Semiconductor device and manufacturing method thereof

A semiconductor device having good production stability and excellent in a contact property between an antireflection film on an Al contained metal film and a conductive plug. The device includes a substrate, an insulating interlayer, and a multi-layer structure. The insulating interlayer is formed in the upper portion of the substrate. The structure is provided on the insulating interlayer. A Ti film, a first TiN film, an AlCu film, a Ti film, a second TiN film, and an etching adjustment film are sequentially formed in the structure. The device includes an insulating interlayer and a conductive plug. The insulating interlayer is provided on the insulating interlayer and the structure. The conductive plug penetrates the insulating interlayer and the etching adjustment film, and an end surface of the conductive plug is located in the second TiN film. The conductive plug includes a Ti film, a TiN film, and a W film.