Replacement metal gate processing with reduced interlevel dielectric layer etch rate

摘要

A method of forming a semiconductor device structure includes forming an interlevel dielectric (ILD) layer over a semiconductor substrate and a dummy transistor gate structure formed on the substrate; infusing a shallow gas cluster ion beam (GCIB) layer in a top portion of the ILD layer; and removing at least one layer from the dummy transistor gate structure, wherein the at least one layer comprises a same material as the ILD layer and wherein the GCIB layer has a slower etch rate with respect to the ILD layer.