Microlithographic projection exposure apparatus
View Patent ↗A microlithographic projection exposure apparatus contains an illumination system ( 12 ) for generating projection light ( 13 ) and a projection lens ( 20; 220; 320; 420; 520; 620; 720; 820; 920; 1020; 1120 ) with which a reticle ( 24 ) that is capable of being arranged in an object plane ( 22 ) of the projection lens can be imaged onto a light-sensitive layer ( 26 ) that is capable of being arranged in an image plane ( 28 ) of the projection lens. The projection lens is designed for immersion mode, in which a final lens element (L 5 ; L 205 ; L 605 ; L 705 ; L 805 ; L 905 ; L 1005 ; L 1105 ) of the projection lens on the image side is immersed in an immersion liquid ( 34; 334 a ; 434 a ; 534 a ). A terminating element ( 44; 244; 444; 544; 644; 744; 844; 944; 1044; 1144 ) that is transparent in respect of the projection light ( 13 ) is fastened between the final lens element on the image side and the light-sensitive layer.
1. An apparatus, comprising:
an illumination system configured to generate projection light,
a projection lens configured to image a reticle onto a light-sensitive layer, wherein the projection lens comprises
a terminating element that
is transparent to the projection light,
has a first surface
has a second surface opposite the first surface, wherein the second surface is immersed in an immersion liquid, and
comprises at least two members consisting of birefringent cubic crystals, wherein the apparatus is a microlithographic projection exposure apparatus.
2. The apparatus according to claim 1 , wherein the terminating element is detachably fixed to another optical element.
3. The apparatus according to claim 1 , wherein the first surface and the second surface are plane and parallel to each other.
4. The apparatus according to claim 1 , wherein the thicknesses of the cubic crystals are so chosen and the crystal lattices of the cubic crystals are so orientated relative to one another that the influence of intrinsic birefringence on projection light passing through the two members is at least approximately compensated.
5. The apparatus according to claim 1 , wherein the two members are joined to one another seamlessly.
6. The apparatus according to claim 1 , wherein an interspace remains between the two members.
7. The apparatus according to claim 6 , wherein the interspace is filled with a liquid.
8. The apparatus according to claim 6 , wherein at least one member has a curved surface adjoining the interspace.
9. The apparatus according to claim 1 , wherein the two members have surfaces that extend at least approximately parallel to one another.
10. The apparatus according to claim 1 , wherein at least one of the surfaces of the terminating element is reworked for the purpose of correcting wavefront errors by a local removal of material.