Characterization of Local Strain Structures in Heteroepitaxial Ge1−x Sn x /Ge Microstructures by Using Microdiffraction Method

Abstract

In this study, we have examined the local growth of Ge1 − x Sn x heteroepitaxial layers on micrometer-scale-patterned Ge substrates with molecular beam epitaxy method. We have investigated the strain relaxation behavior and microscopic local strain structure in both Ge and Ge1 − x Sn x by using x-ray microdiffraction and finite element method calculation. We found that the anisotropic strain relaxation of embedded Ge1 − x Sn x layers preferentially occurs along the direction which is perpendicular to the stripe line. Microdiffraction method revealed that the elastic strain relaxation of the embedded Ge1 − x Sn x layer occurs near the edge region. We demonstrated that the uniaxial compressive strain of 0.2% is locally induced in Ge with Ge1 − x Sn x stressors.