Modelling of doping-dependent subthreshold swing of symmetric double-gate MOSFETs

A simple, yet efficient two-dimensional (2D) model for the doping-dependent subthreshold swing characteristics of symmetric double-gate (DG) MOSFETs has been presented. The 2D Poisson´s equation has been solved by using parabolic potential approximation method to obtain the 2D channel potential function of the device. A closed-form expression for the doping-dependent effective current conducting path distance (d_eff) measured with respect to the centre of the channel of the symmetric DG MOSFET has been presented. Finally, the closed-form expression of the conducting path distance parameter d_eff has been utilised to obtain the subthreshold swing model of the device. The validity of the proposed model has been shown by comparing the analytical results with numerical simulation data obtained by using the commercially available ATLAS™ device simulator.