| 摘要 |
In a reduction objective, especially for EUV microlithography has 4 multilayer mirrors (M1, M2, M3, M4) in a centered array with respect to an optical axis, with primary, secondary, tertiary and quaternary mirrors in this sequence in the path of the rays, a ring field suitable for scanning operation and light guidance free from obscuration. The novelty is that it has a convex primary mirror (M1) and a secondary mirror (M2) giving positive angular enlargement of the principal ray. |
