Effect of pulse risetime on trigger homogeneity in single finger grounded gate nMOSFET electrostatic discharge protection devices

Triggering homogeneity of 0.35 mum and 0.18 mum technology grounded-gate nM OSFET electrostatic discharge (ESD) protection devices is investigated as a function of pulse risetime and current stress level. The current distribut ion along the device width is analysed using a backside interferometric the rmal mapping technique. Differences in the triggering behaviour for differe nt pulse risetimes have been found and have been attributed to a dU/dt trig gering effect. Pulse-to-pulse instabilities in the triggering place have al so been revealed at low stress currents using single shot measurements. (C) 2001 Elsevier Science Ltd. All rights reserved.