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