Channel width dependent subthreshold operation of tri-gate junctionless transistors

Abstract

Junctionless transistors (JLTs) are one of attractive candidates for further scaling down thanks to their promising advantages based on a structural simplicity without PN junctions, and their physical operation is quite different from traditional inversion-mode (IM) transistors. In this paper, we investigated the subthreshold operation of trigate JLTs with various effective width (W-eff) and compared to that of IM transistors. The on current to off current ratio (I-on/I-off) and subthreshold swing (SS) of JLTs were varied dramatically as changing Weff. In addition, a better immunity against short channel effects (SCEs) of JLTs was proven. Physical operation mechanism on the subthreshold regime was also discussed in detail with considering distribution of mobile charge carriers, maximum depletion width, full-depletion mode, bulk neutral and surface accumulation conduction.