| 摘要 |
PROBLEM TO BE SOLVED: To provide a reflective optical element, in particular, a reflective optical element for a microlithographic projection exposure apparatus or a reflective optical element for a mask inspection apparatus.SOLUTION: The reflective optical element has an optically effective surface, an element substrate 12, a reflection layer system 14, and at least one deformation reduction layer 15. When the optically effective surface 11 is irradiated with electromagnetic radiation, a maximum deformation level of the reflection layer system 14 is reduced in comparison with a deformation level of an analogously constructed reflective optical element without the deformation reduction layer. The reflection layer system 14 includes: at least one layer composed of a first material having a first coefficient of thermal expansion; and the above at least one deformation reduction layer 15 comprising a second material having a second coefficient of thermal expansion. The first coefficient of thermal expansion and the second coefficient of thermal expansion have opposite signs. |
