Improved gate dielectric quality for replacement metal gate transistors

摘要

Gate dielectric degradation due to plasma damage during replacement metal gate processing is cured and prevented from further plasma degradation by treatment of the gate dielectric after removing the polysilicon gate. Embodiments include low temperature vacuum annealing after metal deposition and CMP, annealing in oxygen and argon, ozone or a forming gas before metal deposition, or heat soaking in silane or disilane, before metal deposition.