Printing Sub-100 Nanometer Features Near-Field Photolithography

In this paper, a near-field photolithographic method which can realize ultra high resolution beyond the diffraction limit of light is described. Evanescent light generated on a transparent mold with a micro-relief illuminated on the condition of total internal reflection is used to expose a photoresist in contact with the mold. The plastic replica mold is flexible to eliminate the difficulty of close contact with the photoresist, and the replica mold damaged by the contact with the photoresist is disposable to maintain a high yield rate. We printed sub-100 nm features on a commercially available photoresist using 442-nm-wavelength light.