Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
Nat Mater. 2021 May;20(5):683-690. doi: 10.1038/s41563-021-00930-7. Epub 2021 Apr 12.
Lithographic scaling of periodic three-dimensional patterns is critical for advancing scalable nanomanufacturing. Current state-of-the-art quadruple patterning or extreme-ultraviolet lithography produce a line pitch down to around 30 nm, which might be further scaled to sub-20 nm through complex post-fabrication processes. Herein, we report the use of three-dimensional (3D) DNA nanostructures to scale the line pitch down to 16.2 nm, around 50% smaller than state-of-the-art results. We use a DNA modular epitaxy approach to fabricate 3D DNA masks with prescribed structural parameters (geometry, pitch and critical dimensions) along a designer assembly pathway. Single-run reactive ion etching then transfers the DNA patterns to a Si substrate at a lateral critical dimension of 7 nm and a vertical critical dimension of 2 nm. The nanolithography guided by DNA modular epitaxy achieves a smaller pitch than the projected values for advanced technology nodes in field-effect transistors, and provides a potential complement to the existing lithographic tools for advanced 3D nanomanufacturing.
周期性三维图案的光刻缩放对于推进可扩展的纳米制造至关重要。当前最先进的四重图案化或极紫外光刻可将线距缩小到约 30nm，通过复杂的后制造工艺，可能进一步缩小到 20nm 以下。在此，我们报告使用三维（3D）DNA 纳米结构将线距缩小到 16.2nm，比最先进的结果小约 50%。我们使用 DNA 模块外延方法来制造具有预定结构参数（几何形状、间距和关键尺寸）的 3D DNA 掩模，沿着设计的组装路径进行。单次运行的反应离子刻蚀随后将 DNA 图案转移到 Si 衬底上，其横向关键尺寸为 7nm，纵向关键尺寸为 2nm。由 DNA 模块外延引导的纳米光刻实现的间距比场效应晶体管中先进技术节点的预计值小，为先进的 3D 纳米制造提供了现有光刻工具的潜在补充。
