Patent ID: 7898082

Claim:
A semiconductor device, comprising: a material layer disposed over a workpiece; a first metal nitride bather layer disposed over the material layer, the first metal nitride barrier layer comprising a first nitrogen-rich region formed at a first top surface of the first metal nitride barrier layer and the first nitrogen-rich region having a first higher concentration of nitrogen than a first remaining region of the first metal nitride barrier layer; a second metal nitride barrier layer disposed directly over the first metal nitride barrier layer, the second metal nitride barrier layer comprising a second nitrogen-rich region formed at a second top surface of the second metal nitride barrier layer and the second nitrogen rich-region having a second higher concentration of nitrogen than a second remaining region of the second metal nitride barrier layer; and a conductor disposed over the second metal nitride barrier layer such that the first and second remaining regions and the first and second nitrogen-rich regions form a nitride barrier layer between the material layer and the conductor.