ABERRATION MEASURING DEVICE AND METHOD IN PROJECTION OPTICAL SYSTEM, AND MASK AND EXPOSURE DEVICE USED FOR THEM

摘要

PROBLEM TO BE SOLVED: To provide an aberration measuring device and method, capable of measuring accurately in a simple composition an aberration which occurs on the lens axis of a projection optical system, and to provide an exposing device with finer exposing accuracy. SOLUTION: An internal mark Mip and an external mark Mop, which a translucent part Pt and phase shift parts Ppi and Ppo are arranged via a shading part Ps with the same pitch on a phase shift reticle Rps, are formed so that the external mark Mop interposes the internal mark Mip at certain space. The phase difference at the internal mark Mip is set toπ-ϕ(rad) and the phase difference at the external mark Mop is set toπ+ϕ(rad). The displacement of the focal point, which remains in the aberration optical system and caused by spherical surface aberrations, is measured by illuminating marks Mip and Mop vertically with normal illumination and by converting the displacement into the displacement of the relative positions of the images of the marks Mip and Mop on the plane, which is perpendicular to the lens axis.