| abstract |
A method of forming a semiconductor device includes receiving a structure having a substrate, a gate trench over the substrate, and a dielectric layer over the substrate and surrounding the gate trench. The method further includes forming a gate dielectric layer in the gate trench, forming a barrier layer in the gate trench and over the gate dielectric layer, and treating the barrier layer to roughen an outer surface of the barrier layer, resulting in a treated barrier layer. The method further includes forming an n-type work function metal layer over the treated barrier layer. |