REFLECTIVE ILLUMINATING OPTICAL ELEMENT, REFLECTIVE ILLUMINATING OPTICAL SYSTEM, AND DUV TO EUV EXPOSURE DEVICE

摘要

A reflective illuminating optical element (21), comprising two openings (A) and (B) of the same size and shape, wherein the openings are so formed that a ring is partly cut out, namely, that the ring is cut out by two straightlines parallel with a straightline passing through the center of the ring and apart an equal distance from the center of the ring, two openings (22) and (23) are connected to each other through a tubular member and generally formed in a tubular shape, the cross sections of the tubular member are the same in shape as the openings (22) and (23), the inner surface of the tubular member is formed in a reflective surface as shown later, and when light from a light source (P) is projected from the opening (A) into the reflective optical element (21) and viewed through the opening (23), a large number of pseudo light sources can be viewed in addition to the light source (P) so as to function as integrators.