X-ray reflectivity and photoelectron spectroscopy study of interdiffusion at the Si/Fe interface

We have investigated the nature of silicon on iron interface in electron beam deposited Fe/Si bilayers, with various iron and silicon thicknesses. The Fe and Si layer thicknesses are varied from 30 to 330 angstrom and 20 to 86 angstrom, respectively. Grazing incidence x-ray reflectivity and photoelectron spectroscopy measurements were carried out on these samples to determine interface characteristics. Si on Fe (Si_Fe) interlayer thickness, roughness, and composition do not depend on the thickness of Fe and Si. The thickness of the interlayer is around 13 angstrom. A systematic variation in silicide concentration across this interface is observed by x-ray photoelectron spectroscopy measurement. Change in the density of states in valence band across this interface is also observed by ultraviolet photoelectron measurement. (c) 2006 American Institute of Physics.