BEOL compatible graphene/Cu with improved electromigration lifetime for future interconnects

Abstract

We demonstrate a method to grow graphene directly on patterned Cu wires below 400 °C, within the thermal budget of back-end-of-line processes (BEOL). The process flow is compatible with direct etched Cu processes for advanced interconnects technology. The graphene/Cu composite exhibits 2× lower resistivity, 1.4× higher breakdown current density and 40× longer electromigration (EM) lifetime than as-deposited Cu. The EM performance of graphene/Cu is 10× better than 2 nm CoWP on Cu, and is comparable to the industry-standard 3 nm CoWP capping layer. DFT calculations reveal that the binding between the pristine in-situ grown graphene and Cu makes the Cu atom more resilient to external forces.