A New SCR Structure With High Holding Voltage and Low ON-Resistance for 5-V Applications

Abstract

This article proposes a new silicon-controlled rectifier (SCR)-based electrostatic discharge (ESD) protection device suitable for 5-V applications. The proposed ESD protection device has an additional n-p-n parasitic bipolar transistor that provides an extremely short ESD discharge path. Compared with the conventional Low-Voltage-Trigger SCR (LVTSCR) and Low-Ron SCR (LRSCR), it has excellent ON-resistance and improved reverse characteristics. Furthermore, it has structurally enhanced trigger voltage and holding voltage characteristics. A conventional LVTSCR, LRSCR, and the proposed ESD protection device were fabricated with the same width using a 0.18- $\mu \text{m}$ bipolar CMOS DMOS (BCD) process to verify the improvement in electrical characteristics and current driving capability of the new device. Transmission line pulsing (TLP) and a hot chuck control system were used to measure and compare the latch-up, electrical characteristics, and temperature reliability of the three devices. The measurements demonstrate that the proposed ESD protection device provides improved reliability and higher area efficiency for 5 V or similar applications.