Epitaxial Pb(Zr0.2Ti0.8)O-3 (PZT) films with various thicknesses were prepared on an epitaxial SrRuO3(SRO) bottom electrode grown on SrTiO3 (STO) with atomically flat surface. The PZT films with a rms roughness of 0.2-0.3 nm exhibit a typical square-shaped P-E hysteresis loop, which has the P, of approximately 60 mu C/cm(2). The leakage current density of the films increases with decreasing film thickness and the 22-nm-thick PZT films have a leakage current density of approximately 10(-5) A/cm(2) at -1 V. (c) 2005 American Vacuum Society.