Design of a Dual-directional Diode-triggered SCR for Low Voltage ESD Protection

A novel dual-directional diode-triggered silicon controlled rectifier (DDTSCR) for low voltage electrostatic discharge (ESD) protection was designed and realized in a 0.18-µm CMOS process. Compared to the single-directional diode-triggered SCR (SDTSCR), the DDTSCR has dual-directional ESD protection performance due to the symmetric structure, and its ESD protection efficiency per unit area is about 2 times larger than that of SDTSCR under opposite ESD stresses, while remaining the similar trigger voltage of 1.68 V and the figure of merit. The human body model robustness of the DDTSCR measured by the transmission line pulse system is up to 8000 V with an area of 1400 µm2, suitable for low voltage ESD protection requirements.