AVS 49th International Symposium
    Surface Science Friday Sessions
       Session SS-FrM

Paper SS-FrM11
Buffer-Layer-Assisted Nanostructure Growth Via Two-Dimensional Cluster-Cluster Aggregation

Friday, November 8, 2002, 11:40 am, Room C-110

Session: Self-Assembly at Surfaces
Presenter: V.N. Antonov, University of Illinois at Urbana-Champaign
Authors: C.L. Haley, University of Illinois at Urbana-Champaign
V.N. Antonov, University of Illinois at Urbana-Champaign
J.H. Weaver, University of Illinois at Urbana-Champaign
Correspondent: Click to Email
Physical vapor deposition of metals onto Xe multilayers at 20 K produces three-dimensional clusters. Warming to room temperature desorbs the Xe and causes coalescence. The net motion, and hence the extent of coalescence, depends on the buffer layer thickness. Using transmission electron microscopy, we determined the spatial distribution of these nanostructures as a function of Xe thickness. Using the scaling concepts of cluster-cluster aggregation, we found a fractal dimension ranging from 1.42 to 1.72 for initial fractional coverages of 0.04 to 0.20, consistent with Monte Carlo simulations of two-dimensional diffusion-limited cluster aggregation (DLCA). Both the number density and the weighted average nanostructure size show a power law dependence on the Xe layer thickness, where the latter plays the role of time in DCLA modeling. These relationships facilitate the design of nanostructure arrays generated by desorption-assisted coalescence.