GaAs-Ge materials integration for electronic and photonic applications

Antiphase domain defects free GaAs layers grown on Ge(100) offcut substrates with and without an ultra thin AlAs interfacial layer were investigated. SIMS measurements suggest cross-diffusion of Ge, Ga and As atoms at the GaAs/Ge interface has significantly reduced with the presence of the thin AlAs layer. Photoluminescence (PL) measurements suggest complete elimination of PL originated from Ge-based complexes for structure with AlAs interfacial layer. The GaAs/Ge hybrid materials integration will find various applications such as in multijunction photovoltaics, metal-oxide-semiconductor-field-effect-transistors and ultra-low noise avalanche photodiodes. Circular mesas were etched on the GaAs/AlAs/Ge structure and the AlAs layer was oxidized and GaAs-on-insulator-on-Ge structure was demonstrated.