PROJECTION OPTICAL SYSTEM, EXPOSURE APPARATUS, AND EXPOSURE METHOD

摘要

A projection objective includes at least four curved mirrors, which include a first curved mirror that is a most optically forward mirror and a second curved mirror that is a second most optically forward mirror, as defined along a light path. In addition, an intermediate lens element is disposed physically between the first and second mirrors, the intermediate lens element being a single pass type lens. The objective forms an image with a numerical aperture of at least substantially 1.0 in immersion.