Ruthenium (Ru) thin films were grown on thermally-grown SiO 2 substrate using atomic layer deposition (ALD) by a sequential supply of a zero-valent metallorganic precursor,(ethylbenzyl)(1-ethyl-1, 4-cyclohexadienyl) Ru (0)(EBECHRu, C 16 H 22 Ru), and molecular oxygen (O 2) between 140 and 350 C while the typical temperature was 225 C. A self-limiting film growth was confirmed at the deposition temperature of 225 C and the growth rate was∼ 0.042 nm/cycle on the SiO 2 substrate with a negligible number of incubation cycles (approximately 3 cycles). Plan-view transmission electron microscopy analysis showed that nucleation was started after only 3 ALD cycles and the maximum nuclei density of 1.67× 10 12/cm 2 was obtained after 7 ALD cycles. A continuous Ru film with a thickness of∼ 2.3 nm was formed after 60 ALD cycles. The film resistivity was decreased with increasing deposition temperature, which was closely related to its crystallinity and microstructure, and the minimum resistivity of∼ 14 μΩ-cm was obtained at the deposition temperature of 350 C. The step coverage of the film deposited between 225 and 270 C was approximately 100% over the contact holes (bottom diameter: 0.065 μm) with a high aspect ratio (32: 1). Finally, the ALD-Ru film was successfully evaluated in terms of its performance as a seed layer for Cu electroplating and as a bottom electrode for a metal-insulator-metal capacitor using an ALD-TiO 2 single layer or an ALD HfO 2/La 2 O 3/HfO 2 multilayer as a dielectric.