发表机构
IMEC; Chemistry and Biology of Metals laboratory, UMR 5249 CNRS-CEA-UGA; Elettra-Sincrotrone Trieste; Department of Chemistry, University of Iceland, Science Institute（imec; 金属化学与生物学实验室，UMR 5249 CNRS-CEA-UGA; 的里雅斯特 Elettra 同步辐射中心; 冰岛大学科学研究所化学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究发现五氟苯基三氟甲磺酸酯虽具有高EUV吸收，但其解离光电离产生大量碎片且无法生成所需强光酸，因此不适合作为EUV光刻的光致产酸剂，强调了理解基本机制对合理设计光刻胶的重要性。
AI 中文摘要
五氟苯基三氟甲磺酸酯已被探索作为下一代化学放大光刻胶中用于极紫外（EUV）光刻的高吸收性中性光致产酸剂（PAG）候选物。尽管增加氟化程度增强了EUV吸收，但本研究表明，这种方法并不一定提高光酸生成效率。利用EUV扫描仪92 eV光子能量下的光电子-光离子符合（PEPICO）光谱结合量子化学计算，系统研究了五氟苯基三氟甲磺酸酯的解离光电离过程。光电离质谱显示广泛的碎裂，母体离子仅占总信号的3.1%，而CF$_3^+$是主要产物离子。计算出的出现能与实验趋势吻合良好，并支持涉及依次丢失SO$_2$、CF$_3$和CO的连续碎裂途径。关键的是，没有任何主要解离通道产生能够形成三氟甲磺酸的前体，而三氟甲磺酸是化学放大光刻胶中高效脱保护反应所需的强光酸。结合先前表明类似不利碎裂的解离电子附着研究，结果表明尽管五氟苯基三氟甲磺酸酯具有高EUV吸收截面，但它不适合作为EUV光刻的PAG。这些发现强调了理解基本光电离和电子相互作用机制以指导下一代高性能EUV光刻胶合理设计的重要性。
英文摘要
Pentafluorophenyl triflate has been explored as a highly absorbing neutral photoacid generator (PAG) candidate for next generation chemically amplified resists used in extreme ultraviolet (EUV) lithography. Although increased fluorination enhances EUV absorption, this study demonstrates that such an approach does not necessarily improve photoacid generation efficiency. Using photoelectron-photoion coincidence (PEPICO) spectroscopy at the 92 eV photon energy of the EUV scanners in combination with quantum chemical calculations, the dissociative photoionization of pentafluorophenyl triflate was systematically investigated. The photoionization mass spectrum reveals extensive fragmentation, with the parent ion contributing only 3.1 % of the total signal and CF$_3^+$ representing the dominant product ion. Computed appearance energies align well with experimental trends and support a sequential fragmentation pathway involving loss of SO$_2$, CF$_3$, and CO. Crucially, none of the major dissociation channels yield precursors capable of forming triflic acid, the strong photoacid required for efficient deprotection reactions in chemically amplified resists. Combined with previous dissociative electron attachment studies indicating similarly unfavorable fragmentation, the results demonstrate that despite its high EUV absorption cross section, pentafluorophenyl triflate is unsuitable as a PAG for EUV lithography. The findings highlight the importance of understanding fundamental photoionization and electron interaction mechanisms to guide the rational design of next generation high performance EUV photoresists.
