Lithographic method and apparatus
US10078272B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2015 |
| Grant date | Sep 18, 2018 |
| Priority date | — |
| Expiry date | Nov 2, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of correcting aberrations caused by a projection system of a lithographic apparatus, the method including performing a measurement of an aberration caused by the projection system using a sensor located in the lithographic apparatus, determining, based on a history of operation of the lithographic apparatus since a change of machine state, whether to average the measured aberration with one or more aberration measurements previously obtained using the sensor, calculating a correction to be applied to the lithographic apparatus using the measured aberration if it is determined that averaging should not be performed, calculating a correction to be applied to the lithographic apparatus using an averaged aberration measurement if it is determined that averaging should be performed, and applying the calculated correction to the lithographic apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.