Formation and characterization of locally strained Ge1- x Sn x /Ge microstructures

In this study, we have examined the formation of uniaxially strained Ge microstructures with embedded Ge1- x Sn x epitaxial layers and the microscopic local strain structure in Ge and Ge1- x Sn x using synchrotron X-ray microdiffraction and the finite element method. We achieved local heteroepitaxial growth of Ge0.947Sn0.053 layers on the Ge recess regions. Microdiffraction measurements reveal that an average uniaxial compressive strain of 0.19% is induced in Ge locally with Ge1- x Sn x stressors. In addition, we found that the Sn precipitation near the Ge1- x Sn x /Ge(001) interface occurs after post-deposition annealing at 500 degree C without the introduction of dislocation. It is considered that the local Sn precipitation occurs preferentially due to the larger residual stresses near the Ge1- x Sn x /Ge interface.