Importance of As and Ga Balance in Achieving Long GaAs Nanowires by Selective Area Epitaxy

We report on the selective area growth (SAG) of GaAs nanowires (NWs) by the catalyst-free vapor-solid mechanism. Well-ordered GaAs NWs were grown on GaAs(111)B substrates patterned with a dielectric mask using hydride vapor phase epitaxy (HVPE). GaAs NWs were grown along the ⟨111⟩B direction with perfect hexagonal shape when the hole’s opening diameter in SiN x or SiO x mask was varied from 80 to 340 nm. The impact of growth conditions and the …