{HEAD ~ a silicon nitride liner} on the sidewalls and on {TAIL ~ the top surface} of each gate electrode 
on
{ HEAD ~ a silicon nitride liner } on the sidewalls and on { TAIL ~ the top surface } of each gate electrode
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH