Core Viewpoint - The article discusses the challenges and potential solutions related to high numerical aperture (NA) EUV lithography, particularly focusing on the need for larger reticle sizes to improve manufacturing efficiency and yield [2][11][12]. Group 1: Challenges of High NA EUV Lithography - Circuit stitching between exposure fields poses significant challenges for design, yield, and manufacturability in high NA (0.55) EUV lithography [2]. - The transition from 6×6 inch reticles to 6×11 inch reticles could eliminate the need for circuit stitching but would require nearly complete replacement of the reticle manufacturing infrastructure [2][11]. - The area limitation of modern multi-core SoCs complicates the use of 193nm immersion and EUV lithography, as the effective exposure area is reduced due to the use of deformable optics [2][3]. Group 2: Yield and Performance Issues - The process of stitching multiple masks into a single design is becoming a critical challenge across various lithography processes, particularly for high NA EUV exposure [3]. - Misalignment between stitched masks can lead to yield issues, especially for critical layers, with an estimated 2nm misalignment causing at least a 10% error in critical dimensions [3][5]. - The presence of a black border on EUV masks can introduce additional stress and distortion, complicating the printing of features near the stitching boundary [6][12]. Group 3: Design Solutions and Optimizations - To mitigate performance threats, designers are encouraged to keep circuit features away from boundary areas, which can lead to yield and performance degradation [8][9]. - Various design optimizations have been proposed to reduce the number of lines crossing stitching boundaries, with some approaches achieving a reduction in stitching area loss to below 0.5% and performance degradation to around 0.2% [9]. - The industry is prepared to tackle the challenges posed by stitching-aware design, although the impact on throughput remains a concern [9]. Group 4: Future Directions and Industry Perspectives - Increasing reticle sizes could address both stitching and throughput challenges, with estimates suggesting that yield could drop by up to 40% if exposure fields are halved [11]. - The transition to larger reticle sizes will necessitate changes across various manufacturing equipment, potentially doubling costs for some devices [11][12]. - Despite the technical advantages of larger reticles, industry skepticism remains regarding the associated costs and the need for upgrades to meet future technology nodes [12].