The Distribution of Electromigration Failures

This paper presents the results of an evaluation of the statistical distribution of electromigration test failures. Large scale life tests were carried out and the natujre of the failure distributions were determined for lines of varying length and width. In all cases, the distribution were found to be log-normal down to at least the 0.3% failure point. Possible reasons for these results and their implications with regard to the design of a cost effective electromigration testing program are discussed.