Low-Temperature Effects on Electron Transport in Small-Diameter Silicon Nanowire

We report on modeling studies on the effect of very low temperatures (4K-77K) on the behavior of electron transport in a [110] axially aligned, 1.3 nm diameter unstrained silicon nanowire (SiNW). A sp ³ d ⁵ s ^* tight-binding scheme is used to calculate the band structure within an Ensemble Monte Carlo simulation. Electron scattering occurs through bulk-acoustic and bulk-optical phonons and includes intra-subband and inter-subband events. A comparison with room temperature (300K) shows that at lower temperatures, average electron steady-state drift velocity increases by 2 or more times at relatively moderate electric fields. Transient average electron velocity also shows a more pronounced streaming motion. This is attributed to an overall decrease in electron-phonon scattering rates with temperature.