Atomic-scale Thermal Behavior of Nanoimprinted 0.3-nm-High Step Patterns on PMMA Polymer Sheets
Atomic-scale Thermal Behavior of Nanoimprinted 0.3-nm-High Step Patterns on PMMA Polymer Sheets
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PMMA 聚合物片材上纳米压印 0.3 nm 高阶梯图案的原子级热行为
DOI：
10.1038/pj.2015.99
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发表时间：
2016
期刊：
影响因子：
2.8
通讯作者：
A. Matsuda and M. Yoshimoto
中科院分区：
文献类型：
--
作者：
G. Tan;Y. Nozawa;T. Funabasama;K. Koyama;M. Mita;S. Kaneko;M. Komura;A. Matsuda and M. Yoshimoto
图案化聚合物表面的分辨率极限已经引起了实用界和学术界的广泛关注。纳米压印工艺是实现简单、低成本、高通量纳米刻蚀的最有前途的技术之一。1到目前为止，已经展示了5 nm的新特征尺寸。2、3有几种类型的纳米压印。一种是热纳米印迹，它应用于热塑性聚合物，如聚甲基丙烯酸甲酯(PMMA)和聚苯乙烯(PS)。4，5最近，我们报道了利用热纳米压印技术在钠钙硅酸盐玻璃和聚甲基丙烯酸甲酯聚合物薄片上进行亚纳米尺度的表面图案化，6，7我们使用了原子阶梯状蓝宝石(α-Al_2O_3单晶)的自组织纳米图案模板作为压印模板。8原子阶梯蓝宝石衬底也被用来在低温9、10下生长高质量的薄膜，并作为样品阶段，用原子力显微镜(AFM)观察附着在表面的有机分子的空间形状。11、12这些印迹PMMA表面呈现规则排列的原子阶梯，台阶高约0.3 nm，反映了蓝宝石模板的图案。7进一步的原子尺度研究印迹条件，如印刷温度对转录的影响，被认为是发展原子尺度聚合物表面工程所必需的。此外，从科学和技术的角度来看，图案化聚合物表面的热变形和松弛都很有趣。在原子尺度上检查在PMMA表面形成的原子阶梯图案的热稳定性是很重要的，以便为诸如使用衬底观察大分子或生长功能薄膜之类的应用提供信息。在目前的工作中，我们研究了印迹温度对原子阶跃图案转录的影响。我们还利用高温原位原子力显微镜观察到了PMMA表面原子阶梯图案的原子尺度热变化。配备了样品加热平台的原位AFM设备使我们能够在高温下直接观察聚合物表面的热行为。
The resolution limit of patterning polymer surfaces has attracted much attention from both practical and academic viewpoints. The nanoimprint process is one of the most promising techniques for simple, low-cost and high-throughput nanopatterning. 1 To date, novel feature sizes o5nm have been demonstrated. 2, 3 There are several types of nanoimprinting. One is thermal nanoimprinting, which is applied to thermoplastic polymers such as poly (methyl methacrylate)(PMMA) and polystyrene (PS). 4, 5 Recently, we reported subnanometer-scale surface patterning on soda-lime silicate glasses and PMMA polymer sheets by the thermal nanoimprint technique, 6, 7 in which we applied a self-organized nanopattern mold of atomically stepped sapphire (α-Al2O3 single crystal) as the imprint template. 8 The atomically stepped sapphire substrates were also used for growing high quality thin films at low temperatures 9, 10 and as sample stages for observing the steric shape of organic molecules adhered to the surfaces by atomic force microscopy (AFM). 11, 12 These imprinted PMMA surfaces exhibited regularly arrayed atomic stairs with~ 0.3-nm-high steps, reflecting the sapphire template’s pattern. 7 Further atomic-scale investigations into the effect of imprinting conditions such as press temperature on transcription are thought to be necessary for the development of atomic-scale polymer surface engineering. In addition, thermal deformation and relaxation of patterned polymer surfaces are intriguing in the light of both scientific and technological perspectives. 13–15 It is important to examine the thermal stability of the atomically stepped pattern formed on a PMMA surface at the atomic scale to inform applications such as the use of substrates for observing macromolecules or growing functional thin films. In the present work, we examined the effect of imprinting temperature on the transcription of an atomic step pattern. We also observed atomicscale thermal changes in the atomically stepped pattern on the PMMA surface using high temperature in situ AFM. 16, 17 An in situ AFM apparatus equipped with a sample heating stage enabled us to observe the thermal behavior of the polymer surface directly at a high temperature.