IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Semiconductors Thursday Sessions
       Session SC+SS-ThA

Paper SC+SS-ThA10
The Effect of an As-flux on the Surface Structure During the Growth of Si on GaAs(001) c(4x4)

Thursday, November 1, 2001, 5:00 pm, Room 111

Session: Semiconductor Surface Structure
Presenter: T.A.R. Müller, University of Minnesota
Authors: T.A.R. Müller, University of Minnesota
B.D. Schultz, University of Minnesota
H.H. Farrell, Idaho National Engineering and Environmental Laboratory
A. Franciosi, Universita' di Trieste, Italy and Univ. of Minnesota
C.J. Palmstrom, University of Minnesota
Correspondent: Click to Email
Despite the experimental discovery that two atomic monolayers of Si co-deposited with an As-flux are effective in decreasing the barrier height in the Al/Si/GaAs system by 0.5eV, the detailed interfacial atomic structures have yet to be determined. The present work focuses on understanding the evolution of the structure within the first few atomic monolayers caused by the deposition of Si with and without an As-flux on the GaAs(001) c(4x4) surface by MBE. In-situ Reflection High Energy Electron and Low Energy Electron Diffraction, work function measurements, X-ray photoelectron and Auger electron spectroscopies and Scanning Tunneling Microscopy have been used to determine the properties and composition of the surface as a function of Si coverage. For the co-deposition of Si with As, the measured work function increases up to a Si-coverage of 0.5 ML and the intensity ratio of the Ga and As 3d photoemission peaks decreases. However, for Si deposited at pressures <10@super -10@ mbar, the work function shows variations of <50meV from the starting surface and the XPS peak intensity ratio increases for a coverage of 0.5 ML. Atomistic models consistent with electron counting, surface symmetry, work function and composition changes will be presented.