Abstract
High dielectric constant materials have received much attention for use as gate dielectric films and capacitor dielectric films of advanced devices. We plan to use Ta2O5 for capacitor dielectric films and Ru or RuO2 for both top and bottom electrodes because Ta2O5/Ru (RuO2) show excellent performance with the dielectric constant rising to about 70, i.e. an SiO2-equivalent thickness of 0.7nm at a Ta2O5 thichness of 10nm. [1] We have adopted XPS (X-ray photoelectron spectroscopy) for one part of the capacitor evaluation. XPS is used not only for analysis of components and chemical states but also to depict the energy-band diagram from fine structure of the spectrum. This paper discusses part of our evaluation techniques for using XPS to study capacitor materials of advanced memory devices.
