AVS 49th International Symposium
    Surface Science Monday Sessions
       Session SS2-MoA

Paper SS2-MoA9
The Domain Boundary Barrier on Intermixed SbGe(001)

Monday, November 4, 2002, 4:40 pm, Room C-110

Session: Nucleation & Growth of Metals on Oxides & Semiconductors
Presenter: E.I. Altman, Yale University
Authors: M. Li, Yale University
E.I. Altman, Yale University
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The nucleation and growth of epitaxial Ge structures on the intermixed SbGe(001) surface below the Sb segregation temperature was studied using scanning tunneling microscopy (STM). The drastic changes in the density, shape and size of the epitaxial structures as a function of Sb concentration in the Ge(001) substrate reveal the favored nucleation of Ge ad-dimers on Ge instead of Sb. The lack of Ge epitaxial structures on Sb suggests the enhanced surface diffusion on Sb-passivated surface. The Ge epitaxial structures always situate in the proximity of domain boundary between mainly bean-shaped Sb dimer domains and Ge dimer domains in the substrate. A one-directional repulsive potential barrier at the Sb-Ge domain boundary is proposed that inhibits the diffusion of Ge dimers from Ge domains to Sb domains and thus the nucleation of epitaxial structure is confined to Ge domains.