Patent ID: 6867913
Filing Date: 2005-03-15
Classification: G02B,G03F

Abstract:
1. Microlithography projection objective for short wavelengths, with an entrance pupil and an exit pupil for imaging an object field into an image field in an image plane, which represents a segment of a ring field, wherein the segment has an axis of symmetry and an extension perpendicular to the axis of symmetry and the extension is at least 20 mm, comprising: a first (S wherein each of these mirrors have an off-axis segment, in which the light beams traveling through the projection objective impinge, and wherein the diameter of the off-axis segment of the first, second, third, fourth, fifth and sixth mirrors as a function of the numerical aperture NA of the objective at the exit pupil is ≦(1200 mm*NA), wherein the first, second, third, fourth, fifth and sixth mirrors each have a volume claim on the rear side of the mirror, which has a depth parallel to the optical axis measured from the front side of the mirror in the off-axis segment, wherein the depth of the volume claims of the first, second, third, fourth, and sixth mirrors is at least 50 mm, and the depth of the volume claim of the fifth mirror is greater than ⅓ the value of the diameter of the fifth mirror, and wherein the respective volume claims are not penetrated.