Stress-driven interfacial instability of a bilayer structure: The interaction between free surface and interface

Wei Song, Fuqian Yang

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The morphological evolution of strained films is of technological importance to microelectronics and nanotechnology. The morphological instability of a bilayer system is analyzed, consisting of an elastic film and an elastic substrate with a misfit strain on the coherent interface. A kinetic model is derived by considering the morphological fluctuations of different perturbation amplitudes along both the free surface and the interface and the coupling effect between the film and the substrate. The couplings include the misfit strain, surface/interface energy, and surface/interface diffusion, which determine the morphological instability of the system. A quadratic dispersion relationship is established for the growth rate of the longitudinal surface and interfacial perturbations along the free surface and the interface, respectively. The propagation of the surface perturbations is revealed from the free surface to the interface, and the characteristic frequencies are identified for the initiation of the morphological instability.

Original languageEnglish
Pages (from-to)1071-1086
Number of pages16
JournalInternational Journal of Solids and Structures
Issue number3-4
StatePublished - Feb 2008

Bibliographical note

Funding Information:
This research is supported by NSF through the Grant CMS-0508989.


  • Coupling effects
  • Morphological stability
  • Thin films

ASJC Scopus subject areas

  • Modeling and Simulation
  • Materials Science (all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Applied Mathematics


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