Polycrystalline and epitaxial RuO2/TiO2/RuO2 structures were prepared by a combination of metal organic chemical vapor deposition and atomic layer deposition techniques. TiO2 layer grew in a rutile structure due to epitaxial growth on the RuO2 seed layer and exhibited high dielectric constant of 120. Equivalent oxide thickness as low as 0.5 nm with a leakage current density of 6 x 10(-6) A/cm(2) at 0.8 V bias voltage was obtained for the RuO2/TiO2/RuO2 capacitor structure epitaxially grown on (1 (1) over bar 02) sapphire substrate. Analysis of leakage currents revealed uneven distribution of defects in the TiO2 dielectric layer. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3021030]