Blech Effect in Interconnects

Abstract

The majority of the existing experimental, theoretical and modeling works on electromigration (EM) are focused on simple, via-to-via structures, but complex interconnect structures have not been studied well. The lack of correct models for such interconnects may result in either conservative or weak design decisions which may result in catastrophic reliability failures. This paper proposes a physical model which holds for material migration as well as for lattice vacancy generation/annihilation. Using the developed model, well known circuit level EM assessment methods are examined by finite element modeling and simulation. The paper provides a compact model for EM analysis which can be easily implemented in CAD tools. We also explain some recent experimental results and empirical models published by other researchers.