Comprehensive TDDB lifetime prediction methodology for intrinsic and extrinsic failures in Cu interconnect dielectrics

Abstract

This paper presents a comprehensive lifetime prediction methodology for both intrinsic and extrinsic Time-dependent dielectric breakdown (TDDB) failures to provide adequate Design-for-Reliability. For intrinsic failures, it is found that the √E model is suitable for the field acceleration model from long-term TDDB tests. By applying the √E model and estimating the Weibull slope using dedicated single-via test structures, we effectively prevent lifetime underestimation, therefore relaxing design restrictions. For extrinsic failures, by applying the thinning model and Critical area analysis (CAA) it is possible to predict extrinsic failure of breakdown voltage and lifetime only from hard-short defect densities, and we can quantify the failure probabilities for any design layouts of various LSI products.