Wetting of Ga Droplets in SiO₂/Si Cavities: Application to Self-Assisted GaAs Nanowire Growth

In this paper, we compute and compare the surface energy of various Ga liquid droplets wetting a cylindrical cavity in various configurations. While for some of these configurations, the surface energy can be computed explicitly; for others, numerical computation is needed. Motivated by the results obtained for the cylindrical cavities, we explore the case of the more realistic situation, conical cavities. Our results provide a relation between the geometry of the conical cavity and the equilibrium wetting angles of the droplet on the bottom and on the sidewall of the cavity, which insures the dewetting of the lateral surface. This is an important result toward the control of the verticality during nanowire growth by the vapor–liquid–solid method.