| abstract |
Gate structures and methods of forming gate structures are described. In some embodiments, the method includes forming source / drain regions in the substrate, and forming a gate structure between the source / drain regions. The gate structure includes a gate dielectric layer over the substrate, a work function tuning layer over the gate dielectric layer, a first metal over the work function tuning layer, an adhesive layer over the first metal, and a second metal over the adhesive layer . In some embodiments, the adhesive layer may comprise an alloy of a first metal and a second metal, and may be formed by annealing the first and second metals. In another embodiment, the adhesive layer may comprise an oxide of at least one of the first and / or second metal and may be at least partially formed by exposing the first metal to an oxygen containing plasma or a natural environment. |