CNT/graphene technologies for future carbon-based interconnects

With the aim of achieving low-power consumption, high-performance LSIs, our work focuses on the development of low-resistance carbon nanotube (CNT)/graphene interconnect technologies. For vertical interconnects, we report on a previously unseen dense vertical and horizontal graphene (DVHG) structure, which is expected to lead to a low electrical resistance. For horizontal interconnects, we have succeeded in forming multi-layer graphene (MLG) directly on SiO₂ by annealing sputtered amorphous carbon. Furthermore, achieving low-resistance contacts between the vertical CNTs and horizontal graphene represents a critical issue for 3D interconnects. We grew vertically aligned CNTs on MLG, and analyzed the contact structure using cross-sectional TEM-EELS measurements. Migration of Ti and Co into the graphene layers was clearly observed. This may contribute to the reduction of contact resistance between CNTs and graphene.