Patent ID: 6891596
Filing Date: 2005-05-10
Classification: G02B,G03F

Abstract:
1. Refractive projection objective for projecting a pattern arranged in an object plane of the projection objective into an image plane of the projection objective with the aid of an immersion medium which is arranged between a last optical element of the projection objective and the image plane, comprising: a first lens group, following the object plane, with a negative refracting power; a second lens group, following the first lens group, with a positive refracting power; a third lens group, following the second lens group, with a negative refracting power; a fourth lens group, following the third lens group, with a positive refracting power; a fifth lens group, following the fourth lens group, with a positive refracting power; and a system aperture which is arranged in the region of maximum beam diameter between the fourth and the fifth lens group.