RC-Triggered Silicon Controlled Rectifier-based ESD Clamp with Fast Transient Reaction

We demonstrate an RC-triggered Silicon Controlled Rectifier-based electrostatic-discharge (ESD) protection device with a fast transient reaction in a 0.18-um bulk CMOS technology. The proposed ESD device is simply formed by adding a gate-grounded NMOS (ggNMOS) into the silicon controlled rectifier (SCR) device. By connecting both the drain of the ggNMOS and the anode ($\mathrm{P}^{+}$) of the SCR to the ESD zapping pin, the ESD conduction mechanism is determined by the SCR in parallel with the ggNMOS during a 100-ns normal transmission line pulse (TLP) event. By contrast, a ggNMOS (parasitic NPN) dominates the triggering and reacts quickly with respect to the traditional RC-triggered SCR device during a 2.5-ns very fast transmission line pulse (VF-TLP) event.