Temperature-dependent ballistic transport in a channel with length below the scattering-limited mean free path

Abstract

The temperature-dependent ballistic transport, using nonequilibrium Arora distribution function (NEADF), is shown to result in mobility degradation with reduction in channel length, in direct contrast to expectation of a collision-free transport. The ballistic mean free path (mfp) is much higher than the scattering-limited long-channel mfp, yet the mobility is amazingly lower. High-field effects, converting stochastic velocity vectors to streamlined ones, are found to be negligible when the applied voltage is less than the critical voltage appropriate for a ballistic mfp, especially at cryogenic temperatures. Excellent agreement with the experimental data on a metal-oxide-semiconductor field-effect transistor is obtained. The applications of NEADF are shown to cover a wide spectrum, covering regimes from the scattering-limited to ballistic, from nondegenerate to degenerate, from nanowire to bulk, from low- to high-temperature, and from a low electric field to an extremely high electric field.