Thermal vibration amplitudes and structure of As on Si(001)

G. E. Franklin; E. Fontes; Y. Qian; M. J. Bedzyk; J. A. Golovchenko; J. R. Patel

doi:10.1103/PhysRevB.50.7483

Thermal vibration amplitudes and structure of As on Si(001)

G. E. Franklin, E. Fontes, Y. Qian, M. J. Bedzyk, J. A. Golovchenko, and J. R. Patel

Phys. Rev. B 50, 7483 – Published 15 September 1994

Abstract

Using the x-ray standing-wave method, we have measured directly the thermal vibration amplitudes 〈 $u^{2}$ 〉 of symmetric As dimers on a Si(001)-(2×1) surface. For sample temperatures in the range 300 K ≤T≤650 K, the results are Debye-like. Above 650 K 〈 $u^{2}$ 〉 varies more rapidly, indicating the onset of defect-mediated processes. We also found that at room temperature the bond length of the As dimers is 2.58±0.04 Å and that, independent of temperature, they sit 1.40±0.01 Å above the top bulk-extrapolated silicon (004) plane. These results provide a critical test for theoretical structure calculations.

Received 14 April 1994

DOI:https://doi.org/10.1103/PhysRevB.50.7483

Authors & Affiliations

G. E. Franklin

Department of Physics, Harvard University, Cambridge, Massachusetts 02138

E. Fontes

Cornell High-Energy Synchrotron Source, Ithaca, New York 14853

Y. Qian and M. J. Bedzyk

Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439

J. A. Golovchenko