Strain-Dependence of Electron Transport in Bulk Si and Deep-Submicron MOSFETs

The strain-dependence of electron transport in bulk Si and deep-submicron MOSFETs is investigated by full-band Monte Carlo simulation. On the bulk level, the drift velocity at medium field strengths is still enhanced above Ge-contents of 20% in the substrate, where the low-field mobility is already saturated, while the saturation velocity remains unchanged under strain. In an n-MOSFET with a metallurgical channel length of 50nm, the saturation drain current is enhanced by up to 11%, but this maximum improvement is essentially already achieved at a Ge-content of 20% emphasizing the role of the low-field mobility as a key indicator of device performance in the deep-submicron regime.