Conditions for the Formation of Vertical Nanowires and Crystalline Clusters of GaAs during the Self-Catalyzed Growth

The formation of GaAs crystallites is observed during the self-catalyzed growth of vertical GaAs nanowires. The conditions necessary for vertical nanowires and nanocrystallites formation were explored using Monte Carlo simulation. The nanostructure growth was carried out on a GaAs (111)B substrate covered with a mask-film, according to the vapor-liquid-solid mechanism. It was shown that the nanostructure shape depends on both the deposition rates of gallium and arsenic and on the mask-film properties. It was demonstrated that an excessively high deposition rate of arsenic leads to the formation of crystallites only, while vertical nanowires are formed at relatively low Ga and As fluxes.