Core Insights - The article discusses the critical challenges faced by photomasks in the development of lithography technology, particularly as the industry transitions to EUV (Extreme Ultraviolet) and beyond, highlighting the high costs associated with photomask manufacturing and maintenance [1][2][3]. Group 1: EUV and Non-EUV Challenges - The primary challenge for EUV is the high cost of manufacturing, maintaining, and replacing masks, which significantly impacts the overall production costs [1][3]. - Non-EUV applications are also facing similar challenges, as companies aim to stay competitive while managing costs associated with advanced photomask technologies [2][3]. - The lifespan of EUV photomasks is notably shorter compared to DUV (Deep Ultraviolet) masks, leading to increased cleaning frequency and the need for backup masks, which further escalates costs [3][4]. Group 2: Multi-Exposure Techniques - Multi-exposure techniques are deemed necessary for the future of EUV lithography, as they will enhance resolution and pattern fidelity [6][7]. - Companies are actively researching multi-exposure methods to extend the lifespan of EUV technology, with Intel planning to use high-NA EUV for its 14A node due to single-exposure limitations [7][8]. - The industry is exploring various techniques to optimize multi-exposure applications, although challenges remain in terms of cost and complexity [8][9]. Group 3: Photomask Materials and Process Control - The evolution of photomask materials is crucial for supporting finer nodes, with advancements in binary reflective masks and low-refractive-index reflective masks improving image contrast [10][11]. - The introduction of metal oxide resists is highlighted as a significant advancement, offering higher contrast and better etch resistance compared to traditional resists [11][12]. - Customization of mask blank properties presents opportunities for enhancing wafer process margins, although the market for new resist materials remains niche and underdeveloped [11][12]. Group 4: EUV Membrane Challenges - EUV membranes face challenges related to transmission rates and durability, with current membranes requiring frequent replacements that increase costs and downtime [14][15]. - The complexity of EUV membranes compared to 193i membranes complicates the cleaning and replacement processes, impacting throughput and efficiency [15][16]. - Ongoing research into alternative membrane materials, such as carbon nanotube-based versions, shows promise but faces reliability and performance challenges [15][16].