Surface Structure of Semiconductors from Extended X-Ray Absorption Fine Structure

Extended x-ray absorption fine structure (EXAFS). Since EXAFS is an impurity-based structural probe, only foreign atoms not present in the semiconductor substrate can be studied. We review some of the basic structural problems and issues that can be addressed by EXAFS and summarize the physics of the measurement and its limitations. Typical examples of overlayers are Cl, I and Te on Si(111), Ge(111) and Si(100). Interface reactions are observed for tellurium on Ge(111) and Ni on Si(111).