Illumination system for euv projection lithography

A deflection optical unit, comprising:

• a plurality of deflection mirrors on which EUV radiation impinges in a common deflection incidence plane with grazing incidence during use of the deflection optical unit,
• wherein:
• the plurality of deflection mirrors comprises at least four deflection mirrors which jointly have a deflection effect in the common deflection incidence plane of more than 70°;
• and
• at least one of the deflection mirrors is selected from the group consisting of a convex cylindrical mirror and a concave cylindrical mirror.

An illumination system, comprising:

• a beam shaping optical unit configured to generate an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source;
• an output coupling optical unit configured to generate a plurality of EUV individual output beams from the EUV collective output beam;
• for each EUV individual output beam, a beam guiding optical unit configured to guide the EUV individual output beam toward an object field in which a lithography mask is arrangable,
• wherein the illumination system is an EUV projection lithography illumination system.