Atomic Layer Deposition of Ru Thin Films Using 2,4-(Dimethylpentadienyl)(ethylcyclopentadienyl)Ru by a Liquid Injection System

Ru thin films were grown on Si, , , and TiN substrates by atomic-layer deposition using 2,4-(dimethylpentadienyl)(ethylcyclopentadienyl)Ru and as Ru precursor and reactant, respectively, at temperatures ranging from . A saturated growth rate of and a low oxygen concentration (below the detection limit of Auger electron spectroscopy) were obtained at . The Ru film showed a negligible incubation period on all the different types of substrates, and an active nucleation behavior which resulted in a very smooth film surface morphology. The dimethylpentadienyl ligand enhanced the active nucleation of Ru and retarded the oxidation of the grown Ru layer. Good step coverage was obtained from the Ru film grown on a capacitor hole with an aspect ratio of 17 and an opening diameter of by a proper control of the Ar carrier gas flow rate.