Patent ID: 7880228

Claim:
A semiconductor device comprising: a semiconductor substrate; a gate insulating film formed on the semiconductor substrate; a gate electrode formed on the gate insulating film; a first sidewall insulating film formed on a side surface of the gate electrode; a source/drain layer formed on both sides of the gate electrode, the source/drain layer including a silicon germanium layer and an extension layer, the extension layer being formed on the semiconductor substrate below the first sidewall insulating film, the extension layer being arranged between the silicon germanium layer and a channel region below the gate insulating film; a germanium layer including a first portion and a second portion, the first portion being disposed between the first sidewall insulating film and the extension layer, a bottom surface of the first portion contacting a top surface of the extension layer, and a top surface of the first portion contacting a bottom surface of the first sidewall insulating film, and the second portion being disposed on the silicon germanium layer; and a germanide layer contacting the second portion of the germanium layer.