Optical subsystem i.e. projection lens, for projection illumination system for semiconductor lithography, has set of optical elements, where two optical elements are arranged in different places in subsystem and are moveable together

摘要

The subsystem has a set of optical elements (100, 100', 100'') e.g. lenses or mirrors, where the optical elements (100, 100') are arranged in different places in the subsystem and are moveable together. The optical element (100'') is firmly arranged between the moveable optical elements (100, 100') that are moveable in a direction of an optical axis (120) of the subsystem. The position of the optical element (100'') is independent of the movement of the collectively moveable optical elements (100, 100').