California NanoSystems Institute, ‡Department of Chemistry and Biochemistry, §Department of Materials Science and Engineering, and ∥Department of Psychiatry and Biobehavioral Health, Semel Institute for Neuroscience and Human Behavior, and Hatos Center for Neuropharmacology, University of California, Los Angeles , Los Angeles, California 90095, United States.
Department of Chemistry and International Institute for Nanotechnology and #Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
Nano Lett. 2017 May 10;17(5):3302-3311. doi: 10.1021/acs.nanolett.7b01236. Epub 2017 Apr 25.
We designed and fabricated large arrays of polymer pens having sub-20 nm tips to perform chemical lift-off lithography (CLL). As such, we developed a hybrid patterning strategy called polymer-pen chemical lift-off lithography (PPCLL). We demonstrated PPCLL patterning using pyramidal and v-shaped polymer-pen arrays. Associated simulations revealed a nanometer-scale quadratic relationship between contact line widths of the polymer pens and two other variables: polymer-pen base line widths and vertical compression distances. We devised a stamp support system consisting of interspersed arrays of flat-tipped polymer pens that are taller than all other sharp-tipped polymer pens. These supports partially or fully offset stamp weights thereby also serving as a leveling system. We investigated a series of v-shaped polymer pens with known height differences to control relative vertical positions of each polymer pen precisely at the sub-20 nm scale mimicking a high-precision scanning stage. In doing so, we obtained linear-array patterns of alkanethiols with sub-50 nm to sub-500 nm line widths and minimum sub-20 nm line width tunable increments. The CLL pattern line widths were in agreement with those predicted by simulations. Our results suggest that through informed design of a stamp support system and tuning of polymer-pen base widths, throughput can be increased by eliminating the need for a scanning stage system in PPCLL without sacrificing precision. To demonstrate functional microarrays patterned by PPCLL, we inserted probe DNA into PPCLL patterns and observed hybridization by complementary target sequences.
我们设计并制造了具有亚 20nm 尖端的聚合物笔的大型阵列，以进行化学撬离光刻（CLL）。 因此，我们开发了一种称为聚合物笔化学撬离光刻（PPCLL）的混合图案化策略。 我们使用金字塔形和 V 形聚合物笔阵列展示了 PPCLL 图案化。 相关模拟揭示了聚合物笔接触线宽度与另外两个变量之间的纳米级二次关系：聚合物笔基线宽度和垂直压缩距离。 我们设计了一个由间隔排列的平底聚合物笔阵列组成的印章支撑系统，这些笔比所有其他笔尖聚合物笔都高。 这些支撑物部分或完全抵消了印章的重量，因此也起到了调平系统的作用。 我们研究了一系列具有已知高度差的 V 形聚合物笔，以在亚 20nm 范围内精确控制每个聚合物笔的相对垂直位置，从而模拟高精度扫描台。 通过这样做，我们获得了具有亚 50nm 至亚 500nm 线宽和可调节的亚 20nm 线宽的烷硫醇的线性阵列图案。 CLL 图案线宽与模拟预测的线宽一致。 我们的结果表明，通过对印章支撑系统进行明智的设计和对聚合物笔基线宽度进行调整，可以在不牺牲精度的情况下消除 PPCLL 中对扫描台系统的需求，从而提高吞吐量。 为了展示通过 PPCLL 图案化的功能微阵列，我们将探针 DNA 插入 PPCLL 图案中，并观察互补靶序列的杂交。
