| Abstract: |
| In epitaxial thin film growth, elasticity effects often lead to
self-organizing pattern formation which can be important in the fabrication
of nano-structures. We discuss an elasticity model that takes into account of
the lattice misfit between the substrate and the film, and the broken-bond
effect due to surface steps. The former is an attractive while the latter is a
repulsive interaction. It is found that uniform step train is unstable
and will evolve into structures consisting of macroscopic step bunches.
For the case of vicinal surface which consists of a sequence of
monotonically decreasing steps, using a variational formulation, we analyze
the properties of these bunches, notably their energy scaling and bunch width.
We emphasize on a discrete model but continuum description will also be
discussed. |
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