Prospects and challenges of compound conductors for advanced interconnect applications

The resistance of Cu interconnects rises rapidly with decreasing size due to limited barrier and liner scalability and increasing electron scattering at surfaces and grain boundaries. This presents a critical bottleneck for further miniaturization of integrated circuits. To address these challenges, alternative metals beyond Cu have garnered significant attention over the past decade, offering potential improvements in conductivity and reliability at the nanoscale. While early efforts focused on elemental metals, recent advances have broadened the scope to include compound conductors. In this Perspective, we review the current state of knowledge on resistivity size effects in emerging compound metals and identify key challenges that must be overcome for their successful integration in scaled interconnects. Although select compounds exhibit promising scaling behavior, substantial additional research remains necessary to validate their reliability and facilitate their adoption in mainstream device fabrication.