Position controlled self-catalyzed growth of GaAs nanowires by molecular beamepitaxy

Abstract

GaAs nanowires are grown by molecular beam epitaxy using a self-catalyzed,Ga-assisted growth technique. Position control is achieved by nano-patterning aSiO2 layer with arrays of holes with a hole diameter of 85 nm and a hole pitch varying between 200 nm and 2 µm.Gallium droplets form preferentially at the etched holes acting as catalyst for the nanowire growth.The nanowires have hexagonal cross-sections with {110} side facets and crystallize predominantlyin zincblende. The interdistance dependence of the nanowire growth rate indicates a change of theIII/V ratio towards As-rich conditions for large hole distances inhibiting NW growth.