Methylated [(benzene)(1,3-butadiene)Ru0] Derivatives as Novel MOCVD Precursors with Favorable Properties

[(Benzene)(2-methyl-1,3-butadiene)Ru-0] (1), [(benzene)(2,3-dimethyl-1,3-butadiene)Ru-0] (2), and [(2,3-dimethyl-1,3-butadiene)(toluene)Ru-0] (3) are prepared and tested as new metal-organic (MO) ruthenium precursor complexes with favorable deposition properties for the CVD of thin ruthenium films. X-ray diffraction (XRD) studies of single crystals of the complexes are characteristic for true Ru-0 pi-complexes without molecular structure peculiarities or significant intermolecular interactions in the solid state, which can hinder undecomposed evaporation. Differential thermal analysis (DTA) and vapor pressure data qualify the compounds as almost idealMOCVDprecursors. Thin ruthenium films are deposited successfully on silicon wafers at substrate temperatures between 200 and 400 degrees C in a nitrogen gas atmosphere. X-ray photoelectron spectroscopy (XPS), four-point probe conductivity measurements, and atomic force microscopy (AFM) are used to characterize the films. All films consist of polycrystalline metallic ruthenium with a low surface roughness.