Non-Residual Layer Transfer of High Viscous Ultraviolet Photocurable Resin Using Liquid Transfer Technique

Abstract

Ultraviolet-nanoimprint lithography (UV-NIL) is a next-generation lithographic technology. However, its usefulness is negatively affected by the formation of an extra resin layer between the curable resin pattern and the substrate, which is known as the residual layer (RL). Liquid-transfer imprint lithography (LTIL) is a promising technique for reducing the RL. However, it is difficult to ensure a thin RL with LTIL when using a high viscous UV curable resin. A technique combining LTIL and roll press can be used to overcome this drawback. High viscous UV curable resins generally possess high selectivity for dry etching and can exhibit various refractive indices. In this study, master molds were prepared with a patterned design and varying line and space values. The pattern ratio was 1:2, and the line widths were 990 nm, 540 nm, and 270 nm. UV curable resins with viscosities of 2900 mPa·s and 13090 mPa·s could be used to transfer the line and space patterns of three nanoscale widths to eliminate the RL, by using a repeated roll-press and LTIL technique and parallel plate UV-NIL.

Molecular Dynamics Simulation of the Resist Filling Process in UV-nanoimprint Lithography

“…Previously, we investigated the filling of 100 micro-scale patterns with high-viscosity resists (2,900 and 13,090 mPa·s). The pattern filling required high pressures (of the order of megapascals) and long filling times (over one minute) [26]. Therefore, the under-filling of the 3-nm wide trenches in the microsecond time range of the present MD simulations is consistent with the actual behavior of the resist.…”

Fabrication of Flexible Fine Through-hole Electrodes for Printed Devices using UV-NIL

“…Merits of UV-NIL include its high transparency, high throughput, and low cost of equipment [13]. However, a residual layer of thickness [14][15][16][17] typically accumulates at the bottom of the holes formed by UV-NIL. In this study, the amount of the dripping of the low-viscosity resin as well as pressurization were controlled, thereby allowing for a residual film-free transfer.…”