TABLE OF CONTENTS This model is the result of the joint efforts of various semiconductor and EDA companies to develop a new industry standard model for silicon bipolar transistors as a replacement for the 30-year-old SGP. Its name is an abbreviation of the vertical bipolar intercompany model. The intention was that this model should inherit the broad acceptance from SGP, and also should follow the same basic general concept, but with additions in order to overcome some shortcomings and to add a few features. It is hence a more or less eclectic extension to the SGP. It is published in [9], and detailed documentation and source code can be found on the Internet [10].
Its features are:
Base currents defined independently without a fixed current gain parameter;
Early effect improved compared to SGP;
Webster effect;
Quasi-saturation;
Excess transit time due to base pushout;
Partition of the base-emitter junction into intrinsic and extrinsic parts;
Partition of the base-collector capacitance into intrinsic and extrinsic parts;
Self-heating;
Continuous differentiable definition of depletion charges;
BE and BC breakdown;
Parasitic substrate transistor.
Most of the improvements, like the parasitic substrate transistor model, the quasi-saturation model, the partition of the base-emitter junction, and the description of Early and Webster effects, clearly target vertical bipolar transistors. Hence, these parts of the model are of minor interest regarding III V HBTs. However, VBIC provides a self-heating description, which is an enormous improvement over the Gummel-Poon model. However, a proper description for velocity modulation and the respective transit-time and...
