High Sensitive Imaging of Atomic Arrangement of Ge Clusters Buried in a Si Crystal by X-ray Fluorescence Holography

Abstract

We have performed high sensitive imaging of the atomic arrangement of Ge buried in a Si crystal as Ge clusters using the internal detector scheme of X-ray fluorescence holography. The atomic arrangement of Ge buried in a Si crystal is expected to have the strained diamond structure. We have measured holograms of a thin Si/Ge multilayer film composed of thin Si layers and Stranski–Krastanov Ge islands using a crystal analyzer in combination with synchrotron radiation. The atomic arrangement reconstructed from the holograms shows that the Ge islands are indeed of the diamond structure. Comparison of atomic arrangements reconstructed from experimental and simulated holograms allows us to determine the average lattice constant of the Ge islands. The lattice constant obtained shows that the Ge islands are partially relaxed in Si matrix lattice.