MEASUREMENT APPARATUS, MEASUREMENT METHOD, AND METHOD OF MANUFACTURING ARTICLE

摘要

The present invention provides a measurement apparatus for measuring a shape of a test surface, comprising an optical system configured to irradiate a measurement point on the test surface and a reference surface with light, and cause test light and reference light reflected to interfere with each other, a detector configured to detect an optical path length difference between the test light and the reference light by using interfering light and a processor configured to determine a position of the measurement point based on a plurality of detection results by the detector, wherein a detection result includes an error which cyclically changes, and the plurality of detection results include n detection results obtained in n states in which optical path lengths of the test light are different from each other by 1/n (n≧2) of a cycle of the error.

主权项

1. A measurement apparatus for measuring a shape of a test surface, comprising:
an optical system configured to irradiate a measurement point on the test surface and a reference surface with light, and cause test light reflected by the measurement point and reference light reflected by the reference surface to interfere with each other; a detector configured to detect an optical path length difference between the test light and the reference light by using interfering light of the test light and the reference light; and a processor configured to determine a position of the measurement point based on a plurality of detection results by the detector; wherein a detection result among the plurality of detection results includes an error which cyclically changes in accordance with a change of the optical path length difference, and the plurality of detection results include n detection results obtained by causing the detector to detect the optical path length differences in n states in which optical path lengths of the test light are different from each other by 1/n (n≧2) of a cycle of the error.