Automatic Generation of Equivalent Circuits from Device Simulation

We present a novel methodology for the direct extraction of equivalent circuit models from device simulation. The circuit topology is physically based, i.e., each voltage node corresponds to a quasi-Fermi level or to an electrostatic potential. Circuit equations and branch-constitutive equations are derived from the Poisson and continuity equations. Although only d.c., simulation results are employed, the model achieves a.c., predictive power by including charge-storage elements as capacitors. The technique has been implemented for one-dimensional devices. Examples are shown for pn junctions including high frequency and high injection regimes. An example of optical response of a photo-transistor is presented, demonstrating the applicability of the method to optoelectronic and three-terminal devices.