a buffer insulating layer between the silicon nitride liner and {HEAD ~ the self aligned contact pad} at the top portions of {TAIL ~ the first and second gate electrodes}, 
a buffer insulating layer between the silicon nitride liner and { HEAD ~ the self aligned contact pad } at the top portions of { TAIL ~ the first and second gate electrodes } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH