On microarchitectural modeling for CNFET-based circuits

Abstract

Carbon Nanotube Field-Effect-Transistors (CN-FETs) show great promise to be an alternative to traditional CMOS technology, due to their extremely high energy efficiency. Unfortunately, the lack of control over the Carbon NanoTube (CNT) growth process causes CNFET circuits to suffer from the CNT count variation, which degrades the CNFET circuit performance. Compared to the CMOS process variation, the CNT count variation exhibits asymmetric spatial correlation. In this work, we propose an analytic model that integrates the impact of the asymmetric spatial correlation into the key microarchitectural blocks. We use this model to evaluate the variations in circuit performance for different layout styles and microarchitectural parameters. We further explore the opportunity of leveraging the asymmetric spatial correlation for performance enhancement. Experimental results based on SPICE simulation and architectural simulations showed the accuracy and effectiveness of the proposed model.