- Patent Title: Interferometer system, method of determining a mode hop of a laser source of an interferometer system, method of determining a position of a movable object, and lithographic apparatus
-
Application No.: US17613124Application Date: 2020-05-11
-
Publication No.: US11719529B2Publication Date: 2023-08-08
- Inventor: Maarten Jozef Jansen , Manoj Kumar Mridha , Engelbertus Antonius Fransiscus Van der Pasch
- Applicant: ASML NETHERLANDS B.V.
- Applicant Address: NL Veldhoven
- Assignee: ASML NETHERLANDS B.V.
- Current Assignee: ASML NETHERLANDS B.V.
- Current Assignee Address: NL Veldhoven
- Agency: Pillsbury Winthrop Shaw Pittman, LLP
- Priority: EP 179357 2019.06.11 EP 189097 2019.07.30
- International Application: PCT/EP2020/063100 2020.05.11
- International Announcement: WO2020/249339A 2020.12.17
- Date entered country: 2021-11-22
- Main IPC: G01B9/02002
- IPC: G01B9/02002 ; G01B9/02055 ; G01J9/02 ; G03F7/20 ; G03F7/00

Abstract:
An interferometer system including: an optical system arranged to split a radiation beam from a laser source into a first beam along a first optical path and a second beam along a second optical path, and recombine the first beam and the second beam to a recombined beam, a detector to receive the recombined beam and to provide a detector signal based on the received recombined beam, and a processing unit, wherein a first optical path length of the first optical path and a second optical path length of the second optical path have an optical path length difference, and wherein the processing unit is arranged to determine a mode hop of the laser source on the basis of a phase shift in the detector signal.
Public/Granted literature
Information query