A Contact Nano-Imprinting for Direct Metal Transfer Based on Infrared Pulsed Laser Heating

The authors report the development of a new contact imprinting method which can transfer metallic nano-patterns directly from a silicon mold to a substrate, with the help of an infrared pulse laser heating. This new technique integrates the strengths of both soft imprinting lithography and laser assisted imprinting method. It utilizes a Nd:YAG pulse laser of a wavelength 1064 nm to penetrate and heat up a silicon mold which has a thin metal layer pre-evaporated on its surface. The mold has some nano-scaled features and is pressed against the substrate under a given loading pressure. The high temperature caused by the infrared laser heating and the applied contact pressure can transfer the pre-deposited metal film directly from the silicon mold onto the substrate surface with the pattern defined by the mold. This method has several advantages such as fast transfer speed, no need for photoresist as etching mask, and the availability of nano-scaled silicon molds. Preliminary experiments have been carried out and some encouraging results are obtained.