CATADIOPTRIC PROJECTION OBJECTIVE COMPRISING A REFLECTIVE OPTICAL COMPONENT AND A MEASURING DEVICE

摘要

The invention relates to a catadioptric projection objective for imaging an object field onto an image field by means of an imaging radiation. In this case, the projection objective comprises at least one reflective optical component and a measuring device, wherein the reflective optical component, during the operation of the projection objective, reflects a first part of the imaging radiation and transmits a second part of the imaging radiation. While the refleeted, first part of the imaging radiation at least partly contributes to the imaging of the object field, the transmitted, second part of the imaging radiation is at least partly fed to a measuring device. This allows a simultaneous exposure of the photosensitive layer at the location of the image field with the imaging radiation and a monitoring of said imaging radiation with the aid of the measuring