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