abstract |
A method includes method includes forming a dummy gate stack over a semiconductor substrate, wherein the semiconductor substrate is comprised in a wafer, removing the dummy gate stack to form a recess, forming a gate dielectric layer in the recess, and forming a metal layer in the recess and over the gate dielectric layer. The metal layer has an n-work function. A block layer is deposited over the metal layer using Atomic Layer Deposition (ALD). The remaining portion of the recess is filled with metallic materials, wherein the metallic materials are overlying the metal layer. |