GAAS TETRAHEDRAL QUANTUM DOT STRUCTURES FABRICATED USING SELECTIVE AREA MOCVD

New GaAs quantum dot structures, called tetrahedral quantum dots (TQD's), are proposed to make a zero-dimensional electron-hole system. The TQD's are surrounded by crystallographic facets fabricated using selective area MOCVD on GaAs(111)B substrates. The calculated energy sublevel structures of zero-dimensional electrons in a GaAs TQD show large quantum size effects, because electrons are confined three-dimensionally. GaAs and AlGaAs tetrahedral facet structures were grown using MOCVD on GaAs(111)B substrates partially etched into a triangular shape. Tetrahedral growth with {110} facets occurs in the triangular areas. The cathodoluminescence intensity map for GaAs tetrahedrons buried in AlGaAs shows the tetrahedral dot array.