Polymer pen lithography

Abstract

We report a low-cost, high-throughput scanning probe lithography method that uses a soft elastomeric tip array, rather than tips mounted on individual cantilevers, to deliver inks to a surface in a "direct write" manner. Polymer pen lithography merges the feature size control of dip-pen nanolithography with the large-area capability of contact printing. Because ink delivery is time and force dependent, features on the nanometer, micrometer, and macroscopic length scales can be formed with the same tip array. Arrays with as many as about 11 million pyramid-shaped pens can be brought into contact with substrates and readily leveled optically to ensure uniform pattern development.

Fig. 1.

(A) A schematic illustration of the polymer pen lithography setup. (B) A photograph of an 11-million-pen array. (C) Scanning electron microscope image of the polymer pen array. The average tip radius of curvature is 70 ± 10 nm (inset).

Fig. 2.

(A) Optical image of a 480-μm by 360-μm section of a one million gold dot array (6 by 6 within each block) on a silicon substrate (using a pen array with 28,000 pyramid-shaped tips). (B) MHA dot size as a function of relative z-piezo extension. The results were obtained using a polymer pen array with 15,000 pyramid-shaped tips at 25°C with a relative humidity of 40%. (C) Optical image of arrays of gold squares generated at different z-piezo extensions (using a pen array with 28,000 pyramid-shaped tips). (D) An optical microscope image of a multidimensional gold circuit fabricated by PPL. The inset shows a magnified SEM image of the circuit center.

Fig. 3.

(A) SEM image of a representative region of ~15,000 miniaturized duplicates of the 2008 Beijing Olympic logo. (B) A zoom-in optical image of a representative replica. The inset shows a magnified SEM image of the letter “e.”