Preferentially oriented BaTiO3 thin films deposited on silicon with thin intermediate buffer layers
1 Department of Electronics and Information Systems, Ghent University, Sint-Pietersnieuwstraat 41, Gent, 9000, Belgium
2 Department of Information Technology, Photonics Research Group, Ghent University, Sint-Pietersnieuwstraat 41, Gent, 9000, Belgium
3 Department of Solid State Sciences, Ghent University, Krijgslaan 281, Gent, 9000, Belgium
4 Center for Nano-and Biophotonics (NB-Photonics), Ghent University, Gent, 9000, Belgium
Nanoscale Research Letters 2013, 8:62 doi:10.1186/1556-276X-8-62Published: 7 February 2013
Barium titanate (BaTiO3) thin films are prepared by conventional 2-methoxy ethanol-based chemical solution deposition. We report highly c-axis-oriented BaTiO3 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 BaTiO3 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 BaTiO3 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 BaTiO3 film of 150-nm thickness, deposited on a buffer layer of 7.2 nm, shows a dielectric constant of 270, remnant polarization (2Pr) of 5 μC/cm2, and coercive field (Ec) of 60 kV/cm.