PHASE MEASUREMENT DEVICE, PHASE MEASUREMENT PROGRAM, AND PHASE MEASUREMENT METHOD

摘要

PROBLEM TO BE SOLVED: To improve accuracy in phase measurement using a coherence beam.SOLUTION: A phase measurement method of calculating phases of a first coherence beam transmitting through a measurement target portion and a second coherence beam transmitting through a portion other than the measurement target portion on the basis of a plurality of imaged interference fringe images includes the steps of: selecting a straight line across a prescribed area where a refractive index and a thickness of a measuring sample are deemed to be uniform and a selection point on the straight line so that two-dimensional positions thereof in a plurality of interference fringe images different in an imaged relative phase difference are the same; determining an intensity distribution curve of an interference fringe on the straight line for each of the interference fringe images; determining an initial phase which is a phase difference from the selection point to a feature point on the intensity distribution curve; and calculating a phase of the measurement target portion on the basis of the initial phase.