Deep n-well dtscr with fast turn-on speed for low-voltage esd protection applications

In this article, a novel low trigger and fast turn on electrostatic discharge (ESD) protection device, called deep N-well diode-triggered silicon-controlled-rectifier (DNWTSCR), is proposed for 1.8 V I/O protection applications in the advanced 40-nm CMOS technology. By incorporating a deep N-well parasitic diode path into the conventional DTSCR, the triggering diodes-string gets prolonged and possesses higher impedance without area penalty. Owing to this, more current will branch to the inherent SCR during the operation, and consequently the DNWTSCR will present improved turn-on characteristics. The ESD characteristics of the proposed DNWTSCR and the conventional DTSCR were evaluated by Transmission Line Pulse (TLP) and Very Fast TLP (VFTLP). As results, the DNWTSCR presents a low trigger voltage of 3.4 V and an extremely fast turn-on time of 0.85 ns, which are 41 % and 51 % lower than the conventional DTSCR, respectively. Moreover, the TCAD simulation results agree well with the transmission line pulse testing results, further confirming that the proposed DNWTSCR can be widely used as an effective ESD protection device for high-speed ICs.