A new compact model for the avalanche effect in InAlAs/InGaAs HBTs

This letter presents a new compact model for the avalanche effect in InAlAs/InGaAs heterojunction bipolar transistors. Unlike previous models, it is based on the formulation of the avalanche multiplication by Lee (Phys. Rev., vol. 134, p. A761, 1964), which allows the model to be valid for even larger current densities than before. The description of the ionization coefficient takes into account the anomaly of the ionization coefficient of InGaAs at low electric fields. The new model is successfully verified by measurements in a conventional common-base setup.