Patent ID: 8199400

Claim:
A catadioptric projection objective for imaging a pattern provided in an object surface of the projection objective onto an image surface of the projection objective comprising: a first, refractive objective part for imaging the pattern provided in the object surface into a first intermediate image; a second objective part for imaging the first intermediate image into a second intermediate image; a third, refractive objective part for imaging the second intermediate image onto the image surface; wherein the second objective part includes a first concave mirror having a first continuous mirror surface and a second concave mirror having a second continuous mirror surface; pupil surfaces are formed between the object plane and the first intermediate image, between the first and the second intermediate images and between the second intermediate image and the image plane; all concave mirrors are arranged optically remote from a pupil surface; the first objective part has a first number N1 AS of aspheric lenses; the third objective part has a second number N3 AS of aspheric lenses; an aspheric lens ratio ASR=N1 AS /N3 AS is smaller than 1; and an image side numerical aperture NA is larger than 1.2.