Extended Frenkel pairs and band alignment at metal-oxide interfaces

Abstract

We show how oxygen vacancies in metal oxides next to high-work-function metals are stabilized by an oxygen exchange reaction with the metal, and by a charge transfer from the vacancy energy level to the metal Fermi level. The results help explain some of the Fermi-level pinning problems in high-$k$ dielectric gate stacks in complimentary metal oxide semiconductor technology and also explain the driving force behind the strong metal-support interaction in oxide-supported catalysts.