Fractality aspects during agglomeration of solid-phase-epitaxy Co-silicidethin films

Morphology changes of thin CoSi2 films close to the agglomeration threshold have been investigated by in situ scanning tunneling microscopy. Films pri or to agglomeration reveal a strong morphology anisotropy where depending o n direction the roughness correlation g(r) changes from logarithmic [g(r)si milar to ln r] to power law [g(r)similar tor(2c) with c approximate to0.78] at short lateral length scales (r less than or equal to 30 nm). Such an an isotropy reflects the complex nature of diffusion process associated with t he original anisotropic substrate surface and the formation of pinhole netw orks. Annealing above the agglomeration threshold (>600 degreesC), the pinh ole network becomes connected breaking the CoSi2 film into aggregates with a two-dimensional fractal dimension D approximate to1.66 which is close to predictions of diffusion limited aggregation within the mean field theory p rediction D=(d(2) + 1)/(d + 1) for d = 2, and invasion percolation models. (C) 2000 American Vacuum Society. [S0734-211X(00)04605-9].