Continuous increase of transistor count in ultra large scale integrated (ULSI) circuits demands denser interconnection networks to guarantee normal operation. This requires shorter distances between adjacent interconnect lines which in turn causes severe crosstalk effects. Carbon based materials including carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) are among promising materials to replace copper interconnects in future ULSI circuits. In this work carbon based interconnects including multi-wall carbon nanotubes (MWCNTs) and multi-layer graphene nanoribbons (MLGNRs), both horizinoal and vertical, are extensively compared with traditional copper interconnects in terms of crosstalk delay and noise. Due to lower surface roughness, boron nitride (BN) is considered as substrate material for carbon based interconnects. To obtain more accurate and reliable results, layer number dependence of dielectric constant of BN multilayers and surface roughness dependence of the resistivity of horizontal MLGNR (HMLGNR) interconnects are considered. The role of interconnect length, line spacing and interlayer distance (substrate thickness) in crosstalk delay and noise of coupled carbon- and Cu-based interconnect lines is investigated. It is shown that vertical MLGNR (VMLGNR) interconnects with perfect GNR edges exhibit the least crosstalk delay while MWCNT interconnects show far less crosstalk noise than other materials.
