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