Low-temperature epitaxial growth of BaTiO3 films by radio-frequency-mode electron cyclotron resonance sputtering

BaTiO3 (BTO) films have been deposited on SrTiO3 (STO) wafers by a rf-mode electron cyclotron resonance sputtering system. The substrate surface is pretreated in several ways before film deposition. The oxygen plasma irradiation is the best way of pretreating the substrate surface. Single-crystal BTO films with smooth surfaces are deposited on STO at temperatures ranging from 350 to 650 °C at total gas pressures ranging from 0.02 to 0.1 Pa. BTO films with (100) orientation are obtained at temperatures as low as 200 °C. The dielectric constant of films grown at 350 °C reaches 470 and that of films grown at 550 °C reaches 880.