The step of forming {HEAD ~ fin structures} forms fin structures adjacent to {TAIL ~ the recessed sidewalls} 
The step of forming { HEAD ~ fin structures } forms fin structures adjacent to { TAIL ~ the recessed sidewalls }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL