ESD protection structures for 20 V and 40 V power supply suitable for BCD6 smart power technology

In this work we present results concerning ESD protection structures for 20 V and 40 V power supply circuits, compatible with 0.35 mum BCD6 smart power technology (oxide thickness 70 Angstrom), based on the lateral DMOS (LDMOS) to be used in ESD protection structures adopting the "Big-Clamp" approach. Good scaling of the ESD robustness with the device width is observed testifying uniform current distribution along the device structure during the ESD event, however failure analysis carried out on failed structures, shows localized failure, suggesting current crowding phenomena happening at high current regime. We have explained these apparently contradictory results thanks to extensive TLP characterization and failure analysis carried out on tested devices. (C) 2002 Elsevier Science Ltd. All rights reserved.