Accelerated Stress Test Assessment of Through-Silicon Via Using RF Signals

In this paper, radio frequency signal is demonstrated as an effective probe for assessing the effect of thermal cycling on the reliability of through-silicon vias (TSVs) in stacked dies. It is found that the RF signal integrity in TSV daisy chain, particularly its transmission characteristics, degrades considerably with extended thermal cycling, because of the formation and the growth of voids. Early failures are observed in the reliability analysis of the TSV daisy chain and are attributed to processing-related variability across the wafer. However, the maximum failure rate is found to occur at 500 thermal cycles, which is attributed to the initiation of defects and their subsequent propagation.