Morphological instability in epitaxially strained dislocation-free solid films: Linear stability theory

B. J. Spencer*, Peter W Voorhees, Stephen H Davis

*Corresponding author for this work

Research output: Contribution to journalArticle

238 Scopus citations

Abstract

The morphological instability of a growing epitaxially strained dislocation-free solid film is analyzed. An evolution equation for the film surface is derived in the dilute limit of vacancies based on surface diffusion driven by a stress-dependent chemical potential. From the time-dependent linear stability problem the conditions for which a growing film is unstable are determined. It is found that the instability is driven by the lattice mismatch between the film and the substrate; however, low temperatures as well as elastically stiff substrates are stabilizing influences. The results also reveal that the critical film thickness for instability depends on the growth rate of the film itself. Detailed comparison with experimental observations indicates that the instability described exhibits many of the observed features of the onset of the "island instability".

Original languageEnglish (US)
Pages (from-to)4955-4970
Number of pages16
JournalJournal of Applied Physics
Volume73
Issue number10
DOIs
StatePublished - Dec 1 1993

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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