Evolution of cross-sectional structures during selective MBE growth of InGaAs hexagonal nanowire networks on InP [001] and (111)B substrates

This paper investigates temporal evolution of cross-sectional structures during the selective MBE growth of hexagonal InGaAs QWR networks. Patterns combining <-110>- and <510>- directions on the [001] substrate and those combining <-1-12>-directions on the (111)B substrate were compared. Pattern formation process and H*-assisted ridge growth were optimized, showing feasibility of hexagonal node densities above 1 × 10⁹ cm^-2 with better surface uniformity on (111)B substrates. Cross-sectional structure, wire shape, wire size and their temporal evolution strongly depended on substrate orientation and growth conditions, reflecting complicated kinetic process of growth. Data for precise wire width control have been obtained for both substrate orientations.