| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an advantageous technique of highly accurately measuring a shape of a large-diameter surface to be measured at a low cost. <P>SOLUTION: By a three-surface matching method, measurement is executed by the combinations of a surface to be measured and a first reference surface, the surface to be measured and a second reference surface, and the first reference surface and the second reference surface, and on the basis of the result, a coefficient of a fourth-order term when expressing the shape of the surface to be measured in a partial area overlapped with the first reference surface by a Zernike polynomial is calculated. Then, by using a rotation shear method and a shift shear method, the shape to the second reference surface is measured, and a coefficient of rotational asymmetrical components of the fifth and succeeding orders of the shape in the entire area of the surface to be measured is calculated. Then, an error of the coefficient of the fourth-order term is calculated from the coefficient of the term of the fifth and succeeding orders of the shape of the entire area. Then, the coefficient of the fourth-order term of the partial area is corrected using the error and the coefficient of the fourth-order term is calculated. From the coefficient of the fourth-order term, the coefficient of the rotational asymmetrical components of the fifth and succeeding orders and the coefficient of rotational symmetrical components, the shape of the entire area is determined. <P>COPYRIGHT: (C)2012,JPO&INPIT |
