Patent ID: 8891057

Claim:
An apparatus, comprising: illumination optics configured to illuminate object field points of an object field in an object plane; and projection optics configured to image the object field of the illumination optics on an image field in an image plane, wherein: the apparatus is a projection exposure apparatus configured to be used in microlithography; the illumination optics have, for each object field point of the object field, an exit pupil associated with the object point, wherein sin(γ) is a greatest marginal angle value of the exit pupil; the illumination optics comprise a multi-mirror array comprising a plurality of mirrors configured to adjust an intensity distribution in exit pupils associated with the object field points; and the illumination optics comprise at least one optical system configured to temporally stabilise illumination of the multi-mirror array by a superposition of illumination rays in an illumination ray bundle so that, for each object field point, the intensity distribution in the associated exit pupil deviates from a desired intensity distribution in the associated exit pupil: a) in the case of a centroid angle value sin(β) by less than 2% expressed in terms of the greatest marginal angle value sin(γ) of the associated exit pupil; and/or b) in the case of ellipticity by less than 2%; and/or c) in the case of a pole balance by less than 2%.