Effect of in-plane alignment on selective area grown homo-epitaxial nanowires.

In-plane selective area growth (SAG) of III-V nanowires (NWs) has emerged as a scalable materials platform for quantum electronics and photonics applications. Most applications impose strict requirements on the material characteristics which makes optimization of the crystal quality vital. Alignment of in-plane SAG NWs with respect to the substrate symmetry is of importance due to the large substrate-NW interface as well as to obtain nanostructures with well-defined facets. Due to fabrication tolerances, some misalignment is unavoidable. Here we study the effect of mis-orientation on morphology of selectively grown NWs oriented along the [1-1-1] direction on GaAs(211)B. Atomic force microscopy is performed to extract facet roughness as a measure of structural quality. Further, we evaluate the dependence of material incorporation in NWs on the orientation and present the facet evolution in between two high symmetry in-plane orientations. By investigating the length dependence of NW morphology, we find that the morphology of ≈ 1 μm long NWs remains unaffected by misalignment. Finally, we show that using Sb as a surfactant during growth improves facet roughness for large misalignment, but has no effect at small scale.