Nanocarbon interconnects: Current status and prospects

Abstract

Nanocarbon materials represented by graphene and carbon nanotubes (CNTs) are promising candidates for future LSI interconnects. We recently fabricated sub-10-nm-wide graphene interconnects whose resistivity was lower than that of Cu with the same dimensions [1]. In this presentation, we first describe the fabrication and evaluation of such graphene interconnects. Multilayer graphene (MLG) was synthesized by chemical vapor deposition. Intercalation of FeCl3 into MLG was then performed to lower the resistance of MLG. In fact, the resistances of MLG interconnects decreased by about one-twentieth after intercalation [2]. The resultant resistivity of MLG was as low as that of bulk Cu. We further describe the fabrication and evaluation of 8-nm-wide MLG interconnects. In the second part, we explain a newly-developed fabrication process for carbon nanotube (CNT) vias and plugs, which relies on implantation of CNTs into sub-micrometer-sized holes [3]. In fact, we succeeded in implanting bundles of CNTs into holes with dimeters as small as 130 nm. The electrical properties of CNT plugs thus fabricated were then evaluated, exhibiting resistances lower than those of the CNT plugs reported previously.