Analysis of critical-length data from electromigration failure studies

An accurate estimation of the Blech length, the critical line length below which interconnect lines are immortal, is vital as it allows EDA tools to reduce their workload. In lines longer than the Blech length, either a void will inevitably nucleate and grow until the line fails, or the line will rupture. The majority of failure analyses reveal voiding as the failure mechanism however recent analysis suggest Blech length failures are characterised by simultaneous [6] voiding and rupture, and a non-zero steady-state drift velocity. This paper provides an alternative interpretation of results.