NASDAC - A new simulation tool for the electro-thermal analysis of bipolar devices: Application to multi-finger AlGaAs/GaAs HBT's

In this paper a new simulation tool is presented, suitable to describe the electro-thermal behavior in multi-finger AlGaAs/GaAs devices. The program is based on a new analytical formulation to compute the device temperature distribution both for the steady-state and the transient case and incorporates an accurate electro-thermal physically-based model for the elementary transistor. The effect of the geometry of heat dissipating regions is accounted for. Thermal conductivity dependence on temperature and de-biasing effects across metallization layers are also included. Hence the simulator can be efficaciously used to enhance the thermal chip design, by means of illustrative comparisons between different structures.