Barrier film integrity on porous low k dielectrics by application of a hydrocarbon plasma treatment

An interconnect structure comprising:

• vias and trenches defined by an interlayer dielectric disposed above an underlying layer;
• a carbon rich polymer layer is disposed on the surface of the interlayer dielectric, so as to form a liner in line the vias and the trenches;
• a carbide layer over the liner;
• a barrier layer disposed over the carbide layer;
• a copper alloy over the barrier layer, filling the vias and the trenches;
• and
• the surface of the copper coplanar with the surface of the interlayer dielectric layer.