{HEAD ~ The trenches} are then filled with {TAIL ~ semiconductor material} of a conductivity type opposite that of the semiconductor body 
{ HEAD ~ The trenches } are then filled with { TAIL ~ semiconductor material } of a conductivity type opposite that of the semiconductor body
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH