Innovative design solutions for avoiding at-resolution field stitching in high-NA EUV lithography

We introduce innovative design strategies to avoid at-resolution field stitching in high-NA extreme ultraviolet (EUV) lithography. In logic applications, we propose two design solutions at inter- and intra-cell level. The dummy filler cells or relaxed pitch cells insertion, and metal routing blockage offer design solutions to avoid at-resolution stitching enabled by easily integrated place-and-route flow, aiming to simplify the at-resolution stitching relevant process complexities. We also propose a DRAM die aspect ratio optimization method to maximize mask area utilization for a high throughput, leading to stitching scenarios: even number of dies in Y-direction of full imaging field requires a pitch-tolerated field stitching at scribe lane, while odd number of dies case eliminates the need of CD-critical stitching at stitching boundary.