Photocurable silsesquioxane-based formulations as versatile resins for nanoimprint lithography

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Nanoimprint lithography (NIL) requires advanced materials for high-resolution pattern replication.
• Developing functional imprint materials with tailored properties is crucial for NIL advancements.

Purpose of the Study:

• To evaluate methacrylate octafunctionalized silsesquioxane (SSQMA) as a high-performance material for UV-based NIL and step-and-flash imprint lithography (SFIL).
• To characterize the physical and chemical properties of SSQMA-based formulations for NIL applications.

Main Methods:

• Formulation of SSQMA with acrylic additives to achieve desired viscosity (0.8–50 cP).
• Evaluation of cured SSQMA properties: volumetric shrinkage, Young's modulus, plasma resistance, UV transparency, and media resistance.
• Replication of nanostructures using UV-NIL and SFIL techniques with SSQMA-based resins.
• Assessment of mold and replica fidelity, feature size reproduction (down to 50 nm), and durability over multiple imprinting cycles.

Main Results:

• SSQMA formulations exhibited low shrinkage (4%), high Young's modulus (2.445–4.272 GPa), and excellent resistance to plasma and media.
• High-aspect-ratio nanostructures (up to 4.5) and sub-50-nm features were successfully reproduced using UV-NIL and SFIL.
• Replicated structures showed excellent imprint fidelity and minimal residual thickness.
• SSQMA-based resins demonstrated durability over 20 imprinting cycles without collapse or contamination.

Conclusions:

• SSQMA is an ideal functional imprint material for UV-based NIL and SFIL due to its favorable properties.
• The material enables cost-effective and reliable fabrication of high-resolution nanostructures.
• SSQMA-based resins are suitable for various physical contact NIL processes.