Semiconductor device having a multilayer interconnection structure

Abstract

A semiconductor device has a multilayer interconnection structure, wherein the multilayer interconnection structure comprises at least a first interconnection layer and a second interconnection layer formed over the first interconnection layer, the first interconnection layer comprises a first conductor pattern embedded in a first interlayer insulation film and constituting a part of an interconnection pattern and a second, another interconnection pattern embedded in the first interlayer insulation film, the second interconnection layer comprises a third conductor pattern embedded in a second interlayer insulation film and constituting a part of said interconnection pattern, the third conductor pattern has an extension part in a part thereof so as to extend in a layer identical to the third conductor pattern, the third conductor pattern being electrically connected to the first conductor pattern at a first region of the extension part via a first via plug, the extension part making a contact with the second conductor pattern at a second region further away from, or closer to the third conductor pattern with regard to the first region via a second via-plug of a diameter smaller than the first via-plug, the extension part of the third conductor pattern, the first via-plug and the second via-plug form, together with the second interlayer insulation film, a dual damascene structure.