CATADIOPTRIC PROJECTION OBJECTIVE WITH GEOMETRIC BEAM SPLITTING
A projection exposure lens has an object plane, optical elements for separating beams, a concave mirror, an image plane, a first lens system arranged between the object plane and the optical elements for separating beams, a second double pass lens system arranged between the optical elements for separating beams and the concave mirror, a third lens system arranged between the optical elements for separating beams and the image plane. The second lens system has a maximum of five lenses.
1 . (canceled)
2 . A projection objective for projecting a mask pattern arranged in an object plane of the projection objective into an image plane of the projection objective, the projection objective comprising:
a first concave mirror arranged in the vicinity of a first pupil plane of the projection objective;
a second concave mirror arranged in the vicinity of a second pupil plane of the projection objective;
a first folding mirror that reflects light from the object plane toward the first concave mirror;
a second folding mirror that reflects light from the second concave mirror toward the image plane; and
a lens arranged between the second folding mirror and the image plane.
3 . The projection objective of claim 2 , wherein the lens is one of a plurality of lenses arranged between the second folding mirror and the image plane.
4 . The projection objective of claim 2 , further comprising:
a third folding mirror that reflects light from the first concave mirror; and
a fourth folding mirror that reflects light from the third folding mirror toward the second concave mirror.
5 . The projection objective of claim 2 , wherein the projection objective has a magnification not equal to one.
6 . The projection objective of claim 2 , wherein an odd number of intermediate images are formed in the projection objective.
7 . The projection objective of claim 6 , wherein exactly three intermediate images are formed in the projection objective.
8 . The projection objective of claim 6 , wherein a sum of the number of intermediate images and a number of mirrors in the projection objective is an odd whole number.
9 . The projection objective of claim 2 , further comprising a first negative lens that is arranged in front of the first concave mirror at a distance therefrom.
10 . The projection objective of claim 9 , wherein no optical element is arranged between the first negative lens and the first concave mirror.
11 . The projection objective of claim 9 , further comprising a second negative lens that is arranged in front of the second concave mirror at a distance therefrom.
12 . The projection objective of claim 11 , wherein no optical element is arranged between the second negative lens and the second concave mirror.
13 . The projection objective of claim 2 , wherein the image plane is arranged at an element for a liquid crystal display.
14 . A projection objective for projecting a mask pattern arranged in an object plane of the projection objective into an image plane of the projection objective, the projection objective comprising:
a first concave mirror arranged in the vicinity of a first pupil plane of the projection objective;
a second concave mirror arranged in the vicinity of a second pupil plane of the projection objective;
a first folding mirror that reflects light from the object plane toward the first concave mirror;
a second folding mirror that reflects light from the second concave mirror toward the image plane; and
a lens arranged between the object plane and the first folding mirror.
15 . The projection objective of claim 14 , wherein the lens is one of a plurality of lenses arranged between the object plane and the first folding mirror.
16 . A projection objective for projecting a mask pattern arranged in an object plane of the projection objective into an image plane of the projection objective, the projection objective comprising:
a first concave mirror arranged in the vicinity of a first pupil plane of the projection objective;
a second concave mirror arranged in the vicinity of a second pupil plane of the projection objective;
a first folding mirror that reflects light from the object plane toward the first concave mirror; and
a second folding mirror that reflects light from the second concave mirror toward the image plane;
wherein an image-side numerical aperture of the projection objective is greater than 0.7.
17 . The projection objective of claim 16 , wherein the image-side numerical aperture of the projection objective is not less than 1.0.