Immersion lithography fluid control system changing flow velocity of gas outlets based on motion of a surface
AssigneeNikon Corporation
InventorsDerek Coon, Andrew J Hazelton
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Abstract
An immersion lithography apparatus includes an optical member, a gap defined between the optical member and a surface disposed opposite the optical member being filled with an immersion liquid, and a fluid control device including a gas outlet through which a gas is supplied to prevent the immersion liquid from entering a surround area external to an exposure area. A flow velocity of the gas supplied from the gas outlet is controlled based on the motion of the surface such that a pressure exerted by the gas is made stronger or weaker depending on the motion of the surface.
Claims22
An immersion lithography apparatus comprising:
- an optical member of a light projection unit, a gap defined between the optical member and a surface disposed opposite the optical member being filled with an immersion liquid;
- and
- a fluid control device including gas outlets through which a gas is supplied, the fluid control device controlling the gas supplied through the gas outlets to prevent the immersion liquid from entering a surrounding area external to an exposure area,
- wherein pressure of the gas supplied from the gas outlets is controlled based on a moving direction of the surface in a plane substantially parallel to an image-forming surface of rejection unit such that the pressure of the gas is made stronger or weaker depending on the moving direction of the surface.
An immersion lithography method comprising:
- projecting a patterned beam of radiation through an optical member of a light projection unit and a liquid in a gap between the optical member and a substrate, onto a surface of the substrate;
- preventing the liquid from entering a surrounding area external to an exposure area using a gas supplied through gas outlets, the liquid supply outlet and the liquid recovery inlet being provided radially inward of the gas outlets relative to the exposure area;
- and
- controlling a flow velocity of the gas supplied from the gas outlets based on a moving direction of the surface in a plane substantially parallel to an image-forming surface of the optical member such that a pressure exerted by the gas is made stronger or weaker depending on the moving direction of the surface.
Dependencies are inferred from the claim text.