STRESS-INDUCED DEGRADATION FEATURES OF VERY THIN GATE OXIDES

The degradation features of very thin gate oxide after Fowler-Nordheim stress have been studied. Bulk oxide, cathodic and anodic regions hav e been analysed from the charge build-up point of view, as well as the stress induced generation of Si/SiO2 fast interface state density. A physical interpretation of experimental results has been proposed, inv olving two types of stress induced positive charge building up at inte rface regions. It is shown that a critical oxide thickness exists, und er which the degradation mechanisms could be considerably different. ( C) 1998 Elsevier Science Ltd.