Selective Area Growth of GaN Nanowires on Graphene Nanodots
Résumé
We present a new approach to achieve selective area growth of GaN nanowires by plasma-assisted molecular beam epitaxy. The nanowires are grown on graphene nanodots, which are patterned by electron beam lithography from polycrystalline graphene patches transferred to SiO2 substrates. The GaN nanowires grow on these graphene nanodomains with a perfect selectivity with respect to the SiO2 surrounding surface. The results demonstrate that a single monolayer of graphene can withstand the lithography process without losing its ability to induce epitaxial growth. The nanowire length distribution and patterns’ fill factor are analyzed in the framework of a theoretical model, which takes into account an incubation time dependent on the graphene dot size. Overall, these results represent the first demonstration of selective area nanowire growth on a regular array of graphene nanodomains.