Interface profile optimization in novel surface passivation scheme for InGaAs nanostructures using Si interface control layer

Abstract

This paper attempts to control and optimize the interface atomic profiles of a novel surface passivation scheme for InGaAs nanostructures, using a silicon interface control layer (ICL). An in-situ x-ray photoelectron spectroscopy characterization technique was used to establish a process sequence that satisfies the conditions of maintenance of pseudomorphic matching to InGaAs, prevention of direct oxidation of InGaAs, and formation of a good SiO₂/Si interface with minimal suboxide components. It is shown that the above conditions can be satisfied by a new process that is a formation of the thermal SiO₂ at the SiO₂-Si interface by repetition of deposition/oxidation/annealing cycle. A large reduction of interface state density (N_ss) was realized by the optimization of the new process, resulting in a minimum N_ss of 4 × 10¹¹ cm⁻² eV⁻¹. The silicon ICL technique was successfully applied to the passivation of InGaAs wire structures.