TY - JOUR
T1 - Electromigration-Induced Surface Drift and Slit Propagation in Polycrystalline Interconnects
T2 - Insights from Phase-Field Simulations
AU - Mukherjee, Arnab
AU - Ankit, Kumar
AU - Selzer, Michael
AU - Nestler, Britta
PY - 2018/4/4
Y1 - 2018/4/4
N2 - We employ the phase-field method to assess electromigration (EM) damage in wide polycrystalline interconnects due to grain-boundary grooving. An interplay of surface and grain-boundary diffusion is shown to drastically influence the mode of progressive EM damage. Rapid atomic transport along the surface leads to shape-preserving surface drift reminiscent of Blech drift-velocity experiments. On the other hand, a comparatively faster grain-boundary transport localizes the damage, resulting in the proliferation of intergranular slits with a shape-preserving tip. At steady state, the two regimes exhibit exponents of 1 and 3/2, respectively, in Black's law. While surface drift obeys an inverse scaling with grain size, slits exhibit a direct relationship at small sizes, with the dependence becoming weaker at larger ones. Furthermore, we explain the influence of curvature- or EM-mediated healing fluxes running along the surface on groove replenishment. Insights derived from phase-field simulations of EM in bicrystals are extended to investigate the multiphysics of mixed-mode damage of a polycrystalline interconnect line that is characterized by a drift of small grain surfaces, slit propagation, and coarsening. The triple and quadruple junctions are identified as prominent sites of failure.
AB - We employ the phase-field method to assess electromigration (EM) damage in wide polycrystalline interconnects due to grain-boundary grooving. An interplay of surface and grain-boundary diffusion is shown to drastically influence the mode of progressive EM damage. Rapid atomic transport along the surface leads to shape-preserving surface drift reminiscent of Blech drift-velocity experiments. On the other hand, a comparatively faster grain-boundary transport localizes the damage, resulting in the proliferation of intergranular slits with a shape-preserving tip. At steady state, the two regimes exhibit exponents of 1 and 3/2, respectively, in Black's law. While surface drift obeys an inverse scaling with grain size, slits exhibit a direct relationship at small sizes, with the dependence becoming weaker at larger ones. Furthermore, we explain the influence of curvature- or EM-mediated healing fluxes running along the surface on groove replenishment. Insights derived from phase-field simulations of EM in bicrystals are extended to investigate the multiphysics of mixed-mode damage of a polycrystalline interconnect line that is characterized by a drift of small grain surfaces, slit propagation, and coarsening. The triple and quadruple junctions are identified as prominent sites of failure.
UR - http://www.scopus.com/inward/record.url?scp=85045213503&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85045213503&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.9.044004
DO - 10.1103/PhysRevApplied.9.044004
M3 - Article
AN - SCOPUS:85045213503
VL - 9
JO - Physical Review Applied
JF - Physical Review Applied
SN - 2331-7019
IS - 4
M1 - 044004
ER -