Sensitivity analysis of steep subthreshold slope (S-slope) in Junctionless nanotransistors

In this work, we analyze the sensitivity of steep subthreshold slope (S-slope) values exhibited by Junctionless (JL) MOSFETs on device parameters. The steep S-slope values (< 60 mV/decade) achieved by JL MOSFET due to impact ionization are more sensitive to film thickness than gate length and oxide thickness. JL MOSFETs designed with higher doping concentrations show steeper S-slope values at lower drain bias than those doped with lower doping concentrations. It is demonstrated that for certain set of parameters, steep S-slope JL nanotransistors can latch to the on state and fail to turn-off. The work identifies the possible set of device parameters for which steep S-slope values can be observed in JL nanotransistors.