One-dimensional non-quasi-static models for arbitrarily and heavily doped quasi-neutral layers in bipolar transistors

A systematic method is presented for deriving non-quasi-static equivalent-circuit models for arbitrarily doped and heavily doped quasi-neutral layers in bipolar transistors. The large-and small-signal models developed improve various aspects of the one-dimensional Gummel-Poon model for transient and frequency circuit simulation. The improvements are assessed by computer simulation and by experiment. In the simulation of high-speed or high-frequency bipolar integrated circuits, the models show advantages over the conventional Gummel-Poon model. It is shown that non-quasi-static effects are significant in the emitter as well as the base layer. The method is developed for homojunction bipolar transistors but in principle applies also to heterojunction bipolar transistors