Heat dissipation of underlying multilayered graphene layers grown on Cu–Ni alloys for high-performance interconnects

Electromigration with Joule heating under high current results in the failure of metal interconnect, which affects the performance and lifetime of electronic devices. Furthermore, advanced semiconductor technologies, such as three-dimensional integrated chips and power devices, which include insulated-gate bipolar transistors and compound semiconductors, require an electrical conducting line with high charge-carrying capacity for effective transmission of electrical signal. In this study, we investigate the effect of underlying graphene layers on the electrical properties of Cu interconnects. Multilayered graphene with a thickness of a few nanometers and a flat surface is synthesized using Cu–Ni alloys. The maximum current capacity of the Cu interconnect is improved by increasing the graphene width to 1.60 × 10⁸ A/cm², which is approximately seven times greater than that of only Cu. In addition, the wide graphene layer prevents the sudden current drop due to breakage of the Cu interconnect. The results of thermal imaging and simulation reveal the importance of effective heat dissipation for realizing high performance of the interconnect.