Two-dimensional ordered growth of InAs nanowires assisted by randomly deposited silver nanoparticles on a topographically modified surface by a focused ion beam

Self-organized nanowires were formed on topographically and orderly modified surfaces by a focused ion beam. Silver catalyst nanoparticles were deposited on the regular shallow hole arrangements on the InP (001), which were prepared with three different gallium ion doses, and acted as preferential nucleation sites for InAs grown using Metal-Organic Vapor Phase Epitaxy. Ion doses ranging from 0.8 x 10(14) to 4.2 x 10(14) Ga+/cm(2) were used, and InAs was grown with two sub-monolayer coverages. Two-dimensional ordered InAs nanowire arrays were grown in the templates, despite the randomly deposited silver nanoparticles and the cavities full of defects generated by ion beam irradiation. For the 1 s growth time sample using templates produced with a high ion dose, most of the InAs nanostructures were found to fill either entirely or a large fraction of the cavities. Nanowires were grown in the 2 s growth time sample, using low and medium ion dose. Although the nanowires' growth mechanism is described by the most widely employed vapor-liquid-solid model, the site-selective nanowires growth with randomly deposited catalyst nanoparticle occurs due to net adatom flow to the cavities assisted by modified surface potential. The competition between the coarsening and the vapor-liquid-solid mechanisms plays a critical role in determining the growth of nanowires or islands by providing a simple model able to properly describe the type of the nanostructure (islands or nanowires) dependence with the growth time and the ion dose.