An integrated circuit includes a first power rail, a conductive structure, a first active region of a first set of transistors and a second active region of a second set of transistors. The first power rail is on a back-side of a substrate, extends in a first direction, and is configured to supply a first supply voltage. The first active region extends in the first direction, and is on a first level of a front-side of the substrate opposite from the back-side. The second active region extends in the first direction, is on the first level of the front-side of the substrate, and is separated from the first active region in a second direction different from the first direction. The conductive structure is on the back-side of the substrate, extends in the first direction, and is electrically coupled to the first active region and the second active region.