A method of fabricating a semiconductor device includes forming an interlayer dielectric on a substrate, the interlayer dielectric including first and second openings respectively disposed in first and second regions formed separately in the substrate; forming a first conductive layer filling the first and second openings; etching the first conductive layer such that a bottom surface of the first opening is exposed and a portion of the first conductive layer in the second opening remains; and forming a second conductive layer filling the first opening and a portion of the second opening.