Residual strain analysis of In_xGa_{1- x}As/GaAs heteroepitaxial layers

In_xGa_1-xAs/GaAs heteroepitaxial layers, having various compositions and thicknesses, have been analyzed using the high resolution x-ray diffraction technique which has revealed that the residual strain in the epilayers is strongly dependent on both the epilayer composition as well as thickness. However, published theoretical models concerning residual strain in In_xGa_1-xAs/GaAs epilayers suggest that the extent of relaxation is independent of epilayer composition. In this letter, we present an empirical model based on our findings which can be used to accurately predict the extent of lattice relaxation in In_xGa _1-xAs/GaAs epilayers which includes the influence of epilayer composition.