Several 1-D analytical models of the potential distribution across the nMOS/GAA device are proposed and compared. The most accurate result is achieved solving the Poisson equation accounting for both the depletion charges and an approximation of the electron density at the surface of the film. The derived analytical expressions of the drain current and the threshold voltage are in good agreement with numerical simulations.
Francis, P., Terao, A., Flandre, D., & Van de Wiele, F. (1993). Weak inversion models for nMOS Gate-all-Around (GAA) devices. Proceedings of the 23rd European Solid State Device Research Conference, 1993 (ESSDERC ’93), 621-624. https://hdl.handle.net/2078.5/220820