GaAsSb–silicon interface analysis for photodetectors via direct wafer bonding

Direct wafer bonding provides a scalable approach for integrating dissimilar semiconductors without lattice-matching constraints, enabling monolithic III-V integration on silicon (Si). GaAsSb is an attractive alloy owing to its tunable bandgap in the short-wave infrared region, which supports applications in communication, imaging, and sensing. The relatively small conduction band offset with silicon further facilitates efficient carrier transport across the bonded interface. We demonstrate GaAsSb–Si integration using plasma-activated direct wafer bonding, with argon plasma treatment to improve the surface hydrophilicity and bond strength. Structural and electrical characterizations, including contact angle goniometry, current-voltage, transmission electron microscopy, and scanning acoustic microscopy, confirm strong interfacial adhesion and device viability, underscoring the potential of GaAsSb/Si platforms for high-efficiency photodetectors.