Apparatus and methods for recovering fluid in immersion lithography
US8289497B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2009 |
| Grant date | Oct 16, 2012 |
| Priority date | — |
| Expiry date | Apr 22, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70341
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An immersion lithography apparatus includes a projection system having a final optical element, a movable stage that is movable below the projection system such that a gap exists between the final optical element and a surface of the stage, an immersion liquid being filled in the gap, a liquid confinement member and a liquid diverter. The liquid confinement member maintains the immersion liquid in the gap, and includes a liquid recovery portion that faces the stage surface and recovers liquid from the gap. The liquid recovery portion includes a first porous portion through which a first suction force is applied and a second porous portion through which a second suction force less than the first suction force is applied, the second portion being located outward of the first portion. The liquid diverter is positioned between the stage and at least the first porous portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.