Deep submicron defect detection with the energy consumption ratio

Advances in technology and increasing integration are expected to degrade the effectiveness of I/sub ddq/ test. Total leakage currents per IC are expected to be very large, making it difficult to detect the impact of a single defect (T.W. Williams et al., 1996; M. Sachdev, 1997). Test methods which detect faults by monitoring the dynamic supply current have been suggested as one alternative. Almost all the dynamic current techniques proposed in the literature are adversely affected by the impact of process variations. Many are also susceptible to timing and magnitude errors in measurement. The energy consumption ratio (ECR) is a new dynamic current-based test metric (B. Vinnakota et al., 1998), that addresses some of these problems. ECR-based test offers several advantages over other dynamic test methods and the I/sub ddq/ test such as tolerance to process variations, reduced test process complexity and a proven ability to detect faults that escape other techniques. The ECR has been validated through extensive simulation and through application to a 50K gate sub-micron biomedical IC (W. Jiang and B. Vinnakota, 1999). Our contributions are directed towards further validating the real quality of the ECR.