Modelling the Impact of Asymmetric Channel Doping on Electric Field Distribution and Performance of DG MOSFETs

Abstract This paper presents a two-dimensional (2D) analytical model for the electric field and surface potential variations along the channel of a double-gate metal-oxide-semiconductor field-effect transistor (DGMOSFET). The model is developed using the 2D Poisson’s equation to solve in the channel region, subject to appropriate boundary conditions. To mitigate short-channel effects (SCEs), the structure utilizes nonuniform channel doping, with higher doping near the source and lower doping near the drain. The model is comprehensively analyzed for various device parameters, including gate and drain biases, channel thickness, doping concentrations, and the channel region’s length ratio. The proposed analytical model is developed under the full-depletion approximation, neglecting mobile inversion charge, and is therefore applicable to the subthreshold and near-threshold operating regimes of the DG-MOSFET. The analysis demonstrates effective control of the peak electric field along the channel and a gradual variation in surface potential. As a result, SCEs such as the hot- carrier effect and drain-induced barrier lowering (DIBL) are suppressed. The analytical results were validated through comparison with simulation outcomes obtained using a 2D TCAD Silvaco simulator.