Abstract
We study the second layer nucleation on top of islands emerging during epitaxial growth of thin films. By employing kinetic Monte Carlo simulations we determine the critical island radius upon which small stable nuclei form in the second layer. We find that the dependence of on the additional step edge barrier (Schwoebel barrier) is not in accordance with existing theories. Scaling arguments are presented which explain how depends on as well as on adatom diffusion rates and on the incoming atom flux. Based on the theory, the occurrence of smooth layer-by-layer growth as opposed to rough multilayer growth is discussed.
- Received 24 June 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.3490
©1999 American Physical Society