Patent ID: 9429495
Filing Date: 2016-08-30
CPC Classification: G01M,G03F,Y10T

Claim Text:
1. A microlithography projection exposure system, comprising: an illumination system for providing radiation having a wavelength of 193 nm; a projection objective comprising a plurality of optical elements for imaging a pattern arranged in an object plane of the projection objective to an image plane of the projection objective using the radiation, the projection objective being configured for imaging when an immersion liquid is positioned between the image plane and an optical element of the plurality of optical elements located closest to the image plane; a measuring system for measuring at least one imaging parameter of the projection objective, the measuring system comprising: wherein the microlithography projection exposure system is configured to position the measuring system relative to the projection objective so that the at least one aperture is located at the image plane and to provide the immersion liquid between the image plane and the optical element closest to the image plane during operation, wherein the measuring system further comprises a protective system positioned, during operation, between the layer of material and the optical element closest to the image plane.