Ordered domain lateral location, symmetry, and thermal stability in Ge:Si islands

Abstract

International audienceCompositional atomic ordering is a crucial issue in the epitaxial growth of nanoparticles and thin films. Here, we report on a method based on x-ray diffuse scattering close to basis forbidden Bragg reflections to infer the lateral location, the symmetry, and the thermal stability of ordered domains in GeSi dome-shaped islands on Si(001) after growth and during annealing. We observe that atomic ordering does not disappear after annealing, demonstrating that it is a resilient metastable phenomenon. (C) 2015 AIP Publishing LLC

Temperature evolution of defects and atomic ordering in Si1−xGex islands on Si(001)

“…To evaluate the average size of the ordered alloy domains inside the SiGe islands, we suppose that the islands are only composed of at least two ordered domains, which are separated by an antiphase boundary along the [010] or [100] direction. As the same diffraction pattern is observed for all {200} types of reflection, 36 this implies that the model of domain distribution must follow a four-fold symmetry in real space, such as the one from steeper (high index) facets, with antiphase boundaries along the h010i directions to create the observed minimum at q a ¼ 0. By contrast, no minimum of intensity is observed along the radial q r direction, which is strain sensitive.…”

Synthesis and Characterization of Nano-to Meso Scale Ordered Structures in the Si1-xGex Alloy System

“…Ordering in the Si-Ge system is not limited to thin films -ordering has also been reported in SiGe strain-induced 3D islands. [82][83][84][85][86] The ordering in these self-assembled islands are different Proper quantification of the order parameter in these SiGe alloys is very important for comparison work. Surprisingly, only a few papers have accurately and correctly quantified the order parameter in these alloys.…”