Photocurable silsesquioxane-based formulations as versatile resins for nanoimprint lithography.
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.
Lee
Bong Kuk
BK
The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Cha
Nam-Goo
NG
Hong
Lan-Young
LY
Kim
Dong-Pyo
DP
Tanaka
Hidekazu
H
Lee
Hea Yeon
HY
Kawai
Tomoji
T
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
D017646:Organosilicon Compounds; D000644:Quaternary Ammonium Compounds; D012117:Resins, Synthetic; D012997:Solvents; C018408:3-(trimethoxysilyl)propyldimethyloctadecylammonium; D010100:Oxygen