Very High Speed SiGe Heterojunction Bipolar Transistor Reliability Overview

We discuss the major reliability mechanisms and the implications arising from the structural changes required for the implementation of state of the art SiGe HBT's. The current gain shift under forward and reverse device operating conditions has been characterized for 120, 200 and 350 GHz transistors. The effects of electromigration and self-heating versus f
_T
have also been studied. In general, it should be possible to continue scaling beyond today's 350 GHz devices, with straightforward extension of the mechanisms and concerns outlined in this paper