{HEAD ~ a second conductive type high voltage} well, which is formed in the substrate beneath {TAIL ~ the upper surface} 
{ HEAD ~ a second conductive type high voltage } well , which is formed in the substrate beneath { TAIL ~ the upper surface }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL