An eta(3)-allylic complex of ruthenium(II) is used as a precursor for the chemical vapor deposition (CVD) of Ru and RuO2 thin films at low temperatures. The depositions are carried out on alpha-Al2O3 and surface-oxidized Si(100) in N-2, N-2 + H-2, N-2 + O-2, or O-2 flow to tailor the film composition from pure metal Ru to RuO2. The microstructure features of the samples are analyzed by X-ray diffraction and Raman spectroscopy, whereas their surface composition is studied by X-ray photoelectron spectroscopy. Surface and in-depth analyses of the coatings are also performed by secondary ion mass spectrometry, which allows to distinguish the composition of different coating regions along their thickness. The surface morphology and its dependence on the synthesis conditions are investigated by atomic force microscopy. The electrical and optical studies confirm the metallic character of Ru and RuO2 films.