The semiconductor device may include a substrate, a first insulating layer on a bottom surface of the substrate, an interconnection structure in the first insulating layer, a second insulating layer on a bottom surface of the first insulating layer, and a plurality of lower pads provided in the second insulating layer. Each lower pad may be provided such a width of a top surface thereof is smaller than a width of a bottom surface thereof. The lower pads may include first, second, and third lower pads. In a plan view, the first and third lower pads may be adjacent to center and edge portions of the substrate, respectively, and the second lower pad may be disposed therebetween. A width of a bottom surface of the second lower pad may be smaller than that of the first lower pad and may be larger than that of the third lower pad.