OPTICAL SYSTEM FOR EUV PROJECTION MICROLITHOGRAPHY

摘要

Optical system for EUV projection microlithography comprising lighting optics (4) for illuminating a lighting field (5) in a reticle plane (6) comprising at least one facet mirror (18) with a plurality of facet elements (24) for producing different light channels, wherein by means of the light channels a specific lighting setting (25) of the lighting field (5) can be produced, and a projection optics (9) for projecting the lighting field (5) along a projection direction (27) into an image field (10) in an image plane (11) with at least one first obscuration (30; 42) wherein the first obscuration is arranged in a first position relative to the projection direction (27), and wherein the first obscuration (30; 42) and the lighting setting (25) are adjusted to one another such that an intensity of at least one predetermined order of diffraction of an image of at least of one light channel of the lighting setting (25) in the region of the first position has a maximum intensity Imax and a limit intensity Ilim max, and the area in which the intensity of the order of movement is greater than the limit intensity Ilim, and the area of the first obscuration (30; 42) are non-overlapping.