Adsorbate-induced restructuring of surfaces

The purpose of this article is to provide an overview of the surface structures of the clean surfaces of tetrahedrally coordinated semiconductors within the context of identifying the main features of their structural chemistry. We develop the point of view that the surface regions of these materials form twodimensional (2D) compounds whose bonding is constrained by the requirement of epitaxy with the substrate1 and that the coordination chemistry of these compounds differs from that of molecules or (three-dimensional) bulk solids in specific ways.2 Our coverage is confined to low-index faces. Specifically, our interest lies in the atomic geometries of ideal single-crystal regions of surfaces rather than in the morphology of surfaces with multiple domains, steps, or defects. Finally, although similar considerations have been applied to interpret oxide surface structures more generally,3 our attention herein is confined to tetrahedrally coordinated elemental and binary compound semiconductors. The traditional approach to constructing a review of this type is to consider each surface separately and to describe the structural studies4-11 or theoretical predictions of surface structure4-7,12,13 for each individual surface. This procedure offers an abundance of case histories, but little by way of guidance concerning how to make sense out of the wealth of Dr. Charles B. Duke is Senior Research Fellow at Xerox Corporation. Prior to holding this position, he was Deputy Director and Chief Scientist of the Pacific Northwest Division of the Battelle Memorial Institute and Affiliate Professor of Physics at the University of Washington. From 1972 to 1988 he held various technical and management positions at the Xerox Research Laboratories in Webster, NY and was an Adjunct Professor of Physics at the University of Rochester. During 1969−72, he was a Professor of Physics and member of the Materials Research Laboratory and Coordinated Science Laboratory at the University of Illinois in Urbana, IL, following six years as a staff member of the General Electric Corporate Research and Development Center in Schenectady, NY. He received his Ph.D. in physics from Princeton in 1963 following a B.S. Summa Cum Laude with distinction in mathematics from Duke University in 1959. He is a Fellow and an Honorary Member of the American Vacuum Society, a Fellow of the American Physical Society, a Fellow of the IEEE, and a life member of Sigma Xi. In 1977, Dr. Duke received the Medard W. Welch Award in Vacuum Science and Technology. In 1979 he served as President of the American Vacuum Society, and since 1979, as Treasurer of its Electronic Materials and Processing Division. He served on the Board of Directors of the American Vacuum Society for seven years. He was chairman of the 1977 Gordon Research Conference on the Chemistry and Physics of Solids and of the 1983 Gordon Research Conference on Organic Thin Films and Solid Surfaces. In 1981 he was named one of the ISI 1000 internationally most cited scientists. During 1985−86 he served as founding editor-in-chief of the Journal of Materials Research, the official journal of the Materials Research Society. From 1988 to 1992 and 1995 to 1997, he served (will be serving) on the council of the Materials Research Society, serving as Treasurer during 1991−2. In 1992 he was named editor of Surface Science. In 1993 he was elected to the National Academy of Engineering. He is serving on the Council of the American Physical Society during 1995−8. He was chairman of the Board of Editors of the Journal of Vacuum Science and Technology during 1976−82 and is currently a member of the editorial boards of Journal of Materials Research, Critical Reviews of Solid-State and Materials Sciences, Surface Science Reports, the Chemistry and Physics of Surfaces and Interfaces, and the Encyclopedia of Applied Physics. He served on the Governing Board of the American Institute of Physics from 1976 to 1987, being a member of the Board’s Executive Committee, Corporate Associates Committee, Educational Policy Committee, Journals Committee, and Committee on Public Education and Information. He has written over 350 papers on surface science, materials research, semiconductor physics, and the electronic structure of molecular solids, as well as a monograph on electron tunneling in solids. He is the editor of Surface Science: The First Thirty Years. 1237 Chem. Rev. 1996, 96, 1237−1259

Semiconductor Surface Reconstruction: The Structural Chemistry of Two-Dimensional Surface Compounds.

The use of synchrotron radiation techniques in the characterization of strained semiconductor heterostructures and thin films

Adsorption and adsorbate-induced restructuring: a LEED perspective

Charging occurs in ESCA because a non-conductive sample does not have sufficient de-localized, conduction band electrons available to neutralize the charged centers that build from clustering of the positive holes created with the photoelectron and/or Auger electron ejection. As a result, a positive outer (or Volta) potential builds near the materials surface, producing a retardation or “drag” on the outgoing electrons. This retardation appears in the electron spectrum as an additional positive shift, either subtracting from the uncharged kinetic energy or, correspondingly, adding to the “normal” binding energies of the outgoing electrons. Compared to most of the features in these experiments, charging shifts are often relatively slow in their establishment; thus, in the time frame of a normal experiment, charging has both dynamic and static component. Charging also depends upon the macrosurface and bulk morphology of the measured system, as well as its chemistry, and microstructre. As indicated,...

Advances in the Application of X-Ray Photoelectron Spectroscopy (ESCA) Part II. New Methods

This review critically compiles all surface structures derived from low‐energy electron diffraction (LEED) crystallography reported in the referred literature prior to January 1986. Over 250 investigations have been analyzed covering all types of surfaces including clean and adsorbate‐covered metal, semiconductor and other nonmetallic substrates. Particular attention is paid to developing and applying objective criteria that allow an estimation of the reliability of a particular structural determination. The important experimental and theoretical aspects of such investigations have been extracted into easily understood tabular form supplemented by many figures and ancillary tables and complete references. It is hoped that this compilation will provide a valuable

Critical Compilation of Surface Structures Determined by Low‐Energy Electron Diffraction Crystallography

This review critically compiles all surface structures derived by ion‐scattering techniques reported in the refereed literature prior to January 1988. They are compared with the more extensive low‐energy electron diffraction database reported previously [J. Phys. Chem. Ref. Data 16, 953 (1957)]. These investigations cover all types of surfaces including clean and adsorbate‐covered metal, semiconductor, and other nonmetallic substrates. The important experimental and theoretical aspects of such investigations have been extracted into easily understood tabular form supplemented by many figures and ancillary tables and complete references. It is hoped that this compilation will provide a valuable resource both for the surface science specialist and for those nonspecialists in other areas who need surface crystallographic data.

Critical Compilation of Surface Structures Determined by Ion Scattering Methods

This review critically compiles all surface structures derived by the technique of surface extended x‐ray absorption fine‐structure spectroscopy (SEXAFS) and surface electron energy loss fine‐structure spectroscopy (SEELFS) reported in the refereed literature prior to January 1990. They are compared with the extensive low‐energy electron diffraction (LEED) [P. R. Watson, J. Phys. Chem. Ref. Data 16, 953 (1987)] and ion scattering databases [P. R. Watson, J. Phys. Chem. Ref. Data 19, 85 (1990)] previously reported. The important experimental and theoretical aspects of such investigations have been extracted into easily understood tabular form supplemented by many figures and ancillary tables and complete references. It is hoped that this compilation will provide a valuable resource both for the surface science specialist and for those nonspecialists in other areas who need surface crystallographic data.

Critical Compilation of Surface Structures Determined by Surface Extended X‐Ray Absorption Fine Structure (SEXAFS) and Surface Extended Electron Energy Loss Spectroscopy (SEELFS)

Philip R. Watson

Papers

Critical Compilation of Surface Structures Determined by Low‐Energy Electron Diffraction Crystallography

Critical Compilation of Surface Structures Determined by Ion Scattering Methods

Critical Compilation of Surface Structures Determined by Surface Extended X‐Ray Absorption Fine Structure (SEXAFS) and Surface Extended Electron Energy Loss Spectroscopy (SEELFS)