A low-voltage triggering SCR for ESD protection in a 0.35um SiGe BiCMOS process

A Heterojunction bipolar transistor (HBT) trigger Silicon Controlled Rectifier (SCR) device in a 0.35um Silicon-germanium (SiGe) BiCMOS technology is proposed for Electrostatic Discharge (ESD) protection in this paper. The trigger voltage of the HBT trigger SCR (HTSCR) is decided by the collector-to-emitter breakdown voltage (DVcro) of the HBT structure in floating base configuration. Compared to the traditional MLSCRs, the trigger voltage of the fabricated HTSCR can reduce to less 50% of that of the MLSCR The operational mechanisms of the HTSCR is discussed, and the underlying physical mechanisms critical to the trigger voltage are demonstrated based on transmission line pulsing (TLP) measurement.