Atomic structure of the Sb-terminated Si(111) surface:: A photoelectron diffraction study -: art. no. 205326

The deposition under certain conditions of antimony on a Si(111)7x7 surface removes the 7x7 reconstruction, producing a passivated Si(111)-(3root x root3)R30degrees-Sb (1 monolayer) surface. In this work, a quantitative determination of the atomic structure of this reconstruction using photoelectron diffraction is reported. In particular, high-energy photoelectron diffraction (forward-focusing regime) has been applied to investigate the stacking sequence of the atomic layers of the silicon substrate, and scanned-energy photoelectron diffraction (backscattering regime) has been used to determine quantitatively the atomic structure of the surface. Our results show that the formation of a (root3 x 3root)R30degrees phase produces a bulklike-terminated Si(111)1x1 substrate free of stacking faults. Regarding the atomic structure of the interface, this study strongly favors the T4-site milkstool model over the H3 one.