A physical charge-based model for the space charge region of abrupt and linear semiconductor junctions

A new, physically justified, charge-based expression for the semiconductor space charge region capacitance is derived. This equation preserves the traditional meaning of zero-voltage capacitance, built-in potential and junction grading coefficient and, without introducing any new fitting parameters of its own, eliminates the fitting parameter FC currently used in SPICE. This new model eliminates the singularity found in the depletion approximation model, is applicable for any applied voltage, and being charge-based does not suffer from charge-conservation problems reported for capacitance based formulations. In this paper, the new model is formulated and compared with charge/capacitance results extracted from PISCES