Patent ID: 7274505

Claim:
An inspection microscope for a plurality of wavelength regions comprising: at least one illumination beam path and at least one imaging beam path; wherein optical components in the illumination beam path and in the imaging beam path through which beams of all wavelength regions pass are covered with a reflection-reducing layer, wherein the reflection-reducing layer reduces an amount of reflection of light at specific reduced-reflection wavelength regions incident on the optical components relative to an amount of reflection of light at the reduced-reflection wavelength regions incident on the optical components without such a layer, wherein the reduced-reflection wavelength regions are the visible (“VIS”) wavelength region up to approximately 650 nm, the i line at λ=365 nm and the deep ultraviolet (“DUV”) wavelength region from 240 nm to 270 nm, wherein the reflection-reducing layer has a sandwich structure which comprises the materials: M2, and MgF 2 ; wherein the sandwich structure comprises a plurality of layers of M2 and MgF 2 applied alternately and the final layer comprising MgF 2 ; and wherein M2 is a mixed substance comprising La 2 O 3 .3.3 Al 2 O 3 .