Metal Gate Scheme for Device and Methods of Forming

摘要

Gate structures and methods of forming the gate structures are described. In some embodiments, a method includes forming source/drain regions in a 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 adhesion layer over the first metal, and a second metal over the adhesion layer. In some embodiments, the adhesion layer can include an alloy of the first and second metals, and may be formed by annealing the first and second metals. In other embodiments, the adhesion layer can include an oxide of at least one of the first and/or second metal, and may be formed at least in part by exposing the first metal to an oxygen-containing plasma or to a natural environment.

主权项

1. A method comprising:
forming a first source/drain region and a second source/drain region in a substrate; and forming a gate structure between the first source/drain region and the second source/drain region and over the substrate, the gate structure comprising:
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 adhesion layer over the first metal, anda second metal over the adhesion layer, the second metal being different from the first metal.