Channel-Width-Dependent Mobility Degradation in Bulk Conduction Regime of Tri-Gate Junctionless Transistors

Junctionless transistors (JLTs) have promising strengths such as extremely simple structures without p-n junctions, better reliability, and low flicker noise, for overcoming scaling challenges for advanced sub-5-nm nodes. In this article, channel-width-dependent operation in the partially depleted regime of tri-gate JLTs was investigated in comparison to conduction in conventional inversion-mode (IM) transistors. A large difference in transconductance ( ${g} _{m}$ ) against gate-to-channel capacitance ( ${C} _{gc}$ ) and the reduced amplitude of the first peak on $dg_{m}$ / $dV_{g}$ were identified under the partially depleted regime in JLTs, due to a severe transverse ${E}$ -field near-threshold voltage ( ${V} _{th}$ ). However, the impact of ${E}$ -field was weakened as decreasing channel width of JLTs. These works provide key information for a better understanding of the channel-width-dependent performance of JLTs and for implementing practical applications with them.