AVS 45th International Symposium
    Surface Science Division Tuesday Sessions
       Session SS1-TuA

Paper SS1-TuA10
A Scanning Tunneling Microscopy Study of [(t-butyl)GaS]@sub 4@ Adsorption on GaAs

Tuesday, November 3, 1998, 5:00 pm, Room 308

Session: Semiconductor Surface Chemistry
Presenter: R.I. Pelzel, University of California, Santa Barbara
Authors: R.I. Pelzel, University of California, Santa Barbara
B.Z. Nosho, University of California, Santa Barbara
B. Fimland, Norwegian University of Science and Technology, Norway
W.H. Weinberg, University of California, Santa Barbara
Correspondent: Click to Email
Gallium sulfide layers grown using the single-source molecular precursor [(t-butyl)GaS]@sub 4@ have shown promise in providing long-term chemical and electrical surface passivation for GaAs.@footnote 1@ With this in mind, we have conducted an ultrahigh vacuum investigation of the initial stages of [(t-butyl)GaS]@sub 4@ adsorption on GaAs(100)-(2x4) and (4x2). Adsorbing [(t-butyl)GaS]@sub 4@ at elevated surface temperatures (> 650 K) results in carbon-free adsorption as judged by Auger electron spectroscopy. For low coverages on both reconstructions, low energy electron diffraction (LEED) data indicate that both the (2x4) and the (4x2) surface reconstructions remain intact. Scanning tunneling microscopy (STM) images show that the adsorption of submonolayer coverages of [(t-butyl)GaS]@sub 4@ disorders the surface reconstructions. Subsequent deposition results in further disordering until a coverage of approximately 1 ML where a weak (2x1) LEED pattern is observed. The (2x1) surface order is not observable in STM prior to annealing to a temperature of approximately 780 K. The (2x1) surface observed using STM following annealing is well-ordered, and images will be presented. Possible models of GaS growth achieved using [(t-butyl)GaS]@sub 4@ will be discussed. @FootnoteText@ @footnote 1@ P. P. Jenkins, A. N. MacInnes, M. Tabib-Azar, and A. R. Barron, Science 263, 1751 (1994); A. N. MacInnes, M. B. Power, A. R. Barron, P. P. Jenkins, and A. F. Hepp, Appl. Phys. Lett. 62, 771 (1993); M. Tabib-Azar, S. Kang, A. N. MacInnes, M. B. Power, A. R. Barron, P. P. Jenkins, and A. F. Hepp, Appl. Phys. Lett. 63, 625 (1993).