Dielectric enhancement of sol-gel derived BaTiO₃/SrTiO₃ multilayered thin films

Polycrystalline BaTiO₃/SrTiO₃ multilayered thin films have been prepared on Pt/Ti/SiO₂/Si substrates by a sol-gel processing. The X-ray diffraction (XRD) patterns and Auger electron spectroscopy (AES) indicate that the multilayered thin films were formed. The dielectric constant of the multilayered films was significantly enhanced and the dielectric loss was almost the same as that of the uniform BaTiO₃ and SrTiO₃ thin films. A dielectric constant of 660 at 1 kHz was observed for a stacking periodicity of 66 nm at room temperature and the corresponding dielectric loss was maintained below 0.05. The study indicates that there are some differences between the multilayered films and the uniform films in the dielectric constant-frequency relation and capacitance-voltage characteristics. The report also analyzes the mechanism of dielectric enhancement of the multilayered thin films prepared by the sol-gel process.