Core Viewpoint - The article discusses the challenges and innovations in EUV lithography, particularly focusing on the balance of resolution, line width roughness, and sensitivity in photoresist materials, highlighting the need for advancements in photoresist technology to meet the demands of high NA EUV exposure [1][5][14]. Group 1: EUV Lithography Challenges - Balancing resolution, sensitivity, and line width roughness in high NA EUV lithography is increasingly difficult, as the final step between the mask and the patterned wafer is unpredictable [1][5]. - The RLS triangle (Resolution, Line width roughness, Sensitivity) defines the key parameters for evaluating lithography processes, where improving one often sacrifices the others [3][4]. - The sensitivity of photoresists limits the throughput of EUV exposure systems, significantly impacting overall process costs, with potential savings of up to $1 million per year per scanner by reducing exposure dose [3][4]. Group 2: Innovations in Photoresist Materials - Research is ongoing to enhance chemical amplification resists (CAR) by exploring alternative PAG molecules to improve EUV absorption rates, although initial findings indicate that higher electron affinity may not enhance sensitivity [4][8]. - Metal oxide photoresists are gaining interest due to their robustness and excellent etch selectivity, although they present challenges in solubility for positive photoresist applications [8][9]. - Dry photoresist processes, such as those developed by Lam Research, allow real-time adjustments of process chemistry, potentially optimizing the lithography process [11][12]. Group 3: Alternative Approaches - New concepts like multi-trigger photoresists aim to combine the advantages of chemical amplification and metal oxide resists, allowing for selective cross-linking based on exposure conditions [13][14]. - The development of next-generation photoresists that utilize acid to "unzip" polymer chains offers a promising alternative, enabling better optimization of solubility in developers [14].