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