Work function of TaSiN (TaCN) films on HfO2 or SiO2 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 HfO2 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.
Proceedings Title: ECS Transactions
Conference Dates: October 29-November 3, 2006
Conference Location: Cancun, MX
Pub Type: Conferences