SEMICONDUCTOR DEVICE

A semiconductor device includes: a substrate including an upper side and a lower side; first and second active patterns spaced apart from each other; a field insulating film covering side walls of the first and second active patterns; a power rail disposed adjacent to a first side wall of the second active pattern and between the first active pattern and the second active pattern; a power rail via disposed on the power rail and connected to the power rail; a semiconductor etching stop pattern disposed adjacent to a second side wall of the second active pattern; and a first semiconductor pattern disposed on the semiconductor etching stop pattern, wherein a lower surface of the semiconductor etching stop pattern is disposed on substantially a same plane as the lower side of the substrate, and wherein at least part of the first semiconductor pattern is disposed in the field insulating film.