An integrated circuit includes a first, second and third active region and a first, second and third conductive line. The first, second and third active regions extend in a first direction, and are on a first level of a front-side of a substrate. The second active region is between the first active region and the third active region. The first and second conductive line extend in the first direction, and are on a second level of a back-side of the substrate. The first conductive line is between the first and second active region. The second conductive line is between the second and third active region. The third conductive line extends in the second direction, is on a third level of the back-side of the substrate, overlaps the first and second conductive line, and electrically couples the first and second active regions.