SYSTEM FOR MEASURING THE IMAGE QUALITY OF AN OPTICAL IMAGING SYSTEM

摘要

Methods for measuring the image quality of a projection objective include providing a measuring structure on an image-side of the projection objective, providing an immersion fluid between the projection objective and the measuring structure, directing light through the projection objective and the immersion fluid to the measuring structure while shielding the measuring structure from the immersion fluid, detecting light transmitted by the measuring structure, and determining an image quality of the projection objective based on the detected light.