A bonding surface of first semiconductor substrate 11 , and {HEAD ~ a bonding surface} of second semiconductor substrate 12 are {TAIL ~ mirror} finished to provide a surface roughness of below 500 Å each 
are
A bonding surface of first semiconductor substrate 11 , and { HEAD ~ a bonding surface } of second semiconductor substrate 12 are { TAIL ~ mirror } finished to provide a surface roughness of below 500 Å each
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH