A semiconductor device includes contact plugs formed in contact holes defined in an interlayer dielectric. Upper portions of the contact plugs are etched. A first barrier layer is formed on a surface of the interlayer dielectric including the contact plugs. A second barrier layer is formed on the first barrier layer over the interlayer dielectric. The second barrier layer has lower compatibility with a metallic material than the first barrier layer. A first metal layer is formed over the first and second barrier layers. The first metal layer, the first barrier layer and the second barrier layer are then patterned.