Ga-droplet-induced formation of GaAs nano-islands by chemical beam epitaxy

We report on the fabrication of self-assembled GaAs islands in a nanometer scale by chemical beam epitaxy via Ga droplet formation and subsequent supply of arsine. The density and size of GaAs nano-islands were determined by the nucleation and the growth process of Ga droplets, which were fairly sensitive to the growth condition of Ga droplets, such as the substrate temperature and the amount of TEGa supplied. Transmission electron microscopy observation showed that GaAs nano-islands with well-defined zinc-blende structure were coherently grown on the GaAs surface. Ga droplet-induced formation of GaAs nano-island is thought to be a promising method for fabricating GaAs quantum dots.