冷冻电镜如何“跨界”助力芯片光刻取得新突破

Core Insights - The research team from Peking University has made significant advancements in understanding the microstructure and entanglement behavior of photoresist molecules in liquid environments using cryo-electron tomography, which can guide the development of industrial solutions to reduce lithography defects [1][2]. Group 1: Importance of Lithography - Lithography is a critical step in semiconductor manufacturing, essentially "printing" circuit patterns onto semiconductor wafers like silicon [1]. - The development process of photoresist involves a developer solution that selectively dissolves exposed areas, where the adsorption and entanglement of photoresist molecules are key factors affecting defect formation on the wafer surface, directly impacting chip performance and yield [1]. Group 2: Use of Cryo-Electron Tomography - The research team has introduced cryo-electron tomography to the semiconductor field, designing a sample preparation method closely integrated with the lithography process [2]. - After standard lithography exposure, the developer solution containing photoresist polymers is rapidly frozen to capture the true conformation of the photoresist in solution, allowing for high-resolution three-dimensional reconstruction of the polymer structure and interface distribution [2]. Group 3: Implications for the Industry - The three-dimensional reconstruction revealed that previously believed dispersion of dissolved photoresist polymers is primarily adsorbed at the gas-liquid interface, with the team observing "coagulated entanglements" of the polymers [3]. - The research proposes two effective solutions: suppressing entanglement and capturing at the interface, which successfully eliminated over 99% of pattern defects caused by photoresist residues on 12-inch wafers, demonstrating high reliability and repeatability [3]. - This research highlights the potential of cryo-electron tomography as a powerful tool for analyzing liquid-phase interfacial reactions at the atomic/molecular scale, paving the way for improved lithography precision and yield [3].