Semiconductor device

A semiconductor device includes a substrate, a first lower pattern and a second lower pattern on the substrate and arranged in a line in a first direction, a first active pattern stack disposed on and spaced apart from the first lower pattern, a second active pattern stack disposed on and spaced apart from the first lower pattern, a fin-cut gate structure disposed on the first lower pattern and overlapping a portion of the first lower pattern, a first gate structure surrounding the first active pattern stack and extending in a second direction crossing the first direction, a second gate structure surrounding the second active pattern stack and extending in the second direction, and a device isolation layer between the first gate structure and the second gate structure and separating the first lower pattern and the second lower pattern.