AMORPHOUS CARBON LAYER FOR COBALT ETCH PROTECTION IN DUAL DAMASCENE BACK END OF THE LINE INTEGRATED CIRCUIT METALLIZATION INTEGRATION

A method of forming an amorphous carbon (aC) layer as a barrier layer for preventing etching of metals in a dual damascene metallization process and the resulting device are provided. Embodiments include forming an inter-layer dielectric (ILD) layer over a substrate with the first ILD having recesses for a first metallization layer. Then forming a TaN barrier layer and Co liner in the recesses, filling the recesses with a metal, forming a Co cap layer over the metal and forming a conformal aC layer over the substrate are accomplished. Furthermore, an Nblock layer, an ILD layer and a metal hard mask layer completes the stack on top to the aC layer. Subsequently, the embodiments include etching vias through this stack down to the aC layer, thereby protecting the first metallized layer.