Commonality Analysis for Multiple Chain Integrity Failures

This paper presents an alternative approach for analyzing complex scan chain failures in which there are multiple candidates that could be the root cause. It demonstrates the approach on an automotive IC with several failing flip-flops. An analysis of the interconnections shared by the failing devices reveals a common clock branch where the root cause is likely to reside. Photo-emission microscopy (PEM) is then used to verify the existence of a defect which, based on passive voltage contrast, is determined to be an open path.