Modeling CNTFET Performance Variation Due to Spatial Distribution of Carbon Nanotubes

In this paper, we studied the impact of spatial distribution of aligned carbon nanotube (CNT) on the performance variation of CNTFETs. The distribution of CNT spacing for a given density is identified and verified through Monte Carlo simulation. This distribution is then incorporated into a compact model to study its impact on the performance variation. It was identified that the spatial distribution of CNT not only generates a new source of performance variation, it also leads to around 10% lower current compared with the generally assumed uniform distribution case at typical CNT density. The approach is also used to evaluate the variations of inverter gate delay and SRAM static read noise margin which demonstrate its capability for predicting CNTFET-based circuit performance variation.