Core Viewpoint - The article discusses the challenges and potential solutions related to the implementation of high numerical aperture (NA) EUV lithography technology, particularly focusing on the issues of mask stitching and the implications of larger reticle sizes on manufacturing efficiency and yield [1][2][10]. Group 1: Challenges of High NA EUV Lithography - The transition to high NA (0.55) EUV lithography presents significant challenges in circuit stitching between exposure fields, impacting design, yield, and manufacturability [1][2]. - The use of deformable lenses in high NA systems reduces the exposure range of standard 6×6 inch masks by half, complicating the alignment and yield of critical layers [2][3]. - Misalignment issues can lead to significant errors in critical dimensions, with a 2nm mask overlay error potentially causing at least a 10% deviation in pattern sizes [2][4]. Group 2: Design and Performance Implications - Advanced lithography techniques require precise calibration to ensure accurate printing of features, with any overlap between masks needing careful consideration to avoid interference [4][5]. - The design of masks must account for the black border that prevents stray reflections, which can introduce stress relaxation and distort adjacent multilayer structures [5][6]. - Avoiding critical features in boundary areas is essential to mitigate yield risks, as misalignment can lead to increased wire lengths and potential performance degradation [7][8]. Group 3: Solutions and Optimizations - Strategies to optimize designs include clustering I/O ports and minimizing the number of lines crossing boundary areas, which can reduce the impact of stitching on performance [8][9]. - Implementing design rules specific to boundary areas can help ensure that features print correctly, although this may complicate overall design [8][9]. - The potential for larger reticle sizes (6×11 inches) is seen as a solution to eliminate stitching issues, although it poses significant challenges in terms of equipment costs and manufacturing processes [10][11]. Group 4: Industry Perspectives and Future Considerations - Industry experts express cautious optimism about larger reticle sizes, noting that while they could improve efficiency, the associated costs and equipment changes are substantial [10][11]. - The cost of EUV lithography machines is nearing $400 million, and their production efficiency is a critical factor affecting overall wafer fabrication costs [11]. - The shift to larger masks may be necessary for future technology nodes, particularly as the industry approaches 1nm technology, which will require upgrades to many existing tools [11].