Optimizing the vertical profile of SiGe HBTs to mitigate radiation-induced upsets

Profile optimization techniques are investigated for silicon-germanium heterojunction bipolar transistors (SiGe HBTs) intended for inverse-mode (IM) operation. IM device operation, also known as inverse active, involves electrically swapping the emitter and collector terminals and has been shown to improve the radiation tolerance of SiGe HBTs to single event transients (SETs). Multiple profile design variations are explored and trade-offs are analyzed with support of TCAD simulation. Modest design variations show marked improvement on IM performance while having minor impact on forward-mode (normal active) operation.