Near field optical latent imaging with the photon tunneling microscope

We present a simple optical technique for measuring features formed in radiation sensitive materials (photoresists) after exposure. The monitoring of photoresist patterns after exposure, but before development is known as latent imaging. Optical techniques used in the past for latent image detection have really only sensed scattered intensity levels from periodic patterns and not spatially resolved images of the features themselves. The application of photon tunneling microscopy to imaging of latent resist patterns exposed using point-source x-ray and midultraviolet illumination will be demonstrated.