公开(公告)号：US11619886B2

公开(公告)日：2023-04-04

申请号：US16975745

申请日：2019-03-01

Applicant: ASML NETHERLANDS B.V.

Inventor： Johannes Mathias Theodorus Antonius Adriaens ,  Carolus Johannes Catharina Schoormans ,  Thomas Voβ

IPC: G03F7/20 ,  G01B9/02015

Abstract: A position measurement system including a first interferometer and a second interferometer arranged to determine a distance of the object in a first direction when the object is in a first measurement area by emitting beams onto a target surface of the object. The position measurement system further has a third interferometer and a fourth interferometer arranged to determine a distance of the object in the first direction when the object is in a second measurement area by emitting beams onto the target surface of the object. An arrangement of relative positions in a second direction of beams spots impinging on the target surface from the beams emitted by the first and second interferometers is different from an arrangement of relative positions in the second direction of beams spots impinging on the target surface from the beams emitted by the third and fourth interferometers.