Symbolically defined non-linear device modelling including self heating effects in GaAs DHBTs

A semi-physically defined non-linear model, which accounts for several important effects in HBTs is used in the large signal characterisation of self aligned planar InGaP/GaAs double heterojunction bipolar transistors (DHBTs). The model is designed to predict accurately the DC and RF characteristics based on the relevant device physics. In addition to self-heating, the model takes into account the charge storage effects, dependence of junction depletion capacitance, transit time delay and dependence of several important device parameters such as doping, epitaxial layer widths and temperature dependence of physical device parameters. Simulated and measured characteristics are compared to verify the model.