Selective-area growth of GaAs and InAs nanowires—homo- and heteroepitaxy using SiNxSiNx templates

We report on the catalyst-free growth of GaAs and InAs nanowires using the selective-area metal organic vapor phase epitaxy (SA-MOVPE). The nanowires were grown from small circular openings defined by electron-beam lithography and wet chemical etching of a thin SiNxSiNx layer. This layer was deposited on a (1 1 1)B-oriented GaAs substrate using plasma enhanced chemical vapor deposition. We optimized the growth conditions for realizing extremely uniform arrays in a triangular lattice of GaAs and InAs nanowires with diameters down to 100 nm and a length of a few microns. During the growth the nanowires are formed by {1¯10} side facets and a growth direction perpendicular to the substrate surface. We investigated the growth behavior of GaAs nanowires with different diameters varying from 100 to 500 nm at different growth parameters, changing the temperature and the V/III ratio of TMG and AsH3AsH3. With a combination of GaAs and InAs SA-MOVPE growth radial heterostructures were grown. The structures were characterized by scanning electron microscopy, photoluminescence spectroscopy and transmission electron microscopy.