用于EUV图案化的新型氧化锌簇交联策略的辐射化学

Radiation chemistry of a novel zinc-oxo cluster crosslinking strategy for EUV patterning

由于C=C双键交联反应机制的成熟,金属氧化物光刻胶得到了广泛的发展.然而,由于不稳定的C=C双键,这种材料需要低温和遮光存储.在此,首次在金属氧簇中提出了C-F键交联策略用于光刻图案化.以光刻胶Zn-TBA为例,它形成光滑无缺陷的薄膜,且表面粗糙度Rq小于0.2 nm.使用极紫外(EUV)干涉掩模,在65 mJ cm^(-2)曝光剂量下形成37.5 nm的半周期(HP)图案.在EUV曝光和正己烷显影后,通过原子力显微镜(AFM)观察到负性光刻胶形貌.重要的是,Zn-TBA可以在室温和明亮的环境中储存.除了脱羧之外,我们还提出光引发的C-F交联是Zn-TBA图案的主要贡献者,并通过高分辨率X射线光电子能谱(HRXPS)和密度泛函理论(DFT)计算得以证明.这种新颖的光刻机制为下一代金属基材料的设计提供了新的思路.

Metal oxide-based photoresists are extensively developed due to the mature mechanism of C=C double bond crosslinking reaction.However,such materials require low-temperature and light-shielded storage due to unstable C=C double bond.Herein,the C-F bond crosslinking strategy was first proposed in metal-oxo clusters for lithography patterning.Take the photoresist Zn-TBA for example,it could form smooth and defect-free thin films with the surface roughness Rq being smaller than 0.2 nm.With an Extreme ultraviolet interference mask,the patterns could be resolved into 37.5-nm half-pitch at 65 mJ cm^(-2).After being exposed and developed with n-hexane,a negative tone image was observed,and the prominent patterns morphology was confirmed by an atomic force microscope.Importantly,Zn-TBA could be stored at room temperature and bright environment.Besides decarboxylation,we proposed that photoinitiated C-F cross-linking was a major contributor to Zn-TBA patterns,which was convinced by high-resolution X-ray photoelectron spectra and theoretical density functional theory calculations.The novel lithographic mechanism provides excellent insight for the next generation of metal-based materials design.