Ferroelectric thin films of Sr0.8Ba0.2Bi2Ta2O9 were grown on Pt/TiO2/SiO2/Si substrates by using the pulsed laser deposition technique and the effect of annealing on structural and electrical properties of the films has been investigated. The films deposited at 500 °C substrate temperature and 200 mTorr oxygen pressure showed amorphous nature. Perfect crystalline films were obtained after annealing at 750 °C. Increase in grain size with increasing annealing temperature was observed by atomic force microscopy. Good hysteretic behavior with remanent polarization (2Pr) of 11 and 25 μC/cm2 and coercive field (Ec) of 32 and 34 kV/cm with fatigue endurance of up to 1010 switching cycles were obtained with the films annealed at 750 and 800 °C. Moreover, the films annealed at 800 °C had a maximum dielectric constant of ∼375. Increase in dielectric constant with increasing annealing temperature is attributed to the increased grain size, whereas the lower dielectric constant and higher dissipation factor of the 850 °C annealed film is attributed to the presence of the secondary phase, which resulted from the loss of Bi due to evaporation and/or interdiffusion of metallic Bi into the platinum substrate at higher annealing temperature. © 2002 American Vacuum Society.