Stoichiometric and structural properties of pulsed-laser deposited BaTiO3 thin films on silicon

BaTiO3 thin films have been grown on Si (100) substrate by KrF pulsed - laser deposition (PLD). The influence of substrate temperature and background oxygen pressure on the chemical composition and crystal structure of BaTiO3 films was studied. The films were characterized by X-ray diffraction (XRD), UV/VIS/NIR spectrometer, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). In our experiments, the BaTiO3 films with uniform grains were produced at O-2, pressure range of 10-30 mTorr and substrate temperature of 600degreesC-620degreesC. At lower substrate temperature, the XRD patterns of the films displayed weaker peaks with wider FWHM and the AFM images showed grain boundary defects and numerous holes. The compositional analysis performed by XPS indicated that almost stoichiometric 1:1:3 composition BaTiO3 films were grown by PLD at optimized deposition parameters. The excessive oxygen resulted in the formation of other molecules for the film development. The additional XRD peaks of the films were observed when O-2 pressure was increased.