Three-Dimensional Nanolithography Guided by DNA Modular Epitaxy

Abstract

Lithographic scaling of periodic three-dimensional patterns is critical for advancing scalable nanomanufacturing. Current state-of-the-art quadruple patterning or extreme-UV lithography produce line pitch down to around 30 nm, which can be further improved 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 current state-of-the-art results. We use a DNA modular epitaxy approach to fabricate scaled 3D DNA masks with prescribed structural parameters (pitch, shape, 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 resolution of 7 nm and a vertical resolution of 2 nm. The DNA modular epitaxy-directed lithography achieves smaller pitch than the projected values for advanced technology node in field-effect transistors, and provides a potential complement to the existing lithographic tools towards advanced 3D nanomanufacturing.