光刻胶领域，我国取得新突破

Core Insights - The article discusses a new method using cryo-electron tomography to analyze the microscopic behavior of photoresist in liquid environments, which can significantly reduce defects in chip lithography [2][3]. Group 1: Technology and Methodology - The research team from Peking University applied cryo-electron tomography to observe the three-dimensional structure and entanglement behavior of photoresist molecules in situ, marking a breakthrough in semiconductor technology [2]. - This method allows for high-resolution imaging (better than 5 nanometers) and addresses the limitations of traditional techniques that could not observe the microscopic behavior of photoresist in real-time [3]. Group 2: Findings and Implications - The study revealed that contrary to previous beliefs, most dissolved photoresist polymers are adsorbed at the gas-liquid interface rather than dispersed in the liquid [5]. - The team identified "cohesive entanglement" of photoresist polymers, which can lead to the formation of aggregation particles averaging about 30 nanometers in size, posing a risk of defects in circuit patterns [5]. - Two practical solutions were proposed to control entanglement: increasing post-exposure bake temperature to suppress polymer entanglement and optimizing the development process to maintain a continuous liquid film on the wafer surface, successfully reducing defect counts by over 99% [5]. Group 3: Future Applications - The cryo-electron tomography technique provides a powerful tool for analyzing liquid-phase reactions at the atomic/molecular scale, which can enhance defect control and yield improvement in advanced processes such as lithography, etching, and wet cleaning [5].