A novel HBT trigger SCR in 0.35 μm SiGe BiCMOS technology**Project supported by the Central Universities Fundamental Research Project (No. ZYGX2015J035) and the Sichuan Science and Technology Support Project (No. 2016GZ0115).

Abstract

The silicon-controlled rectifier (SCR) device is known as an efficient electrostatic discharge (ESD) protection device due to the highest ESD robustness in the smallest layout area. However, SCR has some drawbacks, such as high trigger voltage and low holding voltage. In order to reduce the trigger voltage of the SCR device for ESD protection, a new heterojunction bipolar transistor (HBT) trigger silicon controlled rectifier (HTSCR) device in 0.35 μm SiGe BiCMOS technology are proposed. The underlying physical mechanisms critical to the trigger voltage are demonstrated based on transmission line pulsing (TLP) measurement and physics-based simulation results. The simulation results prove that the trigger voltage of the HTSCR is decided by the collector-to-emitter breakdown voltage of the HBT structure in floating base configuration. The ESD experiment test results demonstrate the HTSCR can offer superior performance with a small trigger voltage, an adjustable holding voltage and a high ESD robustness. In comparison to the conventional MLSCR, the trigger voltage of the fabricated HTSCR can reduce to less than 50% of that of the MLSCR, and the It2 of the HBT trigger SCR is 80% more than that of the MLSCR.