Comparative study of reliability degradation behaviors of LDMOS and LDMOS-SCR ESD protection devices

This paper presents a comparative study on the electrostatic discharge (ESD) characteristics of Lateral Diffused Metal-Oxide-Semiconductor (LDMOS) and LDMOS with embedded silicon controlled rectifier (LDMOS-SCR) by using transmission line pulsing (TLP) measurements. Results show that the safe operating area (SOA) of LDMOS shrank pronouncedly and its reliability degraded due to the walk-in of trigger voltage (Vt1). The Vt1 walk-in is attributed to the so called weak spot filament created/grown near the N+ drain region in previous ESD strike. The isolation drain structure in LDMOS-SCR can solve this issue. However, both devices were found to be not robust enough when they were subjected to be operated at high temperature ambient. •Devices of LDMOS and LDMOS-SCR are taped out in 0.35 um BCD process and tested by Bath 4002.•LDMOS trigger voltage walk-in effect is researched with different temperature and gate bias voltage.•LDMOS-SCR's trigger voltage and leakage current degrade greatly in high ambient temperature.