A semiconductor device and electronic system, the device including a cell structure stacked on a peripheral circuit structure, wherein the cell structure includes a first interlayer dielectric layer and first metal pads exposed at the first interlayer dielectric layer and connected to gate electrode layers and channel regions, the peripheral circuit structure includes a second interlayer dielectric layer and second metal pads exposed at the second interlayer dielectric layer and connected to a transistor, the first metal pads include adjacent first and second sub-pads, the second metal pads include adjacent third and fourth sub-pads, the first and third sub-pads are coupled, and a width of the first sub-pad is greater than that of the third sub-pad, and the second sub-pad and the fourth sub-pad are coupled, and a width of the fourth sub-pad is greater than that of the second sub-pad.