Analytical modelling of electrical parameters and the analogue performance of cylindrical gate-all-around FinFET

Abstract

This paper presents the cylindrical gate-all-around (GAA) silicon on insulator (SOI) FinFET, which not only eliminates the corner effect but also shows high on-drain current ($I_{\mathrm{ON}}$) ($\sim \!\!10^{-2}~\mathrm{A}$), low leakage current ($I_{\mathrm{OFF}}$) ($\sim \!\!10^{-10}~\mathrm{A}$), high $I_{\mathrm{ON}}$ $/$ $I_{\mathrm{OFF}}$ ($10^{8}>10^{6}$) and reduced subthreshold swing (SS) (64.55 mV / dec, which is nearest to the Boltzmann limit of 60 mV / dec). To have a better understanding of the working principles, analytical modelling of electrical parameters such as surface potential, threshold voltage, drain current and SS has been carried out by solving two-dimensional Poisson’s equation using superposition principle. The behaviour of threshold voltage, drain current and SS has been investigated for different dimensional and electrical parameters such as channel lengths, channel radius, gate work functions, dielectric constants, drain-to-source voltages and channel concentrations. The physics-based models have been cross-examined with extracted three-dimensional TCAD simulation results. The modelled values show good agreement with the simulated data. Moreover, analogue performances such as transconductance, output conductance, intrinsic gain and gate capacitance for different channel lengths and radii of the presented device are also studied.