US 12,265,229 B2
Method and apparatus for coherence scrambling in metrology applications
Zili Zhou, Veldhoven (NL); and Janneke Ravensbergen, Würzburg (NL)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Appl. No. 17/768,851
Filed by ASML Netherlands B.V., Veldhoven (NL)
PCT Filed Sep. 30, 2020, PCT No. PCT/EP2020/077340
§ 371(c)(1), (2) Date Apr. 13, 2022,
PCT Pub. No. WO2021/073873, PCT Pub. Date Apr. 22, 2021.
Claims priority of application No. 19202907 (EP), filed on Oct. 14, 2019.
Prior Publication US 2024/0134208 A1, Apr. 25, 2024
Prior Publication US 2024/0231115 A9, Jul. 11, 2024
Int. Cl. G02B 27/09 (2006.01)
CPC G02B 27/0927 (2013.01) [G02B 27/0944 (2013.01); G02B 27/0994 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A pupil shaping arrangement for obtaining a defined pupil intensity profile for a metrology illumination beam configured for use in a metrology application, the pupil shaping arrangement comprising:
an engineered diffuser having a defined far-field profile configured to impose the defined pupil intensity profile on the metrology illumination beam; and
a multimode fiber located between the engineered diffuser and an output of the pupil shaping arrangement;
wherein the engineered diffuser is configured to impose the pupil intensity profile on an input pupil of the multimode fiber that is greater at a periphery of the input pupil with respect to an inner region of the input pupil.