In this work, a new low voltage-triggered silicon-controlled rectifier named MTSCR is realized in a 65 nm CMOS process for low voltage-integrated circuits electrostatic discharge (ESD) protections. The MTSCR incorporates an external NMOSs-string, which drives the internal NMOS (INMOS) of MTSCR to turn on, and then the INMOS drive SCR structure to turn on. Compared with the existing low trigger voltage (Vt1) ESD component named diodes-string-triggered SCR (DTSCR), the MTSCR can realize the same low Vt1 characteristic but less area penalty of ~44.3% reduction. The results of the transmission line pulsing (TLP) measurement shows that the MTSCR possesses above 2.42 V holding voltage (Vh) and a low Vt1 of ~5.03 V, making it very suitable for the ESD protections for 1.8 V input/output (I/O) ports in CMOS technologies.

Low-voltage-triggered silicon-controlled rectifier (LVTSCR) is expected to provide an electrostatic discharge (ESD) protection for a low-voltage integrated circuit. However, it is normally vulnerable to the latch-up effect due to its extremely low holding voltage. In this paper, a novel LVTSCR embedded with an extra p-type MOSFET called EP-LVTSCR has been proposed and verified in a 28-nm CMOS technology. The proposed device possesses a lower trigger voltage of ~ 6.2 V and a significantly higher holding voltage of ~ 5.5 V with only 23% degradation of the failure current under the transmission line pulse test. It is also shown that the EP-LVTSCR operates with a lower turn-on resistance of ~ 1.8 Ω as well as a reliable leakage current of ~ 1.8 nA measured at 3.63 V, making it suitable for ESD protections in 2.5 V/3.3 V CMOS processes. Moreover, the triggering mechanism and conduction characteristics of the proposed device were explored and demonstrated with TCAD simulation.