Design of compact-diode-SCR with low-trigger voltage for full-chip ESD protection

Abstract

In this article, a compact-diode-silicon-controlled rectifier (CDSCR) for full-chip electrostatic discharge (ESD) protection is proposed and verified in 0.18 μm Silicon-on-Insulator (SOI) Bipolar-CMOS-DMOS (BCD) process. Intrinsic parasitic SCRs and diodes are employed as the main ESD paths, which greatly reduces area consumption. Besides, due to the RC- triggered circuit, low trigger voltage and short turn-on time are realized. With equivalent circuit and two-dimensional (2D) technology computer-aided design (TCAD) simulation, the operation principle and working mechanism are analyzed. In addition, transmission line pulse (TLP) and very fast TLP (VF-TLP) testing results show that the CDSCR could can endure human body model (HBM) pulse of 3420 V without latch-up issue and protect the chip effectively in charge device model (CDM) event. Furthermore, the proposed structure exhibits high current handing ability during ESD stress conditions and sufficiently low leakage current during normal circuit operating conditions. The CDSCR is conformed to provide full-chip ESD protection for 1.2 V application.