{HEAD ~ A first dielectric layer} is formed overlying the substrate and has {TAIL ~ a dielectric island} surrounded by a ring shaped trench 
{ HEAD ~ A first dielectric layer } is formed overlying the substrate and has { TAIL ~ a dielectric island } surrounded by a ring shaped trench
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH