Atomistic modeling of strain distribution in self-assembled interfacial misfit dislocation (IMF) arrays in highly mismatched III–V semiconductor materials

Abstract

We describe a mathematical model to elucidate the strain energy distribution in the atomic arrangement resulting from a periodic pure edge, 90° interfacial misfit dislocation (IMF) arrays in highly mismatched III–V semiconductors. Using molecular mechanics methods, we calculate strain energy at the atomic level by considering the stretch and bend of each bond in the system under consideration. Three highly mismatched systems InAs/GaAs (Δ a o/ a o ∼7.2%), GaSb/GaAs (Δ a o/ a o ∼7.8%) and AlSb/Si (Δ a o/ a o ∼13%) are considered. This model describes that IMF array formation is driven by strain energy minimization and demonstrates the periodicity of the misfit array that is in good agreement with experimental data using cross section high-resolution transmission electron micrograph (HR-TEM) images and also with other theoretical values.