EUV PROJECTION LENS WITH MIRRORS MADE FROM MATERIALS WITH DIFFERING SIGNS FOR THE RISE IN TEMPERATURE DEPENDENCE OF THE THERMAL EXPANSION COEFFICIENT AROUND THE ZERO TRANSITION TEMPERATURE

摘要

The invention relates to a projection lens (1) for short wavelengths, in particular, for wavelengths μ 157 nm, provided with several mirrors (M1, M2, M3, M4, M5 and M6), arranged in a precise position with relation to an optical axis (5). The mirrors (M1, M2, M3, M4, M5 and M6) comprise multi-layer coatings. At least two different mirror materials are provided which differ in the rise in thermal expansion coefficient as a function of temperature around the zero transition of the thermal expansion coefficient, in particular, in the sign of the value.