| 摘要 |
A reduction projection objective for projection lithography has a plurality of optical elements arranged along an optical axis and designed for imaging an effective object field arranged in an object surface of the projection objective into an effective image field arranged in an image surface of the projection objective at a reducing magnification ratio. The optical elements include at least one concave mirror. The optical elements are designed to provide an image-side numerical aperture NA>0.6 in a large effective image field having a maximum image field height Y′>25 mm. A compact, low mass projection objective enabling high throughput of exposed substrates is thereby obtained.
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