Patent attributes
A diffusion barrier film, a second insulating film, and a cap film are sequentially laminated on a first insulating film over a substrate. A wiring trench portion is formed extending therethrough to the first insulating film, assuming that the ratio of a width of the wiring trench portion in a direction orthogonal to its extending direction to a height of the wiring trench portion is 2.8 times even at a maximum. A barrier metal film is formed to cover the cap film and the wiring trench portion. A wiring film is deposited to cover the barrier metal film. The wiring film and the barrier metal film are chipped away until the surface of the cap film is exposed from the surface of the wiring film, thereby to form a wiring portion which buries the wiring trench portion.
