Vinyl ether formulations for step and flash imprint lithography

Abstract

Acrylates have been used as patterning monomers in step and flash imprint lithography. Vinyl ether formulations have a lower viscosity, faster curing rate, and higher tensile strength than acrylate formulations. However, the lack of commercially available, silicon-containing vinyl ether monomers has required the synthesis of several new vinyl ethers. An ideal monomer has low viscosity and low vapor pressure. The vapor pressure of silicon-containing vinyl ethers was predicted using the Joback-Reid, Lyderson, and Lee-Kesler methods. BVMDSO ͑1,1,3,3-tetramethyl-1,3-bis͑vinyloxymethyl͒-disiloxane͒ has the lowest viscosity of the synthesized silicon-containing vinyl ethers that meet the volatility requirement for a 80 pl dispense volume. The formulation of BVMDSO, CHDVE ͑cyclohexanedimethanol divinyl ether͒, and TEGDVE ͑triethylene glycol divinyl ether͒ shows good tensile strength and modulus. The formulation of BVMDSO, CHDVE, TEGDVE, and fluorinated acetate can print a 30 nm line because it has a low separation force and high tensile modulus.

Photocurable Silsesquioxane-Based Formulations as Versatile Resins for Nanoimprint Lithography

“…41 It implies that the imprinted sub-50-nm feature structures with these SSQMA-based formulations would be rigid enough to resist failures, making these formulations appropriate for UV-based NILs. [23][24][25] 3.2. Application of SSQMA-Based Formulations as UV Nanoimprint Resins.…”

Nanoimprint Lithography: Methods and Material Requirements

“…An alternative formulation that uses vinyl ether has been investigated because it is based on cationic polymerization and less sensitive to oxygen. [79] For the majority of other applications, the droplet dispensing method used to apply the liquid resist on a substrate in SFIL significantly limits the throughput of the nanopatterning process. The ability to spin-coat a uniform liquid resist onto a large-area substrate is highly desirable.…”

Vinyl ether resist system for UV-cured nanoimprint lithography

“…2 Because of its sensitivity toward oxygen (air) of radical crosslinking, cationic photocrosslinking of vinyl ethers has been reported. 3,4 We are interested in crosslinking through cationic polymerization to design our imprint materials, which stems in part from our extensive experience with chemical amplification resists based on acid-catalyzed reactions. Therefore, we consider nanoimprint as an extension of the chemical amplification concept but not as a departure from it.…”

“…Initially multifunctional acrylates containing Si along with a radical photoinitiator were selected as an etch barrier material by UT Austin/Molecular Imprints. 2 However, since photochemical curing through a radical mechanism is rather slow and retarded by oxygen (air), the UT Austin team investigated cationic curing of Si-containing vinyl ethers, 3,4 which is faster and insensitive to oxygen. We have initiated a new project to explore the potential of step-and-flash nanoimprint lithography.…”