The impact of uniaxial strain engineering on channel backscattering in nanoscale MOSFETs

The influence of uniaxial process-induced strain on carrier channel backscattering in nanoscale MOSFETs is reported for the first time. It is observed that the backscattering ratio can be reduced by uniaxial tensile strain while it is increased by uniaxial compressive strain mainly due to strain-induced modulation in mean-free-path for backscattering and slight decrease in kBT layer thickness. Nevertheless, both strain polarities improve source-side injection velocity because of reduced carrier effective mass. Impact to current drive under uniaxial strain is analyzed in terms of mean-free-path, kBT layer thickness, ballistic efficiency and injection velocity.