A charge/capacitance model of a simple form that is continuous across the linear and saturation regimes is developed. The model is based on a conductance analysis of the MOSFET which incorporates velocity saturation at a first-principles level. By relating charge layers within the device to characteristics of the conductance, the charge model not only is able to characterize C-V behavior but to also incorporate velocity saturation. Since the basic conductance form is a hyperbola, the model is mathematically simple and robust and yields MOSFET capacitances and charges which are continuous and of infinite differentiability over the linear and saturation regimes of device operation.

A simple, analytical conduction model is presented which is continuous over both the linear and saturation regimes of device operation. It is based on an analysis of the drain conductance in which g/sub DS/ is modeled as a simple hyperbolic form from which drain characteristics are derived. The model is assessed by a chi-square curvefit analysis to show that it is extremely accurate for both long- and short-channel devices. The approach is supported by an analysis which includes the physics of velocity saturation at the fundamental level. Other short-channel effects associated with MOSFET operation may be developed with longitudinal mobility variation as the model foundation. The equation for the hyperbolic asymptotes will reduce to the traditional parabolic model of the MOSFET when classical assumptions are made for the saturation point. This feature of the model demonstrates the fundamental basis of the approach.