Phonon-limited and effective low-field mobility in n- and p-type [100]-, [110]-, and [111]-oriented Si nanowire transistors

Abstract

Ultrascaled n- and p-type Si nanowire field-effect transistors (NW FETs) with [100], [110], and [111] as channel orientations are simulated in the presence of electron-phonon scattering using an atomistic quantum transport solver based on the sp3d5s∗ tight-binding model for electrons and holes, a modified Keating model for phonons, and the nonequilibrium Green’s function formalism. The channel resistances of devices with different gate lengths and carrier concentrations are computed at room temperature and used to extract phonon-limited, ballistic, and effective low-field mobilities. It is found that a [110] channel represents the best choice for high n- and p-type NW FET performances.