Apparatus and method for maintaining immersion fluid in the gap under the projection lens during wafer exchange in an immersion lithography machine
First Claim
1. A lithographic projection apparatus comprising:
- a substrate table on which a substrate is held;
a projection system that projects a patterned beam onto a target portion of the substrate held by the substrate table, an immersion liquid, through which the beam is to be projected, being in a space between the projection system and the substrate; and
a flat pad that keeps the projection system in contact with the immersion liquid when the substrate, at least while held on the substrate table, comes out of contact with the immersion liquid, the flat pad being separate from the substrate table.
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Abstract
An apparatus and method maintain immersion fluid in the gap adjacent to the projection lens during the exchange of a work piece in a lithography machine. The apparatus and method include an optical assembly that projects an image onto a work piece and a stage assembly including a work piece table that supports the work piece adjacent to the optical assembly. An environmental system is provided to supply and remove an immersion fluid from the gap between the optical assembly and the work piece on the stage assembly. After exposure of the work piece is complete, an exchange system removes the work piece and replaces it with a second work piece. An immersion fluid containment system maintains the immersion liquid in the gap during removal of the first work piece and replacement with the second work piece.
362 Citations
18 Claims
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1. A lithographic projection apparatus comprising:
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a substrate table on which a substrate is held; a projection system that projects a patterned beam onto a target portion of the substrate held by the substrate table, an immersion liquid, through which the beam is to be projected, being in a space between the projection system and the substrate; and a flat pad that keeps the projection system in contact with the immersion liquid when the substrate, at least while held on the substrate table, comes out of contact with the immersion liquid, the flat pad being separate from the substrate table. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A device manufacturing method comprising:
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providing an immersion liquid to a space between a projection system and a substrate; projecting a patterned beam of radiation, through the immersion liquid, onto a target portion of the substrate using the projection system; and maintaining the projection system in contact with the immersion liquid when the substrate, at least while on a substrate table, comes out of contact with the immersion liquid by placing a flat pad, which is separate from the substrate table, adjacent to the projection system in place of the substrate. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification