Back to results
US 2006/0187429 A1Published application
Lithographic apparatus and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsJohannes Catharinus Mulkens, Johannes Christiaan Jasper
Life of this patent
Estimating the term…
Abstract
In, for example, an immersion lithography apparatus, a sensor that would normally be provided on the substrate table is replaced by a retro-reflector on the substrate table and a sensor at, for example, patterning device level. This may avoid the need to make the sensor compatible with the immersion liquid and also make incoupling of radiation easier since the numerical aperture may be less at, for example, patterning device level.
Claims21
A lithographic apparatus, comprising:
- a support structure configured to hold a patterning device, the patterning device configured to impart a beam of radiation with a pattern;
- a substrate table configured to hold a substrate;
- a projection system configured to project the patterned beam onto a target portion of the substrate;
- a retro-reflector located on the substrate table and arranged to direct radiation projected onto it by the projection system back into the projection system;
- and
- a sensor mounted other than on the substrate table and adapted to sense a property of radiation and arranged to receive radiation reflected back into the projection system by the retro-reflector.
3 more elements
A device manufacturing method, comprising:
- projecting a patterned beam of radiation using a projection system onto a target portion of a substrate;
- reflecting radiation back into the projection system using a retro-reflector mounted on a substrate table holding the substrate;
- and
- sensing a property of the radiation reflected back into the projection system using a sensor provided other than on the substrate table.
1 more element
A immersion lithographic apparatus, comprising:
- a substrate table configured to hold a substrate;
- a projection system configured to project a patterned beam of radiation onto a target portion of the substrate;
- a liquid supply system configured to supply a liquid to a space between the projection system and the substrate;
- a retro-reflector located at or near the level of the substrate and arranged to direct radiation projected onto it by the projection system back into the projection system;
- and
- a sensor configured to sense a property of the radiation reflected back into the projection system by the retro-reflector.
3 more elements
Dependencies are inferred from the claim text.