title: Wafer-scale patterning of sub-40 nm diameter and high aspect ratio (>50:1) silicon pillar arrays by nanoimprint and etching.
abstract: We demonstrate wide-area fabrication of sub-40 nm diameter, 1.5 µm tall, high aspect ratio silicon pillar arrays with straight sidewalls by combining nanoimprint lithography (NIL) and deep reactive ion etching (DRIE). Imprint molds were used to pre-pattern nanopillar positions precisely on a 200 nm square lattice with long range order. The conventional DRIE etching process was modified and optimized with reduced cycle times and gas flows to achieve vertical sidewalls; with such techniques the pillar sidewall roughness can be reduced below 8 nm (peak-to-peak). In some cases, sub-50 nm diameter pillars, 3 µm tall, were fabricated to achieve aspect ratios greater than 60:1.
authors: Nanostructure Laboratory, Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA.
authors: Keith J
authors: KJ
authors: Morton
authors: Gregory
authors: G
authors: Nieberg
authors: Shufeng
authors: S
authors: Bai
authors: Stephen Y
authors: SY
authors: Chou