US 11,720,028 B2
Measurement illumination optical unit for guiding illumination light into an object field of a projection exposure system for EUV lithography
Thomas Fischer, Aalen (DE); Lars Wischmeier, Aalen (DE); Michael Patra, Oberkochen (DE); and Hubert Holderer, Oberkochen (DE)
Assigned to Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed by Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed on Oct. 26, 2021, as Appl. No. 17/511,234.
Application 17/511,234 is a continuation of application No. PCT/EP2020/061791, filed on Apr. 28, 2020.
Claims priority of application No. 102019206057.9 (DE), filed on Apr. 29, 2019; and application No. 102019217158.3 (DE), filed on Nov. 7, 2019.
Prior Publication US 2022/0057717 A1, Feb. 24, 2022
Int. Cl. G03F 7/20 (2006.01); G03F 7/00 (2006.01)
CPC G03F 7/7015 (2013.01) [G03F 7/70133 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An illumination optical unit configured to guide illumination light into an object field, the illumination optical unit comprising:
a field facet mirror comprising a plurality of field facets;
a pupil facet mirror comprising a plurality of pupil facets configured to overlay field facet images of the field facets in the object field and so that a field facet imaging channel of the illumination light is guided via any one field facet and any one pupil facet; and
a measurement field illumination device comprising a displacement actuator,
wherein:
the illumination optical unit is configured so that a measurement field has a greater extent along one first field dimension than any one of the field facet images;
the measurement field illumination device is configured to influence guidance of the illumination light via the field facet imaging channels so that the entire measurement field is illuminated via the field facet imaging channels; and
the displacement actuator is configured to displace an optical component configured to guide the illumination light between an illumination light source and the object field to sequentially illuminate the entire measurement field via the field facet imaging channels.