a first gate electrode of {HEAD ~ a first MOS transistor} of a first conductivity type formed on said primary surface of {TAIL ~ said substrate} 
a first gate electrode of { HEAD ~ a first MOS transistor } of a first conductivity type formed on said primary surface of { TAIL ~ said substrate }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL