Work Function Characterization of TaSiN and TaCN Electrodes Using CV, IV, IPE and SKPM

摘要

Work function of TaSiN (TaCN) films on HfO{sub}2 or SiO{sub}2 gate dielectrics is investigated for the first time using a combination of Capacitance-Voltage, Fowler-Nordheim tunneling, internal Photoemission, and scanning Kelevin probe microscopy methods, which consistently show ～0.2 eV work function difference between these two metals. These results indicate that Fermi-level pinning on HfO{sub}2 is not an issue for these metal systems. SKPM gives qualitative results. Beveled structure and complicated modeling are needed for the potential quantitative application of SKPM in metal/high-k systems. The capacitive-voltage and internal photoemission measurements were performed on the same test structures. Work function values extracted from these two methods agree well.