Strain effect on interatomic distances in InGaAs/InP epitaxial layers

Using X-ray absorption fine structure spectroscopy (XAFS) with synchrotron radiation, we have performed an in-depth study on the strain-induced deformations in the first three coordination shells of (InGa)As epilayers deposited on InP(0 0 1). In order to obtain information on the second and third coordination shells, we have exploited the directional sensitivity of XAFS. All the experimental results can be reproduced by applying the macroscopic strain matrix to the local scale, independent of the chemical nature of the interatomic correlations.