System for Fabrication of Large-Area Roll Molds by Step-and-Repeat Liquid Transfer Imprint Lithography

Abstract

The effective production of nanopatterned films generally requires a nanopatterned roll mold with a large area. We report on a novel system to fabricate large-area roll molds by recombination of smaller patterned areas in a step-and-repeat imprint lithography process. The process is accomplished in a method similar to liquid transfer imprint lithography (LTIL). The stamp roll with a smaller area takes up the liquid resist by splitting from a donor substrate or a donor roll. The resist is then transferred from a stamp roll to an acceptor roll and stitched together in a longitudinal and, if necessary, in a circumferential direction. During transfer, the nanostructured resist is UV-exposed and crosslinked directly on the acceptor roll. The acceptor roll with the stitched and recombined stamp patterns is ready to be used as a large-area roll mold for roll-based imprinting. A system for this purpose was designed, and its operation was demonstrated taking the example of an acceptor roll of 1 m length and 250 mm diameter, which was covered by 56 patterned areas. Such a system represents an elegant and efficient tool to recombine small patterned areas directly on a large roll mold and opens the way for large-area roll-based processing.

Fabrication System for Large-Area Seamless Nanopatterned Cylinder Mold Using the Spiral Laser Interference Exposure Method

“…In recent years, nanotechnology has developed rapidly with a focus on developing cost-effective methods for the fabrication of nanoscale patterns for large areas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Nanoimprint lithography (NIL) is a low-cost and largearea processing method for fabricating nanopatterns.…”

“…The wrapping process inevitably results in a seam; consequently, it is difficult to implement a continuous roll-to-roll imprinting process. Hence, various researchers have studied the direct patterning process on cylinders without wrapping using electron beam lithography [6][7][8][9][10], photolithography [12][13][14], and ablation using a pulsed laser [15,16]. Electron beam lithography can produce precise nanopatterns; however, this process is implemented in a high-vacuum environment, which is expensive and technically difficult to establish.…”

“…Moreover, producing a line width of less than 500 nm is difficult owing to heat transfer by the photothermal effect. Adequate research on conventional photolithography has been conducted [12][13][14]; however, the resolution that has been adopted is not sufficient for nanofabrication. Herein, we investigate an alternative process known as laser-interference lithography (LIL) to produce nanopatterns.…”

Silicon Metalens Fabrication from Electron Beam to UV-Nanoimprint Lithography

“…As an alternative to both EBL (expensive and time consuming) and photolithography (limited by the light diffraction), the nanoimprint lithography (NIL) technique assures large-scale high pattern resolution in seconds. Usually, the NIL term has been used for various types of techniques, starting with the hot-embossing (thermal) and roll imprint process up to the reverse imprint or ultrasonic nanoimprint lithography [30][31][32][33][34], but in principle, it is connected with the thermomechanical or UV curing processes [35][36][37].…”