An ESD robust high holding voltage dual-direction SCR with symmetrical I-V curve by inserting a floating P+ in PWell

The dual directional silicon-controlled rectifier (DDSCR) device is widely used in on-chip electrostatic discharge (ESD) protection owing to its bi-directional ESD protection and strong current-tolerating capability per area. In this paper, an asymmetrical dual directional ESD protection device for automotive application was developed in a 0.18-µm Bipolar CMOS DMOS (BCD) technology. In order to verify and predict the proposed ESD protection device's characteristics, a transmission line pulse (TLP) testing system and a 2-dimension device simulation platform have been used in this work. According to the measurement results, the asymmetrical dual directional silicon-controlled rectifier with a floating P+ region (ADDSCR_FP+) increases the forward holding voltage (Vh) from 3.89 V to 19.7 V and increases the reverse holding voltage from 3.62 V to 19.5 V which only slightly decrease the failure current compared with the traditional asymmetrical dual directional silicon-controlled rectifier (ADDSCR). The ADDSCR_FP+ has the features of symmetrical forward and reverse I-V curves, high holding voltage and high failure current.