| 摘要 |
PROBLEM TO BE SOLVED: To specify the change in light transmission of a projection optical system depending upon the route of light. SOLUTION: A light radiated from an illumination optical system 1 is repeated by a transparent part and a shielding part in a limited period, introduced to a photomask 3 formed of a pattern by an optical member having a light transmission pattern shielded by a shielding region at the periphery by a diffraction grating pattern in which a plurality of ratios of the transparent parts and the shielding parts are given. Then, a diffracted light passed through the mask 3 is radiated to the projection optical system 4 to transfer the pattern onto a wafer 5. Thus, a change in the transmission depending on the route of the light of the system 4 is measured based on the pattern image of the diffracted light transferred onto the wafer 5. In this case, the mask 3 and the wafer 5 are pattern transferred in a non-conjugate state with respect to the system 4.
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