Performance optimization of nanoscale junctionless transistors through varying device design parameters for ultra-low power logic applications

•Low power performance of nanoscale junctionless (JL) MOSFETs is optimized.•Impact of channel doping, underlap spacer, etc. on performance metrics is studied.•ON-current for a fixed OFF-current, subthreshold swing & delay are optimized.•Our proposed JL MOSFETs outperform Si FinFETs at channel length of 34 nm.

Ultra-low power logic applications at advanced CMOS technology nodes have been extensively investigated nowadays to increase packing density in Integrated Circuits at a lower cost. Junctionless (JL) transistors have emerged as promising alternatives to conventional MOSFETs because of their relatively easy fabrication steps and extreme scalability. We perform a detailed numerical study to evaluate the effects of channel doping concentration, dielectric constant of underlap spacers, source/drain resistance on logic performance of 20 nm gate length JL MOSFETs in terms of ON-current at a given OFF-current, subthreshold swing, gate capacitance and intrinsic delay for supply voltages ranging 0.4–0.75 V. In comparison with the reported experimental data for inversion-mode device, our optimized JL device exhibits enhancement of ION by 15.6%, reduction of drain-induced barrier lowering (DIBL) by 22.5% while preserving equally low SS of 61.5 mV/decade at channel length of 34 nm and supply voltage of 0.75 V.