公开(公告)号：US20180299793A1

公开(公告)日：2018-10-18

申请号：US15766728

申请日：2016-09-30

Applicant: ASML Holding N.V.

Inventor： Hong YE ,  Gerrit Johannes NIJMEIJER

IPC: G03F7/20 ,  G03F9/00

Abstract: A method and apparatus to measure a target (e.g., an alignment mark (e.g., on a substrate)) is disclosed. Relative movement between the target and a measurement spot of a measurement system in a “fly-in” direction (e.g., movement of the target towards the measurement spot) is performed so that a first measurement for the target can be made. Thereafter, relative movement between the target and the measurement spot is made in an opposite “fly-in” direction so that a second measurement for the target can be made. By combining (e.g., averaging) these two measurements, an error is cancelled out, and higher accuracy in the measurement may be achieved.

公开(公告)号：US20220137523A1

公开(公告)日：2022-05-05

申请号：US17432019

申请日：2020-02-06

Applicant: ASML Holding N.V.

Inventor： Joshua ADAMS ,  Yuxiang LIN ,  Krishanu SHOME ,  Gerrit Johannes NIJMEIJER ,  Igor Matheus Petronella AARTS

IPC: G03F9/00

Abstract: An alignment method includes directing an illumination beam with a first polarization state to form a diffracted beam with a second polarization state from an alignment target, and passing the diffracted beam through a polarization analyzer. The alignment method further includes measuring a polarization state of the diffracted beam and determining a location of the alignment target from the measured polarization state relative to its initial polarization state. The alignment target includes a plurality of diffraction gratings with a single pitch and two or more duty cycles, wherein the pitch is smaller than a wavelength of the illumination beam, and the location of the alignment target corresponds to the duty cycle of the diffraction grating.