FuILT: Full Chip ILT System With Boundary Healing

Mask optimization in lithography is becoming increasingly impor- tant as the technology node size shrinks down. Inverse Lithography Technology (ILT) is one of the most performant and robust solutions widely used in the industry, yet it still suffers from heavy time con- sumption and complexity. As the number of transistors scales up, the industry currently focuses more on efficiency improvement and workload distribution. Meanwhile, most recent publications are still tangled in local pattern restoration regardless of real manufacturing conditions. We are trying to extend academia to some real industrial bottlenecks with FuILT, a practical full-chip ILT-based mask opti- mization flow. Firstly, we build a multi-level partitioning strategy with the divide-and-conquer mindset to tackle the full-chip ILT prob- lem. Secondly, we implement a workload distribution framework to maintain hardware efficiency with scalable multi-GPU parallelism. Thirdly, we propose a gradient-fusion technique and a multi-level healing strategy to fix the boundary error at different levels. Our experimental results on different layers from real designs show that FuILT is both effective and generalizable. © 2024 ACM.