Semiconductor device

A semiconductor device includes: an active pattern including a lower pattern and a plurality of sheet patterns spaced apart from the lower pattern in a first direction; a plurality of gate structures disposed on the lower pattern to be spaced apart from each other in the second direction, each gate structure including a gate electrode and a gate insulating film; a source/drain recess defined between adjacent gate structures; and a source/drain pattern filling the source/drain recess. Each source/drain pattern may include a first semiconductor pad extending along sidewalls and a bottom surface of the source/drain recess, a second semiconductor pad on the first semiconductor pad and extending along sidewalls and the bottom surface of the source/drain recess, and a filling semiconductor film on the second semiconductor pad and filling the source/drain recess. The second semiconductor pad may be doped with carbon, and the first semiconductor pad may be in contact with the lower pattern and the sheet pattern, whil