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