Concept for body coupling in SOI MOS transistors to improve multi-finger triggering

Multi-finger SOI MOS devices exhibit a low ESD failure current, related to the thin Si-film and the complete isolation of the transistor body regions, causing non-uniform conduction in bipolar snapback mode. The traditional layout approaches (silicide blocked junctions, increased gate length) are compared and a novel layout concept is proposed to improve uniform triggering. Excellent ESD performance around 3mA/um2 is achieved for minimum dimension, fully silicided devices in a 90 nm SOI technology.