Ferroelectric SrBi2(Ta1-xNbx)(2)O-9 (SBNT) thin films were deposited on Pt/TiOx/SiO2/Si substrates at various substrate temperatures by the pulsed laser ablation deposition method. X-ray diffraction shows that the film has a fluorite structure at a substrate temperature of 500 degreesC. The fluorite structure was transformed into perovskite phase at 550degreesC and was fully crystallized at temperatures greater than or equal to700 degreesC, with a secondary phase present. Secondary ion mass spectroscopy and x-ray photoelectron spectroscopy studies reveal that the secondary phase was a nonferroelectric Bi-deficient pyrochlore phase at the SBNT/Pt interface and the film surface. The pyrochlore structure has a detrimental effect on the ferroelectric properties (i.e., the remanent polarization, coercive field, leakage current and fatigue) of the film. The remanent polarization and coercive field for the film grown at a substrate temperature of 700 degreesC were 4.79 muC/cm(2) and 68.68 kV/cm, respectively, with leakage current <10(-7) A/cm(2) even at an applied voltage of 8 V and 30% degradation in endurance against fatigue after 2x10(12) switching cycles.