Strained Pseudomorphic Ge1–xSnx Multiple Quantum Well Microdisk Using SiNy Stressor Layer

Abstract

We demonstrate tensile-strained pseudomorphic Ge0.934Sn0.066/Ge quantum wells in a microdisk resonator using silicon nitride stressor layers. The hydrostatic and biaxial strain distributions are studied through finite element modeling, while confocal Raman spectroscopy shows local biaxial strain transfers as high as 1.1% at freestanding microdisk edges. These strains are sufficient to overcome the original compressive strain in Ge0.934Sn0.066 epitaxy and reach a direct band gap according to deformation potential theory. A red-shift in microdisk photoluminescence confirms the reduced band gap energies in response to tensile strain and suggests an average biaxial strain transfer of 0.55%.