A novel low trigger voltage low leakage SCR for low-voltage ESD protection

Abstract

Reducing trigger voltage has always been a research hotspot in low-voltage electrostatic discharge (ESD) protection applications for integrated circuit. Thus, a novel low trigger voltage low leakage silicon-controlled rectifier (LTVLLSCR) for low-voltage ESD protection has been proposed. The proposed device uses a PMOS connected with the SCR to reduce the trigger voltage and the PMOS gate can be applied with the supply voltage to further reduce the trigger voltage and the leakage current. The operating principle and the physical mechanism of the proposed device were discussed by the Human Body Model simulation. The ESD characteristics of the proposed device were verified in 55 nm CMOS process. The experimental results demonstrate that the trigger voltage of the proposed device can reach a minimum of 2.86 V with an external bias, and the leakage current at 25 ℃ is about 1 nA which can be reduced by 13% with an external bias. With lower trigger voltage, lower leakage, smaller ESD design window and good ESD robustness, the LTVLLSCR is very suitable for 1 V low voltage applications.