Princeton University

School of Engineering & Applied Science

Flexible Polymer Mold and UV-Curable Materials for Nanoimprint and Advanced Nanofabrication

Qi Zhang
Prof. Chou
Engineering Quadrangle J401
Thursday, May 3, 2018 - 10:00am to 11:30am

As an emerging nanofabrication technique, nanoimprint lithography has inspired and achieved tremendous inventions of high-performance electronic, photonic, biological devices. However, challenges are still present before embracing 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 SiO2 master molds were built with new features from simple 1D grating molds and thermal NILs. (2) Sub-30 nm resolution, large-area PFPE-based flexible hybrid mold structures were proposed, demonstrated and applied to UV NIL with overlay alignment ability, great fidelity 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.