Novel 2D high-NA EUV pattern fidelity monitoring

High-NA EUV lithography is projected to print the most critical features of sub-2nm logic chips and is expected to be inserted into high-volume semiconductor fabs during 2025. High-NA EUV lithography comes with new challenges such as reduced depth-of-focus (DOF), as well as thinner resists for a reasonable aspect ratio. Mask 3D effects are also becoming increasingly important as progressively smaller features are being printed. This creates new challenges for High-NA lithography metrology, as traditional approaches to assess 1D pattern dimension are unable to adequately control High-NA scanners performance. An improved inline metrology to detect scanner focus drift while minimizing EUV resist damage becomes essential. In this paper, we will aim to examine new 2D, low voltage, high-precision CD-SEM system based on the Hitachi GT2000 and Advanced Inline Monitoring Solution (AIMS) to address High-NA EUV lithography monitoring challenges by evaluating a high-NA EUV focus exposure matrix (FEM) wafer imaging the most critical features using low voltage CD-SEM and processing these images with 2D metrology system. A comparison of traditional 1D and 2D measurements on these SEM images will be made to determine new 2D inline metrology sensitivity and usability for High-NA EUV lithography scanners and process control.