{HEAD ~ A cap layer} 130 further included on the gate structure 120 is used as {TAIL ~ a hard mask} while the etching process is performed 
is used as
{ HEAD ~ A cap layer } 130 further included on the gate structure 120 is used as { TAIL ~ a hard mask } while the etching process is performed
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH