Moura Cleverson Alves da Silva, Belmonte Guilherme Kretzmann, Reddy Pulikanti Guruprasad, Gonslaves Kenneth E, Weibel Daniel Eduardo
Department of Chemical Physics, Chemical Institute, UFRGS Porto Alegre 91501-970 RS Brazil
School of Basic Sciences, Indian Institute of Technology Mandi Mandi - 175001 Himachal Pradesh India.
RSC Adv. 2018 Mar 19;8(20):10930-10938. doi: 10.1039/c7ra12934c. eCollection 2018 Mar 16.
A detailed investigation to understand the mechanism of the resist action at a fundamental level is essential for future Extreme Ultraviolet Lithography (EUVL) resists. The photodynamics study of a newly developed hybrid nonchemically amplified 2.15%-MAPDSA-MAPDST resist using synchrotron radiation excitation at 103.5 eV (12 nm) is presented. Antimony was incorporated in the resist as a heavy metal absorption center in the form of antimonate (2.15%). The results showed the fast decomposition rate of the radiation sensitive sulfonium triflate. HR-XPS and sulfur L-NEXAFS spectra of the copolymer films revealed that after irradiation the Ar-S-(CH) sulfonium group bonded to the phenyl ring resisted the EUV excitation. Those results confirmed the polarity switching mechanism from hydrophilic sulfonium triflates to hydrophobic aromatic sulfides obtained in previous results. The inorganic component SbF included in the resist formulations as an EUV absorption enhancer was particularly illustrative of the photofragmentation process. F 1s and O 1s HR-XPS spectra showed that fluorine remains linked to the antimony, even after 15 min of irradiation. A change of the antimony oxidation state was also observed with an increase in irradiation time. The presence of the heavy metal may control the high energy deposited on the resist which finally led to very well resolved 20 nm isolated line patterns by EUVL. The 10 times improved sensitivity compared with previous poly-MAPDST resists studied in the past showed the potential of this class of hybrid resists for next generation semiconductor industry applications.
从基础层面详细研究光刻胶抗蚀作用机制对于未来极紫外光刻（EUVL）光刻胶至关重要。本文介绍了一种新开发的混合非化学放大2.15%-MAPDSA-MAPDST光刻胶在103.5 eV（12 nm）同步辐射激发下的光动力学研究。抗锑酸盐（2.15%）形式的锑作为重金属吸收中心被引入光刻胶中。结果表明，辐射敏感的三氟甲磺酸锍分解速度很快。共聚物薄膜的高分辨X射线光电子能谱（HR-XPS）和硫L边近边X射线吸收精细结构光谱（sulfur L-NEXAFS）显示，辐照后与苯环相连的Ar-S-(CH)锍基团抵抗了EUV激发。这些结果证实了先前结果中得到的从亲水性三氟甲磺酸锍到疏水性芳族硫化物的极性转换机制。作为EUV吸收增强剂包含在光刻胶配方中的无机组分SbF尤其说明了光碎裂过程。F 1s和O 1s HR-XPS光谱表明，即使辐照15分钟后，氟仍与锑相连。随着辐照时间增加，还观察到锑氧化态的变化。重金属的存在可能控制了沉积在光刻胶上的高能，最终通过EUVL得到了分辨率很好的20 nm孤立线条图案。与过去研究的先前聚-MAPDST光刻胶相比，灵敏度提高了10倍，表明这类混合光刻胶在下一代半导体工业应用中的潜力。
