Physics-based large-signal heterojunction bipolar transistor model for circuit simulation

A comprehensive single heterojunction bipolar transistor (HBT) model suited for circuit simulation is presented. The model is developed in the Gummel-Poon homojunction bipolar transistor model tradition, but adds important heterostructure device physics as well as physical properties of three or four compound materials such as AlGaAs and GaAs. In contrast to the existing HBT models, which use the Gummel-Poon model and fit HBT experimental data by optimising a large pool of parameters extracted from HBT measurements, the present physics-based model requires only the knowledge of the device make-up (such as the doping concentration and layer thickness) and the material parameters (such as the energy bandgap and electron affinity). Comparisons between the model and measured dependencies for AlGaAs-GaAs-GaAs HBTs on important device specifications such as the DC current/voltage characteristics, DC current gain, and cutoff frequency are included