Lithographic apparatus and device manufacturing method
US7525638B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2005 |
| Grant date | Apr 28, 2009 |
| Priority date | — |
| Expiry date | Apr 16, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus make use of data representing changes in wavelength of a radiation source to provide control of focal plane position or to provide correction of sensor data. In the first aspect, the wavelength variation data is provided to control systems that control focus by moving apparatus components including, for example, the mask table, the substrate table or optical elements of the projection optical system. In the second aspect, variation data is used in correcting, e.g., focal plane position data measured by a transmitted image sensor. The two aspects may be combined in a single apparatus or may be used separately.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.