Print and imprint method for nanoimprint lithography with high-viscosity photo-curable resins

Abstract

Ultraviolet nanoimprint lithography (UV-NIL) has become one of advanced pattering methods for fabrication of micro- and nano-structures over several inches by replication with designed mold patterns at high throughput and low cost. For practical application of UV-NIL, it is essential to eliminate bubble defects and to make residual layer thicknesses (RLTs) of a fabricated resist pattern uniform after the imprint process for subsequent dry-etching processes. We demonstrated the high-viscosity UV-curable resin (viscosity=12,800 mPas) suitable for bubble-defect-free UV nanoimprinting in a condensable gas atmosphere. We enabled to deposit droplets of the high-viscosity resin on a substrate by screen printing with a through-hole membrane with the volume of sub-pico liter. The method was effective for leveling RLTs in bubble-defect-free UV-NIL. In the present study, we give an overview of ‘Print and Imprint’ method comprising screen printing and UV-NIL, and demonstrate the position-selective placement of high-viscosity resin droplets by screen printing.