Patent ID: 7659199

Claim:
A self-aligned silicide formation method comprising: forming a first metal layer on a silicon body; forming a protective layer on said first metal layer, wherein said protective layer is formed approximately ⅓ as thick as said first metal layer; exposing a top surface only of said protective layer to air outside a deposition chamber for a period of time such that contaminants are introduced onto said top surface, said contaminants comprising at least one of water and oxygen; forming a second metal layer on said top surface of said protective layer; and performing an anneal so as to form a tensile silicide region on said silicon body, wherein said exposing of said protective layer to air alters a mechanical stress exerted upon said first metal layer by said protective layer and said second metal layer during said performing of said anneal and wherein said second metal layer is formed approximately 1 to 5 times thicker than said protective layer.