A Compact and Self-Isolated Dual-Directional Silicon Controlled Rectifier (SCR) for ESD Applications

In this paper, a compact and self-isolated dual directional silicon-controlled rectifier (CSDDSCR) developed in a single N-well has been proposed and demonstrated. Without using the P-well, the N-type isolation structure as well as an auxiliary trigger component, which are normally required in the traditional DDSCR, the novel CSDDSCR possesses a very high area-efficiency and robustness of ~8.81 V/$\mu$ m
²
. It is also shown that the CSDDSCR preserves a lower trigger voltage as 10 V, an adjustable holding voltage from 3.32 to 8.79 V under the TLP test, a smaller overshoot voltage of ~19 V at 2 A VFTLP stress, as well as an extremely low leakage current of ~94 pA measured at 3.3 V, making it a superior candidate for electrostatic discharge protection in the 3.3 V/5 V CMOS processes. Moreover, a holding voltage reversal effect has also been discovered and explained with TCAD simulation.