Mechanism investigation of pre-existing void-induced multi-modal electro-migration behavior

Abstract

Abstract A multi-modal time-to-failure distribution for an electro-migration (EM) structure has been observed and studied from long durationin-situ EM experiment, for which the failure mechanism has been investigated and discussed comprehensively. The mixed EM failure behavior strongly suggest that the fatal voids induced EM failure appear at various locations along the EM structure. This phenomenon is believed to be highly related to the existence of pre-existing voids before EM stress. Meanwhile, the number and location of the pre-existing voids can influence the EM failure mode significantly. Based on our research, a potential direction to improve the EM lifetime of Cu interconnect is presented.