Hard Transparent Arrays for Polymer Pen Lithography James L. Hedrick,†,‡,# Keith A. Brown,‡,§,∥,# Edward J. Kluender,‡,⊥ Maria D. Cabezas,‡,§ Peng-Cheng Chen,‡,⊥ and Chad A. Mirkin*,†,‡,§,⊥ †
Department of Chemical and Biological Engineering, ‡International Institute for Nanotechnology, §Department of Chemistry, and Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States ∥ Department of Mechanical Engineering and Division of Materials Science & Engineering, Boston University, 110 Cummington Mall, Boston, Massachusetts 02215, United States ⊥
ABSTRACT: Patterning nanoscale features across macroscopic areas is challenging due to the vast range of length scales that must be addressed. With polymer pen lithography, arrays of thousands of elastomeric pyramidal pens can be used to write features across centimeter-scales, but deformation of the soft pens limits resolution and minimum feature pitch, especially with polymeric inks. Here, we show that by coating polymer pen arrays with a ∼175 nm silica layer, the resulting hard transparent arrays exhibit a force-independent contact area that improves their patterning capability by reducing the minimum feature size (∼40 nm), minimum feature pitch (
