Defect Diagnosis - Reasoning Methodology

Diagnosis has become a crucial technology for early debugging and yield improvement. However, the conventional diagnosis methods are not good at locating the defects that are not precisely expressed only with logical fault models. In this paper, we propose a novel defect diagnosis methodology, which is based on the evaluation of defect behaviors using physical information. We examine suspected nodes\´ voltages by comparing with the observed responses of ATE. In the examination, we use "defect activation", which is an estimation method of defective nodes\´ voltages using physical information. Using this methodology, we introduce examples of diagnosis for open defects in a cell, and for interconnect open defects. Those successful results show the effectiveness of the defect diagnosis