Pitch-Independent Realization of 30-nm-Diameter InGaAs Nanowire Arrays by Two-Step Growth Method in Selective-Area Metalorganic Vapor-Phase Epitaxy

Control of the diameter and pitch of InGaAs nanowire arrays in selective-area metalorganic vapor-phase epitaxy was investigated. It was found that their nucleation was strongly dependent on the geometry of the mask, resulting in the difficulty of nucleation for a larger mask pitch, particularly for an opening diameter of less than 50 nm. Precise adjustment of the V/III ratio enabled us to control the nucleation independently of the mask pitch for smaller openings, and we successfully obtained 30-nm-diameter InGaAs nanowires independently of the mask pitch by the proposing V/III-ratio-controlled two-step growth method.