公开(公告)号：US20220137517A1

公开(公告)日：2022-05-05

申请号：US17434309

申请日：2020-01-30

Applicant: ASML Netherlands B.V.

Inventor： Maarten Jozef JANSEN ,  Frank AUER

IPC: G03F7/20

Abstract: The invention provides a stage system comprising a stage (ST) which is movable in respect of a reference structure. One of the stage and the reference structure comprises a reflective surface (REFS). An optical position sensor (IF1) is arranged at the other one of the stage and the reference structure and is configured to determine a position of the reflective surface relative to the optical position sensor. An optical shape sensor (IF2) is configured to determine a shape of the reflective surface. The stage system further comprises a position measurement controller configured to derive a stage position of the stage from the position of the reflective surface relative to the optical position sensor and from the shape of the reflective surface as determined by the optical shape sensor.