Exploration of rare earth materials for future interpoly dielectric replacement in Flash memory devices

Rare-earth lanthanates and scandates have been studied for possible use as future Flash interpoly dielectrics. It was shown that a post-deposition anneal in O
₂
at high temperature (~1000°C or above) gives rise to silicate formation. This results in excellent memory retention and larger robustness of the layers as compared to anneal in N
₂
.