ABSTRACT
The direct bonding of various III-V wafers, which are mismatched in terms of surface orientations and lattice constants, was systematically investigated for an In-Ga-As-P system. Despite those mismatches, many wafer combinations were successfully united with sufficient mechanical strength. A dislocation-free interface of (001) GaP and (110) InP bonded at the atomic level was observed by transmission electron microscopy. A (001) InP-based long-wavelength laser fabricated on a (110) GaAs substrate exhibited high reliability. These results suggest that a novel concept "free-orientation integration" can be achieved by direct bonding for III-V system.
