Flexible Polymer Mold And UV-Curable Materials For Nanoimprint And Advanced Nanofabrication

Abstract

As an emerging nanofabrication technique, nanoimprint lithography (NIL) has inspired and realized tremendous inventions of high-performance electronic, photonic, biological and nanodevices. However, challenges are still present in order to embrace NIL in a full-scale industrial production: (1) Large-area, high-throughput and cost-efficient master mold fabrication with novel patterns; (2) New mold architecture with balance of conformal contact and desired resolution; (3) Novel imprinting materials for temporal pattern transfer or direct utilization.

This work contributes several unique solutions: (1) By manipulating post-imprint Cr etching mask transfer (e.g., inversion, transformation and multiplication) with multi-layer material stack, shadowed film deposition and consecutive imprints, large-area (up to 4-inch wafer scale) SiO2 master molds were built with new features (135 nm-pitch pillar array, 1 µm-pitch triangular pillar array and moiré pattern array) from simple 1D grating molds and thermal NILs. (2) Sub-30 nm resolution, 50 × 20 cm2 PFPE-based flexible hybrid mold structures were proposed, demonstrated and applied to UV NIL with overlay alignment ability (< 0.12º orientation error), great fidelity (> 98.5%) and great potential in continuous roller UV NIL fabrication. (3) High-performance POSS UV NIL resist systems, featuring two polymerization mechanisms, ideal mechanical and chemical stability, and great etching selectivity to regular Si-type substrate materials. (4) Novel one-step transfer printing nanofabrication approach to deliver metallic thin-film nanostructures to patterned rigid substrates and extreme fragile and soft plastic films.