Maximum drive current scaling properties of strained Si NMOS in the deca-nanometer regime

The scaling of the drive current of strained Si NMOSFETs with gate lengths from 250 nm down to 50 nm is investigated with the self-consistent full-band Monte Carlo model. Although a degradation of the performance improvement due to strain is observed for decreasing gate length, this effect seems to saturate at very short channel lengths because of quasiballistic transport effects. For a gate length of 50 nm still an improvement of the drive current of more than 30% is found for Ge concentrations in the substrate of more than 15%.