Journal of Vacuum Science & Technology A, Vol.13, No.6, 2772-2780, 1995
Chemical-Reactions of Triethylantimony on GaAs(100)
The surface chemistry of triethylantimony was studied on GaAs(100) using thermal desorption spectroscopy, static secondary ion mass spectroscopy, and x-ray photoelectron spectroscopy. Triethylantimony is reversibly adsorbed following exposures at 160 K. The saturation coverage at 160 K is approximately 0.3 monolayers, Following triethylantimony exposure at 330 K, ethylene, the major hydrocarbon reaction product, desorbs from the GaAs(100) surface during thermal desorption spectroscopy experiments with a peak temperature of 569 K. This indicates a beta-hydride elimination reaction is responsible for the elimination of ethyl groups from the surface, Additionally, a small amount of ethyl radicals desorb from the surface. Our results indicate that ethyl groups migrate to Ga sites and then undergo a beta-hydride elimination reaction at these sites. For saturation coverage (0.3 monolayers), 90% of the triethylantimony is irreversibly adsorbed. Exposures at 675 K led to adsorbed Sb atoms as well as GaSb formation, The reactive sticking coefficient of triethylantimony is low, 4x10(-4), and decreases as the surface becomes Sb rich. Eventually adsorption of triethylantimony ceases at 675 K, indicating self-limiting adsorption.
Keywords:VAPOR-PHASE EPITAXY;SURFACE ELECTRONIC-STRUCTURE;III-V-SEMICONDUCTORS;SB OVERLAYERS;PHOTOELECTRON-SPECTROSCOPY;110 SURFACES;GROWTH;INSB;DEPOSITION;TRIISOPROPYLANTIMONY