Performance analysis of single-walled carbon nanotube and multi-walled carbon nanotube in 32nm technology for on-chip interconnect applications

The semiconductor industry is facing a crucial problem in the interconnect section when IC is scaled down below 32 nm technology. Scaling increases the number of devices per unit area, which in turn increases the performance of the transistor resulting in the overall increase of performance per unit area. But there is a decrease in the performance of interconnect especially in that of global interconnect. The reduction in the cross section of copper interconnects in accordance with technology scaling, increases the resistivity due to size effects. This increase in resistivity affects performance, namely delay and current carrying capability of copper interconnect. Carbon nanotube is proposed as the replacement for copper to alleviate the bottleneck in all levels of interconnects because it has high mean free path and ballistic transport. The performance evaluation of both single-walled carbon nanotube and multi-walled carbon nanotube interconnect delay is carried out and the results are compared with that of the copper interconnects. Both the CNTs and copper interconnects are examined thoroughly with the help of HSPICE simulation using its transmission line model. Comparison shows that MWCNT is the most promising candidate for local, intermediate and global levels of interconnects.