Recessed area patterning via nanoimprint lithography

Three-dimensional structures in the channels of a patterned substrate are typically fabricated via a variety of approaches that include a combination of soft lithography and multiple photolithographic steps which can be complex and time consuming. Moreover, the design of a three-dimensional hierarchical template to carry out the direct recessed imprinting of polymers at the recessed area would be complicated and costly. To overcome this shortcoming, we report a method to fabricate a three-dimensional template that is capable of carrying out a direct recessed area imprint via the use of a polymer material. A sequential nanoimprinting process was used to first fabricate the template. A primary imprint was carried out to emboss micron-sized primary features onto a polymer template after which a secondary imprinting process was then carried out to imprint smaller nanoscale features onto the primary features thereby creating three-dimensional or hierarchical features on the polymer template. The template with ...