Electric-Field-Assisted Contact Mode AFM-Based Nanolithography with Low Stiffness Conductive Probes
Electric-Field-Assisted Contact Mode AFM-Based Nanolithography with Low Stiffness Conductive Probes
复制标题
具有低刚度导电探针的基于电场辅助接触模式 AFM 的纳米光刻
DOI：
10.1115/1.4054316
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发表时间：
2022
影响因子：
1
通讯作者：
Deng, Jia
中科院分区：
文献类型：
--
作者：
Zhou, Huimin;Jiang, Yingchun;Dmuchowski, Christopher M;Ke, Changhong;Deng, Jia
电场辅助原子力显微镜（E-AFM）纳米光刻是一种具有多种应用的新型聚合物图案技术。 E-AFM 使用带有导电涂层的偏置原子力显微镜 (AFM) 尖端来制作探针与样品相互作用很少的图案，从而避免了尖端磨损，这是基于接触模式 AFM 的光刻的一个主要问题，接触模式通常需要高探针与样品接触力来制造纳米图案；然而，相对较大的尖端半径和较大的尖端与样品分离限制了其制造高分辨率纳米图案的能力。在本文中，我们开发了一种接触模式 E-AFM 纳米光刻方法，使用低刚度 (∼0.16 N/m) 的导电 AFM 探针实现聚甲基丙烯酸甲酯 (PMMA) 的高分辨率纳米光刻。纳米光刻工艺通过在金属基底上的聚合物薄膜上偏置 AFM 探针来生成特征。施加在 AFM 尖端上的小恒力 (0.5–1 nN) 有助于尖端与薄膜接触，从而提高纳米加工分辨率。这种 E-AFM 纳米光刻方法可实现高分辨率纳米图案，特征宽度低至~16nm，小于所用导电 AFM 探针标称尖端半径的一半。
Electric-field-assisted atomic force microscope (E-AFM) nanolithography is a novel polymer-patterning technique that has diverse applications. E-AFM uses a biased atomic force microscope (AFM) tip with conductive coatings to make patterns with little probe–sample interaction, which thereby avoids the tip wear that is a major issue for contact-mode AFM-based lithography, which usually requires a high probe–sample contact force to fabricate nanopatterns; however, the relatively large tip radius and large tip-sample separation limit its capacity to fabricate high-resolution nanopatterns. In this paper, we developed a contact mode E-AFM nanolithography approach to achieve high-resolution nanolithography of poly (methyl methacrylate) (PMMA) using a conductive AFM probe with a low stiffness (∼0.16 N/m). The nanolithography process generates features by biasing the AFM probe across a thin polymer film on a metal substrate. A small constant force (0.5–1 nN) applied on the AFM tip helps engage the tip-film contact, which enhances nanomachining resolution. This E-AFM nanolithography approach enables high-resolution nanopatterning with feature width down to ∼16 nm, which is less than one half of the nominal tip radius of the employed conductive AFM probes.