Rigorous thermal treatment of heat generation and heat transfer in GaAs-based HBT device modeling

Performance of integrated circuits is being increasingly dominated by the interconnects which can dramatically affect the actual temperature of a device. Hence, performing a more realistic thermal analysis and modeling of interconnects is critical. This paper presents a detail three-dimensional thermal analysis of the internal structure of the semiconductor device and the inclusion of circuit metal interconnects of GaAs heterogeneous bipolar transistors (HBT) used in power amplifier circuit in mobile telephones and laser drivers. The temperature distribution inside device reveals substantial temperature difference for HBT structure between major heat source located in sub-collector area and thermally sensitive area of emitter-base junction. The effect of metal connected to emitter on the temperature profile and device peak temperature has been demonstrated through number of simulations. Results are compared to the device with no connected metal. It is shown that interconnects can strongly impact the magnitude of the maximum temperature.