Study of solid/solid interface by transmitted x-ray reflectivity

In this paper, we demonstrate investigations of metal thick layer/semiconductor interfaces (Au/Si and Ga/GaAs) by x-ray reflectivity under transmission geometry (TXR), which could not be performed by conventional x-ray reflectivity due to the macroscopic thickness and surface roughness of the overlayers. We obtain precise electron density by using the two maxima in diffuse scattering of TXR caused by the Fresnel transmission function (the so-called Yoneda wings). From in sitter TXR measurements of Ga/GaAs with elevating temperature, the onset of structural variation at the interface is found to be 520 K. Such an interfacial variation at an extraordinarily low temperature agrees with an et sitter SEM study of an etched As surface. Copyright (C) 2005 John Wiley Sons, Ltd.