A semiconductor device includes a semiconductor substrate having a first surface and a second surface, which are opposite to each other, an active pattern protruding from the first surface of the semiconductor substrate, the active pattern including a source/drain region, a power rail electrically connected to the source/drain region, a power delivery network disposed on the second surface of the semiconductor substrate, and a penetration via structure penetrating the semiconductor substrate and electrically connected to the power rail and the power delivery network. The penetration via structure includes a first conductive pattern electrically connected to the power rail and a second conductive pattern electrically connected to the power delivery network. The first conductive pattern includes a material different from the second conductive pattern.