High-Resolution PFPE-based Molding Techniques for Nanofabrication of High-Pattern Density, Sub-20 nm Features: A Fundamental Materials Approach

Abstract

Several perfluoropolyether (PFPE)-based elastomers for high-resolution replica molding applications are explored. The modulus of the elastomeric materials was increased through synthetic and additive approaches while maintaining relatively low surface tension values (<25 mN/m). Using large area (>4 in.(2)) master templates, we experimentally show the relationship between mold resolution and material properties such as modulus and surface tension for materials used in this study. A composite mold approach was used to form flexible molds out of stiff, high modulus materials that allow for replication of sub-20 nm post structures. Sub-100 nm line grating master templates, formed using e-beam lithography, were used to determine the experimental stability of the molding materials. It was observed that as the feature spacing decreased, high modulus PFPE tetramethacrylate (TMA) composite molds were able to effectively replicate the nanograting structures without cracking or tear-out defects that typically occur with high modulus elastomers.

Silicon nanopillar anodes for lithium-ion batteries using nanoimprint lithography with flexible molds

“…The HiF2M mold is comprised of a cross-linked perfluoropolyether (PFPE) patterned layer, attached to chemicalresistant PET backing (Melinex 054, Dupont Teijin Films) with UV-curing optical adhesive (NOA73, Norland Products Inc.) PFPE was chosen due to its low surface energy, high elastic modulus, and impressive solvent resistance. 22 A thermal nanoimprint was conducted at <80 C and 200 psi using a Nanonex, NX-2500 nanoimprinter.…”

Crosslinked perfluoropolyether solid electrolytes for lithium ion transport

“…We present data on two types of crosslinked PFPEs: thermally crosslinked POSS-based PFPE electrolytes inspired by Pan et al [19] and UV crosslinked solids inspired by the work of Williams et al [42] The POSS-based system was obtained by reacting acrylate-functionalized POSS with PFPE. We show that crosslinking increases the solubility of LiTFSI in PFPE-based solids (both POSS and UV crosslinked systems).…”

Tunable nano-replication to explore the omniphobic characteristics of springtail skin

“…25,26 When applying elastomeric moulds, the approach even permits the transfer of high aspect ratios, large overhangs 27 and even closed loops. 28 Successful replication of various different hierarchically assembled biological templates such as plant leaves, 29 insect corneas 30,31 or grasshopper wings 32 was recently demonstrated.…”