| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-accuracy and high-speed oblique incidence interferometer for enabling a measurement in an environment such as a processing field in which a vibration exists. SOLUTION: The oblique incidence interferometer irradiates a light at a predetermined angle to a normal of a measured surface of a measured object 20, and measures a reflection light from the measured object 20. The oblique incidence interferometer includes: a light flux splitting element 14 for splitting the light from a light source 11 into a measurement light irradiated to the measured object 20 and a reference light as a measurement reference; a light flux combining element 16 for combining the measurement light reflected from the measured object 20 and the reference light after they become orthogonal to each other in the deflection direction; a three-way splitting prism 33 for splitting the combined light into a plurality of split lights; imaging sections 35A-35C for imaging a plurality of interference pattern images formed by a plurality of the split lights; a quarter-wavelength plate 31 disposed on one of the entrance side and the exit side of the three-way splitting prism 33; and polarization plates 34A-34C disposed on the imaging plane side of the imaging sections 35A-35C. COPYRIGHT: (C)2008,JPO&INPIT
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