Core Viewpoint - Photolithography is a crucial component of semiconductor manufacturing technology, serving as the starting process for each mask layer. The importance of photolithography lies not only in the demand for mask layers but also in its role in determining the limiting factors for the next technology node [1][9]. Group 1: Photolithography Process - The basic flow of photolithography includes spin coating photoresist, pre-baking, exposure, and development. The prerequisite for device photolithography is the design and manufacturing of the mask [3][26]. - Photolithography technology can be divided into mask-based and maskless lithography. Maskless lithography is currently limited by production efficiency and photolithographic precision, making it unsuitable for large-scale semiconductor manufacturing [3][26]. - The production of photomasks involves three main stages: CAM layout processing, photolithography, and inspection. The mask patterns are typically generated directly on blank mask substrates using direct-write lithography [41][42]. Group 2: Market Trends and Projections - In 2024, the combined market size for wafer exposure equipment, photolithography processing equipment, and mask manufacturing equipment is projected to be approximately $29.367 billion. With the introduction of 2nm processes, the demand for EUV lithography is expected to increase, with related equipment projected to reach $31.274 billion by 2025 [7]. - The server, data center, and storage market is expected to grow at a compound annual growth rate (CAGR) of 9% from 2025 to 2030, driven by the explosive growth of AI, big data, and cloud computing applications. The total semiconductor sales scale is anticipated to exceed $1 trillion [7]. Group 3: Differences in Logic and Memory Chip Lithography - Logic chip metal interconnect layers are more complex, while memory chips (DRAM and NAND) have core storage arrays composed of highly regular line/space structures. The line width and spacing in memory chips are typically pushed to their limits and are very uniform [2][17]. - In DRAM, the word lines and bit lines are designed with the minimum possible line width to achieve maximum capacitance and minimal area occupancy. The challenges in pitch differ between logic circuits and storage arrays [2][17]. Group 4: Equipment and Technology - The imaging system of photolithography machines is critical to semiconductor photolithography technology, with lenses determining the resolution and imaging quality. DUV lenses typically use fluoride materials to ensure low absorption and high laser damage thresholds [6]. - The light source is a key factor determining the wavelength of photolithography machines. For wavelengths above 365nm, high-pressure mercury lamps are commonly used, while KrF and ArF lasers are used for shorter wavelengths [5][6]. Group 5: Advanced Lithography Techniques - Phase shift masks (PSM) introduce phase modulation elements in the light regions of the mask to enhance imaging contrast through interference. PSM can significantly improve resolution by nearly doubling it under the same numerical aperture/wavelength conditions [43][44]. - Attenuated PSMs allow a small portion of light to pass through the opaque regions, enhancing imaging contrast while maintaining a high degree of light absorption [44]. Group 6: Challenges in Lithography - The complexity of logic devices increases the difficulty of interconnecting devices in very small areas, necessitating multiple photolithography steps. Critical layers in logic devices require new processes to ensure performance and yield [24][30]. - The introduction of new technology nodes typically requires new equipment and materials, which are developed in tandem with new processes to produce higher-performance devices [30].