title: Indications of chemical bond contrast in AFM images of a hydrogen-terminated silicon surface.
abstract: The origin of bond-resolved atomic force microscope images remains controversial. Moreover, most work to date has involved planar, conjugated hydrocarbon molecules on a metal substrate thereby limiting knowledge of the generality of findings made about the imaging mechanism. Here we report the study of a very different sample; a hydrogen-terminated silicon surface. A procedure to obtain a passivated hydrogen-functionalized tip is defined and evolution of atomic force microscopy images at different tip elevations are shown. At relatively large tip-sample distances, the topmost atoms appear as distinct protrusions. However, on decreasing the tip-sample distance, features consistent with the silicon covalent bonds of the surface emerge. Using a density functional tight-binding-based method to simulate atomic force microscopy images, we reproduce the experimental results. The role of the tip flexibility and the nature of bonds and false bond-like features are discussed.
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1.|National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Hatem
authors.initials: H
authors.lastname: Labidi
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1.|National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Koleini
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1.
authors.forename: Taleana
authors.initials: T
authors.lastname: Huff
authors.affiliation: National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Mark
authors.identifier: 0000-0002-7488-3032
authors.initials: M
authors.lastname: Salomons
authors.affiliation: National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Martin
authors.initials: M
authors.lastname: Cloutier
authors.affiliation: National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Jason
authors.initials: J
authors.lastname: Pitters
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1.|National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta, Canada T6G 2M9.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Wolkow