title: Photocurable silsesquioxane-based formulations as versatile resins for nanoimprint lithography.
abstract: Methacrylate octafunctionalized silsesquioxane (SSQMA) was shown to be an ideal material with high performance for ultraviolet (UV)-based nanoimprint lithography (NIL). The total viscosity of SSQMA-based formulations was adjusted to between 0.8 and 50 cP by incorporating low-viscosity acrylic additives, making the formulations suitable for UV-based NIL. The cured SSQMA-based formulations showed numerous desirable characteristics, including low volumetric shrinkage (4%), high Young's modulus (2.445-4.272 GPa), high resistance to oxygen plasma, high transparency to UV light, and high resistance to organic/aqueous media, as a functional imprint material for UV-based NIL and step-and-flash imprint lithography (SFIL). Using both techniques, the SSQMA-based formulations were easily transferred to relief structures with excellent imprint fidelity and minimal residual thickness. Formulations containing 50% SSQMA (wt %) were able to reproduce high-aspect-ratio nanostructures with aspect ratios as high as 4.5 using bilayer SFIL. Transparent rigiflex molds and hard replica molds with sub-50-nm size features were reproducibly duplicated by using UV-NIL with the SSQMA-based resin. Nanostructures with feature sizes down to 50 nm were successfully reproduced using these molds in both UV- and thermal-NIL processes. After repeating 20 imprinting cycles at relatively high temperature and pressure, no detectable collapse or contamination on the replica surface was observed. These properties of the SSQMA-based resins make them suitable as inexpensive and convenient components in all NIL processes that are based on physical contact.
authors: The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
authors: Bong Kuk
authors: BK
authors: Lee
authors: Nam-Goo
authors: NG
authors: Cha
authors: Lan-Young
authors: LY
authors: Hong
authors: Dong-Pyo
authors: DP
authors: Kim
authors: Hidekazu
authors: H
authors: Tanaka
authors: Hea Yeon
authors: HY
authors: Lee
authors: Tomoji
authors: T
authors: Kawai
mesh_terms: D036103:Nanotechnology / Q000379:methods*; D017646:Organosilicon Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D055668:Photochemical Processes; D011327:Printing / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014466:Ultraviolet Rays; D014783:Viscosity
chemical_list: D017646:Organosilicon Compounds; D000644:Quaternary Ammonium Compounds; D012117:Resins, Synthetic; D012997:Solvents; C018408:3-(trimethoxysilyl)propyldimethyloctadecylammonium; D010100:Oxygen