Combined theoretical and experimental investigation of the adsorption geometry of Ga on Si(100) at low coverage

Journal Article · Sun Jan 15 00:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.1593· OSTI ID:6660935

Tang, S; Freeman, A J ^[1]; Qian, Y ^[2]; Franklin, G E ^[3]; Bedzyk, M J ^[4]

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1. Materials Research Center, Northwestern University, Evanston, Illinois 60208 (United States) Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)
2. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)
3. Department of Physics, Harvard University, Cambridge, Massachusetts 02142 (United States)
4. Materials Research Center, Northwestern University, Evanston, Illinois 60208 (United States) Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

The atomic and electronic structures of Ga chemisorption on the Si(100)-(2[times]1) at low coverage have been investigated by a combined molecular-cluster total-energy and atomic-force approach and x-ray standing-wave (XSW) measurements. Four possible Ga-dimer adsorption geometries are calculated using cluster models with up to 77 atoms. By comparing the total energies for these optimized geometries, it is found that Ga dimers are centered at valley bridge sites with the Ga-dimer bond oriented parallel to the underlying Si-dimer bonds---a geometry strongly supported by XSW measurements of the Si(100)-(2[times]2)-Ga surface structure. The calculated Ga-dimer height above the ideal Si(100) is in excellent agreement with the XSW result. The stability of this parallel-dimer model is explained through the bonding between Ga-Si and Si-Si and by analyzing the Si-surface distortion when Ga is present.

• DOE Contract Number: W-31-109-ENG-38; AC02-76CH00016; FG02-89ER45399
• OSTI ID: 6660935
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 51:3; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM
CHEMISORPTION
ELECTRONIC STRUCTURE
SILICON
SORPTIVE PROPERTIES
BAND THEORY
DIMERIZATION
EPITAXY
MOLECULAR CLUSTERS
CHEMICAL REACTIONS
ELEMENTS
METALS
POLYMERIZATION
SEMIMETALS
SEPARATION PROCESSES
SORPTION
SURFACE PROPERTIES
360606* - Other Materials- Physical Properties- (1992-)