Embodiments described herein generally relate to enable the formation of a metal gate structure with a reduced effective oxide thickness over a similar structure formed via conventional methods. A plasma hydrogenation process followed by a plasma nitridization process is performed on a metal nitride layer in a film stack, thereby removing oxygen atoms disposed within layers of the film stack and, in some embodiments eliminating an oxygen-containing interfacial layer disposed within the film stack. As a result, an effective oxide thickness of the metal gate structure is reduced with little or no accompanying flatband voltage shift. Further, the metal gate structure operates with an increased leakage current that is as little as one quarter the increase in leakage current associated with a similar metal gate structure formed via conventional techniques.