Bandstructure effects in ballistic nanoscale MOSFETs

Bandstructure effects on ballistic transport in ultra-thin-body unstrained and strained MOSFETs are investigated using a 20 band sp/sup 3/d/sup 5/s*-SO semi-empirical tight-binding model. It is observed that for unstrained Ge n-devices, the effective mass approach fails below 3 nm. Additionally, in strained Si p-MOSFETs, orientation of uniaxial compressive strain axis relative to quantum confinement direction substantially affects performance.