| 摘要 |
A lithography apparatus having a fluid confinement plate, which completely submerges the imaging surface of a substrate, is disclosed. The apparatus includes an imaging element defining an image and a stage configured to support the substrate. A projection optical system is provided to project the image defined by the imaging element onto the imaging surface of the substrate. A gap, filled with immersion fluid, is provided between the imaging surface of the substrate and the last optical element of the projection optical system. The fluid confinement plate, which is positioned within the gap between the last optical element and the substrate, is sufficiently sized so that the imaging surface is completely submerged in the immersion fluid. The fluid confinement plate includes a first surface facing the gap and opposing the imaging surface of the substrate. The first surface includes a droplet control element to control the formation of droplets forming on the first surface. In one embodiment, the droplet control element is a porous surface formed on the first surface. A vacuum is used to pull any excess immersion fluid through the porous region to prevent the formation of droplets. In a second embodiment, the droplet control element is a sloped surface that causes any immersion fluid on the first surface to flow toward to main body of immersion fluid in the gap.
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