Carrier transport characteristics of strained N-MOSFET featuring channel proximate silicon-carbon source/drain stressors for performance boost

Abstract

We report a study of carrier transport in strained n-channel MOSFETs (nFETs) with embedded silicon-carbon (Si:C) source/drain (S/D) stressors formed in close proximity to the channel, taking parasitic resistance into account in the extraction of carrier transport parameters. While bringing the Si:C S/D stressors closer to the channel improves their effectiveness in imparting tensile strain to the channel, a degradation in ballistic efficiency Bsat due to increased carrier scattering is observed. This is compensated, however, by an increase in the carrier injection velocity vinj, thereby resulting in an on-state current IOn enhancement of ∼7 % in nFETs with channel-proximate Si:C S/D over nFETs with conventional e-Si:C S/D. In addition, the impact of channel orientation on carrier transport characteristics for the new process integration scheme is also evaluated in this paper. ©2010 IEEE.