EUV EXPOSURE APPARATUS

The invention relates to a projection lens of an EUV-lithographic projection exposure system, comprising: at least two reflective optical elements Mi, each comprising a body MBiand a reflective surface MSifor projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light with a wavelength in a wavelength range of less than 50 nm, being reflected from the reticle while illuminated by an illumination system of an EUV-lithographic projection exposure system, wherein the bodies MBm, MBnof at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at least two zero cross temperatures T10mnand T20mn, and wherein the lens comprises a support structure for passively or actively supporting the reflective optical elements Mi, wherein the temperature of at least a part of the support structure is at a reference temperature TRef, at least two tempering means for independently heating and/or cooling the at least two bodies MBn, MBm, and a temperature control system for independently controlling the temperature of the at least two heated or cooled bodies MBn, MBmto respective temperatures Tknand a Tkm, and wherein during exposure of the lens with the exposure power of the EUV light the temperatures Tknof the temperature controlled body MBnis within an interval of ± 5K, better ± 2K centered around the first zero cross temperatures T10mn, and the temperatures Tkmof the temperature controlled body MBmis within an interval of ± 5K, better ± 2K centered around the second zero cross temperatures T20mn.