Patent ID: 8574978

Claim:
A method for forming a semiconductor device, comprising: providing a substrate with a gate structure disposed thereon and a spacer surrounding said gate structure, wherein a surface of said spacer consists of silicon nitride; forming a photoresist covering said substrate; performing an implantation step to form a lightly doped drain in said substrate on at least one side of said gate structure in the protection of said photoresist; performing a stripping step to remove said photoresist in the absence of oxygen; performing a protective step to modify said spacer by oxidizing said surface of said spacer for forming an oxide on said surface of said spacer in the presence of oxygen to obtain a modified spacer after said stripping step; forming a material layer consisting of silicon nitride disposed on said modified spacer after said protective step; and performing a removal step after said protective step to remove said material layer without substantially damaging said modified spacer.