title: Dopant activation mechanism of Bi wire-δ-doping into Si crystal, investigated with wavelength dispersive fluorescence x-ray absorption fine structure and density functional theory.
abstract: We successfully characterized the local structures of Bi atoms in a wire-δ-doped layer (1/8 ML) in a Si crystal, using wavelength dispersive fluorescence x-ray absorption fine structure at the beamline BL37XU, in SPring-8, with the help of density functional theory calculations. It was found that the burial of Bi nanolines on the Si(0 0 1) surface, via growth of Si capping layer at 400 °C by molecular beam epitaxy, reduced the Bi-Si bond length from [Formula: see text] to [Formula: see text] Å. We infer that following epitaxial growth the Bi-Bi dimers of the nanoline are broken, and the Bi atoms are located at substitutional sites within the Si crystal, leading to the shorter Bi-Si bond lengths.
authors.affiliation: National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, 305-0044, Japan. Faculty of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8573, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Murata
authors.forename: Christopher
authors.initials: C
authors.lastname: Kirkham
authors.forename: Masaru
authors.initials: M
authors.lastname: Shimomura
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Nitta
authors.forename: Tomoya
authors.initials: T
authors.lastname: Uruga
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Terada
authors.forename: Koh-Ichi
authors.initials: KI
authors.lastname: Nittoh
authors.forename: David R
authors.initials: DR
authors.lastname: Bowler
authors.forename: Kazushi
authors.initials: K
authors.lastname: Miki