光掩膜的变化和挑战

Core Viewpoint - The article discusses the current state and future directions of photomask manufacturing, emphasizing the importance of curved masks and advanced computational tools in extending the viability of non-EUV lithography technologies [1][3][4]. Group 1: Innovations in Photomask Technology - The use of curved photomasks is a significant innovation that leverages current writing technologies to create complex shapes previously unattainable [3]. - Advanced computational tools, such as Mask Process Correction (MPC) and high-level simulations, are increasingly used in the mask design flow, reducing the need for expensive experiments and pushing technological limits [3][6]. - The evolution of variable shape beam (VSB) writing technology to multi-beam writing technology has made curved mask shapes feasible without increasing writing time or costs [5]. Group 2: Challenges and Infrastructure Needs - There is a substantial need for infrastructure development to support the complexity of curved shapes, as traditional rectangular descriptions are simpler to manage [8]. - The transition to curved processes is seen as an exception rather than the norm, impacting economics and infrastructure, particularly in the reliance on GPU-based computing [9]. - Measurement technologies must evolve to handle the complexities of curved shapes, requiring higher resolution and faster measurement tools [11]. Group 3: EUV Masking Issues - EUV masks face challenges such as lower durability compared to 193i masks, necessitating frequent replacements that increase costs and complexity [13]. - The performance of EUV pellicles is currently suboptimal, leading to significant wafer throughput losses due to energy loss during transmission [13][15]. - The balance between using pellicles and the associated costs is contingent on the specific use case, with larger, high-value chips benefiting more from pellicles than smaller, redundant designs [16]. Group 4: Future Directions and Research - Research is ongoing into alternative materials for pellicles, such as carbon nanotube films, which could address current limitations but are not yet in mass production [17]. - The industry is exploring ways to improve the durability and transmission rates of EUV pellicles, which could lead to broader applications if successful [15][16].