Physics in Fermi level pinning at the polySi/Hf-based high-k oxide interface

We report that O vacancy (Vo) formation in ionic Hf-based dielectrics and subsequent electron transfer into poly Si gates across the interface, definitely cause substantial flat band (Vfb) shifts especially for p+ gate MISFETs. Our theory can systematically reproduce experiments related to Hf-based dielectrics, and gives a guiding principle towards gate/high-k oxide interface control.