Showing papers by "Tolek Tyliszczak published in 1991"

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

Abstract: 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 of mixing of the Si and Ge layers is a function of the growth temperature. A weak polarization dependence of the Ge K‐edge EXAFS is observed. The initial quantitative analysis provides estimates of intermixing in the thinnest layers which are compatible with results of complementary Raman measurements.

Interface Structure of Ge/Si Superlattices Determined by X-Ray Absorption Fine Structure

Abstract: We illustrate the usefulness of the Extended X-ray Absorption Fine Structure (EXAFS) technique to determine the amount of interface mixing and strain condition in the study of (SimGen)p short-period superlattices. It is found that for n 4, the Ge-Ge bond length and the number of Si-Ge nearest neighbours increase significantly consistent with partial relaxation and interdiffusion. Raman scattering spectroscopy and x-ray reflectometry measurements are also presented and are consistent with the conclusions of the EXAFS analysis.