For example, {HEAD ~ the gate structures} include a gate stack that has a gate dielectric and a gate electrode, offset spacers, and {TAIL ~ main spacers} 
For example , { HEAD ~ the gate structures } include a gate stack that has a gate dielectric and a gate electrode , offset spacers , and { TAIL ~ main spacers }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL