Preferentially oriented BaTiO3 thin films deposited on silicon with thin intermediate buffer layers

Barium titanate (BaTiO 3 ) thin films are prepared by conventional 2-methoxy ethanol-based chemical solution deposition. We report highly c -axis-oriented BaTiO 3 thin films grown on silicon substrates, coated with a lanthanum oxynitrate buffer layer of 8.9 nm. The influence of the intermediate buffer layer on the crystallization of BaTiO 3 film is investigated. The annealing temperature and buffer layer sintering conditions are optimized to obtain good crystal growth. X-ray diffraction measurements show the growth of highly oriented BaTiO 3 thin films having a single perovskite phase with tetragonal geometry. The scanning electron microscopy and atomic force microscopy studies indicate the presence of smooth, crack-free, uniform layers, with densely packed crystal grains on the silicon surface. A BaTiO 3 film of 150-nm thickness, deposited on a buffer layer of 7.2 nm, shows a dielectric constant of 270, remnant polarization (2P r ) of 5 μC/cm 2 , and coercive field ( E c ) of 60 kV/cm.