Novel nano-faceting structures grown on patterned vicinal (110) GaAs substrates by metal-organic vapor phase epitaxy (MOVPE)

We describe periodic nano-faceting structures formed naturally on patterned vicinal (110) GaAs grown by metal-organic vapor phase epitaxy (MOVPE). Per iodic trenches are formed along the [1-10] direction on initial surfaces wi th pattern periods of 2 mum. 1 mum, 800 nm, and 600 nm. Periodic nano-facet ing structures consisting of (110) and (111)B surfaces are clearly formed o n the GaAs grown surfaces, and the periods are almost exactly equal to the pattern periods. The growth modes are observed from cross-sectional scannin g electron microscope (SEM) images of GaAs/AlGaAs multilayer growth. The gr owth rate of the (111)B sidewall facets is higher than that of the (110) te rraces, which indicates that quantum wire (QWR) structures can be formed na turally at step edges. Quantum well (QW) structures of GaAs/In0.18Ga0.82As/ GaAs are also grown on patterned vicinal substrates. A photoluminescence (P L) spectrum at 4 K shows two sharp emission peaks from QWs on the (111)B si dewall facets at a lower energy and on the (110) terraces at a higher energ y. These results suggest that it is possible to fabricate QWR arrays with h igh uniformity on (111)B sidewall facets.