INTERFEROMETER AND PHASE SHIFT VOLUME MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To realize an interferometer and a phase shift volume measuring device that work well in an EUV region.SOLUTION: An interferometer according to the invention comprises: an illumination source (1) that generates an illumination beam; an illumination system that exposes a sample to the illumination beam emitted from a light source; and an imaging system that forms an image of a reflection beam emitted from the sample on a detector (7). The illumination system includes a first diffraction grating (2) that generates first and second diffraction lights which mutually illuminate two prescribed-distance-separated areas on the sample coherently, and the imaging system includes a second diffraction grating (6) that further diffracts the first and second diffraction lights reflected by the sample, and then forms third and fourth diffraction lights separated from each other by prescribed distance. An interference image by the third and fourth diffraction lights is formed on the detector. Fringe scan is performed by scanning an inclination angle of a stage supporting the sample.