{HEAD ~ a portion} of {TAIL ~ the region} made of the material comprising copper as the main ingredient is in contact with the insulative diffusion barrier layer, 
{ HEAD ~ a portion } of { TAIL ~ the region } made of the material comprising copper as the main ingredient is in contact with the insulative diffusion barrier layer ,
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH