Full Quantum Treatment of Remote Coulomb Scattering in Silicon Nanowire FETs

Abstract

We study the influence of remote Coulomb scattering (RCS) due to trapped charges at the silicon oxide/high- kappa material interface on the electrical performances of silicon nanowire (Si-NW) FETs. We address a full quantum analysis based on the 3-D self-consistent solution of the Poisson-Schrdinger equation within the coupled mode-space non-equilibrium Green's function (NEGF) formalism. We find that the RCS strongly affects the electrical performances of Si-NWs by increasing both the inverse subthreshold voltage slope and the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> current. RCS-limited mobility, which is mainly determined by screening effects, is found to have quasi-linear dependence on the 1-D channel electron density, and its dependence on fixed charge density and interface layer thickness is discussed.