Patent ID: 7205667

Claim:
A semiconductor device comprising: an underlying substrate; a first interlayer insulating film formed over the underlying substrate and made of insulating material; a via hole formed through the first interlayer insulating film; a conductive plug filled in the via hole and made of copper or an alloy containing mainly copper; a second interlayer insulating film formed over the first interlayer insulating film and made of insulating material; a wiring groove formed in the second interlayer insulating film, passing over the conductive plug and exposing an upper surface of the conductive plug; and a wiring filled in the wiring groove and made of copper or an alloy containing mainly copper; wherein said conductive plug and said wiring made of said copper or said alloy containing mainly copper contain carbon, oxygen, nitrogen, sulphur and chlorine; wherein a total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the conductive plug is lower than a total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the wiring.