Patent ID: 8039381

Claim:
A method of fabricating a semiconductor device, comprising: providing a substrate including a dummy gate structure formed thereon; removing the dummy gate structure to form a trench; forming a first metal layer over the substrate to fill a portion of the trench, wherein the first metal layer includes an overhang at an aperture of the trench; forming a protection layer in a remaining portion of the trench, wherein the protection layer fills the remaining portion of the trench, and wherein the forming the protection layer includes spin-coating the protection layer onto the first metal layer; performing an etch back process to remove a portion of the formed protection layer such that the etched back protection layer is planar with a top surface of the trench; removing an unprotected portion of the first metal layer that includes the overhang, wherein the etched back protection layer remains planar to the top surface of the trench during the removing of the unprotected portion of the first metal layer; removing the etched back protection layer from the trench, after removing the unprotected portion of the first metal layer; and thereafter, forming a second metal layer over the substrate to fill the trench.