SrTiO₃ Thin Film Preparation by Ion Beam Sputtering and Its Dielectric Properties

Abstract

SrTiO 3 thin films have been prepared on Pd-coated sapphire substrates by ion beam sputtering of a SrTiO 3 target, and their dielectric properties have been studied. Oxygen flow introduction was necessary to obtain good insulating films. Dielectric constant ε r values were 190 and 240 for 430°C and 540°C substrate temperatures, respectively. These ε r values were not dependent on film thickness in the range from 200 nm down to 50 nm. A 53 nm-thick film indicated leakage current density of less than 10 -8 A/cm 2 at up to 2 V, along with a 230 ε r value.