Fault isolation on marginal failures using dummy signals

Today's complex integrated circuits demand tight process control in manufacturing. In this paper, several case studies due to slight process deviation resulting in yield loss from marginal leakage failure were presented. While conventional fault isolation approach relies on the localization of exclusive laser induced or photon emission hotspot to highlight the defect location and pays little attention on intrinsic or dummy signals which are observable on reference units, the case studies described presented a different perspective of analyzing the slight difference in these dummy signals together with layout and circuit understanding to identify these subtle defects in the absence of exclusive hotspots.