US 12,346,031 B2
Methods and patterning devices and apparatuses for measuring focus performance of a lithographic apparatus, device manufacturing method
Fei Liu, Eindhoven (NL); Jin Lian, Eindhoven (NL); Zhuangxiong Huang, Eindhoven (NL); Laurentius Cornelius De Winter, Vessem (NL); and Frank Staals, Eindhoven (NL)
Assigned to ASML Netherlands B.V., Veldhoven (NL)
Appl. No. 18/018,065
Filed by ASML Netherlands B.V., Veldhoven (NL)
PCT Filed Jul. 6, 2021, PCT No. PCT/EP2021/068589
§ 371(c)(1), (2) Date Jan. 26, 2023,
PCT Pub. No. WO2022/022949, PCT Pub. Date Feb. 3, 2022.
Claims priority of application No. 20188032 (EP), filed on Jul. 28, 2020.
Prior Publication US 2023/0305407 A1, Sep. 28, 2023
Int. Cl. G03F 7/00 (2006.01); G01N 21/47 (2006.01)
CPC G03F 7/70641 (2013.01) [G01N 21/4738 (2013.01); G01N 21/4788 (2013.01); G03F 7/706851 (2023.05)] 13 Claims
OG exemplary drawing
 
1. A method comprising:
printing, on a substrate, a metrology pattern comprising a first sub-target and a second sub-target with a lithographic apparatus using respective first and second angular asymmetric illumination pupils,
receiving the substrate at a metrology tool,
illuminating the metrology pattern with the metrology tool to measure a signal based on radiation scattered by the metrology pattern, and
determining or monitoring a focus of a lithographic process based on the measured signal;
wherein a position of at least part of the metrology pattern is focus dependent.