Structural analysis of the. beta. -SiC(100)- c (2 times 2) surface reconstruction by automated tensor low-energy electron diffraction

Journal Article · Fri Nov 15 04:00:00 EST 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.11159· OSTI ID:5162265

Powers, J M; Wander, A; Rous, P J; Van Hove, M A; Somorjai, G A ^[1]

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1. Materials Sciences Division, Center for Advanced Materials, Lawrence Berkeley Laboratory, University of California, Berkeley, California (USA) Department of Chemistry, University of California, Berkeley, California (USA)

The atomic structure of the {beta}-SiC(100)-{ital c}(2{times}2) surface was analyzed using dynamical calculations of low-energy electron-diffraction intensities. The {ital c}(2{times}2) surface was prepared in ultrahigh vacuum by two different methods. The first utilized the removal of surface silicon by high-temperature annealing in ultrahigh vacuum. The second route utilized the deposition of surface carbon by exposing the stoichiometric (2{times}1) surface at 1125 K to C{sub 2}H{sub 4}. Our results showed that both methods produced a surface terminated with C{sub 2} groups in staggered silicon bridge sites. Weak silicon dimer bonds were found in the second atomic layer of the {ital c}(2{times}2) surface produced by silicon sublimation, but not for the {ital c}(2{times}2) surface produced by C{sub 2}H{sub 4} exposure. We postulate that hydrogen, released by the thermal decomposition of C{sub 2}H{sub 4}, saturated silicon dangling bonds in the second atomic layer, suppressing dimer formation.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5162265
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:20; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ANNEALING
CARBIDES
CARBON COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
DIMERS
ELECTRON DIFFRACTION
HEAT TREATMENTS
IMAGE PROCESSING
PROCESSING
SCATTERING
SILICON CARBIDES
SILICON COMPOUNDS
SURFACE PROPERTIES
ULTRAHIGH VACUUM
VERY HIGH TEMPERATURE