Liu Yue, Wang Dong, Wang Qianqian, Kang Wenbing
National Engineering Research Center for Colloidal Materials, School of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Ji'nan, Shandong, 250100, China.
Small Methods. 2024 Dec;8(12):e2400112. doi: 10.1002/smtd.202400112. Epub 2024 Sep 23.
Advanced photoresists must satisfy stringent sensitivity requirements while maintaining the ability to print ever-shrinking critical dimensions. However, the unavoidable acid diffusion associated with chemically amplified photoresists has led to a trade-off between resolution, line-edge roughness, and sensitivity, which presents a significant challenge for high-resolution lithography. To address this issue, a novel class of alkene-functionalized nonionic perfluorinated photoacid generators (PAGs) is developed. These fluorine-rich compounds significantly enhance the photochemical reactivity due to the introduction of abundant F-elements, thereby improving sensitivity. Upon irradiation by ultraviolet light or electrons, they generate long-chain perfluorinated sulfonic acids with large sizes and minimal diffusion ranges, effectively suppressing acid diffusion. Furthermore, by employing these polymerizable PAG monomers, PAG-bound polymers are synthesized that are likely to achieve higher resolution by minimizing acid diffusion. Lithography performance demonstrated patterning of sub-45 nm lines at an electron beam dose of 29 µC cm. Overall, the developed perfluorinated PAGs and PAG-bound polymer photoresists are promising candidates for achieving high-sensitivity and high-resolution nano-patterning.
先进的光刻胶必须满足严格的感光度要求，同时还要保持印刷不断缩小的关键尺寸的能力。然而，与化学增幅型光刻胶相关的不可避免的酸扩散导致了分辨率、线边缘粗糙度和感光度之间的权衡，这对高分辨率光刻构成了重大挑战。为了解决这个问题，开发了一类新型的烯烃官能化非离子型全氟光酸产生剂（PAG）。这些富含氟的化合物由于引入了大量的氟元素而显著提高了光化学反应活性，从而提高了感光度。在受到紫外线或电子照射时，它们会生成尺寸大且扩散范围最小的长链全氟磺酸，有效抑制酸扩散。此外，通过使用这些可聚合的PAG单体，合成了与PAG结合的聚合物，通过最小化酸扩散可能实现更高的分辨率。光刻性能表明，在电子束剂量为29 μC/cm时可实现45纳米以下线条的图案化。总体而言，所开发的全氟PAG和与PAG结合的聚合物光刻胶是实现高感光度和高分辨率纳米图案化的有前途的候选材料。
