Local Droplet Etching with Indium Droplets on InP(100) by Metal-Organic Vapor Phase Epitaxy

The local droplet etching (LDE) by using indium droplets on bare InP(100) surfaces is demonstrated in a metal-organic vapor phase epitaxy (MOVPE) environment for the first time. The role of an arsenic flow applied to self-assembled metallic indium droplets is systematically studied. Increasing the arsenic supply leads to the formation of ring-like nanostructures and nanoholes. The results are analyzed with reference to LDE in a molecular beam epitaxy environment, where such a technique is well established, particularly for arsenide-based III-V semiconductors, and where only one group-V material is involved. Here, As-P exchange reactions at droplet sites are identified as the drivers for the formation of nanoholes. Such nanoholes can serve as nucleation sites for subsequent fabrication of highly symmetric QDs by nanohole-infilling or as a means for in situ surface nanopatterning. LDE on InP by MOVPE can thus be considered as a promising approach for the cost-effective fabrication of novel quantum emitters at the telecom C-band.