Patent ID: 7799664

Claim:
A method of performing selective epitaxial growth of source/drain (S/D) areas, comprising: providing a substrate of a semiconductor material, the substrate comprising a first substrate area and a second substrate area, the first area comprising at least one gate stack; applying at least a poly-Si or poly-SiGe top layer on the substrate, the top layer being etchable with the same etch chemistry as the substrate; removing the poly-Si or poly-SiGe top layer from the first area of the substrate selectively towards the poly-Si or poly-SiGe top layer in the second substrate area; removing simultaneously the poly-Si or poly-SiGe top layer on the second substrate area and at least a part of the substrate in the S/D areas of the first substrate area selectively toward the at least one gate stack; and performing a selective epitaxial growth of S/D areas in the first substrate area. Wherein between the poly-Si or poly-SiGe top layer and the substrate a stop layer is applied, which is not etchable with the same etch chemistry as the top layer; wherein the removing of the poly-Si or poly-SiGe top layer from the first area is performed until the stop layer is exposed; wherein the simultaneously removing comprises a breakthrough etch process for removing the stop layer.