Nonadiabatic photochemical reaction and application to photolithography

We introduce a unique photochemical reaction, i.e., nonadiabatic photochemical reaction (NPR) described by exciton–phonon polariton model, which seems to violate the Franck–Condon principle. We demonstrated a novel photolithography using optical near field which is based on the NPR. The UV-photoresist was exposed to visible and red light, while the used photoresist are low or non sensitive for visible light. This method in photolithography drastically reduce the problems, coming from wave properties of light, such as diffraction limit, interference fringes, and so on. Finally, we exposed electron-beam resist, which is completely insensitive for light, and succeeded in fabrication of a 50-nm structure.