PROJECTION OPTICAL UNIT FOR IMAGING AN OBJECT FIELD INTO AN IMAGE FIELD, AND PROJECTION EXPOSURE APPARATUS COMPRISING SUCH A PROJECTION OPTICAL UNIT

摘要

A projection optical unit images an object field in an image field. The projection optical unit includes a plurality of mirrors guides imaging light from the object field to the image field. At least two of the mirrors are arranged directly behind one another in the beam path of the imaging light for grazing incidence with an angle of incidence of the imaging light which is greater than 60°. This results in an imaging optical unit that can exhibit a well-corrected imageable field with, at the same time, a high imaging light throughput.

主权项

1. A projection optical unit configured to image an object field into an image field, the projection optical unit comprising:
a plurality of mirrors configured to guide imaging light from the object field to the image field along a beam path, wherein:
at least two of the mirrors are directly behind one another in the beam path; andfor each of the at least two mirrors, an angle of incidence of the imaging light with the mirror is greater than 60°.