High-NA EUV optical proximity correction modeling flow: from data preparation to model validation

Patterning with high-NA EUV lithography has become an inevitable option as the semiconductor industry seeks singlepatterning solutions. However, High-NA EUV modeling presents new challenges due to the anamorphic nature of scanner optics. Lithographers must consider not only the data at the center of the field, but also from the stitching regions where black border and double exposure effects can be significant. Therefore, an accurate topographic mask model is required to account for mask background reflectivity in both areas, with various EUV absorbers. Furthermore, novel metal-oxide photoresist (MOR) creates additional challenges in metrology, imaging, and modeling, due to the thin resist film and postdevelopment resist profiles. Additionally, long-range flare effects beyond the EUV optical influence range, such as optical and chemical flare, must be considered. Thus, a well-calibrated rigorous model reference is essential for validating the quality of the wafer data and to serve as a good starting template for compact modeling. In this paper, we show the importance of advanced metrology and modeling through experimental data. A novel modeling flow of advanced offline metrology, state-of-the-art modeling and validation technology is demonstrated. More specifically, we show that offline CD extraction can generate a modeling input dataset with precise CD valuesfrom accurate design-wafer image registration, especially for 2D patterns. By combining the techniques described, a comprehensive modeling flow of High-NA EUV OPC modeling is demonstrated. The results show that this approach meets the precision requirements for OPC applications in the advanced nodes.