Patent ID: 8766236

Claim:
A semiconductor device comprising: a substrate; a first semiconductor layer provided on the substrate and having a strain, the first semiconductor layer being a single layer; second and third semiconductor layers provided at a distance from each other on the first semiconductor layer, and having a different lattice constant from a lattice constant of the first semiconductor layer; a gate insulating film provided on a first portion of the first semiconductor layer, the first portion being located between the second semiconductor layer and the third semiconductor layer and including a channel; and a gate electrode provided on the gate insulating film, wherein: the first semiconductor layer is a Si layer and the second and third semiconductor layers are SiGe layers, or the first semiconductor layer is a SiGe layer and the second and third semiconductor layers are Si layers, an outer surface region of the second semiconductor layer and a side face region of a second portion of the first semiconductor layer are first silicide regions, the second portion of the first semiconductor layer being located immediately below the second semiconductor layer, and the side face region of the second portion being of the first semiconductor layer a different region from an upper surface of the second portion of the first semiconductor layer, an outer surface region of the third semiconductor layer and a side face region of a third portion of the first semiconductor layer are second silicide regions, the third portion of the first semiconductor layer being located immediately below the third semiconductor layer, and the side face region of the third portion being of the first semiconductor layer a different region from an upper surface of the third portion of the first semiconductor layer, and a silicide region that contains Ge and is included in the first and second silicide regions has a Ge concentration of 50 atomic % or higher.