Nano Science and Technology InstituteNano Science and Technology Institute
Nano Science and Technology Institute 2003 NSTI Nanotechnology Conference & Trade Show
Nanotech 2003
BioNano 2003
Index of Authors
2003 Sub Sections
Press Room
NSTI Events
Site Map
Nanotech Proceedings
Nanotechnology Proceedings
Supporting Organizations
Supporting Organizations
Event Contact
696 San Ramon Valley Blvd., Ste. 423
Danville, CA 94526
Ph: (925) 353-5004
Fx: (925) 886-8461

Submonolayer Growth on a substrate with defect sites using a Level-Set model

R. Vardavas, C. Ratsch , J. Garcia, R.Caflisch

Keywords: Level Set, Defects, Epitaxial Growth, Submonolayer

Submonolayer epitaxy in the presence of point defects is studied by means of a Level-Set method. Here island nucleation occurs by dimer formation and by the atom-defect irreversible attachment. The latter accounts for a new sink term in the evolution of the adatom density proportional to the number of free, non-seeded defect sites. With increasing D/F, the presence of defect sites has the effect that all island nucleation events occur primarily at the defect sites and the formation of dimers is repressed. Furthermore, the time intervals between successive nucleation events are shortened. These observations are in agreement with a rate equation model [1], where for a particular coverage one obtains an extensive plateau region of constant island density equal to the defect density independently from the ratio D/F. We further discuss the evolution of the island size distribution for the cases where the allocation of the point defects over the surface is random or uniform. For randomly allocated defects we observe that with increasing D/F, the island size distribution approaches a scaled gamma distribution of the areas associated to Voronoi cells of the defect sites. This distribution differs from that found by Ratsch et al. [2] for normal growth where dimers are seeded randomly. For uniformly allocated defects and for large D/F the island size distribution becomes very peaked. This suggests that by controlling the positions of the defects we find that the surface morphology can be engineered so that all islands are of similar sizes.

NSTI Nanotech 2003 Conference Technical Program Abstract

Featured Sponsors
Nanotech Sponsors
News Headlines
NSTI Online Community

© Nano Science and Technology Institute, all rights reserved.
Terms of use | Privacy policy | Contact