An Extension to Newton's Method in Device Simulators--On An Efficient Algorithm to Evaluate Small-Signal Parameters and to Predict Initial Guess

The Newton iteration method used in conventional numerical device simulations is extended to include bias conditions as variable parameters in the system of semiconductor equations. This extension leads to a very simple algorithm to evaluate low-frequency, small-signal parameters based on dc solutions. It also provides an elegant way to project an initial guess for subsequent bias conditions. Rigorous mathematical derivation and applications to the evaluation of junction capacitance and breakdown voltage are given. The initial guess projection is also illustrated through examples.