A Facile One-Step Approach to Epitaxially Grow Periodic Arrays of InGaAs/GaAs Nanobars by Metal-Organic Chemical Vapor Deposition: From Site Control to Size Control.

Site and size control of ordered arrays of semiconductor nanostructures in an efficient way has remained a large challenge and has thus attracted intensive research interest due to their potential applications inintegrated optoelectronics. In this work, we report an original approach to grow hexagonally ordered arrays of InGaAs/GaAs nanobars on the designed regions of GaAs substrate coated with silicon dioxide through nanospherelithography (NSL). To control the growth sites of the nanostructures, microsized wells are first fabricated on a thin silicon dioxide film deposited on the GaAs substrate by photolithography, and bilayers of hexagonally ordered polymer nanospheres are then self-assembled on the silicon dioxide films with two different thicknesses. Finally,an array of nanocavities is created by dry etching through the self-assembled nanospheres. By controlling the etching depth, the nanocavities areetched down to the GaAs substrate first in the wells, leading to epitaxial growth of InGaAs/GaAs nanobars only in the wells with one-step metal-organic chemical vapor deposition (MOCVD). To fabricate dual sized InGaAs/GaAs nanobars, combined etchants are used to etch not only the silicon dioxide but also the polymer; the etching front of nanocavities inside the microsized wells reaches the GaAs substrate first and is further widened when the etching front of the nanocavities outside the wells also reaches the bottom. This results in the formation of dual-sized nano openings of the silicon dioxide film on the GaAs substrate for the expitaxial growth of dual-sized InGaAs/GaAs nanobars by one-step MOCVD. [ABSTRACT FROM AUTHOR]