Patent ID: 7078813

Claim:
A semiconductor device comprising: a gate insulated field-effect transistor having a gate electrode that is provided via a gate insulation film on a semiconductor substrate, a metal layer that is provided on the gate electrode, and diffusion layers that are separately provided in the semiconductor substrate such that the gate electrode is provided on a region lying between the diffusion layers, each of the diffusion layers serving as a source or a drain; a first barrier film that is provided on the diffusion layers and on side walls of the transistor; a first insulation layer that is provided on the first barrier film; a second barrier film that is continuously provided on the metal layer and on the first insulation layer; a trench that is opened in the second barrier film with a first width and extends in a first direction; a second insulation layer that is provided on the second barrier film; an upper contact hole portion that penetrates the second insulation layer and has a bottom in the second barrier film, the bottom having a second width greater than the first width in a second direction crossing the first direction; a lower contact hole portion that penetrates the first insulation layer and the first barrier film from the upper contact hole portion through the trench and is provided on the diffusion layer, an upper portion of the lower contact hole portion having the first width in the second direction; and a contact plug provided in the upper contact hole portion and the lower contact hole portion.