Influence of multi-finger layout on the subthreshold behavior of nanometer MOS transistors

This work studies the effects of number of gate finger on the DC subthreshold characteristics of multi-finger nanoscale MOS transistors. We found in not optimally-tempered nanoscale (gate length = 90 nm) MOS transistors that the significantly deteriorated subthreshold characteristics can be effectively improved by increasing the number of gate finger. This observation was explained with a modified subthreshold slope model based on voltage-doping transformation theory. Hence, the multi-finger structure does not only enhance the operation frequency, it also improves the subthreshold DC characteristics of the nanoscale MOS transistors.