Nanolithography using high transmission nanoscale ridge aperture probe

Nanoscale ridge apertures provide a highly confined radiation spot with a high transmission efficiency when used in the near field approach. The radiation confinement and enhancement is due to the electric–magnetic field concentrated in the gap between the ridges. This paper reports the experimental demonstration of radiation enhancement using such antenna apertures and lithography of nanometer size structures. The process utilizes a NSOM (near field scanning optical microscopy) probe with a ridge aperture at the tip, and it combines the nonlinear two photon effect from femtosecond laser irradiation to achieve sub-diffraction limit lithography resolution.