QUANTUM-WELL WIRE FABRICATION METHOD USING SELF-ORGANIZED MULTIATOMICSTEPS ON VICINAL (001)GAAS SURFACES BY METALORGANIC VAPOR-PHASE EPITAXY

Coherent multiatomic steps with extremely straight edges are naturally formed on vicinal (001) GaAs surfaces during metalorganic vapor phase epitaxial growth. GaAs quantum well wires (QWWs) are formed on these self-organized multiatomic steps. In our previous study, a thin AlGaAs layer was grown on GaAs with multiatomic steps as a lower barrier of QWWs. However, the height and spacing of the steps slightly fluctuate on AlGaAs layer surfaces. Therefore, in this experiment, AlAs layer in stead of AlGaAs layer was used as a lower barrier layer to improve the uniformity of the height and spacing of the steps. Atomic force micro scopy observations and photoluminescence (PL) measurements at 20 K rev ealed that the underlying coherent GaAs multiatomic steps were well tr aced by the AlAs barrier layer rather than the AlGaAs barrier layer. F urthermore, we measured the polarization anisotropy of the PL spectra from the QWWs with AlAs. These results suggest that uniform QWWs are s uccessfully formed using multiatomic steps on vicinal (001) GaAs surfa ces.