A successful application of WLR fast test on Al via process optimisation

Abstract

In this paper, a successful application of WLR fast electromigration (EM) test on Al via process optimization is presented. The impact of spin-on-glass (SOG) and pre sputter etch (PSE) on via performance is characterised by using standard wafer-level electromigration accelerated test (SWEAT). By eliminating the potential of SOG outgassing at the via and optimizing per sputter etch oxide loss (PSEOL), the optimization of the via process has been achieved with a 10% reduction in via resistance and a 6.5% improvement in yield.