| 摘要 |
PROBLEM TO BE SOLVED: To measure a surface shape of a specimen in a short period of time. SOLUTION: A shape measuring method separates light emitted from a light source into object light and reference light and measures a surface shape of a specimen having a free curved surface by an interferometer for analyzing interference fringes obtained by a difference in the optical path between the object light and the reference light. The method includes: a first process for fixing a reference surface to a first position on the light axis of the reference light, applying the object light to the specimen, and acquiring a plurality of first interference fringes; a second process for fixing the reference surface to a second position different from the first position and acquiring a plurality of second interference fringes; a third process for fixing the reference surface to a third position different from the first and second positions and acquiring a plurality of third interference fringes; and a phase analysis process S3 for performing a phase analysis of interference fringes by the first, second, and third interference fringes. In at least one of the first, second, and third processes, the interferometer travels relative to the specimen so that the entire surface of the specimen is scanned, and a plurality of interference fringes are acquired intermittently at each travel of prescribed distance. COPYRIGHT: (C)2010,JPO&INPIT |
