Hybrid-integrated GaAs/GaAs and InP/GaAs semiconductors through wafer bonding technology: interface adhesion and mechanical strength

摘要

[[abstract]]In this study, the interface adhesion and mechanical strength of wafer bonded GaAs/GaAs and GaAs/InP semiconductors, each of (100) face, were characterized by combining the measurements of interface fracture energy γo and lap shear strength Es. The relations between the interface adhesion and annealing processes for four different types of bonding configurations, i.e., antiphase bonding, in-phase bonding, and twist bonding with 5° and 30° misalignments, were systematically studied. The surface free energy γα-GaAs/oxide (0.11–0.28 J/m2) of amorphous α-GaAs/oxide mixture was estimated based upon the reported surface free energy γc-GaAs (0.63 J/m2) of crystalline [100] GaAs and measured overall interface fracture energy γtotal (0.525 J/m2) of GaAs/GaAs bonded wafers. The micromorphologies of the bonded and debonded wafer interfaces were characterized by atomic force microscopy (AFM) and transmission electron microcopy (TEM). The interface microfailure mechanism of directly bonded GaAs wafers was proposed based on AFM and TEM microstructural analysis.