Semiconductor device having metal interconnection comprising metal silicide and four conductive layers

Abstract

A semiconductor device having a metal interconnection includes an insulating film provided on a semiconductor substrate via a diffusion layer. An interlayer contact hole is formed in the insulating film. A metal silicide layer is provided at the bottom of the interlayer contact hole. A first conductive film comprises a single or a plurality of metal films provided on the insulating film and the interlayer contact hole. A second conductive film is provided in the interlayer contact hole. A third conductive film is provided on the first conductive film and the second conductive film. A fourth conductive film is provided on the third conductive film. This semiconductor device has improved durability with respect to electromigration or stress migration. Even when the interconnection has a multilevel structure, the contact resistance can be reduced by causing the interlayer contact hole portions to contact one another by the same kind of metal.

Dependencies are inferred from the claim text.