A charge-sheet capacitance model based on drain current modeling

Based upon a common charge-sheet approach analytical models of the drain current and the capacitances of a MOSFET are formulated. Mobility reduction due to velocity saturation and the interface scattering of carriers is taken into account. A saturation criterion is developed from the condition of output conductance continuity. The capacitance modeling requires no additional parameters not contained in the dc model. The comparison with measurement confirms the theory to be useful for analog circuit simulation down to channel lengths of about 1 fm.