X-ray absorption fine structure studies of buried Ge–Si interfaces

We have used Ge K-edge x-ray absorption fine structure (EXAFS) and a gas ionization detector with sample rotation to study the local environment of nominally pure Ge layers buried in single crystal Si. The samples were grown by molecular-beam epitaxy on Si(100). The dependence on thickness, number of Ge layers and growth temperature is explored. Considerable sensitivity to the quality of the epitaxial growth is observed. For instance the degree …