Formation and Characterization of Epitaxial TiO2 and BaTiO3/TiO2 Films on Si Substrate

Rutile-phase TiO2 films were epitaxially grown on Si(100) substrates by oxidizing epitaxial TiN films grown by KrF pulsed excimer laser deposition. The TiO2 film was (110)-oriented and composed of two domains perpendicular to each other in the plane. The electrical resistivity at 2.5 V and the dielectric constant at 1 MHz of the film were 1.1×1010 Ω· cm and 49, respectively. This film could be used as a buffer layer for the growth of epitaxial BaTiO3 film on Si. The BaTiO3 (260 nm)/TiO2 (230 nm) double-layered film showed a high dielectric constant (ε r=91) and a very low leakage current of 5×10-8 A/cm2 at 10 V.