Finite element predictions of the effect of diffusion-accommodated interfacial sliding on thermal stresses in Cu/polymer dielectric and Cu/oxide dielectric single level damascene interconnect structures

Academic Article


  • The finite element method was used to estimate the stresses in single level, 1 μm thick Cu-dielectric interconnect line arrays with Ta liners resulting from heating from 20°C to 400°C assuming that the structure was stress free at 20°C. Benzocyclobutene (BCB) and SiO2 were chosen to represent typical polymer and ceramic dielectric materials being evaluated for Cu damascene interconnect structures. Experimentally observed Cu-Ta and Cu-Cu interfacial sliding was incorporated into the model using a 1 nm thick creep element that was calibrated to match the predictions of a classical diffusion-accommodated sliding model. The effect of Cu-Ta and Cu-Cu interfacial sliding was evaluated by comparing the relaxed and unrelaxed stresses. The effect of line width-to-thickness (w/t) ratio and Ta liner thickness on the shear, normal, and Ta liner-plane stresses at the Cu-Ta-dielectric interface was investigated because this interface is a likely failure site.
  • Authors

  • Kamsah, N
  • Gross, TS
  • Tsukrov, Igor
  • Status

    Publication Date

  • March 2002
  • Published In


  • copper
  • damascene interconnect structure
  • finite element analysis
  • interfacial sliding
  • thermal stresses
  • Digital Object Identifier (doi)

    Start Page

  • 12
  • End Page

  • 21
  • Volume

  • 124
  • Issue

  • 1