Carrier Backscattering Characteristics of Strained N-MOSFET Featuring Silicon-Carbon Source/Drain Regions

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 v_inj accounts for the large drive current I_Dsat enhancement in SiC S/D transistors. The improvement in r_sat, 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 v_inj enhancement. In addition, we evaluate the dependence of drive current performance on carrier injection velocity and ballistic efficiency in a short channel MOSFET