GAAS TETRAHEDRAL QUANTUM DOTS GROWN BY SELECTIVE AREA MOCVD

GaAs tetrahedral quantum dots (TQDs) buried in AlGaAs were fabricated using selective area metalorganic chemical vapor deposition (MOCVD). The substrates were SiO2 masked (111)B GaAs, which were partially etched free of SiO2 over triangular areas using electron beam lithography and reactive ion etching techniques. First, truncated tetrahedral AlGaAs buffer layers with {110} facet sidewalls were grown over the triangular areas. Next, GaAs TQDs were sequentially grown on top of the AlGaAs. Finally, AlGaAs layers were overgrown on the resulting tetrahedral structures. The height of the GaAs tetrahedrons was estimated to be 20 nm. Photoluminescence of GaAs TQDs buried in AlGaAs was measured at 8.5 K. A clear emission peak from GaAs TQDs was observed at 810 nm. The energy shift from the GaAs emission peak is 19meV, which agrees well with the calculation. © 1992.