Fluid handling structure, lithographic apparatus and device manufacturing method
A fluid handling structure has a plurality of openings acting as a meniscus pinning system operating on the gas drag principle and a gas knife outwardly of the meniscus pinning system to break-up any film of liquid left behind. The separation between the gas knife and the meniscus pinning system is selected from the range of 1 mm to 5 mm. Desirably the underside of a barrier member in which the gas knife and the meniscus pinning system are provided is continuous, e.g. has no openings, between the gas knife and the meniscus pinning system.
1. A fluid handling structure for a lithographic apparatus, the fluid handling structure having a plurality of meniscus pinning openings, the fluid handling structure configured such that the openings are directed, in use, towards a substrate and/or a substrate table configured to support the substrate, the fluid handling structure further comprising a gas knife device having an elongate aperture or a plurality of apertures arranged in a line, and a damper arranged between the aperture or the plurality of apertures and the openings, wherein the damper has a width between the aperture or the plurality of apertures and the openings at a certain position that is larger than the width of the damper adjacent on either side of the certain position.
2. The fluid handling structure of claim 1 , wherein the damper comprises a continuous surface opposing, in use, the substrate and/or substrate table.
3. The fluid handling structure of claim 2 , wherein the continuous surface is substantially parallel, in use, to the substrate and/or substrate table.
4. The fluid handling structure of claim 1 , wherein the openings form, in plan, a cornered shape in an underside of the fluid handling structure.
5. The fluid handling structure of claim 4 , wherein at least one of the shapes has at least four corners.
6. The fluid handling structure of claim 4 , wherein at least one of the shapes has an edge with negative radius of curvature.
7. The fluid handling structure of claim 4 , wherein at least one of the shapes has a corner with an obtuse angle.
8. The fluid handling structure of claim 4 , wherein the cornered shape of the line is substantially similar to the cornered shape of the openings.
9. The fluid handling structure of claim 1 , wherein the width of the damper widens towards a corner of the elongate aperture or line of apertures.
10. A lithographic apparatus, comprising:
a substrate table configured to support a substrate;
a projection system configured to project a beam of radiation onto the substrate; and
a fluid handling structure having a plurality of meniscus pinning openings, the fluid handling structure configured such that the openings are directed, in use, towards the substrate and/or the substrate table, the fluid handling structure further comprising a gas knife device having an elongate aperture or a plurality of apertures arranged in a line, and a damper arranged between the aperture or the plurality of apertures and the openings, wherein the damper has a width between the aperture or the plurality of apertures and the openings at a certain position that is larger than the width of the damper adjacent on either side of the certain position.
11. The apparatus of claim 10 , wherein the damper comprises a continuous surface opposing, in use, the substrate and/or substrate table.
12. The apparatus of claim 10 , wherein the openings form, in plan, a cornered shape in an underside of the fluid handling structure.
13. The apparatus of claim 12 , wherein at least one of the shapes has at least four corners.
14. The apparatus of claim 12 , wherein at least one of the shapes has an edge with negative radius of curvature.
15. The apparatus of claim 12 , wherein at least one of the shapes has a corner with an obtuse angle.
16. The apparatus of claim 12 , wherein the cornered shape of the line is substantially similar to the cornered shape of the openings.
17. The apparatus of claim 10 , wherein the width of the damper widens towards a corner of the elongate aperture or line of apertures.
18. A device manufacturing method, comprising:
confining liquid using a fluid handling structure of a lithographic apparatus, the fluid handling structure having a plurality of meniscus pinning openings, the fluid handling structure configured such that the openings are directed, in use, towards a substrate and/or a substrate table configured to support the substrate;
supplying a gas using a gas knife device of the fluid handling structure, the gas knife device having an elongate aperture or a plurality of apertures arranged in a line, and a damper arranged between the aperture or the plurality of apertures and the openings, wherein the damper has a width between the aperture or the plurality of apertures and the openings at a certain position that is larger than the width of the damper adjacent on either side of the certain position; and
projecting a beam of radiation through the liquid onto the substrate.
19. The method of claim 18 , wherein the openings form, in plan, a cornered shape in an underside of the fluid handling structure.
20. The method of claim 18 , wherein the width of the damper widens towards a corner of the elongate aperture or line of apertures.