A MULTI-EMITTER FINGER ALGAAS GAAS HBT MODEL INCLUDING THE EFFECTS OF2-DIMENSIONAL TEMPERATURE DISTRIBUTION ON EMITTER FINGERS/

Two-dimensional temperature distribution on the emitter fingers of mul ti-finger AlGaAs/GaAs heterojunction bipolar transistors (HBTs) is stu died, and a model including such effects was developed to describe the HBT behavior and performance, such as the d.c. current gain and cutof f frequency. Device design issues such as the number of fingers, finge r spacing, and finger dimension were considered. Results obtained from measurements and simulated from a three-dimensional device simulator are included in support of the model. Further, the present model is co mpared against the conventional model to assess the degree of inaccura cy caused by the use of one-dimensional temperature profile in HBT mod eling. (C) 1998 Elsevier Science Ltd.