Annealing effects on the polarity of stored charge of BaTiO/sub 3/ films on Si

A high quality BaTiO/sub 3//p-Si interface was achieved at substrate temperature of 500/spl deg/C by using RF magnetron sputtering. In-situ annealing at the same temperature was carried out to study the charge behavior of BaTiO/sub 3/ films on Si substrate. Depending on the annealing oxygen pressure and annealing condition, both polarities of effective oxide charge in the metal-ferroelectric-semiconductor, Au/BaTiO/sub 3//p-Si, structure was observed. It is believed that the density of electronic states, generated at the interface due to the asymmetry of the structure between BaTiO/sub 3/ and Si substrate, and the positive oxide charges, depending on the degree of the metal-oxygen reaction for different annealing oxygen pressures and annealing durations, determines the behavior of oxide charge.