Fermi-level Pinning in Full Metal/high-K/sio2/si Stacks

Fermi-level pinning (FLP) in full Metal/High-k/SiO2/Si stacks is investigated based on the improved electron state density (IESD) model. The SiO2 interlayer between the high-k layer and Si and the effects of the high-k/SiO2/Si interface on FLP are analyzed. The effective work function (EWF) is influenced by the density of states in high-k/SiO2/Si stacks with the exception of the effects of the electron state density in the metal gate. The IESD model provides physical insights and is a simple and convenient method to calculate the EWF of MOS devices with different types.