Patent ID: 11940608
Assignee: ASML NETHERLANDS B.V.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A dark field metrology device comprising:
an objective lens arrangement configured to direct illumination onto a specimen to be measured and to collect scattered radiation from the specimen, the scattered radiation comprising zeroth order radiation and higher order diffracted radiation, wherein the objective lens arrangement defines a maximum range of illumination angles for accepting the illumination in an illumination path and a maximum range of detection angles for accepting the scattered radiation in a detection path; and
a zeroth order block configured to block the zeroth order radiation,
wherein the dark field metrology device is configured to perform an illumination scan to scan the illumination over at least two different subsets of the maximum range of illumination angles; and simultaneously perform a detection scan which scans the zeroth order block and/or the scattered radiation with respect to each other over a corresponding subset of the maximum range of detection angles during at least part of the illumination scan.