Reconfigurable standard-cell concept in Molecular Field-Coupled Nanocomputing

Year after year, the limits of MOS technologies are becoming more and more tightening. Due to the nanoscale effects of transistors and interconnections, new designs require a lot of effort to keep the performance-increasing trend: thermal and electrical uncertainties have to be counteracted at high design-abstraction levels. Moreover, only a few factories in the world are able to manufacture the latest-technology chips. This is why a key factor of a new technology could be, among the other factors, an easier and faster manufacturing. This could also promote a manufacturing cost reduction, allowing more factories to build state-of-the-art chips. In this framework, molecular electronics plays a central role. Molecular Field-Coupled Nanocomputing (FCN) is a novel computing paradigm that implements, through molecules, the Quantum-Dot Cellular Automata (QCA) paradigm. Molecular FCN binds a logical state to the charge distributions of molecules (Bisferrocene) and has demonstrated correct logic computation and reliable information propagation. In order to further improve the ease of manufacturing, a puzzle-inspired 2D review of Molecular FCN is introduced. Instead of placing single molecules along a precise pattern, which requires a very high technological resolution, this new paradigm requires only a simple and squared self-assembled monolayer (SAM), which results in a grid of molecules placed on a gold substrate. The gold substrate serves also as an electrode plate: vertical electric fields are originated between the substrate and small square electrodes that lie above the molecules. The groups of molecules between these electrodes can hold a logical state. By turning on and off electrodes in adjacent areas, logic operations can be performed. Different models and electrodes arrangements are therefore discussed. The aim of the study was to define a molecular standard-cell concept that takes care of mapping the logic gates (NAND, majority voters, inverters) to the molecular structure. Moreover, electrical characteristics such as area and power dissipation have been compared with state-of-art FinFET technology: the new approach brings a reduction of area and power dissipation up to more than 50%. This review also highlights the new possibilities of reconfigurability of the logic operations (similar to FPGA), which could happen even at run-time.