Overview of on-chip electrostatic discharge protection design with SCR-based devices in CMOS integrated circuits

TLDR

The paper provides an overview of using silicon controlled rectifier (SCR)-based devices for on-chip electrostatic discharge protection in CMOS integrated circuits. The authors review the history and evolution of SCR devices for on-chip ESD protection, and discuss modified device structures and trigger‑assist circuits that lower switching voltage. The study identifies higher switching voltage and transient‑induced latchup as key limitations of SCR-based on‑chip ESD protection, and presents solutions to reduce switching voltage and mitigate latchup.

Abstract

An overview on the electrostatic discharge (ESD) protection circuits by using the silicon controlled rectifier (SCR)-based devices in CMOS ICs is presented. The history and evolution of SCR device used for on-chip ESD protection is introduced. Moreover, two practical problems (higher switching voltage and transient-induced latchup issue) limiting the use of SCR-based devices in on-chip ESD protection are reported. Some modified device structures and trigger-assist circuit techniques to reduce the switching voltage of SCR-based devices are discussed. The solutions to overcome latchup issue in the SCR-based devices are also discussed to safely apply the SCR-based devices for on-chip ESD protection in CMOS IC products.