METHOD OF PREPARING A SEMICONDUCTOR SUBSTRATE FOR SUBSEQUENT SILICIDE FORMATION

摘要

A method for preparing a semiconductor substrate for subsequent silicide formation. In one embodiment, the present invention subjects the semiconductor substrate to an ashing environment. In the present embodiment, the ashing environment is comprised of H>2<O vapor, and a gaseous fluorocarbon or a fluorinated hydrocarbon gas. In so doing, contaminants on the semiconductor substrate are removed. Next, the present invention subjects a mask covering a polysilicon stack to a mask-removal ashing environment. In the present embodiment, the mask-removal ashing environment is comprised of an O>2< plasma. In so doing, the mask covering the polysilicon stack is removed. As a result, the semiconductor substrate and the top surface of the polysilicon stack are prepared for subsequent silicide formation thereon.