Clocking strategy of Reconfigurable Field-Coupled Nanocomputing circuits

From 1965, the trends of innovations in electronic applications follow Moore's law, which specified that the number of transistors on a microchip doubles every two years, allowing faster and efficient computational progress, decreasing costs and increasing performance. Nowadays, due to the physical limits of semiconductor-based technology, the increase of miniaturization is approaching saturation. For this reason, alternative technologies became necessary. One of these is "Beyond-CMOS", where the most promising technology is Field-Coupled Nanocomputing (FCN). It is based on the propagation of information on a device using field's interactions. There is no current transport, enabling higher miniaturization and low power dissipation. In particular, Molecular FCN is the basis of our study. A computing paradigm that implements QuantumDot Cellular Automata (QCA), using bisferrocene molecules, where the electrostatic interaction among molecules allows the information to propagate. The idea of this project is the Reconfigurable FCN, a self-assembled monolayer (SAM), based on a gold substrate above which molecules are located. Vertical electrical fields are generated on molecule cells, inducing them to assume specific logic conditions and propagate the information in the structure by turning on and off electrodes in adjacent areas. The structural problem of this configuration is the presence of a high number of nanometric and independent electrodes that have to be managed, generating a complex physical realization and clock configuration. In this study, the aim is the improving of ease manufacturing of RFCN using the interference of light. With the patterns generated by the interference of light coming from a source that hit a screen with slits, it is possible to induce molecules to assume the wanted logic state. An interference model that can properly work on the RFCN is defined, creating patterns that hit the layer, permitting the achievement of correct logic gates as NAND, majority voters, inverters, half adder and full adder. The obtained patterns of interference are used as input to simulate the molecular structure using the Self Consistent ElectRostatic Potential Algorithm (SCERPA), a tool that analyses iteratively the molecule interactions. Physical and electrical characteristics are evaluated to define costs and physical realization: this approach brings a reduction of area and a simplification of the clock configuration, let the structure have higher flexibility with correct propagation of information.