A thick insulator region is formed on {TAIL ~ a portion} of the drift region at {HEAD ~ the face} 
A thick insulator region is formed on { TAIL ~ a portion } of the drift region at { HEAD ~ the face }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD