Rigid crosslinked hybrid silicone resists for nanoimprint lithography toward high-fidelity replication

Ultraviolet nanoimprint lithography (UV-NIL) has emerged as a critical technology for next-generation nanofabrication, offering a cost-effective and efficient approach for manufacturing micro/nano-structural and photonic devices. However, to achieve high stability and high-fidelity nanoimprint, UV-NIL resists still encounter several challenges including volume shrinkage, difficulty in demolding, and insufficient thermal stability. In this work, a novel nanoimprint resist was designed for high-resolution nanoimprint (below 20 nanometers) formulated with cyclosiloxane as the primary monomer. By employing a pre-polymerization strategy to anchor active functional groups, both low volume shrinkage and exothermic control can be achieved. Utilizing the intrinsic properties of cyclosiloxane, the CSP-100 resist demonstrates several desirable characteristics for successful UV-NIL application, including low viscosity (<15 cP), minimal bulk-volume shrinkage (4.49%), good thermal stability (T_d5%>590°C), and low surface energy (27 mJ/m²). Due to the high crosslinking degree, replicated micro-nano structure can maintain dimensional stability even after 10 cycles of high-temperature treatment at 250°C, making the resist promising for micro/nano structural devices and optical applications for extreme environments.