Metallorganic chemical vapor deposition of metallic Ru thin films on biaxially textured Ni substrates using a Ru(EtCp)2 precursor

Ruthenium (Ru) films on rolling-assisted biaxially textured Ni substrates (RABiTs) were deposited by liquid source chemical vapor deposition using bis-(ethyl-π-cyclopentadienyl)ruthenium (Ru(C2H5C5H4)2). The thermal decomposition process of the precursor was investigated by Fourier transform infrared spectroscopy (FTIR), mass spectroscopy, and differential scanning calorimetry/thermogravimetric analyses (DSC/TGA). The crystalline structure and resistivity of Ru thin films were investigated. The Ru films were polycrystalline and had a grainy structure. Although the thermal decomposition of the precursor required a sufficient amount of oxygen, the experimental results showed that up to a certain concentration of oxygen (i.e. O2/Ar ∼ 30/10), Ru metal film was deposited without any detectable RuO2 impurities. A higher deposition temperature and a higher ratio of O2/Ar will be beneficial to the growth of (0 0 2) orientation. They showed a low resistivity of about 10-20 μΩ cm, which is sufficiently low for them to be used as a buffer layer in superconductor tapes or electrode materials in dielectric capacitors.