Demonstration of Enhanced III-V-On-Silicon Hybrid Integration by Using a Strained Superlattice as a Defect Blocking Layer

Enhanced III-V epitaxial transfer through a low-temperature direct wafer bonding process was observed by including a strained superlattice (SSL) layer right above the bonding layer in III-V to block bonding-induced defects. Compared to previously-used unstrained SL, SSL shows better capacity to pin thermal defects at the bonding interface, preventing them from propagating upwards to the active region. Higher photoluminescence response and lower dark current from fabricated photodetectors (PDs) proved the theory. Compared with SL-free sample, both USL and SSL samples demonstrated much better uniformity in PL response and PD dark current, and well-preserved quantum-well satellite peaks and fringes in X-ray diffraction rocking curve measurement. The employment of SSL is useful to many dissimilar material hybrid integrations.