Patent ID: 7479700

Claim:
A semiconductor device comprising: a first wiring layer which is substantially composed of copper; a second wiring layer which is substantially composed of copper; a first metal capping layer formed on said first wiring layer; and a second metal capping layer formed on said second wiring layer; wherein a thickness of said first metal capping layer is thicker than that of said second metal capping layer wherein the device further comprising a multi-layered wiring structure, said first and second wiring layers being formed in an insulating interlayer included in said multi-layered wiring structure and said insulating interlayer includes a first barrier layer containing tantalum nitride as a main component and formed between said first wiring layer and said insulating interlayer, and a second barrier layer containing tantalum as a main component and formed between said second wiring layer and said insulating interlayer, a nitrogen density of the first barrier layer being larger than that of the second barrier layer.