Formation of the Fe-stepped Si(100) interface as studied by electron spectroscopy

Fe thin films have been deposited on stepped Si(100) surfaces under ultra high vacuum (uhv) conditions and investigated by X-ray-induced Auger electron spectroscopy (XAES) and photoelectron spectroscopy (XPS). The results suggest that even at room temperature a slight Si interdiffusion occurs into the Fe layers, giving rise to an intermixed FeSi phase. With increasing coverage (Θ ⩾ 15 A ) the surface composition becomes Fe richer, and an almost pure Fe film grows on top of the interfacial compound.