{TAIL ~ The semiconductor} filled {HEAD ~ portion} of each trench then serves as a drain and source of a field effect transistor 
{ TAIL ~ The semiconductor } filled { HEAD ~ portion } of each trench then serves as a drain and source of a field effect transistor
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH