X-ray study of misfit strain relaxation in lattice-mismatched heterojunctions

Abstract
High‐resolution x‐ray diffraction measurements have been carried out in AlxGa1−xAs and InxGa1−xAs grown by the molecular beam epitaxy method on (001) GaAs substrates. The thin epitaxial layers in these lattice‐mismatched semiconductor single heterojunctions are uniformly distorted and there is an elastic limit for large x. The epitaxial layer is affected by a thick substrate even over the elastic limit, i.e., the epitaxial layer still shows a strained state beyond the elastic limit. The relationship between the misfit strain and the lattice distortion is discussed.