Patent ID: 7777343

Claim:
A semiconductor integrated circuit device comprising: a first insulating film formed over a semiconductor substrate and having a first wiring trench; a first metal wiring formed in the first wiring trench and including copper as a primary component; a second insulating film formed over the first metal wiring and over the first insulating film, the second insulating film being comprised of a material including silicon, carbon, oxygen and nitrogen; a third insulating film formed over the second insulating film and comprised of a material including silicon and carbon, the material of the second insulating film having a greater barrier property to copper than the material of the third insulating film, and the material of the second insulating film being different from the material of the third insulating film; a fourth insulating film formed over the third insulating film and comprised of a material including silicon, oxygen and carbon, the fourth insulating film having a thickness greater than thicknesses of the second and third insulating films, and having a dielectric constant lower than a dielectric constant of a silicon oxide film; wherein a contact hole is formed in the fourth, third and second insulating films, and is connected to the first metal wiring; a second wiring trench is formed in the fourth insulating film and is connected to the contact hole, and a second metal wiring and a plug including copper as a primary component are formed in the second wiring trench and the contact hole as one combined unit, such that the second metal wiring is connected to the first metal wiring through the plug.