Influence of short circuits on data of contact and via open circuits determined by a novel weave test structure

Generally test structures containing via strings and contact strings are used to control backend isolation layers´ integrity. However, short circuits are the major type of fault resulting from defects during the backend process steps. For this reason, the influence that short circuits have on contact hole open circuits and via hole open circuits in regular string test structures will be investigated here. A novel weave test structure (WTS) is presented to detect open circuits as well as short circuits in adjacent conducting layers of backend process steps. Numerous contact strings or via strings are arranged inside boundary pads like a woven piece of cloth. Thus, short circuits between different strings are also electrically detectable. The separation and localization of defects will be achieved by dividing the chip area into distinguishable subchips inside given standard boundary pads without using any active semiconductor devices. The localization enables a versatile optical defect parameter extraction to precisely determine the reason why and how a defect occurred during the manufacturing process