Morphological evolution of edge-hillocks on single-crystal films having anisotropic drift-diffusion under the capillary and electromigration forces


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Ogurtani T. O. , Celik A., Oren E. E.

THIN SOLID FILMS, vol.515, no.5, pp.2974-2983, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 515 Issue: 5
  • Publication Date: 2007
  • Doi Number: 10.1016/j.tsf.2006.08.020
  • Journal Name: THIN SOLID FILMS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2974-2983
  • Keywords: computer simulations, models of non-equilibrium phenomena, surface diffusion, electromigration, solid-gas interfaces, METALLIC THIN-FILMS, 3-DIMENSIONAL SIMULATIONS, NONLINEAR DYNAMICS, INDUCED FAILURE, SURFACE, INTERCONNECTS, STRESS, PROPAGATION, INSTABILITY, MOTION
  • Middle East Technical University Affiliated: No

Abstract

The morphological evolution of hillocks at the unpassivated sidewalls of single-crystal metallic thin film interconnects is investigated via computer simulations using the free-moving boundary value problem. The effect of drift-diffusion anisotropy on the development of surface topographical scenarios is fully explored under the action of electromigration and capillary forces, utilizing numerous combinations of the surface texture, the drift-diffusion anisotropy and the direction of the applied electric field. The simulation studies yield analytical relationships for the velocity of the surface solitary waves and the drift velocity of electromigration-induced internal voids as a function of the applied current densities, which contain intrinsic and structural properties of the single-crystal thin films. The threshold value of the applied current density, above which electromigration-induced internal voids can be formed and may cause the catastrophic failure of interconnects by breaching, also appears explicitly in this relationship. (c) 2006 Published by Elsevier B.V.