Threshold voltage instability and plasma induced damage of polySi/HfO2 devices - positive impact of deuterium incorporation

Device instability is one of the most challenging issues to implement High-K gate dielectric. Incorporation of deuterium during the ALD process effectively improves the interface quality that enhances High-K device stability and reliability. Compared to H₂O processed HfO₂ devices, devices with D₂O processing result in a significantly smaller Vt shift after constant voltage stressing at room temperature and at 125°C under NBTI/PBTI conditions, as well as a longer CHCI lifetime. This process is independent of transistor process integration and is relatively low cost. It has the potential to become an industry standard if ALD High-K gate dielectric processing is the final choice.