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 30to330A and 20to86A, respectively. Grazing incidence x-ray reflectivity and photoelectron spectroscopy measurements were carried out on these samples to determine interface characteristics. Si on Fe (SiFe) interlayer thickness, roughness, and composition do not depend on the thickness of Fe and Si. The thickness of the interlayer is around 13A. 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.