Electronics at Nanoscale: Fundamental and Practical Challenges, and Emerging Directions

In electronics, i.e. when using charge transport and change of electromagnetic fields in devices and systems, non-linearity, collective effects, and a hierarchy of design across length and time scales is central to efficient information processing through manipulation and transmission of bits. Silicon-based electronics brings together a systematic interdependent framework that connects software and hardware to reproducibility, speed, power, noise margin, reliability, signal restoration and communication, low defect count, and an ability to do predictive design across the scales. In the limits of nanometer scale, the dominant practical constraints arise from power dissipation in ever smaller volumes and of efficient signal interconnectivity commensurate with the large density of devices. These limitations are tied to the physical basis in charge transport and changes of fields, and equally apply to other materials – hard, soft or molecular. At the largest scale, the limitations arise from partitioning and hierarchical apportionment for system performance, ease of design and manufacturing. Power management, behavioral encapsulation, fault tolerance, congestion avoidance, timing, placement, routing, electromagnetic cross-talk, etc. all need to be addressed from the perspective of centimeter scale. We take a hierarchical view of the underlying fundamental and practical challenges of the conventional and unconventional approaches using the analytic framework appropriate to the length scale to distinguish between fact and fantasy, and to point to practical emerging directions with a system-scale perspective.