Efficient and Scalable Post-Layout Optimization for Field-coupled Nanotechnologies

As conventional computing technologies approach their physical limits, the quest for increased computational power intensifies, heightening interest in post-CMOS technologies. Among these, Field-coupled Nanocomputing (FCN), which operates through the repulsion of physical fields at the nanoscale, emerges as a promising alternative. However, realizing specific functionalities within this technology necessitates the development of dedicated FCN physical design methods. Although various methods have been proposed, their reliance on heuristic approaches often results in suboptimal quality, highlighting a significant opportunity for enhancement. In the realm of conventional CMOS design, post-layout optimization techniques are employed to capitalize on this potential, yet such methods for FCN are either not scalable or lack efficiency. This work bridges this gap by introducing the first scalable and efficient post-layout optimization algorithm for FCN. Experimental evaluations demonstrate the efficiency of this approach: when applied to layouts obtained by a state-of-the-art heuristic method, the proposed post-layout optimization achieves area reductions of up to 73.75% (45.58% on average). This significant improvement underscores the transformative potential of post-layout optimization in FCN. Moreover, unlike existing algorithms, the method exhibits scalability even in optimizing layouts with over 20 million tiles. Implementations of the proposed methods are publicly available as part of the Munich Nanotech Toolkit (MNT) at https://github.com/cda-tum/fiction.