Reducing the turn-on time and overshoot voltage for a diode-triggered silicon-controlled rectifier during an electrostatic discharge event

A diode-triggered silicon-controlled rectifier (DTSCR) as an electrostatic discharge (ESD) device is investigated for low-voltage design applications with extremely narrow ESD design margins [1]. DTSCRs are used for protecting sensitive circuit nodes, such as high-frequency analog circuits and thin gate CMOS circuits with high-speed input [1]. Reducing the DTSCR turn-on time and overshoot voltage enhances the use of this device in high-speed applications. We studied the impact of device parameters, such as the p-well tap distance from the anode and the trigger diode placement relative to the SCR, on the turn-on time. We used device-level simulations (TCAD) to improve and predict the turn-on time and overshoot voltage. Our research was performed using a 90 nm BiCMOS technology.