Abstract
Metals thermally evaporated onto warm insulating substrates evolve to the thin-film state via the morphological sequence: compact islands, elongated islands, percolation, hole filling, and finally the thin-film state. The coverage at which the metal percolates () is often considerably higher than that predicted by percolation models, such as inverse swiss cheese or lattice percolation. Using a simple continuum model, we show that high-’s arise naturally in thin films that exhibit a crossover from full coalescence of islands at early stages of growth to partial coalescence at later stages. In this interrupted-coalescence model, full coalescence of islands occurs up to a critical island radius , after which islands overlap, but do not fully coalesce. We present the morphology of films and the critical area coverages generated by this model.
- Received 17 September 1991
DOI:https://doi.org/10.1103/PhysRevB.44.13163
©1991 American Physical Society