Reliability Impact of N-Modular Redundancy in QCA

Nanoelectronic systems are extremely likely to demonstrate high defect and fault rates. As a result, defect and/or fault tolerance may be necessary at several levels throughout the system. Methods for improving defect tolerance, in order to prevent faults, at the component level for quantum-dot cellular automata (QCA)¹ have been studied. However, methods and results considering fault tolerance in QCA have received less attention. In this paper, we present an analysis of how QCA system reliability may be impacted by using various N-modular redundancy (NMR) schemes. Our results demonstrate that using NMR in QCA can improve reliability in some cases, but can harm reliability in others.