Strontium tantalate (STO) films were grown by liquid-delivery (LD) metalorganic chemical vapor deposition (MOCVD) using Sr[Ta(OEt) 5 (OC 2 H 4 OMe)] 2 as precursor. The deposition of the films was investigated in dependence on process conditions, such as substrate temperature, pressure, and concentration of the precursor. The growth rate varied from 4 to 300 nm/h and the highest rates were observed at the higher process temperature, pressure, and concentration of the precursor. The films were annealed at temperatures ranging from 600 to 1000 1C. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and ellipsometry indicated that the as-deposited and the annealed films were uniform and amorphous and a thin (42 nm) SiO 2 interlayer was found. Crystallization took place at temperatures of about 1000 1C. Annealing at moderate temperatures was found to improve the electrical characteristics despite different film thickness (effective dielectric constant up to 40, the leakage current up to 6 Γ 10 Γ8 A/cm 2 , and lowest midgap density value of 8 Γ 10 10 eV Γ1 cm Γ2 ) and did not change the uniformity of the STO films, while annealing at higher temperatures ($1000 1C) created voids in the film and enhanced the SiO 2 interlayer thickness, which made the electrical properties worse. Thus, annealing temperatures of about 800 1C resulted in an optimum of the electrical properties of the STO films for gate dielectric applications.