Investigation of 3D Phenomena in the Triggering of gg-nMOS Electrostatic Discharge Protection Devices

Abstract

We study inhomogeneity in the triggering of the parasitic bipolar transistor during high current stress in the 0.35 μm process grounded-gate nMOS electrostatic discharge (ESD) protection devices by a laser interferometric technique. The current density and triggering width in partially and fully triggered devices are studied as a function of stress current. On the basis of experiments, 3D simulation and a simple model we explain the observed high current I-V characteristics.