Semiconductor device and method for manufacturing the same

Claim 1

A semiconductor device comprising: a plurality of individual devices disposed upon a semiconductor substrate and electrically interconnected in a predetermined arrangement by a plurality of conductive interconnect lines disposed in a plurality of interconnect layers and interconnected from one interconnect layer to another by a plurality of interlayer contacts communicating through a plurality of interlayer insulating layers, one of the plurality of interconnect layers being located at an uppermost position with respect to the semiconductor substrate; the uppermost interconnect layer being disposed in a trench in an uppermost one of the plurality of interlayer insulating layers, and covered by a protective insulating layer containing a plurality of contact holes disposed to make electrical contact from the interconnect layer to an external conductor line, the uppermost interlayer insulating film having a substantially flat top surface; the uppermost interconnect layer including from the bottom in order a first barrier layer comprised of a first conductive material disposed in contact with the uppermost insulating layer, a first conductor layer comprised of a second conductive material disposed in contact with the first barrier layer and not in contact with the uppermost insulating layer, a second barrier layer comprised of a third conductive material disposed in contact with the first conductor layer and not in contact with the uppermost insulating layer, and an external conductor line contact pad layer comprised of a fourth conductive material disposed in contact with the second barrier layer and not in contact with the first conductor layer; wherein an uppermost portion of each of the first barrier layer, the first conductor layer, the second barrier layer and the external conductor line contact pad layer are substantially in the same plane as the substantially flat top surface of the uppermost interlayer insulating film.