Method of fabricating high-k/metal gate device

Abstract

The present disclosure provides a method that includes providing a semiconductor substrate; forming a gate structure over the semiconductor substrate, first gate structure including a dummy dielectric and a dummy gate disposed over the dummy dielectric; removing the dummy gate and the dummy dielectric from the gate structure thereby forming a trench; forming a high-k dielectric layer partially filling the trench; forming a barrier layer over the high-k dielectric layer partially filling the trench; forming an capping layer over the barrier layer partially filling the trench; performing an annealing process; removing the capping layer; forming a metal layer over the barrier layer filling in a remainder of the trench; and performing a chemical mechanical polishing (CMP) to remove the various layers outside the trench.