Imaging optical unit for imaging an object field into an image field, and projection exposure apparatus including such an imaging optical unit

• Main Authors: Rostalski, Hans-Juergen, Wolf, Alexander
• Format: Patent
• Language: English
• Published: 25.06.2019
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS

An imaging optical unit for projection lithography has a plurality of mirrors for guiding imaging light from an object field into an image field. The object field is spanned by a first, larger object field dimension and along a second, smaller object field dimension. The imaging optical unit has at least two GI mirrors and at least one NI mirror. The NI mirror is arranged between two GI mirrors in the imaging light beam path. A used reflection surface of the NI mirror has an aspect ratio between a surface dimension along a first reflection surface coordinate and a surface dimension along a second reflection coordinate parallel to the second object field dimension. The aspect ratio being less than 4.5. An imaging optical unit with reduced production costs emerges.