QUANTITATIVE-ANALYSIS OF ELASTIC STRAINS IN GAAS ALAS QUANTUM DOTS/

We have studied a GaAs/AlAs periodic quantum dot array using reciproca l space mapping around the (004) and <((11)over bar 3)> reciprocal lat tice points. Both the coherently and the diffusely scattered X-ray int ensities were analyzed by performing two-dimensional model calculation s. From the distribution of the diffracted intensities we deduced the average strain status in the dots. From the numerical simulations it i s evident that random elastic strain fields are present, which extend through almost the entire volume of the quantum dot. The simulations o f the X-ray measurements revealed that the crystalline part of the dot s is considerably smaller as scanning electron micrographs would indic ate.