Determination of migration effects in Cu-via structures with respect to process-induced stress

Abstract

State-of-the-art migration calculations and mechanical simulations of interconnect structures are carried out under the assumption of one specific stress-free temperature for the structure. Finite element simulations of mechanical stress induced by the specific process temperatures of every process step are reported. But the connection between migration effects and process-induced stress was not investigated until now. In this paper, stress migration as well as electro- and thermomigration considering the process flow of the copper metallization will be determined and compared with simulations under fixed reference temperatures.