A Gate-Grounded NMOS-Based Dual-Directional ESD Protection With High Holding Voltage for 12V Application

摘要

Dual-direction electrostatic discharge (ESD) protection devices can discharge both positive and negative ESD surges, owing to their excellent area efficiency. This study proposes a novel dual-direction MOSFET ESD protection device with a high holding voltage. Most existing dual-direction ESD protection devices are based on silicon-controlled rectifiers (SCR). Among them, the low triggering dual-directional SCR (LTDDSCR) has good trigger characteristics, but with low holding voltage. In contrast, the proposed high-holding-voltage dual-direction NMOS (HHDDNMOS) operates using two NPN parasitic bipolar transistors connected to the ESD discharge path and has a very high holding voltage and excellent snapback characteristics. The electrical and dual-directional characteristics of HHDDNMOS were analyzed using the transmission-line -pulsing system, and the latch-up immunity was verified by conducting transient-induced latch-up tests using the 0.18-mu m BCD process.