Photoemission study of the CoSi/sub 2/(111)--Si surface
Epitaxial CoSi/sub 2/ terminated with a thin Si bilayer has been studied by synchrotron radiation photoemission. This well-defined surface phase of CoSi/sub 2/ is obtained by high-temperature annealing in the range 450--650 /sup 0/C. The samples used were prepared by molecular-beam epitaxy techniques with a film thickness of /similar to/800 A on Si(111) substrates and capped with a /similar to/100 A film of a-Si to act as an oxide barrier while samples were transferred to the photoemission chamber. The surfaces studied by photoemission were prepared by careful sputtering to remove the oxide and a-Si layer and then anealed to /similar to/450--650 /sup 0/C for 1 min. Photoemission spectra were taken with total resolution in the range 200--237 meV and show evidence for four spin--orbit doublets. Our samples and results are somewhat different from those of previous studies of thin CoSi/sub 2/ films or studies of bulk CoSi/sub 2/ samples. We find three surface Si(2p) components: one shifted to higher binding energy and two shifted below the main Si(2p) spin-orbit doublet in CoSi/sub 2/. We find the Si(2p/sub 3/2/ ) energy in CoSi/sub 2/ is 99.40 eV measured with respect to the Fermi level; the three surface-shifted Si components are at -0.75, 0.17, and -0.18 eV relative to the main component in order of decreasing intensity and thus layer distance from the surface. A structural model previously proposed for thin CoSi/sub 2/ layers is shown to be qualitatively consistent with these results.
- Research Organization:
- ATandT Bell Laboratories, Murray Hill, New Jersey 07974
- OSTI ID:
- 6336280
- Journal Information:
- J. Vac. Sci. Technol., A; (United States), Vol. 7:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COBALT SILICIDES
MOLECULAR BEAM EPITAXY
SURFACE PROPERTIES
SILICON
COATINGS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
EMISSION SPECTROSCOPY
EXPERIMENTAL DATA
INTERFACES
PHOTOEMISSION
SUBSTRATES
THIN FILMS
COBALT COMPOUNDS
DATA
ELEMENTS
EMISSION
EPITAXY
FILMS
INFORMATION
NUMERICAL DATA
SECONDARY EMISSION
SEMIMETALS
SILICIDES
SILICON COMPOUNDS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
360602* - Other Materials- Structure & Phase Studies