Ultrafast patterning of nanostructures in polymers using laser assisted nanoimprint lithography

We propose and demonstrate a nanopatterning technique, laser-assisted nanoimprint lithography (LAN), in which the polymer is melted by a single excimer laser pulse and then imprinted by a mold made of fused quartz. LAN has been used to pattern nanostructures in various polymer films on a Si or quartz substrate with high fidelity over the entire mold area. Here we show 200 nm pitch gratings with 100 nm linewidth and 90 nm height. The entire imprint from melting the polymer to completion of the imprint is less than 500 ns. The mold has been used multiple times without cleaning between each imprint. LAN not only greatly shortens the imprint processing time, but also significantly reduces the heating and expansion of the substrate and mold, leading to better overlay alignment between the two.