Hostname: page-component-7bb8b95d7b-l4ctd Total loading time: 0 Render date: 2024-09-18T18:04:53.934Z Has data issue: false hasContentIssue false
  • English
  • Français

Dissociative Adsorption and Desorption Processes of Cl2/GaAs(001) Surfaces

Published online by Cambridge University Press:  10 February 2011

Takahisa ohno
Takahisa ohno*
Affiliation:
National Research Institute for Metals, Tsukuba-shi, Ibaraki 305, Japan
Get access

Abstract

The energetics of both dissociative adsorption of C12 molecules on reconstructed GaAs(001) surfaces and desorption of chlorides from the chlorinated GaAs(001) surfaces is theoretically investigated, employing the first-principles pseudopotential density-functional approach within the generalized gradient approximation. On the Ga-rich GaAs(001)-(4x2) surface a C12 molecule is found to dissociate with no potential barrier over a Ga dimer and the Ga dimer is also simultaneously broken upon chlorination, resulting in formation of GaC1 with two backbonds to the As layer below. The desorption energy of a GaCl molecule is smaller than that of a Cl atom, although the former involves breaking two Ga-As backbonds and the latter involves the breakup of one Ga-Cl bond. On the As-rich (2x4) surface, the dissociation of a C12 molecule over an As dimer is an activated process and the As dimer is not broken by the Cl adsorption. The desorption energy of a AsCI molecule is larger than that of a Cl atom. The obtained results are consistent with recent experiments such as temperature-programmed desorption measurements.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 408: Symposium P – Materials Theory, Simulations, and Parallel Algorithms , 1995 , 451
Copyright
Copyright © Materials Research Society 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Ludviksson, A., Xu, M., and Martin, R. M., Surf. Sci. 277, 282 (1992).Google Scholar
[2] Teter, M.P., Payne, M.C., and Allan, D.C., Phys. Rev. B 40, 12255 (1989).Google Scholar
[3] Perdew, J.P., Chevary, J.A., Vosko, S.H., Jackson, K.A., Pederson, M.R., Singh, D.J., and Fiolhais, C., Phys. Rev. B46, 6671 (1992).Google Scholar
[4] Hammer, B., Jacobsen, K.W., and Norskov, J.K., Phys. Rev. Lett. 70, 3971 (1993).Google Scholar
[5] Kleinman, L. and Bylander, D.M., Phys. Rev. Lett. 48, 1425 (1982).Google Scholar
[6] Pashley, M.D., Haberern, K.W., Friday, W., Woodall, J.M., and Kirchner, P.D., Phys. Rev.Lett. 60, 2176 (1988).Google Scholar
[7] Ohno, T., Phys. Rev. Lett. 70, 631 (1993).Google Scholar
[8] Ohno, T. and Shiraishi, K., Phys. Rev. B 42, 11194 (1990); K. Shiraishi, J. Phys. Soc. Jpn.59, 3455 (1990).Google Scholar