Improved statistical analysis at low failure rates in Cu electromigration using an innovative multilink test structure

An innovative electromigration test structure is described in this paper. This new structure consisting of serial connected links is designed to address very early percentiles of lognormal electromigration failure time distribution and highlight extrinsic failures. The simplicity of implementation, data treatment and the correlation with elemental dual damascene test lines make this structure a pretty good candidate for the future of interconnects reliability.