Provided are semiconductor devices and methods for fabricating the same. A method for fabricating a semiconductor device includes: forming an interlayer dielectric layer including an opening in which a lower conductive layer is exposed; forming a barrier layer on the interlayer dielectric layer and on the lower conductive layer the opening; forming an anti-seed generation region on a surface of the barrier layer which is provided on a top surface of the interlayer dielectric layer and an upper sidewall of the opening; and filling the opening with conductive material to form a conductive layer.