A Novel Nanoimprint Lithography Thiol-ene Resist for Sub-70 nm Nanostructures

In this paper, we propose a novel kind of UV click-polymerization thiol-ene copolymers as nanoimprint lithography resists for sub-70 nm resolution patterns. High-precision mold imprint and release are two of the most critical steps of nanoimprint lithography, which requires the resists with properties of excellent conformal replication and low surface energy. Conventional UV-curable resists used in nanoimprint lithography, such as acrylate, epoxy resin, and vinyl ether, cannot satisfy all these properties requirements because they exhibit surface oxygen inhibition during polymerization, or materials fracture and delamination during mold releasing. A novel kind of thiol-ene copolymers have been investigated in this study, which have many properties favorable for use as nanoimprint lithography resists to imprint sub-70 nm and high-aspect-ratio nanostructures. These properties include sufficiently low viscosity and high Young's modulus, low surface energy for easy demolding, polymerization in benign ambient, and in particular, high chemical-etch resistance. These excellent properties give improve nanoimprinting results.