Patent ID: 7279790

Claim:
A semiconductor device, comprising: an inter-layer insulation film; a first wiring prepared on an upper surface of the inter-layer insulation film; a second wiring prepared under a lower surface of the inter-layer insulation film, wherein the first wiring and the second wiring are formed by one of copper and a copper alloy; a via plug that connects the first wiring and the second wiring through the inter-layer insulation film, the via plug including at least one layer formed by one of copper and copper alloy and at least one layer of a high melting-point metal for suppressing electromigration of copper atoms of said one of copper and copper alloy between the first wiring and second wiring, said layer of high melting-point metal does not extend on a top surface of the inter-layer insulation film and has a melting point higher than a melting point of a metal that forms the first wiring and the second wiring; and a barrier metal layer that touches the first wiring, wherein the high melting-point metal layer electrically contacts the first wiring via the barrier metal layer.