Carrier backscattering characteristics of strained N-MOSFET featuring silicon-carbon source/drain regions

Abstract

The physics of carrier transport in a sub-90nm strained SOI n-MOSFET with silicon-carbon (SiC) source/drain (S/D) regions is investigated for the first time. Significant improvement in carrier backscattering coefficient r sat and source injection velocity Vinj accounts for the large drive current IDsat enhancement in SiC S/D transistors. The improvement in rsat is attributed to the modulation of conduction band barrier which results in a shorter critical length for carrier backscattering. On the other hand, strain-induced conduction band valley splitting leads to a reduced electron effective mass and thus contributes to the Vinj enhancement. In addition, we evaluate the dependence of drive current performance on carrier injection velocity and ballistic efficiency in a short channel MOSFET. © 2006 IEEE.