Fundamentals of Interconnect Reliability: Physics, Failure Mechanisms, and Qualification

As on-chip interconnect technology continues to scale to meet increasingly stringent power, performance, and area requirements, ensuring interconnect reliability remains a fundamental challenge in semiconductor development. This tutorial introduces the core concepts of back-end-of-line (BEOL) reliability and provides a structured overview of the key physical failure mechanisms affecting interconnects, including time-dependent dielectric breakdown (TDDB), electromigration (EM), stress migration (SM), and thermal cycling (TC). The tutorial emphasizes the underlying reliability physics, commonly used qualification methodologies, and practical process optimization approaches used to mitigate scaling-induced reliability risks. In addition, reliability considerations and qualification strategies for BEOL passive devices are covered.