A selective etch process is performed so as to form {HEAD ~ self aligned contact openings} that extend through the pre metal dielectric film and through {TAIL ~ the barrier layer} in the core region 
A selective etch process is performed so as to form { HEAD ~ self aligned contact openings } that extend through the pre metal dielectric film and through { TAIL ~ the barrier layer } in the core region
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH