Interconnect structure with enhanced reliability

An interconnect structure comprising:

• a dielectric layer having a conductive feature embedded therein, said conductive feature having a first top surface that is substantially coplanar with a second top surface of said dielectric layer;
• a metal cap layer located directly on said first top surface, wherein said metal cap layer does not substantially extend onto said second top surface;
• a first dielectric cap layer located directly on said second top surface, wherein said first dielectric cap layer has bottom surface that is substantially flush with a bottom surface of the metal cap layer, wherein the first dielectric cap layer has a substantially uniform composition profile, and wherein said first dielectric cap layer is thicker than said metal cap layer;
• and
• a second dielectric cap layer directly on said metal cap layer and directly on said first dielectric cap layer, wherein the first dielectric cap layer and the second dielectric layer consist of a material having no elements in common with the metal cap layer.