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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 2 Issue 3 (1998) pp 409-412
Noise-assisted mound coarsening in epitaxial growth
L.-H. Tang (1)(2) (a), P. Smilauer (1)(3), D.D. Vvedensky (1)
(1) The Blackett Laboratory, Imperial College, London SW7 2BZ, UK
(2) Department of Physics and Center for Nonlinear Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong
(3) Institute of Physics, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
Received: 11 November 1997 / Revised in final form: 28 November 1997 / Accepted: 28 November 1997
Abstract: Two types of mechanisms are proposed for mound coarsening during unstable epitaxial growth: stochastic, due to deposition noise, and deterministic, due to mass currents driven by surface energy differences. Both yield the relation H=(RWL)2 between the typical mound height W, mound size L, and the film thickness H. An analysis of simulations and experimental data shows that the parameter R saturates to a value which discriminates sharply between stochastic ($R\simeq1$) and deterministic ($R\ll 1$) coarsening. We derive a scaling relation between the coarsening exponent 1/z and the mound-height exponent $\beta$ which, for a saturated mound slope, yields $\beta=1/z=1/4$.
PACS. 68.55.-a Thin film structure morphology - 05.70.Ln Nonequilibrium thermodynamics, irreversible processes - 81.10.Aj Theory and models of crystal growth; physics of crystal growth, crytal morphology and orientation
(a) email: lhtang@hkbu.edu.hk
Online publication: May 27, 1998
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