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