Design of SCR devices for SiGe BiCMOS applications

An optimum vertical SiGe SCR design is presented for on-chip electrostatic discharge (ESD) protection. The device response to fast transients, emulating ESD CDM-type events, is compared with standard clamp structures having similar footprint-area, loading-capacitance and current handling ability. SCR designs include variation in the device's anode construction, anode geometry and triggering mechanism.