Assessment of charge-induced damage to ultra-thin gate MOSFETs

Abstract

We have devised a novel antenna structure that distinguishes the regimes of charging during an etch process. Using this technique, we show instances in an Inductively Coupled Plasma (ICP) metal etch where charging occurs exclusively during metal clear or overetch or both depending on process and hardware. We have seen instances where ultra-thin gate (21 /spl Aring/) devices are severely degraded compared to thicker gate (25-32 /spl Aring/) devices under certain ICP metal etch process conditions. Remote Plasma Nitrided (RPN) oxides are shown to be robust down to 25 /spl Aring/ with respect to antenna effects. We report here for the first time enhanced passivation of plasma damaged device with deuterium anneal.