Next-Generation Lithography Technique Using Mold Pressuring

摘要

Next-generation lithographic technology needs not only high resolution but also high throughput, large process latitude and low cost. Nanoimprint lithography (NIL) is a major breakthrough in nano-patterning because it can produce nm feature size over a large area with a high throughput and low cost. In order to obtain high productivity, the mold requires durability for repeated NIL process and mechanical strength in a moment of contact with the substrate. Diamond is a candidate material for the above requirements, because diamond has numerous excellent properties such as large Knoop hardness, large compressive strength and low thermal expansion coefficient. Therefore, nanoimprint lithography using diamond mold was examined. The electron beam (EB) lithography and reactive ion etching (RIE) with oxygen gas were used to fabricate fine patterns in diamond mold. The dented line pattern with 2 mu m width and 340 nm depth was obtained using this process. This diamond mold was pressed to PMMA on silicon substrate and diamond substrate, and convex PMMA line patterns were replicated. Direct aluminum patterns were obtained by diamond mold at the pressure of 130.8 MPa in room temperature.