Strain determination in mismatched semiconductor heterostructures by the digital analysis of lattice images

摘要

The evaluation program DALI (Digital Analysis of Lattice Images) is applied to determine strain and composition of In_xGa_(1-x)As islands which were grown on (001)GaAs substrates and capped with 10 nm GaAs. Finite element calculations are used to find the reduction of the tetragonal distortion use to the small sample thickness below 40 nm which is determined by the combination of the real space method QUANTITEM and the consideration of local Fourier coefficients.