A unified submicrometer MOS transistor charge/capacitance model for mixed-signal IC's

A unified modeling approach for the submicrometer MOS transistor charge/cap acitance characteristics in all operation regions is presented. Development of this MOS charge model is based on the charge-density approximation to r educe the complexity of the analytical expression. To model the charge dens ity more accurately, the conductance-degradation coefficient is determined by the derivative of drain-to-source saturation voltage with respect to gat e-to-channel potential. The unified charge densities in gate, channel, and bulk regions are obtained with the assistance of the sigmoid, hyperbola, an d exponential interpolation techniques. Good agreement between the measurem ent data and simulation results is obtained.