CHARACTERISTICS OF SRTIO3 THIN-FILMS DEPOSITED UNDER VARIOUS OXYGEN PARTIAL PRESSURES

SrTiO3 thin films were deposited by rf-magnetron sputtering under vari ous sputtering conditions followed by conventional furnace annealing a t 600 and 700 degrees C. The amorphous SrTiO3 thin films crystallized into polycrystals at 600 degrees C. The leakage current of the SrTiO3 thin films decreased with increasing oxygen partial pressure in the sp uttering gas. On the contrary, the dielectric constant increased with increasing the oxygen content in the sputtering gas. The leakage curre nt and dielectric constant increased with increasing substrate tempera ture and post-annealing temperature. The ratio of Sr:Ti approached 1:1 with increasing oxygen content in the sputtering gas and substrate te mperature during deposition. The oxygen content in the film decreased with increasing the substrate temperature. The capacitance-voltage (C- V) curves showed that the capacitance was nearly independent of the ap plied voltage. Scanning electron microscopy (SEM) micrographs showed t hat interdiffusion between the bottom electrode (Pt) and the buffer la yer (Ti) occurred during post-annealing, but that the interface betwee n SrTiO3 and Pt was stable.