Semiconductor device having trench interconnection and manufacturing method of semiconductor device

摘要

A semiconductor device includes a first interconnection layer and a interlayer insulating layer. The first interconnection layer is formed on a upper side of a substrate, and includes a first interconnection. The interlayer insulating layer is formed on the first interconnection layer, and includes a via connected with the first interconnection at one end of the via and a second interconnection connected with the via at another end of the via. The interlayer insulating layer has a relative dielectric constant lower than that of a silicon oxide film. An upper portion of the interlayer insulating layer includes a silicon-oxide film, a silicon nitride film and a silicon oxide film in order from a lower portion.