IN-SITU FABRICATION OF BURIED GAAS ALGAAS QUANTUM-WELL MESA-STRIPE STRUCTURES WITH IMPROVED REGROWN INTERFACES/

The mesa-stripe structures of GaAs/AlGaAs multi-quantum-wells (MQWs) w ere buried by AlGaAs overgrown layers using an in situ fabrication tec hnique, including Cl-2 gas etching and molecular-beam epitaxial regrow th without air exposure. In these structures, having stripe widths of less than several microns, the photoluminescence intensities from the MQWs were considerably improved, compared to conventionally fabricated buried structures as well as to as-etched open-sidewall structures. C orrespondingly, it was observed by transmission-electron-microscope th at the densities of the crystal defects at the in situ regrown interfa ces were greatly reduced, indicating great usefulness of in situ techn iques in fabricating high-quality microstructures.