Gallium diffusion flow direction during deposition on the surface with regular hole arrays

Autocalytic growth of GaAs and GaP semiconductor nanowires is frequently carried out using SiO$_x$/Si(111) substrates with lithographically prepared hole arrays, on which Ga droplets are created by preliminary deposition in the absence of As flow. It was previously believed that the diffusion flow of gallium is directed from the mask to holes. In the present work, it has been shown that the direction of this diffusion flow can vary depending on the growth parameters. The proposed model is applicable to description of the time of droplet incubation and can explain long-term delay in the growth of droplets and nucleation of nanowires.