SEMICONDUCTOR DEVICE

A semiconductor device includes first standard cells arranged in a first row on a substrate and respectively including a first base active region, second standard cells arranged in a second row adjacent to the first row and respectively including a second base active region, a power line extending in a first direction along a boundary between the first and second standard cells, and a device isolation layer on side surfaces of the first and second base active regions, wherein, in a plan view, the first standard cells and the second standard cells have a same cell height, the first base active region of each of the first standard cells includes a first active line having a first conductivity-type and a second active line having a second conductivity-type, the second base active region of each of the second standard cells includes a third active line having the first conductivity-type and a fourth active line having the second conductivity-type, the first active lines of the first standard cells arranged in the first row have a same first width, the third active lines of the second standard cells arranged in the second row have a same second width, and the first width is narrower than the second width.