Sub-100 nm photolithography using TE-polarized waves in transparent nanostructures

The optical near field and its polarization anisotropy in transparent nanostructures were studied by polarization near-field optical microscopy. From experimental results and finite-difference time-domain calculations, we conclude that localized optical near fields exist at topographically higher regions of nanostructures under the TE-polarization condition. Optical near fields with a feature size smaller than 100 nm are applied for contact photomask lithography. We demonstrate photolithographic patterns with 80 nm width by using a 442 nm helium cadmium laser.