Microstructural and Electrical Characteristics of Rapid Thermally Processed (Ba1—xSrx)TiO3 Thin Films Prepared by Metalorganic Solution Deposition Technique

Abstract

Barium strontium titanate thin films including barium titanate BaTiO3 and strontium titanate SrTiO3 end members were fabricated on Pt-coated silicon and bare silicon substrates by metalorganic solution deposition (MOSD) technique using acetate precursors. Polycrystalline (Ba1—xSrx)TiO3 thin films were obtained by rapid thermal annealing at 700 °C for 60 s. The films were characterized for electrical properties in terms of dielectric permitivity, dissipation factor, and dc leakage current characteristics. A peak in dielectric constant was observed for (Ba0.6Sr0.4)TiO3 composition at room temperature. The typical measured small signal dielectric constant and dissipation factor for 0.5 μm-thick (Ba0.6Sr0.4)TiO3 films at 100 kHz were 450 and 0.012, respectively. (Ba0.6Sr0.4)TiO3 thin films exhibited a high voltage dependent tunability of 47% at an applied electric field of 0.5 MV/cm. The interfacial properties of Au/(Ba0.6Sr0.4)TiO3/Si structure were examined by high frequency C—V measurements. A charge storage density of 39.6 fC/μm2 and leakage current density of less than 10—8 A/cm2 were obtained for (Ba0.6Sr0.4)TiO3 thin films at an applied electric field of 100 kV/cm.