SNM: Massively Parallel Nanopatterning by Print and Repeat Nanopantography with Reusable Stencil Masks

对越来越小的电子和光子设备的需求并没有停止的迹象，实际上还在加速。对于制造速度和功能远远超过当前能力的未来集成电路来说，制造尺寸小于10纳米(十亿分之一米，或者说比人的头发小约1万倍)的图案是必不可少的，这可能会给计算机、信息存储和清洁能源设备带来革命性的变化。生物应用，如快速DNA测序，也需要如此小的维度。尽管技术已经证明了这一点，但它们与制造业的整合受到严重的技术和/或经济问题的阻碍。此前，研究人员展示了一种可以解决这些问题的纳米造影术方法。在这个过程中，通过将一束正离子引导到基板上，在诸如硅片之类的基板上形成图案。离子被聚焦在数十亿个位置同时写入尺寸小至3纳米的图案。过去的研究受到聚焦结构(聚焦离子的透镜阵列，就像玻璃透镜聚焦光线一样)必须结合在基片上的事实的限制，这导致了低吞吐量。新的研究将通过允许透镜阵列分开来解决这个问题，这样它就可以在多个衬底上使用。这将使许多先进电子设备的应用受益于现代生活的方方面面，特别是能源和健康行业，具有明显的社会效益。这个具有挑战性的项目将带来新的知识，并将促进这一重要科学技术领域的教育。静电微透镜建立在衬底上，使用标准的微电子制造方法。施加到透镜阵列的电压使进入数十亿个微透镜中的每个微透镜的离子束聚焦在衬底上。利用纳米造影术，直径300纳米的静电透镜阵列在硅中创建尺寸小至3纳米的纳米图案。虽然纳米技术可以形成分辨率非常高的复杂图案，但这项技术依赖于在每个衬底上制造微透镜阵列，这增加了工艺的复杂性。为了解决这个问题，PI计划将微透镜阵列与衬底分离，以便它可以重复用于后续衬底的图案化。这包括制作包含微透镜阵列的模板掩模，该模板掩模将被放置在连续的基板上以演示打印和重复过程。采用这种方法将极大地提高生产能力，使纳米制版成为一种值得制造的工艺。实验工作将由离子轨迹模拟来补充，以实现最佳聚焦，这是模板掩模和衬底之间的间隙以及等离子束条件的函数。利用分子动力学模拟研究了O+和O2+在石墨烯上的纳米特征刻蚀，重点研究了离子能量和质量对特征尺寸的影响。将为潜在的试生产生产线演示质量控制措施。这项工作将展示一种大规模并行的方法，使用可重复使用的模板掩模透镜阵列，在2-D材料(石墨烯和WS2)的衬底上重复写入纳米管，分辨率高于最先进的3 nm。在2D层中形成的纳米孔、点和带将被表征为等离子体和其他光电特性。纳米盘将从大面积的WS2薄膜中雕刻出来。显微光致发光将被用来表征它们的发光性能。

The demand for ever-smaller electronic and photonic devices shows no sign of stopping, and in fact it is accelerating. Fabricating patterns with sizes less than 10 nanometers (10 billionths of a meter, or about 10,000 times smaller than a human hair) is essential for the manufacturing of future integrated circuits with speeds and functionality far exceeding current capabilities, that could revolutionize computers, information storage, and clean energy devices. Biological applications such as rapid DNA sequencing also require such small dimensions. Although techniques have demonstrated this resolution, their integration into manufacturing is hampered by serious technical and/or economic issues. Previously, the researchers demonstrated a nanopantography method that could address these issues. In this process, patterns are formed on a substrate such as a silicon wafer by directing a beam of positive ions at the substrate. Ions are focused to write patterns at sizes as small as 3 nanometers simultaneously at billions of locations. The past research was limited by the fact that the focusing structure (an array of lenses that focus ions much as glass lenses focus light) had to be incorporated on the substrate, which resulted in low throughput. The new studies will solve this problem by allowing the lens array to be separate, so that it can be used on multiple substrates. This will enable many applications for advanced electronic devices that benefit all aspects of modern life, especially the energy and health industries, with clear societal benefits. This challenging project will lead to new knowledge and will advance education in this important area of science and technology.The electrostatic microlenses were built on the substrate, using standard microelectronic manufacturing methods. Voltages applied to the lens array cause ion beamlets entering each of billions of microlenses to be focused on the substrate. Using nanopantography, arrays of 300 nm diameter electrostatic lenses create nano-patterns in Si with sizes as small as 3 nm. While nanopantography can form complex patterns with very high resolution, the technique relies on the fabrication of a microlens array on each substrate, adding complexity to the process. To address this issue, the PIs plan on separating the microlens array from the substrate, so that it can be reused for patterning of subsequent substrates. This involves the fabrication of a stencil mask, containing the microlens array, which will be placed on sequential substrates to demonstrate a print-and-repeat process. Following this approach will greatly improve throughput, making nanopantography a manufacturing-worthy process. Experimental work will be complemented by ion trajectory simulations to achieve best focus, as a function of gap between the stencil mask and the substrate, and plasma beam conditions. Molecular Dynamics simulations will be used to study nanofeature etching in graphene on SiO2 by O+ and O2+, with an emphasis on the effect of ion energy and mass on feature size. Quality control measures will be demonstrated for potential pilot line manufacturing. The work will demonstrate a massively parallel method to repeatedly write nanopatterns in 2-D materials (graphene and WS2) on a substrate with a better than the state-of-the-art resolution of 3 nm, using a reusable stencil mask lens array. Nano holes, dots, and ribbons formed in the 2D layers will be characterized for plasmonic and other optoelectronic properties. Nanodisks will be carved out of large area WS2 films. Micro-photoluminescence will be used to characterize their light emitting properties.