Abstract: Disclosed is a method of forming a metal interconnection line for a semiconductor device. A metal interconnection line for semiconductor device according to the present invention is formed by the following processes. A semiconductor substrate having a conductive layer thereon is provided and an insulating layer is formed on the semiconductor substrate. A contact hole is formed by etching a selected portion of the insulating layer existing on the conductive layer to expose a predetermined portion of the conductive layer. A barrier metal film is then formed on a surface of the contact hole and the insulating film. A first aluminum alloy film is uniformly formed on the barrier metal film and a metal film for use as a plug is formed on the first aluminum alloy film filling the contact hole wherein the contact hole is covered with the first aluminum alloy film. A contact plug is then formed by etching back the metal film to expose the first aluminum alloy film.