TiO2 thin films with high dielectric constants (83 - 100) were grown on sputtered and atomic-layer-deposited (ALD) Ru electrode at a growth temperature of 250oC using the atomic- layer-deposition method. The as-deposited films were crystallized with rutile structure. Further improvements in the leakage current characteristics are achieved by proper doping of Al and Hf, thereby an equivalent oxide thickness (tox) ~ 0.6 nm with small enough leakage current density (1 x 10-7 A/cm2 at 0.8V) was achieved. These good properties are also realized from 3D structured hole-type capacitors. The rutile structured TiO2 films were also obtained from Ru electrode which is deposited by an ALD process using a newly developed noble precursor. In addition, it was confirmed that the Ru metal film step coverage on the capacitor hole structure with an aspect ratio of 17 is > 90 %. The thermal stability of the Ru electrode on severe 3D holes was improved with the adoption of hydrogen plasma process.