Abstract: An uppermost metal wiring layer is formed of titan Ti and titan nitride TiN formed thereon, on which tungsten W for filling a via hole can be deposited. The via hole is filled with W. The surface of a metal wiring layer below the uppermost metal wiring layer is covered with a low reflectivity film made of titan nitride. Thus, light incident on the surface of the semiconductor chip is prevented from reaching a substrate transistor within a semiconductor device and malfunctioning of the semiconductor device is prevented.

Abstract: A method for manufacturing semiconductor device is provided, this method comprises the steps of: depositing a metal film for forming wirings on a substrate; forming a wiring layer, wherein dummy wiring is inserted between wiring space where the dummy wiring can be inserted, and wiring space, where the dummy wiring cannot be inserted, is reduced by widening wiring pattern facing the wiring space; forming an interlayer insulating film on said wiring layer; and flattening surface of the interlayer insulating film. The film can be flattened by a CMP method or by an etchback of entire surface of the film. It is possible to flatten the surface of the semiconductor device cost-effectively and precisely.