Modeling and Simulation for Epitaxial Growth with Strain
Russel E. Caflisch and Erding Luo, (UCLA), Mark Gyure and Geoff Simms, (HRL Labs), Dimitri Vvedensky (Imperial), Cameron Connell (NJIT)
Keywords: epitaxy, strain, lattice statics, island dynamics, level set
We describe a new approach to simulation of epitaxial growth with strain. An island
dynamics model with a level set numerical method is used for the growth; a lattice
statics model is used for the strain. The model is partly atomistic in order to properly
treat atomistic scale variation of the strain field at a step, but partly continuum in order
to reduce its computational complexity. Compared with previous methods based on purely
atomistic or continuum models, this method is both more robust and more efficient.
It is capable of simulating the full range of morphology for very thin films, as occur in
quantum well structures. The computational speed is sufficient for growth of multilayers
in both 2D and 3D. New results from this method include pinning of steps on an epitaxial
surface due to buried steps at the substrate/film interface.
We also have a new determination of intrinsic surface stress coefficient in terms of microscopic strain parameters. Qualitative comparisons to experimental results will be presented.
NSTI Nanotech 2003 Conference Technical Program Abstract