Nanoimprint lithography for scalable manufacturing of optical metasurfaces
1 Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
2 Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
3 Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
4 POSCO-POSCTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
Abstract

Metasurfaces, composed of two-dimensional meta-atoms with subwavelength dimensions, enable precise manipulation of light wavefronts, facilitating lensing, color filtering, holography, and augmented reality in a compact form factor. To realize desired optical functionalities, metasurface fabrication requires nanoscale patterning of high‑refractive‑index (high-index) materials. Conventionally, electron beam lithography (EBL) has been widely utilized in combination with deposition techniques such as plasma-enhanced chemical vapor deposition. Despite offering high-resolution capabilities, EBL suffers from low throughput, high cost, and limited scalability due to its direct-writing nature. To overcome these limitations, nanoimprint lithography (NIL) has emerged as a promising low-cost, high-throughput alternative. However, conventional NIL resins have low refractive indices (~1.5), restricting their direct optical use and necessitating additional steps to enhance the refractive index. To address this challenge, we review two strategies for the scalable fabrication of metasurfaces: hybrid materials, which apply high‑index atomic layer deposition (ALD) coatings onto imprinted patterns, and particle‑embedded resins (PERs), which incorporate high‑index nanoparticles directly into the imprint resin. This review highlights recent progress in these NIL‑based approaches and discusses their potential to bridge the gap between laboratory‑scale demonstrations and large‑scale industrial production of metasurfaces.

Keywords

nanoimprint lithography; metasurface; commercialization of metasurfaces; metaphotonics; manufacturing platform; high refractive index

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