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

Claim 19:
20. A method comprising:
by an objective lens arrangement, directing illumination onto a specimen to be measured and collecting 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
blocking the zeroth order radiation using a zeroth order block,
wherein the directing comprising performing an illumination scan to scan the illumination over at least two different subsets of the maximum range of illumination angles, and simultaneously with the illumination scan, the collecting comprises performing 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.