Phonon-limited mobility and injection velocity in n- and p-doped ultrascaled nanowire field-effect transistors with different crystal orientations

In this paper, ultrascaled n- and p-channel 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 a sp
³
d
⁵
s* tight-binding approach and confined phonon dispersions. The low field mobility, the injection velocity, and the ballisticity of these devices are extracted and compared to n-type InAs and p-type Ge NW FETs. It is found that a [110] Si channel represents the best compromise between high n- and p-type performances in the considered NW FETs.