Nanofabrication using nonadiabatic near-field photolithography

This paper presents a novel photolithography method based on a nonadiabatic photochemical process, which is photo-activation via the molecular vibration energy level using an optical near field, to exceed light diffraction limits. We used this process to expose UV-photoresist, which does not react to visible light, using a 672-nm light source. Using independent coherence and polarization, which are intrinsic features of optical near-fields, we succeeded in forming T-, L-, and ring-shaped two-dimensional arrays. Finally, we found that even an electron-beam resist, which is completely photo-insensitive, could be exposed using this method, and we obtained a fine structure 50 nm wide.