title: Homogeneous crystalline FeSi2 films of c (4 × 8) phase grown on Si (111) by reactive deposition epitaxy.
abstract: The growth of iron silicides on Si (111) using reactive deposition epitaxy method was studied by scanning tunneling microscopy and X-ray photoelectron spectroscopy (XPS). Instead of the mixture of different silicide phases, a homogeneous crystalline film of c (4 × 8) phase was formed on the Si (111) surface at approximately 750°C. Scanning tunneling spectra show that the film exhibits a semiconducting character with a band gap of approximately 0.85 eV. Compared with elemental Fe, the Fe 2p peaks of the film exhibit a lower spin-orbit splitting (-0.3 eV) and the Fe 2p3/2 level has a smaller full-width at half maximum (-0.6 eV) and a higher binding energy (+0.3 eV). Quantitative XPS analysis shows that the c (4 × 8) phase is in the FeSi2 stoichiometry regime. The c (4 × 8) pattern could result from the ordered arrangement of defects of Fe vacancies in the buried Fe layers.
authors.affiliation: Center for Analysis and Testing, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China. zqzou@sjtu.edu.cn.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Zou
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Sun
authors.forename: Gao-Ming
authors.initials: GM
authors.lastname: Shi
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Liu
authors.forename: Xu
authors.initials: X
authors.lastname: Li