Methods of manufacturing semiconductor devices may include forming a first layer on a first active region (P-channel FET), forming a second layer on a second active region (N-channel FET), the first and second layers including a silicon germanium (SiGe) epitaxial layer sequentially stacked on a silicon (Si) epitaxial layer, forming a first contact hole in an interlayer insulating film including a first lower region exposing the SiGe epitaxial layer of the first layer, forming a second contact hole in the interlayer insulating film including a second lower region penetrating through the SiGe epitaxial layer of the second layer and exposing the Si epitaxial layer of the second layer, forming a first metal silicide film including germanium (Ge) in the first lower region, forming a second metal silicide film not including Ge in the second lower region simultaneously with the forming of the first metal silicide film.