Fabrication of multi-tiered structures on step and flash imprint lithography templates

Abstract

Step and flash imprint lithography (SFIL) replicates patterns by using a transparent template with relief images etched into its surface. Recent work has examined alternative methods for template fabrication. One scheme incorporates a conductive and transparent layer of indium tin oxide (ITO) on the surface of the substrate. Features are defined on the templates by patterning a thin layer of PECVD oxide that is deposited on the ITO layer. A second method bypasses the oxide etch process by imaging a thin layer of hydrogen silsesquioxane (HSQ). By combining or iterating the two methods, it is possible to form multi-tiered structures on a template. Two and three tier structures were fabricated on silicon wafers and templates. A two layer structure was fabricated on a quartz photoplate by patterning PECVD oxide and subsequently patterning a second tier using HSQ. The resulting relief structures were successfully replicated on wafers using SFIL.