US 12,287,585 B2
Polarization selection metrology system, lithographic apparatus, and methods thereof
Douglas C. Cappelli, Norwalk, CT (US)
Assigned to ASML Holding N.V., Veldhoven (NL)
Appl. No. 18/033,530
Filed by ASML Holding N.V., Veldhoven (NL)
PCT Filed Oct. 14, 2021, PCT No. PCT/EP2021/078546
§ 371(c)(1), (2) Date Apr. 24, 2023,
PCT Pub. No. WO2022/096249, PCT Pub. Date May 12, 2022.
Claims priority of provisional application 63/109,803, filed on Nov. 4, 2020.
Prior Publication US 2023/0400782 A1, Dec. 14, 2023
Int. Cl. G03F 7/00 (2006.01)
CPC G03F 7/706849 (2023.05) [G03F 7/706845 (2023.05); G03F 7/706847 (2023.05)] 10 Claims
OG exemplary drawing
 
1. A system comprising:
an illumination system configured to generate an illumination beam;
an optical system configured to split the illumination beam into a first sub-beam and a second sub-beam,
wherein the optical system comprises a prism system comprising a first frustrated total internal reflection (FTIR) switch surface, a second FTIR switch surface, and a polarizing beam splitter (PBS), and
wherein the first and the second FTIR switch surfaces are disposed in parallel on opposite sides on the PBS;
a shutter system configured to independently control a transmittance of the first sub-beam and the second sub-beam, wherein the first sub-beam and the second sub-beam are recombined after the first and second sub-beams have passed through the shutter system;
an objective system configured to receive the recombined first and second sub-beams from the optical system and to direct the recombined first and second sub-beams towards a substrate having a target structure; and
a detector configured to receive an image or a diffracted image of the target structure.