Role of the extensions in Double-Gate Junctionless MOSFETs in the drain current at high gate voltage

Abstract

This work studies the effect of doping level applied to the extensions on the electrical characteristics of short channel double gate junctionless transistor. Structures with homogeneous doping profile between source and drain contacts and structures with additional doping in the extensions are studied. 2D simulations were performed for structures with doping concentration of 5×1018 and 1019 cm-3, silicon layer thickness of 10 and 15 nm and with/without extensions of 30 nm. Above flat band voltage, the drain current in saturation presents an important decrease for homogeneously doped structures with extensions attributed to the reduction of potentials at high gate voltage. Lower short channel effects, as less threshold voltage roll off and less subthreshold slope take place in this type of structures due to the shift of minimum potential in the extension regions.