Detection and analysis of early failures in electromigration

The early failure issue in electromigration (EM) has been an unresolved sub ject of study over the last several decades. A satisfying experimental appr oach for the detection and analysis of early failures has not been establis hed yet. In this study, a technique utilizing large interconnect arrays in conjunction with the well-known Wheatstone Bridge is presented. A total of more than 20 000 interconnects were tested. The results indicate that the E M failure mechanism studied here follows lognormal behavior down to the fou r sigma level. (C) 2000 American Institute of Physics. [S0003-6951(00)03007 -2].