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