Ballistic transport in nanoscale devices

Ballistic transport from low-field to high-field regime is reviewed with transition from low-field ballistic mobility to high-field drift velocity limited to the intrinsic velocity for a given dimensionality. Equilibrium Fermi-Dirac to Boltzmann to nonequilibrium Arora distribution is delineated and applied. Ballistic injection from the contacts is shown to be of paramount importance as channels scale down to lengths below the scattering-limited mean free path (mfp). Mobility and drift velocity expressions covering the wide spectrum are obtained and compared with existing experimental data. The gamut spans low to high field transport, nondegenerate to degenerate statistics, and scattering-limited stochastic to unilateral streamlined regime.