System-Level Design for Nano-Electronics

Latest fabrication technologies of self-assembly nano-circuits (carbon nanotubes, silicon nanowires, etc.) have deployed bottom-up techniques that reach feature sizes well below 65nm, holding great promise for future large silicon-based integrated circuits. However, new nano-devices intrinsically have much higher failure rates than CMOS-based ones. Thus, new design methodologies must address the combination of devicelevel error-prone technologies with system integration constraints (low power, performance) to deliver competitive devices at the nanometer scale. In this paper we show that a very promising way to achieve nano-scale devices is combining imperfection-aware design techniques during fabrication with gate defect modeling at circuit level. Our results using this approach to define a Carbon Nanotube Field-Effect Transistor (CNFET)-based design flow for nanoscale logic circuits attain more than 3x energy-delay-product advantage compared to 65nm CMOS-based ones

A survey of fault-tolerance algorithms for reconfigurable nano-crossbar arrays

ACM Comput. Surv. Volume 50, issue 6 (November 2017)Nano-crossbar arrays have emerged as a promising and viable technology to improve computing performance of electronic circuits beyond the limits of current CMOS. Arrays offer both structural efficiency with reconfiguration and prospective capability of integration with different technologies. However, certain problems need to be addressed, and the most important one is the prevailing occurrence of faults. Considering fault rate projections as high as 20% that is much higher than those of CMOS, it is fair to expect sophisticated fault-tolerance methods. The focus of this survey article is the assessment and evaluation of these methods and related algorithms applied in logic mapping and configuration processes. As a start, we concisely explain reconfigurable nano-crossbar arrays with their fault characteristics and models. Following that, we demonstrate configuration techniques of the arrays in the presence of permanent faults and elaborate on two main fault-tolerance methodologies, namely defect-unaware and defect-aware approaches, with a short review on advantages and disadvantages. For both methodologies, we present detailed experimental results of related algorithms regarding their strengths and weaknesses with a comprehensive yield, success rate and runtime analysis. Next, we overview fault-tolerance approaches for transient faults. As a conclusion, we overview the proposed algorithms with future directions and upcoming challenges.This work is supported by the EU-H2020-RISE project NANOxCOMP no 691178 and the TUBITAK-Career project no 113E760