Transient electro-thermal modelling of AlGas/GaAs HBTs

This paper describes the self-consistent simulation of the current and temperature distributions within AlGaAs/GaAs heterojunction bipolar transistors (HBTs) during power transients. The modelling technique employed for this purpose, which has been implemented by combining a transmission line matrix (TLM) thermal diffusion simulator with The standard circuit simulator SPICE, is based on a discretised equivalent circuit model of an HBT finger. The form of this model is presented, along with examples that illustrate the utility of the simulation system in providing insight into a number of electro-thermally related phenomena associated with the AlGaAs/GaAs HBT.