Structure, twinning behavior, and interface composition of epitaxial Si(111) films on hex-Pr2O3(0001)/Si(111) support systems.

The structure of epitaxial Si overlayers on a hexagonal Pr₂O₃(0001)/Si(111) substrate system was investigated by a combination of x-ray reflectivity, specular x-ray diffraction, off-specular grazing incidence x-ray diffraction, and transmission electron microscopy. The Pr₂O₃ film grows on the Si(111) substrate in the (0001)-oriented hexagonal phase matching the in-plane symmetry by aligning the [1010] oxide along the bulk [011] Si direction. The hexagonal Pr₂O₃(0001) surface induces the growth of [111]-oriented cubic-Si epilayers exhibiting a microstructure which is composed of two types of domains. The ABC-stacked domains preserve the crystal orientation of the substrate, while the CBA-stacked domains are rotated by 180°. A depth profile of the chemical composition of the epi-Si/Pr₂O₃/Si(111) material stack was recorded by combining ion-beam sputtering techniques with x-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]