The 3D strain landscape of Ge/SiGe multiquantum well stacks deposited on complex Si(001) virtual substrates.

We will use six-dimensional (6D) dark-field X-ray microscopy (DFXM) at the ID01 beamline to obtain a three-dimensional map of the strain landscape in parabolic Ge/Si1-xGex quantum wells (pQWs), which are deposited on GeSi virtual substrates, for applications in micro- and optoelectronics, including non-linear infrared optics, THz light generation and detection, and polariton physics. Specifically, our goal is to completely map the full strain tensor of these complex multilayered heterostructures with approximately 100 nm spatial resolution in all three dimensions. This detailed knowledge of the spatial distribution of lattice strain will allow us to refine our Finite Element Method (FEM) models to predict device performance and provide a fundamental understanding of plastic relaxation mechanisms in complex epitaxial heterostructures.