Substrate effect on graphene-based interconnects

We investigated major performance metrics of graphene interconnects on 2D layered insulator - hexagonal boron nitride (h-BN). Comparative study was made on three different material systems, including CVD graphene on h-BN, CVD graphene on SiO₂, and exfoliated graphene on SiO₂, with respect to electrical conduction and breakdown power density. Remarkable improvement in conductivity is observed in CVD graphene on h-BN substrate as compared with CVD graphene on SiO₂ and exfoliated graphene on SiO₂. The carrier mobility in CVD graphene on h-BN exhibits a value of ~15,000 cm²/V-s at carrier density of 1×10¹² cm^-2. Higher thermal conductivity of h-BN (as compared with that of SiO₂) facilitates heat dissipation, leading to improvement in breakdown power density. It is demonstrated that using h-BN as substrate material could help breaking the performance and reliability limits imposed by SiO₂ substrate.