Patent ID: 6878597

Claim:
A method of forming a source/drain region, the method comprising: forming a gate electrode on a substrate; forming a lightly doped source/drain region in the substrate self-aligned to the gate electrode; forming a first spacer on a side wall of the gate electrode to expose a part of the substrate; conformally forming an etch stop layer to cover the gate electrode, the first spacer, and the substrate; forming a second spacer on the etch stop layer on the first spacer on the side wall separated from the first spacer to provide a multilayer spacer on the side wall; forming a heavily doped source/drain region in the substrate by using the gate electrode, the first spacer and the second spacer as ion implantation masks; and on the etch stop layer on the first spacer on the side wall of the gate electrode; and forming a silicided contact on the source/drain region self-aligned to the first spacer.