FABRICATION OF GAAS ALGAAS QUANTUM DOTS BY METALORGANIC VAPOR-PHASE EPITAXY ON PATTERNED GAAS SUBSTRATES/

We report on a growth process on patterned GaAs (001) substrate during metalorganic vapor-phase epitaxy (MOVPE) and a novel approach for the fabrication of AlGaAs/GaAs quantum dot (QD) structures. The patterned substrate has an array of holes on the surface and those holes are pa rtially filled with GaAs by MOVPE growth, followed by GaAs/AlGaAs quan tum well structures. Detailed investigation on the growth process on s uch patterned substrates revealed the presence of complicated two-dime nsional duffusion of Ga and Al between two different surfaces. Formati on of GaAs dots was directly confirmed by spatially resolved cathodolu minescence measurements.