Norbornene and Epoxide-Substituted Silsesquioxane Photoresists with High-Sensitivity and Stability

作者：Ruisheng Zhang, Miao Li, Xinyu Lu, Qiang Li, Feng Luo, Huayu Qiu, Guang‐Peng Wu · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.5c06472 · 被引用次数：5 · 研究领域：Silicone and Siloxane Chemistry、Copper Interconnects and Reliability、Photopolymerization techniques and applications

The evolution of photoresists has been accelerated by escalating demands for pattern fidelity, particularly with the breakthrough of extreme ultraviolet (EUV) lithography in achieving sub-20 nm resolution. Herein, we report two kinds of partially alkyl-substituted silsesquioxane (PASS) resists to overcome the dual challenges of hydrogen silsesquioxane (HSQ) in EUV applications: inherent instability and unsatisfactory sensitivity. Through strategic integration with a photoacid generator (PAG), the optimized formulation demonstrates exceptional lithographic performance, achieving 14 nm resolution (line edge roughness of 1.3 nm) with a sensitivity of 4.3 μC/cm 2 and a contrast of 5.1 under electron beam lithography. Besides, the PASS resist exhibits a 360-day gelation period and a 160-fold improvement over conventional HSQ. Systematic investigations combining micro-Raman spectroscopy and model compound studies reveal that PAG enhances both sensitivity and shelf stability through dual mechanisms: (1) a photoacid-catalyzed cross-linking reaction between siloxanes and (2) nucleophilic attack inhibition at silicon centers. These advances, coupled with successful electron-beam and ultraviolet patterning demonstrations and structural tunability, establish PASS resists as viable candidates for EUV lithography in semiconductor nanofabrication.