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