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