Abstract:
The invention relates to a mirror, more particularly for a microlithographic projection exposure apparatus. A mirror (10, 20, 30, 40) according to the invention has an optical effective surface (10a, 20a, 30a, 40a), a mirror substrate (11, 21, 31, 41) and a reflection layer stack (14, 24, 34, 44) for reflecting electromagnetic radiation impinging on the optical effective surface (10a, 20a, 30a, 40a), wherein a layer (13, 23, 33, 43) composed of a group III nitride is arranged between the mirror substrate (11, 21, 31, 41) and the reflection layer stack (14, 24, 34, 44), wherein the group III nitride is selected from the group containing gallium nitride (GaN), aluminum nitride (AlN) and aluminum gallium nitride (AlGaN).
Abstract:
The invention relates to an optical system and a method for measuring the intensity of electromagnetic radiation in an optical system, more particularly an optical system having a microlithographic projection exposure apparatus or a mask inspection apparatus. An optical system which has at least one arrangement for measuring the intensity of electromagnetic radiation, and which is designed for a working wavelength of less than 30 nm, comprises a detector material. The intensity is measured on the basis of an interaction between the electromagnetic radiation and the detector material, which contains a Group III nitride.