Photoemission study of the impact of carbon content on Mn silicate barrier formation on low-k dielectric materials

In this x-ray photoelectron spectroscopy (XPS) study ultra-thin Si and MnO films were deposited on a range of low dielectric constant carbon doped oxides (CDO) with varying carbon content, in order to accurately determine the binding energy (BE) positions of the Si 2p and O 1s core level peaks as a function of carbon concentration. The results show a measurable correlation between carbon content and BE position of both the Si 2p and O 1s core level peaks. Furthermore, it has been shown that the full width at half maximum (FWHM) of the various CDO substrate peaks are significantly larger than for SiO₂ making it difficult to unambiguously determine manganese silicate barrier layer formation on these substrates. In a separate set of experiments, the formation of a manganese silicate barrier layer on these CDO substrates following the deposition and high temperature annealing of thin MnO layers is inferred from analysis of the O1s and Mn2p core level spectra.