A capacitance-based methodology for work function extraction of metals on high-κ

This letter presents a methodology to accurately extract the work function of metal electrodes on high-κ dielectrics with various charge distributions. A mathematical analysis including sources of errors was used to study the effect of charge distribution in gate dielectric stacks on the flatband voltage of the device. The calculations are verified by experimental results obtained for Ru-Ta alloys on HfO₂ and SiO₂ gate dielectric stacks. It is shown that accounting for the appropriate charge model is imperative for accurate calculation of workfunction on high-κ/SiO₂ gate dielectric stacks.