Self-heating in high performance bipolar transistors fabricated on SOI substrates

The effects of self-heating on the characteristics of bipolar transistors fabricated on silicon-on-insulator (SOI) substrates are discussed through measurements and simulations. It is shown that the SOI substrate's buried oxide affects the thermal characteristics of the transistor. A three fold increase in thermal resistivity is observed on transistors fabricated on SOI substrates over identical transistors fabricated on regular silicon substrates. Moreover, thermal gradients within the device footprint are also discussed and evaluated both experimentally and using MEDICI simulations. Finally, a simple thermal model is presented which predicts transistor characteristics with good accuracy.<>