Semiconductor devices and methods of fabricating the same are disclosed. The methods include forming a first interlayer insulating layer and a conductive contact plug that penetrates the first interlayer insulating layer, forming a second interlayer insulating layer and a first interlayer wiring on the first interlayer insulating layer. The first interlayer wiring penetrates the second interlayer insulating layer and overlaps the first metal contact plug. The second interlayer insulating layer is etched using the first interlayer wiring as a mask until the first metal contact plug is exposed, and an exposed portion of the conductive contact plug is etched using the first interlayer wiring as the mask.