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