Patent ID: 8294902
Filing Date: 2012-10-23
Classification: G01B

Abstract:
1. A method for measuring the shape of a measurement surface using a measuring device for measuring the shape of the measurement surface utilizing interference between light from the measurement surface and light from a reference surface, the method comprising: a step of obtaining data on a rotationally symmetric component of the shape of a measurement surface of a reference standard having a mark; a reference standard measuring step of measuring the measurement surface of the reference standard several times at different rotation angles about the optical axis of the reference standard by the measuring device; a calculation step of calculating a measurement error of the measuring device in a direction normal to the measurement surface by calculating a rotationally asymmetric component of the shape of the measurement surface of the reference standard using the measurement data corresponding to the respective rotation angles obtained in the reference standard measuring step and by subtracting the rotationally symmetric component and the rotationally asymmetric component from the measurement data corresponding to the respective rotation angles; a calculation step of calculating a measurement error of the measuring device in a direction tangent to the measurement surface using data on the position of the mark contained in the measurement data corresponding to the respective rotation angles obtained in the reference standard measuring step; a measurement object measuring step of measuring a measurement surface of a measurement object by the measuring device; and a step of calibrating the measurement data of the measurement surface of the measurement object obtained in the measurement object measuring step using the measurement errors calculated in the calculation steps.