ABSTRACT
This chapter examines the operation of silicon–germanium (SiGe) heterojunction bipolar transistors (HBTs) at cryogenic temperatures, at elevated temperatures, and in a radiation environment. “Extreme environment” electronics represents an important niche market in the trillion dollar global electronics industry, and spans the operation of electronic circuits and systems in surroundings lying outside the domain of conventional commercial or military environmental specifications. Commercial SiGe technology embodies three distinct generations in production worldwide, at more than two dozen companies, and via multiple foundries which anyone can access. SiGe-on- Silicon-on-insulator technology, the go-to platform for high-performance analog needs, will only help this SiGe-for-high-temperature scenario, since the substrate leakage path will be effectively truncated. More understanding on other possible approaches for SEE mitigation in SiGe HBTs are being addressed, and the application of such approaches to other types of SiGe HBT circuits is progressing.
