High-Resolution Functional Epoxysilsesquioxane-Based Patterning Layers for Large-Area Nanoimprinting

Abstract

Epoxysilsesquioxane (SSQ)-based materials have been developed as patterning layers for large-area and high-resolution nanoimprinting. The SSQ polymers, poly(methyl-co-3-glycidoxypropyl) silsesquioxanes (T(Me)T(Ep)), poly(phenyl-co-3-glycidoxypropyl) silsesquioxanes (T(Ph)T(Ep)), and poly(phenyl-co-3-glycidoxypropyl-co-perfluorooctyl) silsesquioxanes (T(Ph)T(Ep)T(Fluo)), were precisely designed and synthesized by incorporating the necessary functional groups onto the SSQ backbone. The materials possess a variety of characteristics desirable for NIL, such as great coatability, high modulus, good mold release, and excellent dry etch resistance. In particular, the presence of epoxy functional groups allows the resists to be solidified within seconds under UV exposure at room temperature, and the presence of the fluoroalkyl groups in the SSQ resins greatly facilitate mold release after the imprint process. In addition, the absence of metal in the resins makes the materials highly compatible with applications involving Si CMOS integrated circuits fabrication.

Rapid and conformal coating of polymer resins by airbrushing for continuous and high-speed roll-to-roll nanopatterning: parametric quality controls and extended applications

“…For the substrate materials, we choose polyethylene terephthalate (PET) films and Si wafers as the representatives of flexible and rigid substrates, respectively. In this study, we use epoxy-silsesquioxane (SSQ) mixed with 3 wt% photoacid generator as a UV-curable resist material [13] whose concentration can be modulated (e.g., 2, 5, 10, and 20 wt%) by diluting in propylene glycol methyl ether acetate (PGMEA). Airbrushing time of the diluted SSQ resist onto the target substrate is varied (e.g., 1, 2, and 3 s).…”

Continuous Patterning of Nanogratings by Nanochannel‐Guided Lithography on Liquid Resists

“…As a suitable liquid resist, we introduce UV-curable epoxy-based silsesquioxane (SSQ), which is a viscous liquid polymer that solidifi es into a cross-linked high-modulus material upon UV curing without signifi cant volume shrinkage. [ 8 ] Whereas a relatively large force is required to "inscribe" nanopatterns on a solid substrate by plastically deforming the material, a liquid resist can readily "infi ltrate" the openings in the mold grating upon contact under slight mechanical force. These nanochannelguided liquid streaks are continuously extruded from the contact region as the mold translates along the surface, enabling continuous formation of nanograting patterns without elastic recovery.…”

“…To prepare the substrates, a sheet of PFA or PET was fi rst cleaned by acetone and isopropyl alcohol (IPA) followed by nitrogen drying and was then treated by O 2 plasma (17 sccm, 80 W, 30 s) to remove residual moisture and increase the surface energy by forming -OH surface groups for the ease of resist coating. Fluorine treatment on the PET surface was performed by vapor deposition of a fl uorinated surfactant, (tridecafl uoro-1,1,2,2-tetrahydrooctyl)trichlorosilane (GELEST, Inc.), for 15 min at 90 ° C. To coat the substrates with UV-curable liquid resist, an epoxy-based SSQ (T Phenyl 0.4 Q 0.1 T Epoxy 0.5 ) [ 8 ] mixed with 3 wt% photoacid generator (UV-9820, Dow Corning Corp.) was diluted with propylene glycol monomethyl ether acetate (PGMEA) to make a SSQ resist solution containing 10-20 wt% SSQ. In this study the SSQ solution was spin-casted onto the substrate sheet at 500-1000 rpm.…”

Thiol-yne Photo-curable Hybrid Resist: An Alternative for UV Nanoimprint Lithography (UV-NIL)

“…Despite the great achievement in the NIL technology, its progress is limited to the availability of the suitable resist materials. At present, the UV curable photoresists include (meth)acrylate [7][8][9], vinyl ether [10][11][12], epoxy resin [13][14][15]. Although such materials have presented good performance for patterning high resolution feature, it still face some challenges in UV-NIL process.…”