Patent ID: 8030214

Claim:
A method of forming metal gate structures, comprising: providing a substrate; forming a first dummy gate electrode and a second dummy gate electrode on the substrate, wherein the first dummy gate electrode comprises first spacers on its sidewalls and the second dummy gate electrode comprises second spacers on its sidewalls; forming a hardmask layer over both the first dummy gate electrode and the second dummy gate electrode; forming a patterned photoresist layer on the hardmask layer that covers a portion of the hardmask layer over the second dummy gate electrode and that leaves a portion of the hardmask layer over the first dummy gate electrode exposed; removing the portion of the exposed hardmask layer over the first dummy gate electrode; exposing the first spacers and the first dummy gate electrode to a first plasma environment comprising O 2 , HBr, and Cl 2 ; removing the first dummy gate electrode in a second plasma environment comprising NF 3 , Cl 2 and HBr thereby leaving a hole surrounded by the first spacers; and filling the hole with a metal gate layer.