A closed-loop evaluation and validation of a method for determining the scattering limited carrier velocity in MOSFETs

A closed-loop evaluation of a saturation transconductance (g/sub msat//sup (i)/) based method for determining the scattering limited carrier velocity ( nu /sub sat/) in enhancement MOSFETs was performed with the use of a 2-D device simulator. Consistency in the extracted nu /sub sat/ over a wide range of gate oxide thickness (T/sub ox/), channel doping concentration, and bias condition was tested and verified. Also analyzed are the appropriate measurement condition, the significance of the parasitic effect due to the source and drain resistances, the applicability of the method used for compensating this parasitic effect, and the expected accuracy of the extracted nu /sub sat/ under ideal conditions. A plausible explanation is provided for the inconsistency between nu /sub sat/ determined from g/sub msat//sup (i)/(0), the extrapolated transconductance, and nu /sub sat/ determined from the slope of (g/sub msat//sup (i)/(0))/sup -1/ versus T/sub ox/ characteristics observed in published results. The g/sub msat/ /sup (i)/-based method for extracting nu /sub sat/ has been applied to MOSFETs fabricated with three vastly different technologies, and the experimentally-based nu /sub sat/ of electrons at 300 K ranges from 7.37*10/sup 6/ to 7.92*10/sup 6/ cm/s, which shows its independence of technology.>