large amount of defects near the oxide-silicon interface. Improved MOS electrical characteristics were obtained by annealing in an O2 environment. This however resulted in the growth of a SiO2 layer that can be 10 nm thick at the silicon interface which will thus reduce the capacitance of the grown structure. Annealing in argon and argon followed by oxygen environments were investigated as means to reduce the defects while minimizing the intermediate SiO2 layer thickness. The annealed films were compared based on their RBS yields, breakdown voltages and capacitance-voltage characteristics. Growth and annealing conditions were optimized to achieve device quality MOS structures.