An improved GGNMOS triggered SCR for high holding voltage ESD protection applications

The ESD Characteristics of a pMOS-Triggered Bidirectional SCR in SOI BCD Technology

In this work, the electrostatic discharge (ESD) characteristics of a pMOS-triggered bidirectional silicon-controlled rectifier (PTBSCR) that was fabricated in a 0.18 μm silicon-on-insulator (SOI) bipolar-CMOS-DMOS (BCD) process, is investigated. The multi-snapback phenomenon was observed under the transmission line pulsing (TLP) test system. It was found that gate voltage and inserting shallow trench isolation (STI) can significantly affect the trigger voltage and holding voltage. The underlying physical mechanism related to the multi-snapback phenomenon and the effects of gate voltage on the critical parameters was investigated through the experimental results and the assistance of technology computer-aided design (TCAD) simulations. The adjustments of gate voltage and STI on the critical ESD parameters of the device provide an effective design idea for low-voltage ESD protection in the SOI BCD process.

Robust and Latch-Up-Immune LVTSCR Device with an Embedded PMOSFET for ESD Protection in a 28-nm CMOS Process

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.