Motivated by the need for at-wavelength observation of extreme ultraviolet (EUV) lithography masks, we developed a full-field EUV microscope that has a multilayer-mirror objective. This objective is based on an innovative optical design that gives a magnification of over ×1400, enabling us to use a conventional charge-coupled device (CCD) camera as the detector. In addition, when the objective is corrected for off-axis aberrations, it has a large field of view of a few hundred micrometers, permitting rapid inspection of a whole mask. We demonstrate this novel design by presenting at-wavelength images of a mask.
ASJC Scopus subject areas
- Physics and Astronomy(all)