SO phonon scattering rates at the Si-HfO2 interface in Si MOSFETs

Abstract

Silicon MOSFETs with high κ gate stacks offer a significant reduction in gate leakage current, but the presence of soft surface optic phonon modes degrades the mobility. A progressively more complex set of models for SO phonon scattering at the Si-HfO2 interface is presented based upon dynamic screening models. Landau damping of the electron-phonon-plasmon coupling is examined by simple approximations. A novel approach to determining the re-normalised phonon spectrum based on Padé approximants is outlined as a route to obtaining practical scattering rate for Monte Carlo simulation. © 2006 IOP Publishing Ltd.