Improving spatial resolution of passive near-field microscope by fabricating 10 nm tungsten tips

Abstract

In recent years, we have developed a home-made passive Scanning Near-field Optical Microscope (SNOM) utilized to probe spontaneous emission from metals and dielectric materials. The evanescent waves generated on the sample surface are scattered by sharp tungsten tips made by electro-chemical etching. Previous study confirmed that the spatial resolution of the passive SNOM is determined by the tip apex size. This research aims to fabricate 10 nm sharp tungsten tips by AC/DC two-step electro-chemical etching and improve spatial resolution of passive near-field signals to 10 nm with the fabricated sharp tungsten tips.