Microlitographic projection exposure apparatus and immersion liquid therefore
AssigneeCarl Zeiss SMT GmbH
InventorKarl-Heinz Schuster
Life of this patent
Estimating the term…
Abstract
An immersion liquid for a microlithographic projection exposure apparatus is enriched with heavy isotopes. This reduces the chemical reactivity, which leads to an extension of the lifetime of optical elements which come in contact with the immersion liquid. For example, heavy water (D2O), deuterated sulfuric acid, (D2SO4) or deuterated phosphoric acid D3P16O4 may be used. Organic compounds such as perfluoro polyethers, which have been deuterated or enriched with heavy oxygen (18O), are furthermore suitable.
Claims26
1-37. (canceled)
An exposure apparatus that exposes a substrate through an immersion region, comprising:
- an optical element that has a concave surface from which exposure light emerges;
- and a surface that is provided to surround an optical path of the exposure light, an interface of a liquid of the immersion region being held between the surface and an object, the object being disposed at a position where the object can be irradiated by the exposure light.
An exposure method, comprising:
- forming an immersion region so that a space between an object and a concave surface of an optical element is filled with a liquid, an interface of the liquid being positioned between the object and a surface, the surface being provided to surround the optical path of exposure light;
- and exposing a substrate through the immersion region.
An exposure apparatus that exposes a substrate by radiating exposure light onto the substrate, comprising:
- a projection optical system that projects a pattern image onto the substrate and that comprises a first optical element, the first optical element having a first surface that the exposure light impinges and a second surface from which the exposure light emerges;
- wherein, the first surface and the second surface are substantially concentric and are spherical surfaces;
- and the first optical element is an element of a plurality of optical elements of the projection optical system that is closest to an image plane of the projection optical system.
An exposure apparatus that exposes a substrate by radiating exposure light onto the substrate, comprising:
- an optical element that has a concave surface part from which the exposure light emerges;
- a lower surface that is provided to surround the concave surface part;
- and a side surface that is provided on the outer side of the lower surface with respect to the optical axis of the optical element and that faces the optical axis.
An exposure method that exposes a substrate by radiating exposure light onto the substrate, comprising:
- radiating the exposure light to an optical element, the optical element opposing a front surface of the substrate and having a concave surface part from which the exposure light emerges;
- and irradiating the substrate with the exposure light in a state in which a liquid is filled between the concave surface part of the optical element and a front surface of the substrate;
- wherein the liquid is contacted with a lower surface, which is provided to surround the concave surface part, and a side surface, which is provided on the outer side of the lower surface with respect to the optical axis of the optical element and that faces the optical axis.
Dependencies are inferred from the claim text.