an etched portion formed by selectively etching said insulation film and said first semiconductor substrate of {HEAD ~ said composite substrate} to reach at least said {TAIL ~ second semiconductor substrate} 
to reach
an etched portion formed by selectively etching said insulation film and said first semiconductor substrate of { HEAD ~ said composite substrate } to reach at least said { TAIL ~ second semiconductor substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL