Semiconductor device featuring copper wiring layers of different widths having metal capping layers of different thickness formed thereon, and method for manufacturing the same

A semiconductor device comprising:

• at least two first wiring layers which are substantially composed of copper, and which are arranged so as to be apart from each other at a first pitch;
• at least two second wiring layers which are substantially composed of copper, and which are arranged so as to be apart from each other at a second pitch narrower than said first pitch;
• a plurality of first metal capping layers, each of which is formed on one of said first wiring layers;
• and
• a plurality of second metal capping layers, each of which is formed on one of said second wiring layers;
• wherein a thickness of said first metal capping layers 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.

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, and
• wherein bottom surfaces of said first and second wiring layers are substantially coplanar 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.