The heterogeneous integration of InAlAs/InGaAs heterojunction diodes on GaAs: impact of wafer bonding on structural and electrical characteristics

We have investigated the influence of low temperature wafer bonding on the electrical and structural characteristics of InAlAs/InGaAs n-p heterojunction structures with similar structure to an emitter-base junction of InAlAs/InGaAs HBTs. Those n-p junction heterostructures were grown on an InP [100] substrate by solid source MBE. The effect of the wafer bonding process on the structural properties of the epitaxial layers was studied by comparing triple crystal X-ray diffraction measurements and simulations before and after bonding. In addition, the influence of the bonding process on the electrical properties of the heterojunction structures was assessed through SIMS analysis of both the bonded and nonbonded samples and an analysis of the I-V characteristics of diodes fabricated on both the bonded and non-bonded sample. These analyses show that the structural and electrical properties of the as-grown epitaxial layers were negligibly changed by the low temperature wafer transfer process.