A CONFOCAL PHOTOLUMINESCENCE STUDY OF METALORGANIC CHEMICAL-VAPOR-DEPOSITION GROWTH ON PATTERNED GAAS SUBSTRATES

New insight is provided into the properties of GaAs/AlGaAs quantum wel ls and associated heterostructure layers grown by metalorganic chemica l vapor deposition over grooves etched into GaAs substrates, an import ant class of geometries for multidimensional quantum confinement. A ne w, noncontact, simple characterization technique, confocal photolumine scence (CPL), provides composition, thickness, and electronic quality information with less than or similar to 1 mum spatial resolution, sig nificantly improved over the traditional diffusion length limit of pho toluminescence. Room temperature CPL spectra show: AlGaAs composition variations along the groove sidewall, including large compositional fl uctuations on a 1 mum scale; variations in AlGaAs composition and mate rial quality extending several mum's from the groove edges; and rapid variations in quantum well thickness and optical properties, particula rly along high-index growth planes.