On the modeling of the current-voltage characteristics of a symmetrical double-gate metal-oxide-semiconductor field-effect transistor with an undoped body

Three general sets of solutions are formulated to model an arbitrarily configured double-gate (DG) metal-oxide-semiconductor (MOS) capacitor with an undoped silicon body under general bias conditions. The "zero-field" and the "zero-potential" solutions are separated by the "zero-field and zero-potential" solution. Based on the zero-field solution, approximate expressions are proposed to explicitly relate the potential (Ψ_s) and the electric field (E_s) on the silicon side of the oxide/silicon interface of a symmetrical DG MOS capacitor. Based on these expressions, models of the threshold voltage and the current-voltage (IV) characteristics incorporating the mobility degradation effect at high "vertical" electric field and the velocity saturation effect at high "lateral" electric field of a symmetrical DG MOS field-effect transistor are developed. Comparisons are made among the presently proposed IV model, some previously proposed IV models and numerical simulations.